release/src/router/busybox/shell/ash.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ash shell port for busybox
   4  *
   5  * Copyright (c) 1989, 1991, 1993, 1994
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Copyright (c) 1997-2005 Herbert Xu <herbert@gondor.apana.org.au>
   9  * was re-ported from NetBSD and debianized.
  10  *
  11  * This code is derived from software contributed to Berkeley by
  12  * Kenneth Almquist.
  13  *
  14  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
  15  *
  16  * Original BSD copyright notice is retained at the end of this file.
  17  */
  18
  19 /*
  20  * The following should be set to reflect the type of system you have:
  21  *      JOBS -> 1 if you have Berkeley job control, 0 otherwise.
  22  *      define SYSV if you are running under System V.
  23  *      define DEBUG=1 to compile in debugging ('set -o debug' to turn on)
  24  *      define DEBUG=2 to compile in and turn on debugging.
  25  *
  26  * When debugging is on, debugging info will be written to ./trace and
  27  * a quit signal will generate a core dump.
  28  */
  29 #define DEBUG 0
  30 /* Tweak debug output verbosity here */
  31 #define DEBUG_TIME 0
  32 #define DEBUG_PID 1
  33 #define DEBUG_SIG 1
  34
  35 #define PROFILE 0
  36
  37 #define IFS_BROKEN
  38
  39 #define JOBS ENABLE_ASH_JOB_CONTROL
  40
  41 #if DEBUG
  42 # ifndef _GNU_SOURCE
  43 #  define _GNU_SOURCE
  44 # endif
  45 #endif
  46
  47 #include "busybox.h" /* for applet_names */
  48 //TODO: pull in some .h and find out do we have SINGLE_APPLET_MAIN?
  49 //#include "applet_tables.h" doesn't work
  50 #include <paths.h>
  51 #include <setjmp.h>
  52 #include <fnmatch.h>
  53 #include "math.h"
  54
  55 #if defined SINGLE_APPLET_MAIN
  56 /* STANDALONE does not make sense, and won't compile */
  57 #undef CONFIG_FEATURE_SH_STANDALONE
  58 #undef ENABLE_FEATURE_SH_STANDALONE
  59 #undef USE_FEATURE_SH_STANDALONE
  60 #undef SKIP_FEATURE_SH_STANDALONE(...)
  61 #define ENABLE_FEATURE_SH_STANDALONE 0
  62 #define USE_FEATURE_SH_STANDALONE(...)
  63 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
  64 #endif
  65
  66 #ifndef PIPE_BUF
  67 # define PIPE_BUF 4096           /* amount of buffering in a pipe */
  68 #endif
  69
  70 #if defined(__uClinux__)
  71 # error "Do not even bother, ash will not run on NOMMU machine"
  72 #endif
  73
  74
  75 /* ============ Hash table sizes. Configurable. */
  76
  77 #define VTABSIZE 39
  78 #define ATABSIZE 39
  79 #define CMDTABLESIZE 31         /* should be prime */
  80
  81
  82 /* ============ Shell options */
  83
  84 static const char *const optletters_optnames[] = {
  85         "e"   "errexit",
  86         "f"   "noglob",
  87         "I"   "ignoreeof",
  88         "i"   "interactive",
  89         "m"   "monitor",
  90         "n"   "noexec",
  91         "s"   "stdin",
  92         "x"   "xtrace",
  93         "v"   "verbose",
  94         "C"   "noclobber",
  95         "a"   "allexport",
  96         "b"   "notify",
  97         "u"   "nounset",
  98         "\0"  "vi"
  99 #if DEBUG
 100         ,"\0"  "nolog"
 101         ,"\0"  "debug"
 102 #endif
 103 };
 104
 105 #define optletters(n) optletters_optnames[(n)][0]
 106 #define optnames(n) (&optletters_optnames[(n)][1])
 107
 108 enum { NOPTS = ARRAY_SIZE(optletters_optnames) };
 109
 110
 111 /* ============ Misc data */
 112
 113 static const char homestr[] ALIGN1 = "HOME";
 114 static const char snlfmt[] ALIGN1 = "%s\n";
 115 static const char illnum[] ALIGN1 = "Illegal number: %s";
 116
 117 /*
 118  * We enclose jmp_buf in a structure so that we can declare pointers to
 119  * jump locations.  The global variable handler contains the location to
 120  * jump to when an exception occurs, and the global variable exception_type
 121  * contains a code identifying the exception.  To implement nested
 122  * exception handlers, the user should save the value of handler on entry
 123  * to an inner scope, set handler to point to a jmploc structure for the
 124  * inner scope, and restore handler on exit from the scope.
 125  */
 126 struct jmploc {
 127         jmp_buf loc;
 128 };
 129
 130 struct globals_misc {
 131         /* pid of main shell */
 132         int rootpid;
 133         /* shell level: 0 for the main shell, 1 for its children, and so on */
 134         int shlvl;
 135 #define rootshell (!shlvl)
 136         char *minusc;  /* argument to -c option */
 137
 138         char *curdir; // = nullstr;     /* current working directory */
 139         char *physdir; // = nullstr;    /* physical working directory */
 140
 141         char *arg0; /* value of $0 */
 142
 143         struct jmploc *exception_handler;
 144
 145 // disabled by vda: cannot understand how it was supposed to work -
 146 // cannot fix bugs. That's why you have to explain your non-trivial designs!
 147 //      /* do we generate EXSIG events */
 148 //      int exsig; /* counter */
 149         volatile int suppressint; /* counter */
 150 // TODO: rename
 151 // pendingsig -> pending_sig
 152 // intpending -> pending_int
 153         volatile /*sig_atomic_t*/ smallint intpending; /* 1 = got SIGINT */
 154         /* last pending signal */
 155         volatile /*sig_atomic_t*/ smallint pendingsig;
 156         smallint exception_type; /* kind of exception (0..5) */
 157         /* exceptions */
 158 #define EXINT 0         /* SIGINT received */
 159 #define EXERROR 1       /* a generic error */
 160 #define EXSHELLPROC 2   /* execute a shell procedure */
 161 #define EXEXEC 3        /* command execution failed */
 162 #define EXEXIT 4        /* exit the shell */
 163 #define EXSIG 5         /* trapped signal in wait(1) */
 164
 165         smallint isloginsh;
 166         char nullstr[1];        /* zero length string */
 167
 168         char optlist[NOPTS];
 169 #define eflag optlist[0]
 170 #define fflag optlist[1]
 171 #define Iflag optlist[2]
 172 #define iflag optlist[3]
 173 #define mflag optlist[4]
 174 #define nflag optlist[5]
 175 #define sflag optlist[6]
 176 #define xflag optlist[7]
 177 #define vflag optlist[8]
 178 #define Cflag optlist[9]
 179 #define aflag optlist[10]
 180 #define bflag optlist[11]
 181 #define uflag optlist[12]
 182 #define viflag optlist[13]
 183 #if DEBUG
 184 #define nolog optlist[14]
 185 #define debug optlist[15]
 186 #endif
 187
 188         /* trap handler commands */
 189         /*
 190          * Sigmode records the current value of the signal handlers for the various
 191          * modes.  A value of zero means that the current handler is not known.
 192          * S_HARD_IGN indicates that the signal was ignored on entry to the shell.
 193          */
 194         char sigmode[NSIG - 1];
 195 #define S_DFL      1            /* default signal handling (SIG_DFL) */
 196 #define S_CATCH    2            /* signal is caught */
 197 #define S_IGN      3            /* signal is ignored (SIG_IGN) */
 198 #define S_HARD_IGN 4            /* signal is ignored permenantly */
 199
 200         /* indicates specified signal received */
 201         uint8_t gotsig[NSIG - 1]; /* offset by 1: "signal" 0 is meaningless */
 202         char *trap[NSIG];
 203
 204         /* Rarely referenced stuff */
 205 #if ENABLE_ASH_RANDOM_SUPPORT
 206         /* Random number generators */
 207         int32_t random_galois_LFSR; /* Galois LFSR (fast but weak). signed! */
 208         uint32_t random_LCG;        /* LCG (fast but weak) */
 209 #endif
 210         pid_t backgndpid;        /* pid of last background process */
 211         smallint job_warning;    /* user was warned about stopped jobs (can be 2, 1 or 0). */
 212 };
 213 extern struct globals_misc *const ash_ptr_to_globals_misc;
 214 #define G_misc (*ash_ptr_to_globals_misc)
 215 #define rootpid     (G_misc.rootpid    )
 216 #define shlvl       (G_misc.shlvl      )
 217 #define minusc      (G_misc.minusc     )
 218 #define curdir      (G_misc.curdir     )
 219 #define physdir     (G_misc.physdir    )
 220 #define arg0        (G_misc.arg0       )
 221 #define exception_handler (G_misc.exception_handler)
 222 #define exception_type    (G_misc.exception_type   )
 223 #define suppressint       (G_misc.suppressint      )
 224 #define intpending        (G_misc.intpending       )
 225 //#define exsig             (G_misc.exsig            )
 226 #define pendingsig        (G_misc.pendingsig       )
 227 #define isloginsh   (G_misc.isloginsh  )
 228 #define nullstr     (G_misc.nullstr    )
 229 #define optlist     (G_misc.optlist    )
 230 #define sigmode     (G_misc.sigmode    )
 231 #define gotsig      (G_misc.gotsig     )
 232 #define trap        (G_misc.trap       )
 233 #define random_galois_LFSR (G_misc.random_galois_LFSR)
 234 #define random_LCG         (G_misc.random_LCG        )
 235 #define backgndpid  (G_misc.backgndpid )
 236 #define job_warning (G_misc.job_warning)
 237 #define INIT_G_misc() do { \
 238         (*(struct globals_misc**)&ash_ptr_to_globals_misc) = xzalloc(sizeof(G_misc)); \
 239         barrier(); \
 240         curdir = nullstr; \
 241         physdir = nullstr; \
 242 } while (0)
 243
 244
 245 /* ============ DEBUG */
 246 #if DEBUG
 247 static void trace_printf(const char *fmt, ...);
 248 static void trace_vprintf(const char *fmt, va_list va);
 249 # define TRACE(param)    trace_printf param
 250 # define TRACEV(param)   trace_vprintf param
 251 # define close(fd) do { \
 252         int dfd = (fd); \
 253         if (close(dfd) < 0) \
 254                 bb_error_msg("bug on %d: closing %d(%x)", \
 255                         __LINE__, dfd, dfd); \
 256 } while (0)
 257 #else
 258 # define TRACE(param)
 259 # define TRACEV(param)
 260 #endif
 261
 262
 263 /* ============ Utility functions */
 264 #define xbarrier() do { __asm__ __volatile__ ("": : :"memory"); } while (0)
 265
 266 /* C99 say: "char" declaration may be signed or unsigned by default */
 267 #define signed_char2int(sc) ((int)(signed char)(sc))
 268
 269 static int isdigit_str9(const char *str)
 270 {
 271         int maxlen = 9 + 1; /* max 9 digits: 999999999 */
 272         while (--maxlen && isdigit(*str))
 273                 str++;
 274         return (*str == '\0');
 275 }
 276
 277
 278 /* ============ Interrupts / exceptions */
 279 /*
 280  * These macros allow the user to suspend the handling of interrupt signals
 281  * over a period of time.  This is similar to SIGHOLD or to sigblock, but
 282  * much more efficient and portable.  (But hacking the kernel is so much
 283  * more fun than worrying about efficiency and portability. :-))
 284  */
 285 #define INT_OFF do { \
 286         suppressint++; \
 287         xbarrier(); \
 288 } while (0)
 289
 290 /*
 291  * Called to raise an exception.  Since C doesn't include exceptions, we
 292  * just do a longjmp to the exception handler.  The type of exception is
 293  * stored in the global variable "exception_type".
 294  */
 295 static void raise_exception(int) NORETURN;
 296 static void
 297 raise_exception(int e)
 298 {
 299 #if DEBUG
 300         if (exception_handler == NULL)
 301                 abort();
 302 #endif
 303         INT_OFF;
 304         exception_type = e;
 305         longjmp(exception_handler->loc, 1);
 306 }
 307 #if DEBUG
 308 #define raise_exception(e) do { \
 309         TRACE(("raising exception %d on line %d\n", (e), __LINE__)); \
 310         raise_exception(e); \
 311 } while (0)
 312 #endif
 313
 314 /*
 315  * Called from trap.c when a SIGINT is received.  (If the user specifies
 316  * that SIGINT is to be trapped or ignored using the trap builtin, then
 317  * this routine is not called.)  Suppressint is nonzero when interrupts
 318  * are held using the INT_OFF macro.  (The test for iflag is just
 319  * defensive programming.)
 320  */
 321 static void raise_interrupt(void) NORETURN;
 322 static void
 323 raise_interrupt(void)
 324 {
 325         int ex_type;
 326
 327         intpending = 0;
 328         /* Signal is not automatically unmasked after it is raised,
 329          * do it ourself - unmask all signals */
 330         sigprocmask_allsigs(SIG_UNBLOCK);
 331         /* pendingsig = 0; - now done in onsig() */
 332
 333         ex_type = EXSIG;
 334         if (gotsig[SIGINT - 1] && !trap[SIGINT]) {
 335                 if (!(rootshell && iflag)) {
 336                         /* Kill ourself with SIGINT */
 337                         signal(SIGINT, SIG_DFL);
 338                         raise(SIGINT);
 339                 }
 340                 ex_type = EXINT;
 341         }
 342         raise_exception(ex_type);
 343         /* NOTREACHED */
 344 }
 345 #if DEBUG
 346 #define raise_interrupt() do { \
 347         TRACE(("raising interrupt on line %d\n", __LINE__)); \
 348         raise_interrupt(); \
 349 } while (0)
 350 #endif
 351
 352 static USE_ASH_OPTIMIZE_FOR_SIZE(inline) void
 353 int_on(void)
 354 {
 355         xbarrier();
 356         if (--suppressint == 0 && intpending) {
 357                 raise_interrupt();
 358         }
 359 }
 360 #define INT_ON int_on()
 361 static USE_ASH_OPTIMIZE_FOR_SIZE(inline) void
 362 force_int_on(void)
 363 {
 364         xbarrier();
 365         suppressint = 0;
 366         if (intpending)
 367                 raise_interrupt();
 368 }
 369 #define FORCE_INT_ON force_int_on()
 370
 371 #define SAVE_INT(v) ((v) = suppressint)
 372
 373 #define RESTORE_INT(v) do { \
 374         xbarrier(); \
 375         suppressint = (v); \
 376         if (suppressint == 0 && intpending) \
 377                 raise_interrupt(); \
 378 } while (0)
 379
 380
 381 /* ============ Stdout/stderr output */
 382
 383 static void
 384 outstr(const char *p, FILE *file)
 385 {
 386         INT_OFF;
 387         fputs(p, file);
 388         INT_ON;
 389 }
 390
 391 static void
 392 flush_stdout_stderr(void)
 393 {
 394         INT_OFF;
 395         fflush(stdout);
 396         fflush(stderr);
 397         INT_ON;
 398 }
 399
 400 static void
 401 flush_stderr(void)
 402 {
 403         INT_OFF;
 404         fflush(stderr);
 405         INT_ON;
 406 }
 407
 408 static void
 409 outcslow(int c, FILE *dest)
 410 {
 411         INT_OFF;
 412         putc(c, dest);
 413         fflush(dest);
 414         INT_ON;
 415 }
 416
 417 static int out1fmt(const char *, ...) __attribute__((__format__(__printf__,1,2)));
 418 static int
 419 out1fmt(const char *fmt, ...)
 420 {
 421         va_list ap;
 422         int r;
 423
 424         INT_OFF;
 425         va_start(ap, fmt);
 426         r = vprintf(fmt, ap);
 427         va_end(ap);
 428         INT_ON;
 429         return r;
 430 }
 431
 432 static int fmtstr(char *, size_t, const char *, ...) __attribute__((__format__(__printf__,3,4)));
 433 static int
 434 fmtstr(char *outbuf, size_t length, const char *fmt, ...)
 435 {
 436         va_list ap;
 437         int ret;
 438
 439         va_start(ap, fmt);
 440         INT_OFF;
 441         ret = vsnprintf(outbuf, length, fmt, ap);
 442         va_end(ap);
 443         INT_ON;
 444         return ret;
 445 }
 446
 447 static void
 448 out1str(const char *p)
 449 {
 450         outstr(p, stdout);
 451 }
 452
 453 static void
 454 out2str(const char *p)
 455 {
 456         outstr(p, stderr);
 457         flush_stderr();
 458 }
 459
 460
 461 /* ============ Parser structures */
 462
 463 /* control characters in argument strings */
 464 #define CTLESC '\201'           /* escape next character */
 465 #define CTLVAR '\202'           /* variable defn */
 466 #define CTLENDVAR '\203'
 467 #define CTLBACKQ '\204'
 468 #define CTLQUOTE 01             /* ored with CTLBACKQ code if in quotes */
 469 /*      CTLBACKQ | CTLQUOTE == '\205' */
 470 #define CTLARI  '\206'          /* arithmetic expression */
 471 #define CTLENDARI '\207'
 472 #define CTLQUOTEMARK '\210'
 473
 474 /* variable substitution byte (follows CTLVAR) */
 475 #define VSTYPE  0x0f            /* type of variable substitution */
 476 #define VSNUL   0x10            /* colon--treat the empty string as unset */
 477 #define VSQUOTE 0x80            /* inside double quotes--suppress splitting */
 478
 479 /* values of VSTYPE field */
 480 #define VSNORMAL        0x1     /* normal variable:  $var or ${var} */
 481 #define VSMINUS         0x2     /* ${var-text} */
 482 #define VSPLUS          0x3     /* ${var+text} */
 483 #define VSQUESTION      0x4     /* ${var?message} */
 484 #define VSASSIGN        0x5     /* ${var=text} */
 485 #define VSTRIMRIGHT     0x6     /* ${var%pattern} */
 486 #define VSTRIMRIGHTMAX  0x7     /* ${var%%pattern} */
 487 #define VSTRIMLEFT      0x8     /* ${var#pattern} */
 488 #define VSTRIMLEFTMAX   0x9     /* ${var##pattern} */
 489 #define VSLENGTH        0xa     /* ${#var} */
 490 #if ENABLE_ASH_BASH_COMPAT
 491 #define VSSUBSTR        0xc     /* ${var:position:length} */
 492 #define VSREPLACE       0xd     /* ${var/pattern/replacement} */
 493 #define VSREPLACEALL    0xe     /* ${var//pattern/replacement} */
 494 #endif
 495
 496 static const char dolatstr[] ALIGN1 = {
 497         CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
 498 };
 499
 500 #define NCMD      0
 501 #define NPIPE     1
 502 #define NREDIR    2
 503 #define NBACKGND  3
 504 #define NSUBSHELL 4
 505 #define NAND      5
 506 #define NOR       6
 507 #define NSEMI     7
 508 #define NIF       8
 509 #define NWHILE    9
 510 #define NUNTIL   10
 511 #define NFOR     11
 512 #define NCASE    12
 513 #define NCLIST   13
 514 #define NDEFUN   14
 515 #define NARG     15
 516 #define NTO      16
 517 #if ENABLE_ASH_BASH_COMPAT
 518 #define NTO2     17
 519 #endif
 520 #define NCLOBBER 18
 521 #define NFROM    19
 522 #define NFROMTO  20
 523 #define NAPPEND  21
 524 #define NTOFD    22
 525 #define NFROMFD  23
 526 #define NHERE    24
 527 #define NXHERE   25
 528 #define NNOT     26
 529 #define N_NUMBER 27
 530
 531 union node;
 532
 533 struct ncmd {
 534         smallint type; /* Nxxxx */
 535         union node *assign;
 536         union node *args;
 537         union node *redirect;
 538 };
 539
 540 struct npipe {
 541         smallint type;
 542         smallint pipe_backgnd;
 543         struct nodelist *cmdlist;
 544 };
 545
 546 struct nredir {
 547         smallint type;
 548         union node *n;
 549         union node *redirect;
 550 };
 551
 552 struct nbinary {
 553         smallint type;
 554         union node *ch1;
 555         union node *ch2;
 556 };
 557
 558 struct nif {
 559         smallint type;
 560         union node *test;
 561         union node *ifpart;
 562         union node *elsepart;
 563 };
 564
 565 struct nfor {
 566         smallint type;
 567         union node *args;
 568         union node *body;
 569         char *var;
 570 };
 571
 572 struct ncase {
 573         smallint type;
 574         union node *expr;
 575         union node *cases;
 576 };
 577
 578 struct nclist {
 579         smallint type;
 580         union node *next;
 581         union node *pattern;
 582         union node *body;
 583 };
 584
 585 struct narg {
 586         smallint type;
 587         union node *next;
 588         char *text;
 589         struct nodelist *backquote;
 590 };
 591
 592 /* nfile and ndup layout must match!
 593  * NTOFD (>&fdnum) uses ndup structure, but we may discover mid-flight
 594  * that it is actually NTO2 (>&file), and change its type.
 595  */
 596 struct nfile {
 597         smallint type;
 598         union node *next;
 599         int fd;
 600         int _unused_dupfd;
 601         union node *fname;
 602         char *expfname;
 603 };
 604
 605 struct ndup {
 606         smallint type;
 607         union node *next;
 608         int fd;
 609         int dupfd;
 610         union node *vname;
 611         char *_unused_expfname;
 612 };
 613
 614 struct nhere {
 615         smallint type;
 616         union node *next;
 617         int fd;
 618         union node *doc;
 619 };
 620
 621 struct nnot {
 622         smallint type;
 623         union node *com;
 624 };
 625
 626 union node {
 627         smallint type;
 628         struct ncmd ncmd;
 629         struct npipe npipe;
 630         struct nredir nredir;
 631         struct nbinary nbinary;
 632         struct nif nif;
 633         struct nfor nfor;
 634         struct ncase ncase;
 635         struct nclist nclist;
 636         struct narg narg;
 637         struct nfile nfile;
 638         struct ndup ndup;
 639         struct nhere nhere;
 640         struct nnot nnot;
 641 };
 642
 643 struct nodelist {
 644         struct nodelist *next;
 645         union node *n;
 646 };
 647
 648 struct funcnode {
 649         int count;
 650         union node n;
 651 };
 652
 653 /*
 654  * Free a parse tree.
 655  */
 656 static void
 657 freefunc(struct funcnode *f)
 658 {
 659         if (f && --f->count < 0)
 660                 free(f);
 661 }
 662
 663
 664 /* ============ Debugging output */
 665
 666 #if DEBUG
 667
 668 static FILE *tracefile;
 669
 670 static void
 671 trace_printf(const char *fmt, ...)
 672 {
 673         va_list va;
 674
 675         if (debug != 1)
 676                 return;
 677         if (DEBUG_TIME)
 678                 fprintf(tracefile, "%u ", (int) time(NULL));
 679         if (DEBUG_PID)
 680                 fprintf(tracefile, "[%u] ", (int) getpid());
 681         if (DEBUG_SIG)
 682                 fprintf(tracefile, "pending s:%d i:%d(supp:%d) ", pendingsig, intpending, suppressint);
 683         va_start(va, fmt);
 684         vfprintf(tracefile, fmt, va);
 685         va_end(va);
 686 }
 687
 688 static void
 689 trace_vprintf(const char *fmt, va_list va)
 690 {
 691         if (debug != 1)
 692                 return;
 693         if (DEBUG_TIME)
 694                 fprintf(tracefile, "%u ", (int) time(NULL));
 695         if (DEBUG_PID)
 696                 fprintf(tracefile, "[%u] ", (int) getpid());
 697         if (DEBUG_SIG)
 698                 fprintf(tracefile, "pending s:%d i:%d(supp:%d) ", pendingsig, intpending, suppressint);
 699         vfprintf(tracefile, fmt, va);
 700 }
 701
 702 static void
 703 trace_puts(const char *s)
 704 {
 705         if (debug != 1)
 706                 return;
 707         fputs(s, tracefile);
 708 }
 709
 710 static void
 711 trace_puts_quoted(char *s)
 712 {
 713         char *p;
 714         char c;
 715
 716         if (debug != 1)
 717                 return;
 718         putc('"', tracefile);
 719         for (p = s; *p; p++) {
 720                 switch (*p) {
 721                 case '\n':  c = 'n';  goto backslash;
 722                 case '\t':  c = 't';  goto backslash;
 723                 case '\r':  c = 'r';  goto backslash;
 724                 case '"':  c = '"';  goto backslash;
 725                 case '\\':  c = '\\';  goto backslash;
 726                 case CTLESC:  c = 'e';  goto backslash;
 727                 case CTLVAR:  c = 'v';  goto backslash;
 728                 case CTLVAR+CTLQUOTE:  c = 'V'; goto backslash;
 729                 case CTLBACKQ:  c = 'q';  goto backslash;
 730                 case CTLBACKQ+CTLQUOTE:  c = 'Q'; goto backslash;
 731  backslash:
 732                         putc('\\', tracefile);
 733                         putc(c, tracefile);
 734                         break;
 735                 default:
 736                         if (*p >= ' ' && *p <= '~')
 737                                 putc(*p, tracefile);
 738                         else {
 739                                 putc('\\', tracefile);
 740                                 putc(*p >> 6 & 03, tracefile);
 741                                 putc(*p >> 3 & 07, tracefile);
 742                                 putc(*p & 07, tracefile);
 743                         }
 744                         break;
 745                 }
 746         }
 747         putc('"', tracefile);
 748 }
 749
 750 static void
 751 trace_puts_args(char **ap)
 752 {
 753         if (debug != 1)
 754                 return;
 755         if (!*ap)
 756                 return;
 757         while (1) {
 758                 trace_puts_quoted(*ap);
 759                 if (!*++ap) {
 760                         putc('\n', tracefile);
 761                         break;
 762                 }
 763                 putc(' ', tracefile);
 764         }
 765 }
 766
 767 static void
 768 opentrace(void)
 769 {
 770         char s[100];
 771 #ifdef O_APPEND
 772         int flags;
 773 #endif
 774
 775         if (debug != 1) {
 776                 if (tracefile)
 777                         fflush(tracefile);
 778                 /* leave open because libedit might be using it */
 779                 return;
 780         }
 781         strcpy(s, "./trace");
 782         if (tracefile) {
 783                 if (!freopen(s, "a", tracefile)) {
 784                         fprintf(stderr, "Can't re-open %s\n", s);
 785                         debug = 0;
 786                         return;
 787                 }
 788         } else {
 789                 tracefile = fopen(s, "a");
 790                 if (tracefile == NULL) {
 791                         fprintf(stderr, "Can't open %s\n", s);
 792                         debug = 0;
 793                         return;
 794                 }
 795         }
 796 #ifdef O_APPEND
 797         flags = fcntl(fileno(tracefile), F_GETFL);
 798         if (flags >= 0)
 799                 fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND);
 800 #endif
 801         setlinebuf(tracefile);
 802         fputs("\nTracing started.\n", tracefile);
 803 }
 804
 805 static void
 806 indent(int amount, char *pfx, FILE *fp)
 807 {
 808         int i;
 809
 810         for (i = 0; i < amount; i++) {
 811                 if (pfx && i == amount - 1)
 812                         fputs(pfx, fp);
 813                 putc('\t', fp);
 814         }
 815 }
 816
 817 /* little circular references here... */
 818 static void shtree(union node *n, int ind, char *pfx, FILE *fp);
 819
 820 static void
 821 sharg(union node *arg, FILE *fp)
 822 {
 823         char *p;
 824         struct nodelist *bqlist;
 825         int subtype;
 826
 827         if (arg->type != NARG) {
 828                 out1fmt("<node type %d>\n", arg->type);
 829                 abort();
 830         }
 831         bqlist = arg->narg.backquote;
 832         for (p = arg->narg.text; *p; p++) {
 833                 switch (*p) {
 834                 case CTLESC:
 835                         putc(*++p, fp);
 836                         break;
 837                 case CTLVAR:
 838                         putc('$', fp);
 839                         putc('{', fp);
 840                         subtype = *++p;
 841                         if (subtype == VSLENGTH)
 842                                 putc('#', fp);
 843
 844                         while (*p != '=')
 845                                 putc(*p++, fp);
 846
 847                         if (subtype & VSNUL)
 848                                 putc(':', fp);
 849
 850                         switch (subtype & VSTYPE) {
 851                         case VSNORMAL:
 852                                 putc('}', fp);
 853                                 break;
 854                         case VSMINUS:
 855                                 putc('-', fp);
 856                                 break;
 857                         case VSPLUS:
 858                                 putc('+', fp);
 859                                 break;
 860                         case VSQUESTION:
 861                                 putc('?', fp);
 862                                 break;
 863                         case VSASSIGN:
 864                                 putc('=', fp);
 865                                 break;
 866                         case VSTRIMLEFT:
 867                                 putc('#', fp);
 868                                 break;
 869                         case VSTRIMLEFTMAX:
 870                                 putc('#', fp);
 871                                 putc('#', fp);
 872                                 break;
 873                         case VSTRIMRIGHT:
 874                                 putc('%', fp);
 875                                 break;
 876                         case VSTRIMRIGHTMAX:
 877                                 putc('%', fp);
 878                                 putc('%', fp);
 879                                 break;
 880                         case VSLENGTH:
 881                                 break;
 882                         default:
 883                                 out1fmt("<subtype %d>", subtype);
 884                         }
 885                         break;
 886                 case CTLENDVAR:
 887                         putc('}', fp);
 888                         break;
 889                 case CTLBACKQ:
 890                 case CTLBACKQ|CTLQUOTE:
 891                         putc('$', fp);
 892                         putc('(', fp);
 893                         shtree(bqlist->n, -1, NULL, fp);
 894                         putc(')', fp);
 895                         break;
 896                 default:
 897                         putc(*p, fp);
 898                         break;
 899                 }
 900         }
 901 }
 902
 903 static void
 904 shcmd(union node *cmd, FILE *fp)
 905 {
 906         union node *np;
 907         int first;
 908         const char *s;
 909         int dftfd;
 910
 911         first = 1;
 912         for (np = cmd->ncmd.args; np; np = np->narg.next) {
 913                 if (!first)
 914                         putc(' ', fp);
 915                 sharg(np, fp);
 916                 first = 0;
 917         }
 918         for (np = cmd->ncmd.redirect; np; np = np->nfile.next) {
 919                 if (!first)
 920                         putc(' ', fp);
 921                 dftfd = 0;
 922                 switch (np->nfile.type) {
 923                 case NTO:      s = ">>"+1; dftfd = 1; break;
 924                 case NCLOBBER: s = ">|"; dftfd = 1; break;
 925                 case NAPPEND:  s = ">>"; dftfd = 1; break;
 926 #if ENABLE_ASH_BASH_COMPAT
 927                 case NTO2:
 928 #endif
 929                 case NTOFD:    s = ">&"; dftfd = 1; break;
 930                 case NFROM:    s = "<"; break;
 931                 case NFROMFD:  s = "<&"; break;
 932                 case NFROMTO:  s = "<>"; break;
 933                 default:       s = "*error*"; break;
 934                 }
 935                 if (np->nfile.fd != dftfd)
 936                         fprintf(fp, "%d", np->nfile.fd);
 937                 fputs(s, fp);
 938                 if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) {
 939                         fprintf(fp, "%d", np->ndup.dupfd);
 940                 } else {
 941                         sharg(np->nfile.fname, fp);
 942                 }
 943                 first = 0;
 944         }
 945 }
 946
 947 static void
 948 shtree(union node *n, int ind, char *pfx, FILE *fp)
 949 {
 950         struct nodelist *lp;
 951         const char *s;
 952
 953         if (n == NULL)
 954                 return;
 955
 956         indent(ind, pfx, fp);
 957         switch (n->type) {
 958         case NSEMI:
 959                 s = "; ";
 960                 goto binop;
 961         case NAND:
 962                 s = " && ";
 963                 goto binop;
 964         case NOR:
 965                 s = " || ";
 966  binop:
 967                 shtree(n->nbinary.ch1, ind, NULL, fp);
 968                 /* if (ind < 0) */
 969                         fputs(s, fp);
 970                 shtree(n->nbinary.ch2, ind, NULL, fp);
 971                 break;
 972         case NCMD:
 973                 shcmd(n, fp);
 974                 if (ind >= 0)
 975                         putc('\n', fp);
 976                 break;
 977         case NPIPE:
 978                 for (lp = n->npipe.cmdlist; lp; lp = lp->next) {
 979                         shcmd(lp->n, fp);
 980                         if (lp->next)
 981                                 fputs(" | ", fp);
 982                 }
 983                 if (n->npipe.pipe_backgnd)
 984                         fputs(" &", fp);
 985                 if (ind >= 0)
 986                         putc('\n', fp);
 987                 break;
 988         default:
 989                 fprintf(fp, "<node type %d>", n->type);
 990                 if (ind >= 0)
 991                         putc('\n', fp);
 992                 break;
 993         }
 994 }
 995
 996 static void
 997 showtree(union node *n)
 998 {
 999         trace_puts("showtree called\n");
1000         shtree(n, 1, NULL, stdout);
1001 }
1002
1003 #endif /* DEBUG */
1004
1005
1006 /* ============ Parser data */
1007
1008 /*
1009  * ash_vmsg() needs parsefile->fd, hence parsefile definition is moved up.
1010  */
1011 struct strlist {
1012         struct strlist *next;
1013         char *text;
1014 };
1015
1016 struct alias;
1017
1018 struct strpush {
1019         struct strpush *prev;   /* preceding string on stack */
1020         char *prev_string;
1021         int prev_left_in_line;
1022 #if ENABLE_ASH_ALIAS
1023         struct alias *ap;       /* if push was associated with an alias */
1024 #endif
1025         char *string;           /* remember the string since it may change */
1026 };
1027
1028 struct parsefile {
1029         struct parsefile *prev; /* preceding file on stack */
1030         int linno;              /* current line */
1031         int fd;                 /* file descriptor (or -1 if string) */
1032         int left_in_line;       /* number of chars left in this line */
1033         int left_in_buffer;     /* number of chars left in this buffer past the line */
1034         char *next_to_pgetc;    /* next char in buffer */
1035         char *buf;              /* input buffer */
1036         struct strpush *strpush; /* for pushing strings at this level */
1037         struct strpush basestrpush; /* so pushing one is fast */
1038 };
1039
1040 static struct parsefile basepf;        /* top level input file */
1041 static struct parsefile *g_parsefile = &basepf;  /* current input file */
1042 static int startlinno;                 /* line # where last token started */
1043 static char *commandname;              /* currently executing command */
1044 static struct strlist *cmdenviron;     /* environment for builtin command */
1045 static uint8_t exitstatus;             /* exit status of last command */
1046
1047
1048 /* ============ Message printing */
1049
1050 static void
1051 ash_vmsg(const char *msg, va_list ap)
1052 {
1053         fprintf(stderr, "%s: ", arg0);
1054         if (commandname) {
1055                 if (strcmp(arg0, commandname))
1056                         fprintf(stderr, "%s: ", commandname);
1057                 if (!iflag || g_parsefile->fd)
1058                         fprintf(stderr, "line %d: ", startlinno);
1059         }
1060         vfprintf(stderr, msg, ap);
1061         outcslow('\n', stderr);
1062 }
1063
1064 /*
1065  * Exverror is called to raise the error exception.  If the second argument
1066  * is not NULL then error prints an error message using printf style
1067  * formatting.  It then raises the error exception.
1068  */
1069 static void ash_vmsg_and_raise(int, const char *, va_list) NORETURN;
1070 static void
1071 ash_vmsg_and_raise(int cond, const char *msg, va_list ap)
1072 {
1073 #if DEBUG
1074         if (msg) {
1075                 TRACE(("ash_vmsg_and_raise(%d, \"", cond));
1076                 TRACEV((msg, ap));
1077                 TRACE(("\") pid=%d\n", getpid()));
1078         } else
1079                 TRACE(("ash_vmsg_and_raise(%d, NULL) pid=%d\n", cond, getpid()));
1080         if (msg)
1081 #endif
1082                 ash_vmsg(msg, ap);
1083
1084         flush_stdout_stderr();
1085         raise_exception(cond);
1086         /* NOTREACHED */
1087 }
1088
1089 static void ash_msg_and_raise_error(const char *, ...) NORETURN;
1090 static void
1091 ash_msg_and_raise_error(const char *msg, ...)
1092 {
1093         va_list ap;
1094
1095         va_start(ap, msg);
1096         ash_vmsg_and_raise(EXERROR, msg, ap);
1097         /* NOTREACHED */
1098         va_end(ap);
1099 }
1100
1101 static void raise_error_syntax(const char *) NORETURN;
1102 static void
1103 raise_error_syntax(const char *msg)
1104 {
1105         ash_msg_and_raise_error("syntax error: %s", msg);
1106         /* NOTREACHED */
1107 }
1108
1109 static void ash_msg_and_raise(int, const char *, ...) NORETURN;
1110 static void
1111 ash_msg_and_raise(int cond, const char *msg, ...)
1112 {
1113         va_list ap;
1114
1115         va_start(ap, msg);
1116         ash_vmsg_and_raise(cond, msg, ap);
1117         /* NOTREACHED */
1118         va_end(ap);
1119 }
1120
1121 /*
1122  * error/warning routines for external builtins
1123  */
1124 static void
1125 ash_msg(const char *fmt, ...)
1126 {
1127         va_list ap;
1128
1129         va_start(ap, fmt);
1130         ash_vmsg(fmt, ap);
1131         va_end(ap);
1132 }
1133
1134 /*
1135  * Return a string describing an error.  The returned string may be a
1136  * pointer to a static buffer that will be overwritten on the next call.
1137  * Action describes the operation that got the error.
1138  */
1139 static const char *
1140 errmsg(int e, const char *em)
1141 {
1142         if (e == ENOENT || e == ENOTDIR) {
1143                 return em;
1144         }
1145         return strerror(e);
1146 }
1147
1148
1149 /* ============ Memory allocation */
1150
1151 /*
1152  * It appears that grabstackstr() will barf with such alignments
1153  * because stalloc() will return a string allocated in a new stackblock.
1154  */
1155 #define SHELL_ALIGN(nbytes) (((nbytes) + SHELL_SIZE) & ~SHELL_SIZE)
1156 enum {
1157         /* Most machines require the value returned from malloc to be aligned
1158          * in some way.  The following macro will get this right
1159          * on many machines.  */
1160         SHELL_SIZE = sizeof(union {int i; char *cp; double d; }) - 1,
1161         /* Minimum size of a block */
1162         MINSIZE = SHELL_ALIGN(504),
1163 };
1164
1165 struct stack_block {
1166         struct stack_block *prev;
1167         char space[MINSIZE];
1168 };
1169
1170 struct stackmark {
1171         struct stack_block *stackp;
1172         char *stacknxt;
1173         size_t stacknleft;
1174         struct stackmark *marknext;
1175 };
1176
1177
1178 struct globals_memstack {
1179         struct stack_block *g_stackp; // = &stackbase;
1180         struct stackmark *markp;
1181         char *g_stacknxt; // = stackbase.space;
1182         char *sstrend; // = stackbase.space + MINSIZE;
1183         size_t g_stacknleft; // = MINSIZE;
1184         int    herefd; // = -1;
1185         struct stack_block stackbase;
1186 };
1187 extern struct globals_memstack *const ash_ptr_to_globals_memstack;
1188 #define G_memstack (*ash_ptr_to_globals_memstack)
1189 #define g_stackp     (G_memstack.g_stackp    )
1190 #define markp        (G_memstack.markp       )
1191 #define g_stacknxt   (G_memstack.g_stacknxt  )
1192 #define sstrend      (G_memstack.sstrend     )
1193 #define g_stacknleft (G_memstack.g_stacknleft)
1194 #define herefd       (G_memstack.herefd      )
1195 #define stackbase    (G_memstack.stackbase   )
1196 #define INIT_G_memstack() do { \
1197         (*(struct globals_memstack**)&ash_ptr_to_globals_memstack) = xzalloc(sizeof(G_memstack)); \
1198         barrier(); \
1199         g_stackp = &stackbase; \
1200         g_stacknxt = stackbase.space; \
1201         g_stacknleft = MINSIZE; \
1202         sstrend = stackbase.space + MINSIZE; \
1203         herefd = -1; \
1204 } while (0)
1205
1206 #define stackblock()     ((void *)g_stacknxt)
1207 #define stackblocksize() g_stacknleft
1208
1209
1210 static void *
1211 ckrealloc(void * p, size_t nbytes)
1212 {
1213         p = realloc(p, nbytes);
1214         if (!p)
1215                 ash_msg_and_raise_error(bb_msg_memory_exhausted);
1216         return p;
1217 }
1218
1219 static void *
1220 ckmalloc(size_t nbytes)
1221 {
1222         return ckrealloc(NULL, nbytes);
1223 }
1224
1225 static void *
1226 ckzalloc(size_t nbytes)
1227 {
1228         return memset(ckmalloc(nbytes), 0, nbytes);
1229 }
1230
1231 /*
1232  * Make a copy of a string in safe storage.
1233  */
1234 static char *
1235 ckstrdup(const char *s)
1236 {
1237         char *p = strdup(s);
1238         if (!p)
1239                 ash_msg_and_raise_error(bb_msg_memory_exhausted);
1240         return p;
1241 }
1242
1243 /*
1244  * Parse trees for commands are allocated in lifo order, so we use a stack
1245  * to make this more efficient, and also to avoid all sorts of exception
1246  * handling code to handle interrupts in the middle of a parse.
1247  *
1248  * The size 504 was chosen because the Ultrix malloc handles that size
1249  * well.
1250  */
1251 static void *
1252 stalloc(size_t nbytes)
1253 {
1254         char *p;
1255         size_t aligned;
1256
1257         aligned = SHELL_ALIGN(nbytes);
1258         if (aligned > g_stacknleft) {
1259                 size_t len;
1260                 size_t blocksize;
1261                 struct stack_block *sp;
1262
1263                 blocksize = aligned;
1264                 if (blocksize < MINSIZE)
1265                         blocksize = MINSIZE;
1266                 len = sizeof(struct stack_block) - MINSIZE + blocksize;
1267                 if (len < blocksize)
1268                         ash_msg_and_raise_error(bb_msg_memory_exhausted);
1269                 INT_OFF;
1270                 sp = ckmalloc(len);
1271                 sp->prev = g_stackp;
1272                 g_stacknxt = sp->space;
1273                 g_stacknleft = blocksize;
1274                 sstrend = g_stacknxt + blocksize;
1275                 g_stackp = sp;
1276                 INT_ON;
1277         }
1278         p = g_stacknxt;
1279         g_stacknxt += aligned;
1280         g_stacknleft -= aligned;
1281         return p;
1282 }
1283
1284 static void *
1285 stzalloc(size_t nbytes)
1286 {
1287         return memset(stalloc(nbytes), 0, nbytes);
1288 }
1289
1290 static void
1291 stunalloc(void *p)
1292 {
1293 #if DEBUG
1294         if (!p || (g_stacknxt < (char *)p) || ((char *)p < g_stackp->space)) {
1295                 write(STDERR_FILENO, "stunalloc\n", 10);
1296                 abort();
1297         }
1298 #endif
1299         g_stacknleft += g_stacknxt - (char *)p;
1300         g_stacknxt = p;
1301 }
1302
1303 /*
1304  * Like strdup but works with the ash stack.
1305  */
1306 static char *
1307 ststrdup(const char *p)
1308 {
1309         size_t len = strlen(p) + 1;
1310         return memcpy(stalloc(len), p, len);
1311 }
1312
1313 static void
1314 setstackmark(struct stackmark *mark)
1315 {
1316         mark->stackp = g_stackp;
1317         mark->stacknxt = g_stacknxt;
1318         mark->stacknleft = g_stacknleft;
1319         mark->marknext = markp;
1320         markp = mark;
1321 }
1322
1323 static void
1324 popstackmark(struct stackmark *mark)
1325 {
1326         struct stack_block *sp;
1327
1328         if (!mark->stackp)
1329                 return;
1330
1331         INT_OFF;
1332         markp = mark->marknext;
1333         while (g_stackp != mark->stackp) {
1334                 sp = g_stackp;
1335                 g_stackp = sp->prev;
1336                 free(sp);
1337         }
1338         g_stacknxt = mark->stacknxt;
1339         g_stacknleft = mark->stacknleft;
1340         sstrend = mark->stacknxt + mark->stacknleft;
1341         INT_ON;
1342 }
1343
1344 /*
1345  * When the parser reads in a string, it wants to stick the string on the
1346  * stack and only adjust the stack pointer when it knows how big the
1347  * string is.  Stackblock (defined in stack.h) returns a pointer to a block
1348  * of space on top of the stack and stackblocklen returns the length of
1349  * this block.  Growstackblock will grow this space by at least one byte,
1350  * possibly moving it (like realloc).  Grabstackblock actually allocates the
1351  * part of the block that has been used.
1352  */
1353 static void
1354 growstackblock(void)
1355 {
1356         size_t newlen;
1357
1358         newlen = g_stacknleft * 2;
1359         if (newlen < g_stacknleft)
1360                 ash_msg_and_raise_error(bb_msg_memory_exhausted);
1361         if (newlen < 128)
1362                 newlen += 128;
1363
1364         if (g_stacknxt == g_stackp->space && g_stackp != &stackbase) {
1365                 struct stack_block *oldstackp;
1366                 struct stackmark *xmark;
1367                 struct stack_block *sp;
1368                 struct stack_block *prevstackp;
1369                 size_t grosslen;
1370
1371                 INT_OFF;
1372                 oldstackp = g_stackp;
1373                 sp = g_stackp;
1374                 prevstackp = sp->prev;
1375                 grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
1376                 sp = ckrealloc(sp, grosslen);
1377                 sp->prev = prevstackp;
1378                 g_stackp = sp;
1379                 g_stacknxt = sp->space;
1380                 g_stacknleft = newlen;
1381                 sstrend = sp->space + newlen;
1382
1383                 /*
1384                  * Stack marks pointing to the start of the old block
1385                  * must be relocated to point to the new block
1386                  */
1387                 xmark = markp;
1388                 while (xmark != NULL && xmark->stackp == oldstackp) {
1389                         xmark->stackp = g_stackp;
1390                         xmark->stacknxt = g_stacknxt;
1391                         xmark->stacknleft = g_stacknleft;
1392                         xmark = xmark->marknext;
1393                 }
1394                 INT_ON;
1395         } else {
1396                 char *oldspace = g_stacknxt;
1397                 size_t oldlen = g_stacknleft;
1398                 char *p = stalloc(newlen);
1399
1400                 /* free the space we just allocated */
1401                 g_stacknxt = memcpy(p, oldspace, oldlen);
1402                 g_stacknleft += newlen;
1403         }
1404 }
1405
1406 static void
1407 grabstackblock(size_t len)
1408 {
1409         len = SHELL_ALIGN(len);
1410         g_stacknxt += len;
1411         g_stacknleft -= len;
1412 }
1413
1414 /*
1415  * The following routines are somewhat easier to use than the above.
1416  * The user declares a variable of type STACKSTR, which may be declared
1417  * to be a register.  The macro STARTSTACKSTR initializes things.  Then
1418  * the user uses the macro STPUTC to add characters to the string.  In
1419  * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
1420  * grown as necessary.  When the user is done, she can just leave the
1421  * string there and refer to it using stackblock().  Or she can allocate
1422  * the space for it using grabstackstr().  If it is necessary to allow
1423  * someone else to use the stack temporarily and then continue to grow
1424  * the string, the user should use grabstack to allocate the space, and
1425  * then call ungrabstr(p) to return to the previous mode of operation.
1426  *
1427  * USTPUTC is like STPUTC except that it doesn't check for overflow.
1428  * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
1429  * is space for at least one character.
1430  */
1431 static void *
1432 growstackstr(void)
1433 {
1434         size_t len = stackblocksize();
1435         if (herefd >= 0 && len >= 1024) {
1436                 full_write(herefd, stackblock(), len);
1437                 return stackblock();
1438         }
1439         growstackblock();
1440         return (char *)stackblock() + len;
1441 }
1442
1443 /*
1444  * Called from CHECKSTRSPACE.
1445  */
1446 static char *
1447 makestrspace(size_t newlen, char *p)
1448 {
1449         size_t len = p - g_stacknxt;
1450         size_t size = stackblocksize();
1451
1452         for (;;) {
1453                 size_t nleft;
1454
1455                 size = stackblocksize();
1456                 nleft = size - len;
1457                 if (nleft >= newlen)
1458                         break;
1459                 growstackblock();
1460         }
1461         return (char *)stackblock() + len;
1462 }
1463
1464 static char *
1465 stack_nputstr(const char *s, size_t n, char *p)
1466 {
1467         p = makestrspace(n, p);
1468         p = (char *)memcpy(p, s, n) + n;
1469         return p;
1470 }
1471
1472 static char *
1473 stack_putstr(const char *s, char *p)
1474 {
1475         return stack_nputstr(s, strlen(s), p);
1476 }
1477
1478 static char *
1479 _STPUTC(int c, char *p)
1480 {
1481         if (p == sstrend)
1482                 p = growstackstr();
1483         *p++ = c;
1484         return p;
1485 }
1486
1487 #define STARTSTACKSTR(p)        ((p) = stackblock())
1488 #define STPUTC(c, p)            ((p) = _STPUTC((c), (p)))
1489 #define CHECKSTRSPACE(n, p) do { \
1490         char *q = (p); \
1491         size_t l = (n); \
1492         size_t m = sstrend - q; \
1493         if (l > m) \
1494                 (p) = makestrspace(l, q); \
1495 } while (0)
1496 #define USTPUTC(c, p)           (*(p)++ = (c))
1497 #define STACKSTRNUL(p) do { \
1498         if ((p) == sstrend) \
1499                 (p) = growstackstr(); \
1500         *(p) = '\0'; \
1501 } while (0)
1502 #define STUNPUTC(p)             (--(p))
1503 #define STTOPC(p)               ((p)[-1])
1504 #define STADJUST(amount, p)     ((p) += (amount))
1505
1506 #define grabstackstr(p)         stalloc((char *)(p) - (char *)stackblock())
1507 #define ungrabstackstr(s, p)    stunalloc(s)
1508 #define stackstrend()           ((void *)sstrend)
1509
1510
1511 /* ============ String helpers */
1512
1513 /*
1514  * prefix -- see if pfx is a prefix of string.
1515  */
1516 static char *
1517 prefix(const char *string, const char *pfx)
1518 {
1519         while (*pfx) {
1520                 if (*pfx++ != *string++)
1521                         return NULL;
1522         }
1523         return (char *) string;
1524 }
1525
1526 /*
1527  * Check for a valid number.  This should be elsewhere.
1528  */
1529 static int
1530 is_number(const char *p)
1531 {
1532         do {
1533                 if (!isdigit(*p))
1534                         return 0;
1535         } while (*++p != '\0');
1536         return 1;
1537 }
1538
1539 /*
1540  * Convert a string of digits to an integer, printing an error message on
1541  * failure.
1542  */
1543 static int
1544 number(const char *s)
1545 {
1546         if (!is_number(s))
1547                 ash_msg_and_raise_error(illnum, s);
1548         return atoi(s);
1549 }
1550
1551 /*
1552  * Produce a possibly single quoted string suitable as input to the shell.
1553  * The return string is allocated on the stack.
1554  */
1555 static char *
1556 single_quote(const char *s)
1557 {
1558         char *p;
1559
1560         STARTSTACKSTR(p);
1561
1562         do {
1563                 char *q;
1564                 size_t len;
1565
1566                 len = strchrnul(s, '\'') - s;
1567
1568                 q = p = makestrspace(len + 3, p);
1569
1570                 *q++ = '\'';
1571                 q = (char *)memcpy(q, s, len) + len;
1572                 *q++ = '\'';
1573                 s += len;
1574
1575                 STADJUST(q - p, p);
1576
1577                 len = strspn(s, "'");
1578                 if (!len)
1579                         break;
1580
1581                 q = p = makestrspace(len + 3, p);
1582
1583                 *q++ = '"';
1584                 q = (char *)memcpy(q, s, len) + len;
1585                 *q++ = '"';
1586                 s += len;
1587
1588                 STADJUST(q - p, p);
1589         } while (*s);
1590
1591         USTPUTC(0, p);
1592
1593         return stackblock();
1594 }
1595
1596
1597 /* ============ nextopt */
1598
1599 static char **argptr;                  /* argument list for builtin commands */
1600 static char *optionarg;                /* set by nextopt (like getopt) */
1601 static char *optptr;                   /* used by nextopt */
1602
1603 /*
1604  * XXX - should get rid of. Have all builtins use getopt(3).
1605  * The library getopt must have the BSD extension static variable
1606  * "optreset", otherwise it can't be used within the shell safely.
1607  *
1608  * Standard option processing (a la getopt) for builtin routines.
1609  * The only argument that is passed to nextopt is the option string;
1610  * the other arguments are unnecessary. It returns the character,
1611  * or '\0' on end of input.
1612  */
1613 static int
1614 nextopt(const char *optstring)
1615 {
1616         char *p;
1617         const char *q;
1618         char c;
1619
1620         p = optptr;
1621         if (p == NULL || *p == '\0') {
1622                 /* We ate entire "-param", take next one */
1623                 p = *argptr;
1624                 if (p == NULL)
1625                         return '\0';
1626                 if (*p != '-')
1627                         return '\0';
1628                 if (*++p == '\0') /* just "-" ? */
1629                         return '\0';
1630                 argptr++;
1631                 if (LONE_DASH(p)) /* "--" ? */
1632                         return '\0';
1633                 /* p => next "-param" */
1634         }
1635         /* p => some option char in the middle of a "-param" */
1636         c = *p++;
1637         for (q = optstring; *q != c;) {
1638                 if (*q == '\0')
1639                         ash_msg_and_raise_error("illegal option -%c", c);
1640                 if (*++q == ':')
1641                         q++;
1642         }
1643         if (*++q == ':') {
1644                 if (*p == '\0') {
1645                         p = *argptr++;
1646                         if (p == NULL)
1647                                 ash_msg_and_raise_error("no arg for -%c option", c);
1648                 }
1649                 optionarg = p;
1650                 p = NULL;
1651         }
1652         optptr = p;
1653         return c;
1654 }
1655
1656
1657 /* ============ Shell variables */
1658
1659 /*
1660  * The parsefile structure pointed to by the global variable parsefile
1661  * contains information about the current file being read.
1662  */
1663 struct shparam {
1664         int nparam;             /* # of positional parameters (without $0) */
1665 #if ENABLE_ASH_GETOPTS
1666         int optind;             /* next parameter to be processed by getopts */
1667         int optoff;             /* used by getopts */
1668 #endif
1669         unsigned char malloced; /* if parameter list dynamically allocated */
1670         char **p;               /* parameter list */
1671 };
1672
1673 /*
1674  * Free the list of positional parameters.
1675  */
1676 static void
1677 freeparam(volatile struct shparam *param)
1678 {
1679         if (param->malloced) {
1680                 char **ap, **ap1;
1681                 ap = ap1 = param->p;
1682                 while (*ap)
1683                         free(*ap++);
1684                 free(ap1);
1685         }
1686 }
1687
1688 #if ENABLE_ASH_GETOPTS
1689 static void getoptsreset(const char *value);
1690 #endif
1691
1692 struct var {
1693         struct var *next;               /* next entry in hash list */
1694         int flags;                      /* flags are defined above */
1695         const char *text;               /* name=value */
1696         void (*func)(const char *);     /* function to be called when  */
1697                                         /* the variable gets set/unset */
1698 };
1699
1700 struct localvar {
1701         struct localvar *next;          /* next local variable in list */
1702         struct var *vp;                 /* the variable that was made local */
1703         int flags;                      /* saved flags */
1704         const char *text;               /* saved text */
1705 };
1706
1707 /* flags */
1708 #define VEXPORT         0x01    /* variable is exported */
1709 #define VREADONLY       0x02    /* variable cannot be modified */
1710 #define VSTRFIXED       0x04    /* variable struct is statically allocated */
1711 #define VTEXTFIXED      0x08    /* text is statically allocated */
1712 #define VSTACK          0x10    /* text is allocated on the stack */
1713 #define VUNSET          0x20    /* the variable is not set */
1714 #define VNOFUNC         0x40    /* don't call the callback function */
1715 #define VNOSET          0x80    /* do not set variable - just readonly test */
1716 #define VNOSAVE         0x100   /* when text is on the heap before setvareq */
1717 #if ENABLE_ASH_RANDOM_SUPPORT
1718 # define VDYNAMIC       0x200   /* dynamic variable */
1719 #else
1720 # define VDYNAMIC       0
1721 #endif
1722
1723 #ifdef IFS_BROKEN
1724 static const char defifsvar[] ALIGN1 = "IFS= \t\n";
1725 #define defifs (defifsvar + 4)
1726 #else
1727 static const char defifs[] ALIGN1 = " \t\n";
1728 #endif
1729
1730
1731 /* Need to be before varinit_data[] */
1732 #if ENABLE_LOCALE_SUPPORT
1733 static void
1734 change_lc_all(const char *value)
1735 {
1736         if (value && *value != '\0')
1737                 setlocale(LC_ALL, value);
1738 }
1739 static void
1740 change_lc_ctype(const char *value)
1741 {
1742         if (value && *value != '\0')
1743                 setlocale(LC_CTYPE, value);
1744 }
1745 #endif
1746 #if ENABLE_ASH_MAIL
1747 static void chkmail(void);
1748 static void changemail(const char *);
1749 #endif
1750 static void changepath(const char *);
1751 #if ENABLE_ASH_RANDOM_SUPPORT
1752 static void change_random(const char *);
1753 #endif
1754
1755 static const struct {
1756         int flags;
1757         const char *text;
1758         void (*func)(const char *);
1759 } varinit_data[] = {
1760 #ifdef IFS_BROKEN
1761         { VSTRFIXED|VTEXTFIXED       , defifsvar   , NULL            },
1762 #else
1763         { VSTRFIXED|VTEXTFIXED|VUNSET, "IFS\0"     , NULL            },
1764 #endif
1765 #if ENABLE_ASH_MAIL
1766         { VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL\0"    , changemail      },
1767         { VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH\0", changemail      },
1768 #endif
1769         { VSTRFIXED|VTEXTFIXED       , bb_PATH_root_path, changepath },
1770         { VSTRFIXED|VTEXTFIXED       , "PS1=$ "    , NULL            },
1771         { VSTRFIXED|VTEXTFIXED       , "PS2=> "    , NULL            },
1772         { VSTRFIXED|VTEXTFIXED       , "PS4=+ "    , NULL            },
1773 #if ENABLE_ASH_GETOPTS
1774         { VSTRFIXED|VTEXTFIXED       , "OPTIND=1"  , getoptsreset    },
1775 #endif
1776 #if ENABLE_ASH_RANDOM_SUPPORT
1777         { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM\0", change_random },
1778 #endif
1779 #if ENABLE_LOCALE_SUPPORT
1780         { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_ALL\0"  , change_lc_all   },
1781         { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_CTYPE\0", change_lc_ctype },
1782 #endif
1783 #if ENABLE_FEATURE_EDITING_SAVEHISTORY
1784         { VSTRFIXED|VTEXTFIXED|VUNSET, "HISTFILE\0", NULL            },
1785 #endif
1786 };
1787
1788 struct redirtab;
1789
1790 struct globals_var {
1791         struct shparam shellparam;      /* $@ current positional parameters */
1792         struct redirtab *redirlist;
1793         int g_nullredirs;
1794         int preverrout_fd;   /* save fd2 before print debug if xflag is set. */
1795         struct var *vartab[VTABSIZE];
1796         struct var varinit[ARRAY_SIZE(varinit_data)];
1797 };
1798 extern struct globals_var *const ash_ptr_to_globals_var;
1799 #define G_var (*ash_ptr_to_globals_var)
1800 #define shellparam    (G_var.shellparam   )
1801 //#define redirlist     (G_var.redirlist    )
1802 #define g_nullredirs  (G_var.g_nullredirs )
1803 #define preverrout_fd (G_var.preverrout_fd)
1804 #define vartab        (G_var.vartab       )
1805 #define varinit       (G_var.varinit      )
1806 #define INIT_G_var() do { \
1807         unsigned i; \
1808         (*(struct globals_var**)&ash_ptr_to_globals_var) = xzalloc(sizeof(G_var)); \
1809         barrier(); \
1810         for (i = 0; i < ARRAY_SIZE(varinit_data); i++) { \
1811                 varinit[i].flags = varinit_data[i].flags; \
1812                 varinit[i].text  = varinit_data[i].text; \
1813                 varinit[i].func  = varinit_data[i].func; \
1814         } \
1815 } while (0)
1816
1817 #define vifs      varinit[0]
1818 #if ENABLE_ASH_MAIL
1819 # define vmail    (&vifs)[1]
1820 # define vmpath   (&vmail)[1]
1821 # define vpath    (&vmpath)[1]
1822 #else
1823 # define vpath    (&vifs)[1]
1824 #endif
1825 #define vps1      (&vpath)[1]
1826 #define vps2      (&vps1)[1]
1827 #define vps4      (&vps2)[1]
1828 #if ENABLE_ASH_GETOPTS
1829 # define voptind  (&vps4)[1]
1830 # if ENABLE_ASH_RANDOM_SUPPORT
1831 #  define vrandom (&voptind)[1]
1832 # endif
1833 #else
1834 # if ENABLE_ASH_RANDOM_SUPPORT
1835 #  define vrandom (&vps4)[1]
1836 # endif
1837 #endif
1838
1839 /*
1840  * The following macros access the values of the above variables.
1841  * They have to skip over the name.  They return the null string
1842  * for unset variables.
1843  */
1844 #define ifsval()        (vifs.text + 4)
1845 #define ifsset()        ((vifs.flags & VUNSET) == 0)
1846 #if ENABLE_ASH_MAIL
1847 # define mailval()      (vmail.text + 5)
1848 # define mpathval()     (vmpath.text + 9)
1849 # define mpathset()     ((vmpath.flags & VUNSET) == 0)
1850 #endif
1851 #define pathval()       (vpath.text + 5)
1852 #define ps1val()        (vps1.text + 4)
1853 #define ps2val()        (vps2.text + 4)
1854 #define ps4val()        (vps4.text + 4)
1855 #if ENABLE_ASH_GETOPTS
1856 # define optindval()    (voptind.text + 7)
1857 #endif
1858
1859
1860 #define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
1861 #define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))
1862
1863 #if ENABLE_ASH_GETOPTS
1864 static void
1865 getoptsreset(const char *value)
1866 {
1867         shellparam.optind = number(value);
1868         shellparam.optoff = -1;
1869 }
1870 #endif
1871
1872 /*
1873  * Return of a legal variable name (a letter or underscore followed by zero or
1874  * more letters, underscores, and digits).
1875  */
1876 static char *
1877 endofname(const char *name)
1878 {
1879         char *p;
1880
1881         p = (char *) name;
1882         if (!is_name(*p))
1883                 return p;
1884         while (*++p) {
1885                 if (!is_in_name(*p))
1886                         break;
1887         }
1888         return p;
1889 }
1890
1891 /*
1892  * Compares two strings up to the first = or '\0'.  The first
1893  * string must be terminated by '='; the second may be terminated by
1894  * either '=' or '\0'.
1895  */
1896 static int
1897 varcmp(const char *p, const char *q)
1898 {
1899         int c, d;
1900
1901         while ((c = *p) == (d = *q)) {
1902                 if (!c || c == '=')
1903                         goto out;
1904                 p++;
1905                 q++;
1906         }
1907         if (c == '=')
1908                 c = '\0';
1909         if (d == '=')
1910                 d = '\0';
1911  out:
1912         return c - d;
1913 }
1914
1915 static int
1916 varequal(const char *a, const char *b)
1917 {
1918         return !varcmp(a, b);
1919 }
1920
1921 /*
1922  * Find the appropriate entry in the hash table from the name.
1923  */
1924 static struct var **
1925 hashvar(const char *p)
1926 {
1927         unsigned hashval;
1928
1929         hashval = ((unsigned char) *p) << 4;
1930         while (*p && *p != '=')
1931                 hashval += (unsigned char) *p++;
1932         return &vartab[hashval % VTABSIZE];
1933 }
1934
1935 static int
1936 vpcmp(const void *a, const void *b)
1937 {
1938         return varcmp(*(const char **)a, *(const char **)b);
1939 }
1940
1941 /*
1942  * This routine initializes the builtin variables.
1943  */
1944 static void
1945 initvar(void)
1946 {
1947         struct var *vp;
1948         struct var *end;
1949         struct var **vpp;
1950
1951         /*
1952          * PS1 depends on uid
1953          */
1954 #if ENABLE_FEATURE_EDITING && ENABLE_FEATURE_EDITING_FANCY_PROMPT
1955         vps1.text = "PS1=\\w \\$ ";
1956 #else
1957         if (!geteuid())
1958                 vps1.text = "PS1=# ";
1959 #endif
1960         vp = varinit;
1961         end = vp + ARRAY_SIZE(varinit);
1962         do {
1963                 vpp = hashvar(vp->text);
1964                 vp->next = *vpp;
1965                 *vpp = vp;
1966         } while (++vp < end);
1967 }
1968
1969 static struct var **
1970 findvar(struct var **vpp, const char *name)
1971 {
1972         for (; *vpp; vpp = &(*vpp)->next) {
1973                 if (varequal((*vpp)->text, name)) {
1974                         break;
1975                 }
1976         }
1977         return vpp;
1978 }
1979
1980 /*
1981  * Find the value of a variable.  Returns NULL if not set.
1982  */
1983 static const char *
1984 lookupvar(const char *name)
1985 {
1986         struct var *v;
1987
1988         v = *findvar(hashvar(name), name);
1989         if (v) {
1990 #if ENABLE_ASH_RANDOM_SUPPORT
1991         /*
1992          * Dynamic variables are implemented roughly the same way they are
1993          * in bash. Namely, they're "special" so long as they aren't unset.
1994          * As soon as they're unset, they're no longer dynamic, and dynamic
1995          * lookup will no longer happen at that point. -- PFM.
1996          */
1997                 if ((v->flags & VDYNAMIC))
1998                         (*v->func)(NULL);
1999 #endif
2000                 if (!(v->flags & VUNSET))
2001                         return strchrnul(v->text, '=') + 1;
2002         }
2003         return NULL;
2004 }
2005
2006 /*
2007  * Search the environment of a builtin command.
2008  */
2009 static const char *
2010 bltinlookup(const char *name)
2011 {
2012         struct strlist *sp;
2013
2014         for (sp = cmdenviron; sp; sp = sp->next) {
2015                 if (varequal(sp->text, name))
2016                         return strchrnul(sp->text, '=') + 1;
2017         }
2018         return lookupvar(name);
2019 }
2020
2021 /*
2022  * Same as setvar except that the variable and value are passed in
2023  * the first argument as name=value.  Since the first argument will
2024  * be actually stored in the table, it should not be a string that
2025  * will go away.
2026  * Called with interrupts off.
2027  */
2028 static void
2029 setvareq(char *s, int flags)
2030 {
2031         struct var *vp, **vpp;
2032
2033         vpp = hashvar(s);
2034         flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1));
2035         vp = *findvar(vpp, s);
2036         if (vp) {
2037                 if ((vp->flags & (VREADONLY|VDYNAMIC)) == VREADONLY) {
2038                         const char *n;
2039
2040                         if (flags & VNOSAVE)
2041                                 free(s);
2042                         n = vp->text;
2043                         ash_msg_and_raise_error("%.*s: is read only", strchrnul(n, '=') - n, n);
2044                 }
2045
2046                 if (flags & VNOSET)
2047                         return;
2048
2049                 if (vp->func && (flags & VNOFUNC) == 0)
2050                         (*vp->func)(strchrnul(s, '=') + 1);
2051
2052                 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
2053                         free((char*)vp->text);
2054
2055                 flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
2056         } else {
2057                 if (flags & VNOSET)
2058                         return;
2059                 /* not found */
2060                 vp = ckzalloc(sizeof(*vp));
2061                 vp->next = *vpp;
2062                 /*vp->func = NULL; - ckzalloc did it */
2063                 *vpp = vp;
2064         }
2065         if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE)))
2066                 s = ckstrdup(s);
2067         vp->text = s;
2068         vp->flags = flags;
2069 }
2070
2071 /*
2072  * Set the value of a variable.  The flags argument is ored with the
2073  * flags of the variable.  If val is NULL, the variable is unset.
2074  */
2075 static void
2076 setvar(const char *name, const char *val, int flags)
2077 {
2078         char *p, *q;
2079         size_t namelen;
2080         char *nameeq;
2081         size_t vallen;
2082
2083         q = endofname(name);
2084         p = strchrnul(q, '=');
2085         namelen = p - name;
2086         if (!namelen || p != q)
2087                 ash_msg_and_raise_error("%.*s: bad variable name", namelen, name);
2088         vallen = 0;
2089         if (val == NULL) {
2090                 flags |= VUNSET;
2091         } else {
2092                 vallen = strlen(val);
2093         }
2094         INT_OFF;
2095         nameeq = ckmalloc(namelen + vallen + 2);
2096         p = (char *)memcpy(nameeq, name, namelen) + namelen;
2097         if (val) {
2098                 *p++ = '=';
2099                 p = (char *)memcpy(p, val, vallen) + vallen;
2100         }
2101         *p = '\0';
2102         setvareq(nameeq, flags | VNOSAVE);
2103         INT_ON;
2104 }
2105
2106 #if ENABLE_ASH_GETOPTS
2107 /*
2108  * Safe version of setvar, returns 1 on success 0 on failure.
2109  */
2110 static int
2111 setvarsafe(const char *name, const char *val, int flags)
2112 {
2113         int err;
2114         volatile int saveint;
2115         struct jmploc *volatile savehandler = exception_handler;
2116         struct jmploc jmploc;
2117
2118         SAVE_INT(saveint);
2119         if (setjmp(jmploc.loc))
2120                 err = 1;
2121         else {
2122                 exception_handler = &jmploc;
2123                 setvar(name, val, flags);
2124                 err = 0;
2125         }
2126         exception_handler = savehandler;
2127         RESTORE_INT(saveint);
2128         return err;
2129 }
2130 #endif
2131
2132 /*
2133  * Unset the specified variable.
2134  */
2135 static int
2136 unsetvar(const char *s)
2137 {
2138         struct var **vpp;
2139         struct var *vp;
2140         int retval;
2141
2142         vpp = findvar(hashvar(s), s);
2143         vp = *vpp;
2144         retval = 2;
2145         if (vp) {
2146                 int flags = vp->flags;
2147
2148                 retval = 1;
2149                 if (flags & VREADONLY)
2150                         goto out;
2151 #if ENABLE_ASH_RANDOM_SUPPORT
2152                 vp->flags &= ~VDYNAMIC;
2153 #endif
2154                 if (flags & VUNSET)
2155                         goto ok;
2156                 if ((flags & VSTRFIXED) == 0) {
2157                         INT_OFF;
2158                         if ((flags & (VTEXTFIXED|VSTACK)) == 0)
2159                                 free((char*)vp->text);
2160                         *vpp = vp->next;
2161                         free(vp);
2162                         INT_ON;
2163                 } else {
2164                         setvar(s, 0, 0);
2165                         vp->flags &= ~VEXPORT;
2166                 }
2167  ok:
2168                 retval = 0;
2169         }
2170  out:
2171         return retval;
2172 }
2173
2174 /*
2175  * Process a linked list of variable assignments.
2176  */
2177 static void
2178 listsetvar(struct strlist *list_set_var, int flags)
2179 {
2180         struct strlist *lp = list_set_var;
2181
2182         if (!lp)
2183                 return;
2184         INT_OFF;
2185         do {
2186                 setvareq(lp->text, flags);
2187                 lp = lp->next;
2188         } while (lp);
2189         INT_ON;
2190 }
2191
2192 /*
2193  * Generate a list of variables satisfying the given conditions.
2194  */
2195 static char **
2196 listvars(int on, int off, char ***end)
2197 {
2198         struct var **vpp;
2199         struct var *vp;
2200         char **ep;
2201         int mask;
2202
2203         STARTSTACKSTR(ep);
2204         vpp = vartab;
2205         mask = on | off;
2206         do {
2207                 for (vp = *vpp; vp; vp = vp->next) {
2208                         if ((vp->flags & mask) == on) {
2209                                 if (ep == stackstrend())
2210                                         ep = growstackstr();
2211                                 *ep++ = (char *) vp->text;
2212                         }
2213                 }
2214         } while (++vpp < vartab + VTABSIZE);
2215         if (ep == stackstrend())
2216                 ep = growstackstr();
2217         if (end)
2218                 *end = ep;
2219         *ep++ = NULL;
2220         return grabstackstr(ep);
2221 }
2222
2223
2224 /* ============ Path search helper
2225  *
2226  * The variable path (passed by reference) should be set to the start
2227  * of the path before the first call; padvance will update
2228  * this value as it proceeds.  Successive calls to padvance will return
2229  * the possible path expansions in sequence.  If an option (indicated by
2230  * a percent sign) appears in the path entry then the global variable
2231  * pathopt will be set to point to it; otherwise pathopt will be set to
2232  * NULL.
2233  */
2234 static const char *pathopt;     /* set by padvance */
2235
2236 static char *
2237 padvance(const char **path, const char *name)
2238 {
2239         const char *p;
2240         char *q;
2241         const char *start;
2242         size_t len;
2243
2244         if (*path == NULL)
2245                 return NULL;
2246         start = *path;
2247         for (p = start; *p && *p != ':' && *p != '%'; p++)
2248                 continue;
2249         len = p - start + strlen(name) + 2;     /* "2" is for '/' and '\0' */
2250         while (stackblocksize() < len)
2251                 growstackblock();
2252         q = stackblock();
2253         if (p != start) {
2254                 memcpy(q, start, p - start);
2255                 q += p - start;
2256                 *q++ = '/';
2257         }
2258         strcpy(q, name);
2259         pathopt = NULL;
2260         if (*p == '%') {
2261                 pathopt = ++p;
2262                 while (*p && *p != ':')
2263                         p++;
2264         }
2265         if (*p == ':')
2266                 *path = p + 1;
2267         else
2268                 *path = NULL;
2269         return stalloc(len);
2270 }
2271
2272
2273 /* ============ Prompt */
2274
2275 static smallint doprompt;                   /* if set, prompt the user */
2276 static smallint needprompt;                 /* true if interactive and at start of line */
2277
2278 #if ENABLE_FEATURE_EDITING
2279 static line_input_t *line_input_state;
2280 static const char *cmdedit_prompt;
2281 static void
2282 putprompt(const char *s)
2283 {
2284         if (ENABLE_ASH_EXPAND_PRMT) {
2285                 free((char*)cmdedit_prompt);
2286                 cmdedit_prompt = ckstrdup(s);
2287                 return;
2288         }
2289         cmdedit_prompt = s;
2290 }
2291 #else
2292 static void
2293 putprompt(const char *s)
2294 {
2295         out2str(s);
2296 }
2297 #endif
2298
2299 #if ENABLE_ASH_EXPAND_PRMT
2300 /* expandstr() needs parsing machinery, so it is far away ahead... */
2301 static const char *expandstr(const char *ps);
2302 #else
2303 #define expandstr(s) s
2304 #endif
2305
2306 static void
2307 setprompt(int whichprompt)
2308 {
2309         const char *prompt;
2310 #if ENABLE_ASH_EXPAND_PRMT
2311         struct stackmark smark;
2312 #endif
2313
2314         needprompt = 0;
2315
2316         switch (whichprompt) {
2317         case 1:
2318                 prompt = ps1val();
2319                 break;
2320         case 2:
2321                 prompt = ps2val();
2322                 break;
2323         default:                        /* 0 */
2324                 prompt = nullstr;
2325         }
2326 #if ENABLE_ASH_EXPAND_PRMT
2327         setstackmark(&smark);
2328         stalloc(stackblocksize());
2329 #endif
2330         putprompt(expandstr(prompt));
2331 #if ENABLE_ASH_EXPAND_PRMT
2332         popstackmark(&smark);
2333 #endif
2334 }
2335
2336
2337 /* ============ The cd and pwd commands */
2338
2339 #define CD_PHYSICAL 1
2340 #define CD_PRINT 2
2341
2342 static int docd(const char *, int);
2343
2344 static int
2345 cdopt(void)
2346 {
2347         int flags = 0;
2348         int i, j;
2349
2350         j = 'L';
2351         while ((i = nextopt("LP"))) {
2352                 if (i != j) {
2353                         flags ^= CD_PHYSICAL;
2354                         j = i;
2355                 }
2356         }
2357
2358         return flags;
2359 }
2360
2361 /*
2362  * Update curdir (the name of the current directory) in response to a
2363  * cd command.
2364  */
2365 static const char *
2366 updatepwd(const char *dir)
2367 {
2368         char *new;
2369         char *p;
2370         char *cdcomppath;
2371         const char *lim;
2372
2373         cdcomppath = ststrdup(dir);
2374         STARTSTACKSTR(new);
2375         if (*dir != '/') {
2376                 if (curdir == nullstr)
2377                         return 0;
2378                 new = stack_putstr(curdir, new);
2379         }
2380         new = makestrspace(strlen(dir) + 2, new);
2381         lim = (char *)stackblock() + 1;
2382         if (*dir != '/') {
2383                 if (new[-1] != '/')
2384                         USTPUTC('/', new);
2385                 if (new > lim && *lim == '/')
2386                         lim++;
2387         } else {
2388                 USTPUTC('/', new);
2389                 cdcomppath++;
2390                 if (dir[1] == '/' && dir[2] != '/') {
2391                         USTPUTC('/', new);
2392                         cdcomppath++;
2393                         lim++;
2394                 }
2395         }
2396         p = strtok(cdcomppath, "/");
2397         while (p) {
2398                 switch (*p) {
2399                 case '.':
2400                         if (p[1] == '.' && p[2] == '\0') {
2401                                 while (new > lim) {
2402                                         STUNPUTC(new);
2403                                         if (new[-1] == '/')
2404                                                 break;
2405                                 }
2406                                 break;
2407                         }
2408                         if (p[1] == '\0')
2409                                 break;
2410                         /* fall through */
2411                 default:
2412                         new = stack_putstr(p, new);
2413                         USTPUTC('/', new);
2414                 }
2415                 p = strtok(0, "/");
2416         }
2417         if (new > lim)
2418                 STUNPUTC(new);
2419         *new = 0;
2420         return stackblock();
2421 }
2422
2423 /*
2424  * Find out what the current directory is. If we already know the current
2425  * directory, this routine returns immediately.
2426  */
2427 static char *
2428 getpwd(void)
2429 {
2430         char *dir = getcwd(NULL, 0); /* huh, using glibc extension? */
2431         return dir ? dir : nullstr;
2432 }
2433
2434 static void
2435 setpwd(const char *val, int setold)
2436 {
2437         char *oldcur, *dir;
2438
2439         oldcur = dir = curdir;
2440
2441         if (setold) {
2442                 setvar("OLDPWD", oldcur, VEXPORT);
2443         }
2444         INT_OFF;
2445         if (physdir != nullstr) {
2446                 if (physdir != oldcur)
2447                         free(physdir);
2448                 physdir = nullstr;
2449         }
2450         if (oldcur == val || !val) {
2451                 char *s = getpwd();
2452                 physdir = s;
2453                 if (!val)
2454                         dir = s;
2455         } else
2456                 dir = ckstrdup(val);
2457         if (oldcur != dir && oldcur != nullstr) {
2458                 free(oldcur);
2459         }
2460         curdir = dir;
2461         INT_ON;
2462         setvar("PWD", dir, VEXPORT);
2463 }
2464
2465 static void hashcd(void);
2466
2467 /*
2468  * Actually do the chdir.  We also call hashcd to let the routines in exec.c
2469  * know that the current directory has changed.
2470  */
2471 static int
2472 docd(const char *dest, int flags)
2473 {
2474         const char *dir = 0;
2475         int err;
2476
2477         TRACE(("docd(\"%s\", %d) called\n", dest, flags));
2478
2479         INT_OFF;
2480         if (!(flags & CD_PHYSICAL)) {
2481                 dir = updatepwd(dest);
2482                 if (dir)
2483                         dest = dir;
2484         }
2485         err = chdir(dest);
2486         if (err)
2487                 goto out;
2488         setpwd(dir, 1);
2489         hashcd();
2490  out:
2491         INT_ON;
2492         return err;
2493 }
2494
2495 static int
2496 cdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
2497 {
2498         const char *dest;
2499         const char *path;
2500         const char *p;
2501         char c;
2502         struct stat statb;
2503         int flags;
2504
2505         flags = cdopt();
2506         dest = *argptr;
2507         if (!dest)
2508                 dest = bltinlookup(homestr);
2509         else if (LONE_DASH(dest)) {
2510                 dest = bltinlookup("OLDPWD");
2511                 flags |= CD_PRINT;
2512         }
2513         if (!dest)
2514                 dest = nullstr;
2515         if (*dest == '/')
2516                 goto step7;
2517         if (*dest == '.') {
2518                 c = dest[1];
2519  dotdot:
2520                 switch (c) {
2521                 case '\0':
2522                 case '/':
2523                         goto step6;
2524                 case '.':
2525                         c = dest[2];
2526                         if (c != '.')
2527                                 goto dotdot;
2528                 }
2529         }
2530         if (!*dest)
2531                 dest = ".";
2532         path = bltinlookup("CDPATH");
2533         if (!path) {
2534  step6:
2535  step7:
2536                 p = dest;
2537                 goto docd;
2538         }
2539         do {
2540                 c = *path;
2541                 p = padvance(&path, dest);
2542                 if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
2543                         if (c && c != ':')
2544                                 flags |= CD_PRINT;
2545  docd:
2546                         if (!docd(p, flags))
2547                                 goto out;
2548                         break;
2549                 }
2550         } while (path);
2551         ash_msg_and_raise_error("can't cd to %s", dest);
2552         /* NOTREACHED */
2553  out:
2554         if (flags & CD_PRINT)
2555                 out1fmt(snlfmt, curdir);
2556         return 0;
2557 }
2558
2559 static int
2560 pwdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
2561 {
2562         int flags;
2563         const char *dir = curdir;
2564
2565         flags = cdopt();
2566         if (flags) {
2567                 if (physdir == nullstr)
2568                         setpwd(dir, 0);
2569                 dir = physdir;
2570         }
2571         out1fmt(snlfmt, dir);
2572         return 0;
2573 }
2574
2575
2576 /* ============ ... */
2577
2578
2579 #define IBUFSIZ COMMON_BUFSIZE
2580 /* buffer for top level input file */
2581 #define basebuf bb_common_bufsiz1
2582
2583 /* Syntax classes */
2584 #define CWORD     0             /* character is nothing special */
2585 #define CNL       1             /* newline character */
2586 #define CBACK     2             /* a backslash character */
2587 #define CSQUOTE   3             /* single quote */
2588 #define CDQUOTE   4             /* double quote */
2589 #define CENDQUOTE 5             /* a terminating quote */
2590 #define CBQUOTE   6             /* backwards single quote */
2591 #define CVAR      7             /* a dollar sign */
2592 #define CENDVAR   8             /* a '}' character */
2593 #define CLP       9             /* a left paren in arithmetic */
2594 #define CRP      10             /* a right paren in arithmetic */
2595 #define CENDFILE 11             /* end of file */
2596 #define CCTL     12             /* like CWORD, except it must be escaped */
2597 #define CSPCL    13             /* these terminate a word */
2598 #define CIGN     14             /* character should be ignored */
2599
2600 #if ENABLE_ASH_ALIAS
2601 #define SYNBASE       130
2602 #define PEOF         -130
2603 #define PEOA         -129
2604 #define PEOA_OR_PEOF PEOA
2605 #else
2606 #define SYNBASE       129
2607 #define PEOF         -129
2608 #define PEOA_OR_PEOF PEOF
2609 #endif
2610
2611 /* number syntax index */
2612 #define BASESYNTAX 0    /* not in quotes */
2613 #define DQSYNTAX   1    /* in double quotes */
2614 #define SQSYNTAX   2    /* in single quotes */
2615 #define ARISYNTAX  3    /* in arithmetic */
2616 #define PSSYNTAX   4    /* prompt */
2617
2618 #if ENABLE_ASH_OPTIMIZE_FOR_SIZE
2619 #define USE_SIT_FUNCTION
2620 #endif
2621
2622 #if ENABLE_SH_MATH_SUPPORT
2623 static const char S_I_T[][4] = {
2624 #if ENABLE_ASH_ALIAS
2625         { CSPCL, CIGN, CIGN, CIGN },            /* 0, PEOA */
2626 #endif
2627         { CSPCL, CWORD, CWORD, CWORD },         /* 1, ' ' */
2628         { CNL, CNL, CNL, CNL },                 /* 2, \n */
2629         { CWORD, CCTL, CCTL, CWORD },           /* 3, !*-/:=?[]~ */
2630         { CDQUOTE, CENDQUOTE, CWORD, CWORD },   /* 4, '"' */
2631         { CVAR, CVAR, CWORD, CVAR },            /* 5, $ */
2632         { CSQUOTE, CWORD, CENDQUOTE, CWORD },   /* 6, "'" */
2633         { CSPCL, CWORD, CWORD, CLP },           /* 7, ( */
2634         { CSPCL, CWORD, CWORD, CRP },           /* 8, ) */
2635         { CBACK, CBACK, CCTL, CBACK },          /* 9, \ */
2636         { CBQUOTE, CBQUOTE, CWORD, CBQUOTE },   /* 10, ` */
2637         { CENDVAR, CENDVAR, CWORD, CENDVAR },   /* 11, } */
2638 #ifndef USE_SIT_FUNCTION
2639         { CENDFILE, CENDFILE, CENDFILE, CENDFILE }, /* 12, PEOF */
2640         { CWORD, CWORD, CWORD, CWORD },         /* 13, 0-9A-Za-z */
2641         { CCTL, CCTL, CCTL, CCTL }              /* 14, CTLESC ... */
2642 #endif
2643 };
2644 #else
2645 static const char S_I_T[][3] = {
2646 #if ENABLE_ASH_ALIAS
2647         { CSPCL, CIGN, CIGN },                  /* 0, PEOA */
2648 #endif
2649         { CSPCL, CWORD, CWORD },                /* 1, ' ' */
2650         { CNL, CNL, CNL },                      /* 2, \n */
2651         { CWORD, CCTL, CCTL },                  /* 3, !*-/:=?[]~ */
2652         { CDQUOTE, CENDQUOTE, CWORD },          /* 4, '"' */
2653         { CVAR, CVAR, CWORD },                  /* 5, $ */
2654         { CSQUOTE, CWORD, CENDQUOTE },          /* 6, "'" */
2655         { CSPCL, CWORD, CWORD },                /* 7, ( */
2656         { CSPCL, CWORD, CWORD },                /* 8, ) */
2657         { CBACK, CBACK, CCTL },                 /* 9, \ */
2658         { CBQUOTE, CBQUOTE, CWORD },            /* 10, ` */
2659         { CENDVAR, CENDVAR, CWORD },            /* 11, } */
2660 #ifndef USE_SIT_FUNCTION
2661         { CENDFILE, CENDFILE, CENDFILE },       /* 12, PEOF */
2662         { CWORD, CWORD, CWORD },                /* 13, 0-9A-Za-z */
2663         { CCTL, CCTL, CCTL }                    /* 14, CTLESC ... */
2664 #endif
2665 };
2666 #endif /* SH_MATH_SUPPORT */
2667
2668 #ifdef USE_SIT_FUNCTION
2669
2670 static int
2671 SIT(int c, int syntax)
2672 {
2673         static const char spec_symbls[] ALIGN1 = "\t\n !\"$&'()*-/:;<=>?[\\]`|}~";
2674 #if ENABLE_ASH_ALIAS
2675         static const char syntax_index_table[] ALIGN1 = {
2676                 1, 2, 1, 3, 4, 5, 1, 6,         /* "\t\n !\"$&'" */
2677                 7, 8, 3, 3, 3, 3, 1, 1,         /* "()*-/:;<" */
2678                 3, 1, 3, 3, 9, 3, 10, 1,        /* "=>?[\\]`|" */
2679                 11, 3                           /* "}~" */
2680         };
2681 #else
2682         static const char syntax_index_table[] ALIGN1 = {
2683                 0, 1, 0, 2, 3, 4, 0, 5,         /* "\t\n !\"$&'" */
2684                 6, 7, 2, 2, 2, 2, 0, 0,         /* "()*-/:;<" */
2685                 2, 0, 2, 2, 8, 2, 9, 0,         /* "=>?[\\]`|" */
2686                 10, 2                           /* "}~" */
2687         };
2688 #endif
2689         const char *s;
2690         int indx;
2691
2692         if (c == PEOF) {         /* 2^8+2 */
2693                 return CENDFILE;
2694         }
2695 #if ENABLE_ASH_ALIAS
2696         if (c == PEOA) {         /* 2^8+1 */
2697                 indx = 0;
2698         } else
2699 #endif
2700         {
2701                 if ((unsigned char)c >= (unsigned char)(CTLESC)
2702                  && (unsigned char)c <= (unsigned char)(CTLQUOTEMARK)
2703                 ) {
2704                         return CCTL;
2705                 }
2706                 s = strchrnul(spec_symbls, c);
2707                 if (*s == '\0') {
2708                         return CWORD;
2709                 }
2710                 indx = syntax_index_table[s - spec_symbls];
2711         }
2712         return S_I_T[indx][syntax];
2713 }
2714
2715 #else   /* !USE_SIT_FUNCTION */
2716
2717 #if ENABLE_ASH_ALIAS
2718 #define CSPCL_CIGN_CIGN_CIGN                     0
2719 #define CSPCL_CWORD_CWORD_CWORD                  1
2720 #define CNL_CNL_CNL_CNL                          2
2721 #define CWORD_CCTL_CCTL_CWORD                    3
2722 #define CDQUOTE_CENDQUOTE_CWORD_CWORD            4
2723 #define CVAR_CVAR_CWORD_CVAR                     5
2724 #define CSQUOTE_CWORD_CENDQUOTE_CWORD            6
2725 #define CSPCL_CWORD_CWORD_CLP                    7
2726 #define CSPCL_CWORD_CWORD_CRP                    8
2727 #define CBACK_CBACK_CCTL_CBACK                   9
2728 #define CBQUOTE_CBQUOTE_CWORD_CBQUOTE           10
2729 #define CENDVAR_CENDVAR_CWORD_CENDVAR           11
2730 #define CENDFILE_CENDFILE_CENDFILE_CENDFILE     12
2731 #define CWORD_CWORD_CWORD_CWORD                 13
2732 #define CCTL_CCTL_CCTL_CCTL                     14
2733 #else
2734 #define CSPCL_CWORD_CWORD_CWORD                  0
2735 #define CNL_CNL_CNL_CNL                          1
2736 #define CWORD_CCTL_CCTL_CWORD                    2
2737 #define CDQUOTE_CENDQUOTE_CWORD_CWORD            3
2738 #define CVAR_CVAR_CWORD_CVAR                     4
2739 #define CSQUOTE_CWORD_CENDQUOTE_CWORD            5
2740 #define CSPCL_CWORD_CWORD_CLP                    6
2741 #define CSPCL_CWORD_CWORD_CRP                    7
2742 #define CBACK_CBACK_CCTL_CBACK                   8
2743 #define CBQUOTE_CBQUOTE_CWORD_CBQUOTE            9
2744 #define CENDVAR_CENDVAR_CWORD_CENDVAR           10
2745 #define CENDFILE_CENDFILE_CENDFILE_CENDFILE     11
2746 #define CWORD_CWORD_CWORD_CWORD                 12
2747 #define CCTL_CCTL_CCTL_CCTL                     13
2748 #endif
2749
2750 static const char syntax_index_table[258] = {
2751         /* BASESYNTAX_DQSYNTAX_SQSYNTAX_ARISYNTAX */
2752         /*   0  PEOF */      CENDFILE_CENDFILE_CENDFILE_CENDFILE,
2753 #if ENABLE_ASH_ALIAS
2754         /*   1  PEOA */      CSPCL_CIGN_CIGN_CIGN,
2755 #endif
2756         /*   2  -128 0x80 */ CWORD_CWORD_CWORD_CWORD,
2757         /*   3  -127 CTLESC       */ CCTL_CCTL_CCTL_CCTL,
2758         /*   4  -126 CTLVAR       */ CCTL_CCTL_CCTL_CCTL,
2759         /*   5  -125 CTLENDVAR    */ CCTL_CCTL_CCTL_CCTL,
2760         /*   6  -124 CTLBACKQ     */ CCTL_CCTL_CCTL_CCTL,
2761         /*   7  -123 CTLQUOTE     */ CCTL_CCTL_CCTL_CCTL,
2762         /*   8  -122 CTLARI       */ CCTL_CCTL_CCTL_CCTL,
2763         /*   9  -121 CTLENDARI    */ CCTL_CCTL_CCTL_CCTL,
2764         /*  10  -120 CTLQUOTEMARK */ CCTL_CCTL_CCTL_CCTL,
2765         /*  11  -119      */ CWORD_CWORD_CWORD_CWORD,
2766         /*  12  -118      */ CWORD_CWORD_CWORD_CWORD,
2767         /*  13  -117      */ CWORD_CWORD_CWORD_CWORD,
2768         /*  14  -116      */ CWORD_CWORD_CWORD_CWORD,
2769         /*  15  -115      */ CWORD_CWORD_CWORD_CWORD,
2770         /*  16  -114      */ CWORD_CWORD_CWORD_CWORD,
2771         /*  17  -113      */ CWORD_CWORD_CWORD_CWORD,
2772         /*  18  -112      */ CWORD_CWORD_CWORD_CWORD,
2773         /*  19  -111      */ CWORD_CWORD_CWORD_CWORD,
2774         /*  20  -110      */ CWORD_CWORD_CWORD_CWORD,
2775         /*  21  -109      */ CWORD_CWORD_CWORD_CWORD,
2776         /*  22  -108      */ CWORD_CWORD_CWORD_CWORD,
2777         /*  23  -107      */ CWORD_CWORD_CWORD_CWORD,
2778         /*  24  -106      */ CWORD_CWORD_CWORD_CWORD,
2779         /*  25  -105      */ CWORD_CWORD_CWORD_CWORD,
2780         /*  26  -104      */ CWORD_CWORD_CWORD_CWORD,
2781         /*  27  -103      */ CWORD_CWORD_CWORD_CWORD,
2782         /*  28  -102      */ CWORD_CWORD_CWORD_CWORD,
2783         /*  29  -101      */ CWORD_CWORD_CWORD_CWORD,
2784         /*  30  -100      */ CWORD_CWORD_CWORD_CWORD,
2785         /*  31   -99      */ CWORD_CWORD_CWORD_CWORD,
2786         /*  32   -98      */ CWORD_CWORD_CWORD_CWORD,
2787         /*  33   -97      */ CWORD_CWORD_CWORD_CWORD,
2788         /*  34   -96      */ CWORD_CWORD_CWORD_CWORD,
2789         /*  35   -95      */ CWORD_CWORD_CWORD_CWORD,
2790         /*  36   -94      */ CWORD_CWORD_CWORD_CWORD,
2791         /*  37   -93      */ CWORD_CWORD_CWORD_CWORD,
2792         /*  38   -92      */ CWORD_CWORD_CWORD_CWORD,
2793         /*  39   -91      */ CWORD_CWORD_CWORD_CWORD,
2794         /*  40   -90      */ CWORD_CWORD_CWORD_CWORD,
2795         /*  41   -89      */ CWORD_CWORD_CWORD_CWORD,
2796         /*  42   -88      */ CWORD_CWORD_CWORD_CWORD,
2797         /*  43   -87      */ CWORD_CWORD_CWORD_CWORD,
2798         /*  44   -86      */ CWORD_CWORD_CWORD_CWORD,
2799         /*  45   -85      */ CWORD_CWORD_CWORD_CWORD,
2800         /*  46   -84      */ CWORD_CWORD_CWORD_CWORD,
2801         /*  47   -83      */ CWORD_CWORD_CWORD_CWORD,
2802         /*  48   -82      */ CWORD_CWORD_CWORD_CWORD,
2803         /*  49   -81      */ CWORD_CWORD_CWORD_CWORD,
2804         /*  50   -80      */ CWORD_CWORD_CWORD_CWORD,
2805         /*  51   -79      */ CWORD_CWORD_CWORD_CWORD,
2806         /*  52   -78      */ CWORD_CWORD_CWORD_CWORD,
2807         /*  53   -77      */ CWORD_CWORD_CWORD_CWORD,
2808         /*  54   -76      */ CWORD_CWORD_CWORD_CWORD,
2809         /*  55   -75      */ CWORD_CWORD_CWORD_CWORD,
2810         /*  56   -74      */ CWORD_CWORD_CWORD_CWORD,
2811         /*  57   -73      */ CWORD_CWORD_CWORD_CWORD,
2812         /*  58   -72      */ CWORD_CWORD_CWORD_CWORD,
2813         /*  59   -71      */ CWORD_CWORD_CWORD_CWORD,
2814         /*  60   -70      */ CWORD_CWORD_CWORD_CWORD,
2815         /*  61   -69      */ CWORD_CWORD_CWORD_CWORD,
2816         /*  62   -68      */ CWORD_CWORD_CWORD_CWORD,
2817         /*  63   -67      */ CWORD_CWORD_CWORD_CWORD,
2818         /*  64   -66      */ CWORD_CWORD_CWORD_CWORD,
2819         /*  65   -65      */ CWORD_CWORD_CWORD_CWORD,
2820         /*  66   -64      */ CWORD_CWORD_CWORD_CWORD,
2821         /*  67   -63      */ CWORD_CWORD_CWORD_CWORD,
2822         /*  68   -62      */ CWORD_CWORD_CWORD_CWORD,
2823         /*  69   -61      */ CWORD_CWORD_CWORD_CWORD,
2824         /*  70   -60      */ CWORD_CWORD_CWORD_CWORD,
2825         /*  71   -59      */ CWORD_CWORD_CWORD_CWORD,
2826         /*  72   -58      */ CWORD_CWORD_CWORD_CWORD,
2827         /*  73   -57      */ CWORD_CWORD_CWORD_CWORD,
2828         /*  74   -56      */ CWORD_CWORD_CWORD_CWORD,
2829         /*  75   -55      */ CWORD_CWORD_CWORD_CWORD,
2830         /*  76   -54      */ CWORD_CWORD_CWORD_CWORD,
2831         /*  77   -53      */ CWORD_CWORD_CWORD_CWORD,
2832         /*  78   -52      */ CWORD_CWORD_CWORD_CWORD,
2833         /*  79   -51      */ CWORD_CWORD_CWORD_CWORD,
2834         /*  80   -50      */ CWORD_CWORD_CWORD_CWORD,
2835         /*  81   -49      */ CWORD_CWORD_CWORD_CWORD,
2836         /*  82   -48      */ CWORD_CWORD_CWORD_CWORD,
2837         /*  83   -47      */ CWORD_CWORD_CWORD_CWORD,
2838         /*  84   -46      */ CWORD_CWORD_CWORD_CWORD,
2839         /*  85   -45      */ CWORD_CWORD_CWORD_CWORD,
2840         /*  86   -44      */ CWORD_CWORD_CWORD_CWORD,
2841         /*  87   -43      */ CWORD_CWORD_CWORD_CWORD,
2842         /*  88   -42      */ CWORD_CWORD_CWORD_CWORD,
2843         /*  89   -41      */ CWORD_CWORD_CWORD_CWORD,
2844         /*  90   -40      */ CWORD_CWORD_CWORD_CWORD,
2845         /*  91   -39      */ CWORD_CWORD_CWORD_CWORD,
2846         /*  92   -38      */ CWORD_CWORD_CWORD_CWORD,
2847         /*  93   -37      */ CWORD_CWORD_CWORD_CWORD,
2848         /*  94   -36      */ CWORD_CWORD_CWORD_CWORD,
2849         /*  95   -35      */ CWORD_CWORD_CWORD_CWORD,
2850         /*  96   -34      */ CWORD_CWORD_CWORD_CWORD,
2851         /*  97   -33      */ CWORD_CWORD_CWORD_CWORD,
2852         /*  98   -32      */ CWORD_CWORD_CWORD_CWORD,
2853         /*  99   -31      */ CWORD_CWORD_CWORD_CWORD,
2854         /* 100   -30      */ CWORD_CWORD_CWORD_CWORD,
2855         /* 101   -29      */ CWORD_CWORD_CWORD_CWORD,
2856         /* 102   -28      */ CWORD_CWORD_CWORD_CWORD,
2857         /* 103   -27      */ CWORD_CWORD_CWORD_CWORD,
2858         /* 104   -26      */ CWORD_CWORD_CWORD_CWORD,
2859         /* 105   -25      */ CWORD_CWORD_CWORD_CWORD,
2860         /* 106   -24      */ CWORD_CWORD_CWORD_CWORD,
2861         /* 107   -23      */ CWORD_CWORD_CWORD_CWORD,
2862         /* 108   -22      */ CWORD_CWORD_CWORD_CWORD,
2863         /* 109   -21      */ CWORD_CWORD_CWORD_CWORD,
2864         /* 110   -20      */ CWORD_CWORD_CWORD_CWORD,
2865         /* 111   -19      */ CWORD_CWORD_CWORD_CWORD,
2866         /* 112   -18      */ CWORD_CWORD_CWORD_CWORD,
2867         /* 113   -17      */ CWORD_CWORD_CWORD_CWORD,
2868         /* 114   -16      */ CWORD_CWORD_CWORD_CWORD,
2869         /* 115   -15      */ CWORD_CWORD_CWORD_CWORD,
2870         /* 116   -14      */ CWORD_CWORD_CWORD_CWORD,
2871         /* 117   -13      */ CWORD_CWORD_CWORD_CWORD,
2872         /* 118   -12      */ CWORD_CWORD_CWORD_CWORD,
2873         /* 119   -11      */ CWORD_CWORD_CWORD_CWORD,
2874         /* 120   -10      */ CWORD_CWORD_CWORD_CWORD,
2875         /* 121    -9      */ CWORD_CWORD_CWORD_CWORD,
2876         /* 122    -8      */ CWORD_CWORD_CWORD_CWORD,
2877         /* 123    -7      */ CWORD_CWORD_CWORD_CWORD,
2878         /* 124    -6      */ CWORD_CWORD_CWORD_CWORD,
2879         /* 125    -5      */ CWORD_CWORD_CWORD_CWORD,
2880         /* 126    -4      */ CWORD_CWORD_CWORD_CWORD,
2881         /* 127    -3      */ CWORD_CWORD_CWORD_CWORD,
2882         /* 128    -2      */ CWORD_CWORD_CWORD_CWORD,
2883         /* 129    -1      */ CWORD_CWORD_CWORD_CWORD,
2884         /* 130     0      */ CWORD_CWORD_CWORD_CWORD,
2885         /* 131     1      */ CWORD_CWORD_CWORD_CWORD,
2886         /* 132     2      */ CWORD_CWORD_CWORD_CWORD,
2887         /* 133     3      */ CWORD_CWORD_CWORD_CWORD,
2888         /* 134     4      */ CWORD_CWORD_CWORD_CWORD,
2889         /* 135     5      */ CWORD_CWORD_CWORD_CWORD,
2890         /* 136     6      */ CWORD_CWORD_CWORD_CWORD,
2891         /* 137     7      */ CWORD_CWORD_CWORD_CWORD,
2892         /* 138     8      */ CWORD_CWORD_CWORD_CWORD,
2893         /* 139     9 "\t" */ CSPCL_CWORD_CWORD_CWORD,
2894         /* 140    10 "\n" */ CNL_CNL_CNL_CNL,
2895         /* 141    11      */ CWORD_CWORD_CWORD_CWORD,
2896         /* 142    12      */ CWORD_CWORD_CWORD_CWORD,
2897         /* 143    13      */ CWORD_CWORD_CWORD_CWORD,
2898         /* 144    14      */ CWORD_CWORD_CWORD_CWORD,
2899         /* 145    15      */ CWORD_CWORD_CWORD_CWORD,
2900         /* 146    16      */ CWORD_CWORD_CWORD_CWORD,
2901         /* 147    17      */ CWORD_CWORD_CWORD_CWORD,
2902         /* 148    18      */ CWORD_CWORD_CWORD_CWORD,
2903         /* 149    19      */ CWORD_CWORD_CWORD_CWORD,
2904         /* 150    20      */ CWORD_CWORD_CWORD_CWORD,
2905         /* 151    21      */ CWORD_CWORD_CWORD_CWORD,
2906         /* 152    22      */ CWORD_CWORD_CWORD_CWORD,
2907         /* 153    23      */ CWORD_CWORD_CWORD_CWORD,
2908         /* 154    24      */ CWORD_CWORD_CWORD_CWORD,
2909         /* 155    25      */ CWORD_CWORD_CWORD_CWORD,
2910         /* 156    26      */ CWORD_CWORD_CWORD_CWORD,
2911         /* 157    27      */ CWORD_CWORD_CWORD_CWORD,
2912         /* 158    28      */ CWORD_CWORD_CWORD_CWORD,
2913         /* 159    29      */ CWORD_CWORD_CWORD_CWORD,
2914         /* 160    30      */ CWORD_CWORD_CWORD_CWORD,
2915         /* 161    31      */ CWORD_CWORD_CWORD_CWORD,
2916         /* 162    32  " " */ CSPCL_CWORD_CWORD_CWORD,
2917         /* 163    33  "!" */ CWORD_CCTL_CCTL_CWORD,
2918         /* 164    34  """ */ CDQUOTE_CENDQUOTE_CWORD_CWORD,
2919         /* 165    35  "#" */ CWORD_CWORD_CWORD_CWORD,
2920         /* 166    36  "$" */ CVAR_CVAR_CWORD_CVAR,
2921         /* 167    37  "%" */ CWORD_CWORD_CWORD_CWORD,
2922         /* 168    38  "&" */ CSPCL_CWORD_CWORD_CWORD,
2923         /* 169    39  "'" */ CSQUOTE_CWORD_CENDQUOTE_CWORD,
2924         /* 170    40  "(" */ CSPCL_CWORD_CWORD_CLP,
2925         /* 171    41  ")" */ CSPCL_CWORD_CWORD_CRP,
2926         /* 172    42  "*" */ CWORD_CCTL_CCTL_CWORD,
2927         /* 173    43  "+" */ CWORD_CWORD_CWORD_CWORD,
2928         /* 174    44  "," */ CWORD_CWORD_CWORD_CWORD,
2929         /* 175    45  "-" */ CWORD_CCTL_CCTL_CWORD,
2930         /* 176    46  "." */ CWORD_CWORD_CWORD_CWORD,
2931         /* 177    47  "/" */ CWORD_CCTL_CCTL_CWORD,
2932         /* 178    48  "0" */ CWORD_CWORD_CWORD_CWORD,
2933         /* 179    49  "1" */ CWORD_CWORD_CWORD_CWORD,
2934         /* 180    50  "2" */ CWORD_CWORD_CWORD_CWORD,
2935         /* 181    51  "3" */ CWORD_CWORD_CWORD_CWORD,
2936         /* 182    52  "4" */ CWORD_CWORD_CWORD_CWORD,
2937         /* 183    53  "5" */ CWORD_CWORD_CWORD_CWORD,
2938         /* 184    54  "6" */ CWORD_CWORD_CWORD_CWORD,
2939         /* 185    55  "7" */ CWORD_CWORD_CWORD_CWORD,
2940         /* 186    56  "8" */ CWORD_CWORD_CWORD_CWORD,
2941         /* 187    57  "9" */ CWORD_CWORD_CWORD_CWORD,
2942         /* 188    58  ":" */ CWORD_CCTL_CCTL_CWORD,
2943         /* 189    59  ";" */ CSPCL_CWORD_CWORD_CWORD,
2944         /* 190    60  "<" */ CSPCL_CWORD_CWORD_CWORD,
2945         /* 191    61  "=" */ CWORD_CCTL_CCTL_CWORD,
2946         /* 192    62  ">" */ CSPCL_CWORD_CWORD_CWORD,
2947         /* 193    63  "?" */ CWORD_CCTL_CCTL_CWORD,
2948         /* 194    64  "@" */ CWORD_CWORD_CWORD_CWORD,
2949         /* 195    65  "A" */ CWORD_CWORD_CWORD_CWORD,
2950         /* 196    66  "B" */ CWORD_CWORD_CWORD_CWORD,
2951         /* 197    67  "C" */ CWORD_CWORD_CWORD_CWORD,
2952         /* 198    68  "D" */ CWORD_CWORD_CWORD_CWORD,
2953         /* 199    69  "E" */ CWORD_CWORD_CWORD_CWORD,
2954         /* 200    70  "F" */ CWORD_CWORD_CWORD_CWORD,
2955         /* 201    71  "G" */ CWORD_CWORD_CWORD_CWORD,
2956         /* 202    72  "H" */ CWORD_CWORD_CWORD_CWORD,
2957         /* 203    73  "I" */ CWORD_CWORD_CWORD_CWORD,
2958         /* 204    74  "J" */ CWORD_CWORD_CWORD_CWORD,
2959         /* 205    75  "K" */ CWORD_CWORD_CWORD_CWORD,
2960         /* 206    76  "L" */ CWORD_CWORD_CWORD_CWORD,
2961         /* 207    77  "M" */ CWORD_CWORD_CWORD_CWORD,
2962         /* 208    78  "N" */ CWORD_CWORD_CWORD_CWORD,
2963         /* 209    79  "O" */ CWORD_CWORD_CWORD_CWORD,
2964         /* 210    80  "P" */ CWORD_CWORD_CWORD_CWORD,
2965         /* 211    81  "Q" */ CWORD_CWORD_CWORD_CWORD,
2966         /* 212    82  "R" */ CWORD_CWORD_CWORD_CWORD,
2967         /* 213    83  "S" */ CWORD_CWORD_CWORD_CWORD,
2968         /* 214    84  "T" */ CWORD_CWORD_CWORD_CWORD,
2969         /* 215    85  "U" */ CWORD_CWORD_CWORD_CWORD,
2970         /* 216    86  "V" */ CWORD_CWORD_CWORD_CWORD,
2971         /* 217    87  "W" */ CWORD_CWORD_CWORD_CWORD,
2972         /* 218    88  "X" */ CWORD_CWORD_CWORD_CWORD,
2973         /* 219    89  "Y" */ CWORD_CWORD_CWORD_CWORD,
2974         /* 220    90  "Z" */ CWORD_CWORD_CWORD_CWORD,
2975         /* 221    91  "[" */ CWORD_CCTL_CCTL_CWORD,
2976         /* 222    92  "\" */ CBACK_CBACK_CCTL_CBACK,
2977         /* 223    93  "]" */ CWORD_CCTL_CCTL_CWORD,
2978         /* 224    94  "^" */ CWORD_CWORD_CWORD_CWORD,
2979         /* 225    95  "_" */ CWORD_CWORD_CWORD_CWORD,
2980         /* 226    96  "`" */ CBQUOTE_CBQUOTE_CWORD_CBQUOTE,
2981         /* 227    97  "a" */ CWORD_CWORD_CWORD_CWORD,
2982         /* 228    98  "b" */ CWORD_CWORD_CWORD_CWORD,
2983         /* 229    99  "c" */ CWORD_CWORD_CWORD_CWORD,
2984         /* 230   100  "d" */ CWORD_CWORD_CWORD_CWORD,
2985         /* 231   101  "e" */ CWORD_CWORD_CWORD_CWORD,
2986         /* 232   102  "f" */ CWORD_CWORD_CWORD_CWORD,
2987         /* 233   103  "g" */ CWORD_CWORD_CWORD_CWORD,
2988         /* 234   104  "h" */ CWORD_CWORD_CWORD_CWORD,
2989         /* 235   105  "i" */ CWORD_CWORD_CWORD_CWORD,
2990         /* 236   106  "j" */ CWORD_CWORD_CWORD_CWORD,
2991         /* 237   107  "k" */ CWORD_CWORD_CWORD_CWORD,
2992         /* 238   108  "l" */ CWORD_CWORD_CWORD_CWORD,
2993         /* 239   109  "m" */ CWORD_CWORD_CWORD_CWORD,
2994         /* 240   110  "n" */ CWORD_CWORD_CWORD_CWORD,
2995         /* 241   111  "o" */ CWORD_CWORD_CWORD_CWORD,
2996         /* 242   112  "p" */ CWORD_CWORD_CWORD_CWORD,
2997         /* 243   113  "q" */ CWORD_CWORD_CWORD_CWORD,
2998         /* 244   114  "r" */ CWORD_CWORD_CWORD_CWORD,
2999         /* 245   115  "s" */ CWORD_CWORD_CWORD_CWORD,
3000         /* 246   116  "t" */ CWORD_CWORD_CWORD_CWORD,
3001         /* 247   117  "u" */ CWORD_CWORD_CWORD_CWORD,
3002         /* 248   118  "v" */ CWORD_CWORD_CWORD_CWORD,
3003         /* 249   119  "w" */ CWORD_CWORD_CWORD_CWORD,
3004         /* 250   120  "x" */ CWORD_CWORD_CWORD_CWORD,
3005         /* 251   121  "y" */ CWORD_CWORD_CWORD_CWORD,
3006         /* 252   122  "z" */ CWORD_CWORD_CWORD_CWORD,
3007         /* 253   123  "{" */ CWORD_CWORD_CWORD_CWORD,
3008         /* 254   124  "|" */ CSPCL_CWORD_CWORD_CWORD,
3009         /* 255   125  "}" */ CENDVAR_CENDVAR_CWORD_CENDVAR,
3010         /* 256   126  "~" */ CWORD_CCTL_CCTL_CWORD,
3011         /* 257   127      */ CWORD_CWORD_CWORD_CWORD,
3012 };
3013
3014 #define SIT(c, syntax) (S_I_T[(int)syntax_index_table[(int)(c) + SYNBASE]][syntax])
3015
3016 #endif  /* USE_SIT_FUNCTION */
3017
3018
3019 /* ============ Alias handling */
3020
3021 #if ENABLE_ASH_ALIAS
3022
3023 #define ALIASINUSE 1
3024 #define ALIASDEAD  2
3025
3026 struct alias {
3027         struct alias *next;
3028         char *name;
3029         char *val;
3030         int flag;
3031 };
3032
3033
3034 static struct alias **atab; // [ATABSIZE];
3035 #define INIT_G_alias() do { \
3036         atab = xzalloc(ATABSIZE * sizeof(atab[0])); \
3037 } while (0)
3038
3039
3040 static struct alias **
3041 __lookupalias(const char *name) {
3042         unsigned int hashval;
3043         struct alias **app;
3044         const char *p;
3045         unsigned int ch;
3046
3047         p = name;
3048
3049         ch = (unsigned char)*p;
3050         hashval = ch << 4;
3051         while (ch) {
3052                 hashval += ch;
3053                 ch = (unsigned char)*++p;
3054         }
3055         app = &atab[hashval % ATABSIZE];
3056
3057         for (; *app; app = &(*app)->next) {
3058                 if (strcmp(name, (*app)->name) == 0) {
3059                         break;
3060                 }
3061         }
3062
3063         return app;
3064 }
3065
3066 static struct alias *
3067 lookupalias(const char *name, int check)
3068 {
3069         struct alias *ap = *__lookupalias(name);
3070
3071         if (check && ap && (ap->flag & ALIASINUSE))
3072                 return NULL;
3073         return ap;
3074 }
3075
3076 static struct alias *
3077 freealias(struct alias *ap)
3078 {
3079         struct alias *next;
3080
3081         if (ap->flag & ALIASINUSE) {
3082                 ap->flag |= ALIASDEAD;
3083                 return ap;
3084         }
3085
3086         next = ap->next;
3087         free(ap->name);
3088         free(ap->val);
3089         free(ap);
3090         return next;
3091 }
3092
3093 static void
3094 setalias(const char *name, const char *val)
3095 {
3096         struct alias *ap, **app;
3097
3098         app = __lookupalias(name);
3099         ap = *app;
3100         INT_OFF;
3101         if (ap) {
3102                 if (!(ap->flag & ALIASINUSE)) {
3103                         free(ap->val);
3104                 }
3105                 ap->val = ckstrdup(val);
3106                 ap->flag &= ~ALIASDEAD;
3107         } else {
3108                 /* not found */
3109                 ap = ckzalloc(sizeof(struct alias));
3110                 ap->name = ckstrdup(name);
3111                 ap->val = ckstrdup(val);
3112                 /*ap->flag = 0; - ckzalloc did it */
3113                 /*ap->next = NULL;*/
3114                 *app = ap;
3115         }
3116         INT_ON;
3117 }
3118
3119 static int
3120 unalias(const char *name)
3121 {
3122         struct alias **app;
3123
3124         app = __lookupalias(name);
3125
3126         if (*app) {
3127                 INT_OFF;
3128                 *app = freealias(*app);
3129                 INT_ON;
3130                 return 0;
3131         }
3132
3133         return 1;
3134 }
3135
3136 static void
3137 rmaliases(void)
3138 {
3139         struct alias *ap, **app;
3140         int i;
3141
3142         INT_OFF;
3143         for (i = 0; i < ATABSIZE; i++) {
3144                 app = &atab[i];
3145                 for (ap = *app; ap; ap = *app) {
3146                         *app = freealias(*app);
3147                         if (ap == *app) {
3148                                 app = &ap->next;
3149                         }
3150                 }
3151         }
3152         INT_ON;
3153 }
3154
3155 static void
3156 printalias(const struct alias *ap)
3157 {
3158         out1fmt("%s=%s\n", ap->name, single_quote(ap->val));
3159 }
3160
3161 /*
3162  * TODO - sort output
3163  */
3164 static int
3165 aliascmd(int argc UNUSED_PARAM, char **argv)
3166 {
3167         char *n, *v;
3168         int ret = 0;
3169         struct alias *ap;
3170
3171         if (!argv[1]) {
3172                 int i;
3173
3174                 for (i = 0; i < ATABSIZE; i++) {
3175                         for (ap = atab[i]; ap; ap = ap->next) {
3176                                 printalias(ap);
3177                         }
3178                 }
3179                 return 0;
3180         }
3181         while ((n = *++argv) != NULL) {
3182                 v = strchr(n+1, '=');
3183                 if (v == NULL) { /* n+1: funny ksh stuff */
3184                         ap = *__lookupalias(n);
3185                         if (ap == NULL) {
3186                                 fprintf(stderr, "%s: %s not found\n", "alias", n);
3187                                 ret = 1;
3188                         } else
3189                                 printalias(ap);
3190                 } else {
3191                         *v++ = '\0';
3192                         setalias(n, v);
3193                 }
3194         }
3195
3196         return ret;
3197 }
3198
3199 static int
3200 unaliascmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
3201 {
3202         int i;
3203
3204         while ((i = nextopt("a")) != '\0') {
3205                 if (i == 'a') {
3206                         rmaliases();
3207                         return 0;
3208                 }
3209         }
3210         for (i = 0; *argptr; argptr++) {
3211                 if (unalias(*argptr)) {
3212                         fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
3213                         i = 1;
3214                 }
3215         }
3216
3217         return i;
3218 }
3219
3220 #endif /* ASH_ALIAS */
3221
3222
3223 /* ============ jobs.c */
3224
3225 /* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
3226 #define FORK_FG 0
3227 #define FORK_BG 1
3228 #define FORK_NOJOB 2
3229
3230 /* mode flags for showjob(s) */
3231 #define SHOW_PGID       0x01    /* only show pgid - for jobs -p */
3232 #define SHOW_PID        0x04    /* include process pid */
3233 #define SHOW_CHANGED    0x08    /* only jobs whose state has changed */
3234
3235 /*
3236  * A job structure contains information about a job.  A job is either a
3237  * single process or a set of processes contained in a pipeline.  In the
3238  * latter case, pidlist will be non-NULL, and will point to a -1 terminated
3239  * array of pids.
3240  */
3241
3242 struct procstat {
3243         pid_t   pid;            /* process id */
3244         int     status;         /* last process status from wait() */
3245         char    *cmd;           /* text of command being run */
3246 };
3247
3248 struct job {
3249         struct procstat ps0;    /* status of process */
3250         struct procstat *ps;    /* status or processes when more than one */
3251 #if JOBS
3252         int stopstatus;         /* status of a stopped job */
3253 #endif
3254         uint32_t
3255                 nprocs: 16,     /* number of processes */
3256                 state: 8,
3257 #define JOBRUNNING      0       /* at least one proc running */
3258 #define JOBSTOPPED      1       /* all procs are stopped */
3259 #define JOBDONE         2       /* all procs are completed */
3260 #if JOBS
3261                 sigint: 1,      /* job was killed by SIGINT */
3262                 jobctl: 1,      /* job running under job control */
3263 #endif
3264                 waited: 1,      /* true if this entry has been waited for */
3265                 used: 1,        /* true if this entry is in used */
3266                 changed: 1;     /* true if status has changed */
3267         struct job *prev_job;   /* previous job */
3268 };
3269
3270 static struct job *makejob(/*union node *,*/ int);
3271 #if !JOBS
3272 #define forkshell(job, node, mode) forkshell(job, mode)
3273 #endif
3274 static int forkshell(struct job *, union node *, int);
3275 static int waitforjob(struct job *);
3276
3277 #if !JOBS
3278 enum { doing_jobctl = 0 };
3279 #define setjobctl(on) do {} while (0)
3280 #else
3281 static smallint doing_jobctl; //references:8
3282 static void setjobctl(int);
3283 #endif
3284
3285 /*
3286  * Ignore a signal.
3287  */
3288 static void
3289 ignoresig(int signo)
3290 {
3291         /* Avoid unnecessary system calls. Is it already SIG_IGNed? */
3292         if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
3293                 /* No, need to do it */
3294                 signal(signo, SIG_IGN);
3295         }
3296         sigmode[signo - 1] = S_HARD_IGN;
3297 }
3298
3299 /*
3300  * Signal handler. Only one usage site - in setsignal()
3301  */
3302 static void
3303 onsig(int signo)
3304 {
3305         gotsig[signo - 1] = 1;
3306
3307         if (/* exsig || */ (signo == SIGINT && !trap[SIGINT])) {
3308                 if (!suppressint) {
3309                         pendingsig = 0;
3310                         raise_interrupt(); /* does not return */
3311                 }
3312                 intpending = 1;
3313         } else {
3314                 pendingsig = signo;
3315         }
3316 }
3317
3318 /*
3319  * Set the signal handler for the specified signal.  The routine figures
3320  * out what it should be set to.
3321  */
3322 static void
3323 setsignal(int signo)
3324 {
3325         char *t;
3326         char cur_act, new_act;
3327         struct sigaction act;
3328
3329         t = trap[signo];
3330         new_act = S_DFL;
3331         if (t != NULL) { /* trap for this sig is set */
3332                 new_act = S_CATCH;
3333                 if (t[0] == '\0') /* trap is "": ignore this sig */
3334                         new_act = S_IGN;
3335         }
3336
3337         if (rootshell && new_act == S_DFL) {
3338                 switch (signo) {
3339                 case SIGINT:
3340                         if (iflag || minusc || sflag == 0)
3341                                 new_act = S_CATCH;
3342                         break;
3343                 case SIGQUIT:
3344 #if DEBUG
3345                         if (debug)
3346                                 break;
3347 #endif
3348                         /* man bash:
3349                          * "In all cases, bash ignores SIGQUIT. Non-builtin
3350                          * commands run by bash have signal handlers
3351                          * set to the values inherited by the shell
3352                          * from its parent". */
3353                         new_act = S_IGN;
3354                         break;
3355                 case SIGTERM:
3356                         if (iflag)
3357                                 new_act = S_IGN;
3358                         break;
3359 #if JOBS
3360                 case SIGTSTP:
3361                 case SIGTTOU:
3362                         if (mflag)
3363                                 new_act = S_IGN;
3364                         break;
3365 #endif
3366                 }
3367         }
3368 //TODO: if !rootshell, we reset SIGQUIT to DFL,
3369 //whereas we have to restore it to what shell got on entry
3370 //from the parent. See comment above
3371
3372         t = &sigmode[signo - 1];
3373         cur_act = *t;
3374         if (cur_act == 0) {
3375                 /* current setting is not yet known */
3376                 if (sigaction(signo, NULL, &act)) {
3377                         /* pretend it worked; maybe we should give a warning,
3378                          * but other shells don't. We don't alter sigmode,
3379                          * so we retry every time.
3380                          * btw, in Linux it never fails. --vda */
3381                         return;
3382                 }
3383                 if (act.sa_handler == SIG_IGN) {
3384                         cur_act = S_HARD_IGN;
3385                         if (mflag
3386                          && (signo == SIGTSTP || signo == SIGTTIN || signo == SIGTTOU)
3387                         ) {
3388                                 cur_act = S_IGN;   /* don't hard ignore these */
3389                         }
3390                 }
3391         }
3392         if (cur_act == S_HARD_IGN || cur_act == new_act)
3393                 return;
3394
3395         act.sa_handler = SIG_DFL;
3396         switch (new_act) {
3397         case S_CATCH:
3398                 act.sa_handler = onsig;
3399                 act.sa_flags = 0; /* matters only if !DFL and !IGN */
3400                 sigfillset(&act.sa_mask); /* ditto */
3401                 break;
3402         case S_IGN:
3403                 act.sa_handler = SIG_IGN;
3404                 break;
3405         }
3406         sigaction_set(signo, &act);
3407
3408         *t = new_act;
3409 }
3410
3411 /* mode flags for set_curjob */
3412 #define CUR_DELETE 2
3413 #define CUR_RUNNING 1
3414 #define CUR_STOPPED 0
3415
3416 /* mode flags for dowait */
3417 #define DOWAIT_NONBLOCK WNOHANG
3418 #define DOWAIT_BLOCK    0
3419
3420 #if JOBS
3421 /* pgrp of shell on invocation */
3422 static int initialpgrp; //references:2
3423 static int ttyfd = -1; //5
3424 #endif
3425 /* array of jobs */
3426 static struct job *jobtab; //5
3427 /* size of array */
3428 static unsigned njobs; //4
3429 /* current job */
3430 static struct job *curjob; //lots
3431 /* number of presumed living untracked jobs */
3432 static int jobless; //4
3433
3434 static void
3435 set_curjob(struct job *jp, unsigned mode)
3436 {
3437         struct job *jp1;
3438         struct job **jpp, **curp;
3439
3440         /* first remove from list */
3441         jpp = curp = &curjob;
3442         do {
3443                 jp1 = *jpp;
3444                 if (jp1 == jp)
3445                         break;
3446                 jpp = &jp1->prev_job;
3447         } while (1);
3448         *jpp = jp1->prev_job;
3449
3450         /* Then re-insert in correct position */
3451         jpp = curp;
3452         switch (mode) {
3453         default:
3454 #if DEBUG
3455                 abort();
3456 #endif
3457         case CUR_DELETE:
3458                 /* job being deleted */
3459                 break;
3460         case CUR_RUNNING:
3461                 /* newly created job or backgrounded job,
3462                    put after all stopped jobs. */
3463                 do {
3464                         jp1 = *jpp;
3465 #if JOBS
3466                         if (!jp1 || jp1->state != JOBSTOPPED)
3467 #endif
3468                                 break;
3469                         jpp = &jp1->prev_job;
3470                 } while (1);
3471                 /* FALLTHROUGH */
3472 #if JOBS
3473         case CUR_STOPPED:
3474 #endif
3475                 /* newly stopped job - becomes curjob */
3476                 jp->prev_job = *jpp;
3477                 *jpp = jp;
3478                 break;
3479         }
3480 }
3481
3482 #if JOBS || DEBUG
3483 static int
3484 jobno(const struct job *jp)
3485 {
3486         return jp - jobtab + 1;
3487 }
3488 #endif
3489
3490 /*
3491  * Convert a job name to a job structure.
3492  */
3493 #if !JOBS
3494 #define getjob(name, getctl) getjob(name)
3495 #endif
3496 static struct job *
3497 getjob(const char *name, int getctl)
3498 {
3499         struct job *jp;
3500         struct job *found;
3501         const char *err_msg = "No such job: %s";
3502         unsigned num;
3503         int c;
3504         const char *p;
3505         char *(*match)(const char *, const char *);
3506
3507         jp = curjob;
3508         p = name;
3509         if (!p)
3510                 goto currentjob;
3511
3512         if (*p != '%')
3513                 goto err;
3514
3515         c = *++p;
3516         if (!c)
3517                 goto currentjob;
3518
3519         if (!p[1]) {
3520                 if (c == '+' || c == '%') {
3521  currentjob:
3522                         err_msg = "No current job";
3523                         goto check;
3524                 }
3525                 if (c == '-') {
3526                         if (jp)
3527                                 jp = jp->prev_job;
3528                         err_msg = "No previous job";
3529  check:
3530                         if (!jp)
3531                                 goto err;
3532                         goto gotit;
3533                 }
3534         }
3535
3536         if (is_number(p)) {
3537 // TODO: number() instead? It does error checking...
3538                 num = atoi(p);
3539                 if (num < njobs) {
3540                         jp = jobtab + num - 1;
3541                         if (jp->used)
3542                                 goto gotit;
3543                         goto err;
3544                 }
3545         }
3546
3547         match = prefix;
3548         if (*p == '?') {
3549                 match = strstr;
3550                 p++;
3551         }
3552
3553         found = 0;
3554         while (1) {
3555                 if (!jp)
3556                         goto err;
3557                 if (match(jp->ps[0].cmd, p)) {
3558                         if (found)
3559                                 goto err;
3560                         found = jp;
3561                         err_msg = "%s: ambiguous";
3562                 }
3563                 jp = jp->prev_job;
3564         }
3565
3566  gotit:
3567 #if JOBS
3568         err_msg = "job %s not created under job control";
3569         if (getctl && jp->jobctl == 0)
3570                 goto err;
3571 #endif
3572         return jp;
3573  err:
3574         ash_msg_and_raise_error(err_msg, name);
3575 }
3576
3577 /*
3578  * Mark a job structure as unused.
3579  */
3580 static void
3581 freejob(struct job *jp)
3582 {
3583         struct procstat *ps;
3584         int i;
3585
3586         INT_OFF;
3587         for (i = jp->nprocs, ps = jp->ps; --i >= 0; ps++) {
3588                 if (ps->cmd != nullstr)
3589                         free(ps->cmd);
3590         }
3591         if (jp->ps != &jp->ps0)
3592                 free(jp->ps);
3593         jp->used = 0;
3594         set_curjob(jp, CUR_DELETE);
3595         INT_ON;
3596 }
3597
3598 #if JOBS
3599 static void
3600 xtcsetpgrp(int fd, pid_t pgrp)
3601 {
3602         if (tcsetpgrp(fd, pgrp))
3603                 ash_msg_and_raise_error("can't set tty process group (%m)");
3604 }
3605
3606 /*
3607  * Turn job control on and off.
3608  *
3609  * Note:  This code assumes that the third arg to ioctl is a character
3610  * pointer, which is true on Berkeley systems but not System V.  Since
3611  * System V doesn't have job control yet, this isn't a problem now.
3612  *
3613  * Called with interrupts off.
3614  */
3615 static void
3616 setjobctl(int on)
3617 {
3618         int fd;
3619         int pgrp;
3620
3621         if (on == doing_jobctl || rootshell == 0)
3622                 return;
3623         if (on) {
3624                 int ofd;
3625                 ofd = fd = open(_PATH_TTY, O_RDWR);
3626                 if (fd < 0) {
3627         /* BTW, bash will try to open(ttyname(0)) if open("/dev/tty") fails.
3628          * That sometimes helps to acquire controlling tty.
3629          * Obviously, a workaround for bugs when someone
3630          * failed to provide a controlling tty to bash! :) */
3631                         fd = 2;
3632                         while (!isatty(fd))
3633                                 if (--fd < 0)
3634                                         goto out;
3635                 }
3636                 fd = fcntl(fd, F_DUPFD, 10);
3637                 if (ofd >= 0)
3638                         close(ofd);
3639                 if (fd < 0)
3640                         goto out;
3641                 /* fd is a tty at this point */
3642                 close_on_exec_on(fd);
3643                 do { /* while we are in the background */
3644                         pgrp = tcgetpgrp(fd);
3645                         if (pgrp < 0) {
3646  out:
3647                                 ash_msg("can't access tty; job control turned off");
3648                                 mflag = on = 0;
3649                                 goto close;
3650                         }
3651                         if (pgrp == getpgrp())
3652                                 break;
3653                         killpg(0, SIGTTIN);
3654                 } while (1);
3655                 initialpgrp = pgrp;
3656
3657                 setsignal(SIGTSTP);
3658                 setsignal(SIGTTOU);
3659                 setsignal(SIGTTIN);
3660                 pgrp = rootpid;
3661                 setpgid(0, pgrp);
3662                 xtcsetpgrp(fd, pgrp);
3663         } else {
3664                 /* turning job control off */
3665                 fd = ttyfd;
3666                 pgrp = initialpgrp;
3667                 /* was xtcsetpgrp, but this can make exiting ash
3668                  * loop forever if pty is already deleted */
3669                 tcsetpgrp(fd, pgrp);
3670                 setpgid(0, pgrp);
3671                 setsignal(SIGTSTP);
3672                 setsignal(SIGTTOU);
3673                 setsignal(SIGTTIN);
3674  close:
3675                 if (fd >= 0)
3676                         close(fd);
3677                 fd = -1;
3678         }
3679         ttyfd = fd;
3680         doing_jobctl = on;
3681 }
3682
3683 static int
3684 killcmd(int argc, char **argv)
3685 {
3686         int i = 1;
3687         if (argv[1] && strcmp(argv[1], "-l") != 0) {
3688                 do {
3689                         if (argv[i][0] == '%') {
3690                                 struct job *jp = getjob(argv[i], 0);
3691                                 unsigned pid = jp->ps[0].pid;
3692                                 /* Enough space for ' -NNN<nul>' */
3693                                 argv[i] = alloca(sizeof(int)*3 + 3);
3694                                 /* kill_main has matching code to expect
3695                                  * leading space. Needed to not confuse
3696                                  * negative pids with "kill -SIGNAL_NO" syntax */
3697                                 sprintf(argv[i], " -%u", pid);
3698                         }
3699                 } while (argv[++i]);
3700         }
3701         return kill_main(argc, argv);
3702 }
3703
3704 static void
3705 showpipe(struct job *jp, FILE *out)
3706 {
3707         struct procstat *sp;
3708         struct procstat *spend;
3709
3710         spend = jp->ps + jp->nprocs;
3711         for (sp = jp->ps + 1; sp < spend; sp++)
3712                 fprintf(out, " | %s", sp->cmd);
3713         outcslow('\n', out);
3714         flush_stdout_stderr();
3715 }
3716
3717
3718 static int
3719 restartjob(struct job *jp, int mode)
3720 {
3721         struct procstat *ps;
3722         int i;
3723         int status;
3724         pid_t pgid;
3725
3726         INT_OFF;
3727         if (jp->state == JOBDONE)
3728                 goto out;
3729         jp->state = JOBRUNNING;
3730         pgid = jp->ps->pid;
3731         if (mode == FORK_FG)
3732                 xtcsetpgrp(ttyfd, pgid);
3733         killpg(pgid, SIGCONT);
3734         ps = jp->ps;
3735         i = jp->nprocs;
3736         do {
3737                 if (WIFSTOPPED(ps->status)) {
3738                         ps->status = -1;
3739                 }
3740                 ps++;
3741         } while (--i);
3742  out:
3743         status = (mode == FORK_FG) ? waitforjob(jp) : 0;
3744         INT_ON;
3745         return status;
3746 }
3747
3748 static int
3749 fg_bgcmd(int argc UNUSED_PARAM, char **argv)
3750 {
3751         struct job *jp;
3752         FILE *out;
3753         int mode;
3754         int retval;
3755
3756         mode = (**argv == 'f') ? FORK_FG : FORK_BG;
3757         nextopt(nullstr);
3758         argv = argptr;
3759         out = stdout;
3760         do {
3761                 jp = getjob(*argv, 1);
3762                 if (mode == FORK_BG) {
3763                         set_curjob(jp, CUR_RUNNING);
3764                         fprintf(out, "[%d] ", jobno(jp));
3765                 }
3766                 outstr(jp->ps->cmd, out);
3767                 showpipe(jp, out);
3768                 retval = restartjob(jp, mode);
3769         } while (*argv && *++argv);
3770         return retval;
3771 }
3772 #endif
3773
3774 static int
3775 sprint_status(char *s, int status, int sigonly)
3776 {
3777         int col;
3778         int st;
3779
3780         col = 0;
3781         if (!WIFEXITED(status)) {
3782 #if JOBS
3783                 if (WIFSTOPPED(status))
3784                         st = WSTOPSIG(status);
3785                 else
3786 #endif
3787                         st = WTERMSIG(status);
3788                 if (sigonly) {
3789                         if (st == SIGINT || st == SIGPIPE)
3790                                 goto out;
3791 #if JOBS
3792                         if (WIFSTOPPED(status))
3793                                 goto out;
3794 #endif
3795                 }
3796                 st &= 0x7f;
3797                 col = fmtstr(s, 32, strsignal(st));
3798                 if (WCOREDUMP(status)) {
3799                         col += fmtstr(s + col, 16, " (core dumped)");
3800                 }
3801         } else if (!sigonly) {
3802                 st = WEXITSTATUS(status);
3803                 if (st)
3804                         col = fmtstr(s, 16, "Done(%d)", st);
3805                 else
3806                         col = fmtstr(s, 16, "Done");
3807         }
3808  out:
3809         return col;
3810 }
3811
3812 static int
3813 dowait(int wait_flags, struct job *job)
3814 {
3815         int pid;
3816         int status;
3817         struct job *jp;
3818         struct job *thisjob;
3819         int state;
3820
3821         TRACE(("dowait(0x%x) called\n", wait_flags));
3822
3823         /* Do a wait system call. If job control is compiled in, we accept
3824          * stopped processes. wait_flags may have WNOHANG, preventing blocking.
3825          * NB: _not_ safe_waitpid, we need to detect EINTR */
3826         pid = waitpid(-1, &status,
3827                         (doing_jobctl ? (wait_flags | WUNTRACED) : wait_flags));
3828         TRACE(("wait returns pid=%d, status=0x%x, errno=%d(%s)\n",
3829                                 pid, status, errno, strerror(errno)));
3830         if (pid <= 0)
3831                 return pid;
3832
3833         INT_OFF;
3834         thisjob = NULL;
3835         for (jp = curjob; jp; jp = jp->prev_job) {
3836                 struct procstat *sp;
3837                 struct procstat *spend;
3838                 if (jp->state == JOBDONE)
3839                         continue;
3840                 state = JOBDONE;
3841                 spend = jp->ps + jp->nprocs;
3842                 sp = jp->ps;
3843                 do {
3844                         if (sp->pid == pid) {
3845                                 TRACE(("Job %d: changing status of proc %d "
3846                                         "from 0x%x to 0x%x\n",
3847                                         jobno(jp), pid, sp->status, status));
3848                                 sp->status = status;
3849                                 thisjob = jp;
3850                         }
3851                         if (sp->status == -1)
3852                                 state = JOBRUNNING;
3853 #if JOBS
3854                         if (state == JOBRUNNING)
3855                                 continue;
3856                         if (WIFSTOPPED(sp->status)) {
3857                                 jp->stopstatus = sp->status;
3858                                 state = JOBSTOPPED;
3859                         }
3860 #endif
3861                 } while (++sp < spend);
3862                 if (thisjob)
3863                         goto gotjob;
3864         }
3865 #if JOBS
3866         if (!WIFSTOPPED(status))
3867 #endif
3868                 jobless--;
3869         goto out;
3870
3871  gotjob:
3872         if (state != JOBRUNNING) {
3873                 thisjob->changed = 1;
3874
3875                 if (thisjob->state != state) {
3876                         TRACE(("Job %d: changing state from %d to %d\n",
3877                                 jobno(thisjob), thisjob->state, state));
3878                         thisjob->state = state;
3879 #if JOBS
3880                         if (state == JOBSTOPPED) {
3881                                 set_curjob(thisjob, CUR_STOPPED);
3882                         }
3883 #endif
3884                 }
3885         }
3886
3887  out:
3888         INT_ON;
3889
3890         if (thisjob && thisjob == job) {
3891                 char s[48 + 1];
3892                 int len;
3893
3894                 len = sprint_status(s, status, 1);
3895                 if (len) {
3896                         s[len] = '\n';
3897                         s[len + 1] = '\0';
3898                         out2str(s);
3899                 }
3900         }
3901         return pid;
3902 }
3903
3904 static int
3905 blocking_wait_with_raise_on_sig(struct job *job)
3906 {
3907         pid_t pid = dowait(DOWAIT_BLOCK, job);
3908         if (pid <= 0 && pendingsig)
3909                 raise_exception(EXSIG);
3910         return pid;
3911 }
3912
3913 #if JOBS
3914 static void
3915 showjob(FILE *out, struct job *jp, int mode)
3916 {
3917         struct procstat *ps;
3918         struct procstat *psend;
3919         int col;
3920         int indent_col;
3921         char s[80];
3922
3923         ps = jp->ps;
3924
3925         if (mode & SHOW_PGID) {
3926                 /* just output process (group) id of pipeline */
3927                 fprintf(out, "%d\n", ps->pid);
3928                 return;
3929         }
3930
3931         col = fmtstr(s, 16, "[%d]   ", jobno(jp));
3932         indent_col = col;
3933
3934         if (jp == curjob)
3935                 s[col - 2] = '+';
3936         else if (curjob && jp == curjob->prev_job)
3937                 s[col - 2] = '-';
3938
3939         if (mode & SHOW_PID)
3940                 col += fmtstr(s + col, 16, "%d ", ps->pid);
3941
3942         psend = ps + jp->nprocs;
3943
3944         if (jp->state == JOBRUNNING) {
3945                 strcpy(s + col, "Running");
3946                 col += sizeof("Running") - 1;
3947         } else {
3948                 int status = psend[-1].status;
3949                 if (jp->state == JOBSTOPPED)
3950                         status = jp->stopstatus;
3951                 col += sprint_status(s + col, status, 0);
3952         }
3953
3954         goto start;
3955
3956         do {
3957                 /* for each process */
3958                 col = fmtstr(s, 48, " |\n%*c%d ", indent_col, ' ', ps->pid) - 3;
3959  start:
3960                 fprintf(out, "%s%*c%s",
3961                         s, 33 - col >= 0 ? 33 - col : 0, ' ', ps->cmd
3962                 );
3963                 if (!(mode & SHOW_PID)) {
3964                         showpipe(jp, out);
3965                         break;
3966                 }
3967                 if (++ps == psend) {
3968                         outcslow('\n', out);
3969                         break;
3970                 }
3971         } while (1);
3972
3973         jp->changed = 0;
3974
3975         if (jp->state == JOBDONE) {
3976                 TRACE(("showjob: freeing job %d\n", jobno(jp)));
3977                 freejob(jp);
3978         }
3979 }
3980
3981 /*
3982  * Print a list of jobs.  If "change" is nonzero, only print jobs whose
3983  * statuses have changed since the last call to showjobs.
3984  */
3985 static void
3986 showjobs(FILE *out, int mode)
3987 {
3988         struct job *jp;
3989
3990         TRACE(("showjobs(%x) called\n", mode));
3991
3992         /* Handle all finished jobs */
3993         while (dowait(DOWAIT_NONBLOCK, NULL) > 0)
3994                 continue;
3995
3996         for (jp = curjob; jp; jp = jp->prev_job) {
3997                 if (!(mode & SHOW_CHANGED) || jp->changed) {
3998                         showjob(out, jp, mode);
3999                 }
4000         }
4001 }
4002
4003 static int
4004 jobscmd(int argc UNUSED_PARAM, char **argv)
4005 {
4006         int mode, m;
4007
4008         mode = 0;
4009         while ((m = nextopt("lp"))) {
4010                 if (m == 'l')
4011                         mode = SHOW_PID;
4012                 else
4013                         mode = SHOW_PGID;
4014         }
4015
4016         argv = argptr;
4017         if (*argv) {
4018                 do
4019                         showjob(stdout, getjob(*argv,0), mode);
4020                 while (*++argv);
4021         } else
4022                 showjobs(stdout, mode);
4023
4024         return 0;
4025 }
4026 #endif /* JOBS */
4027
4028 static int
4029 getstatus(struct job *job)
4030 {
4031         int status;
4032         int retval;
4033
4034         status = job->ps[job->nprocs - 1].status;
4035         retval = WEXITSTATUS(status);
4036         if (!WIFEXITED(status)) {
4037 #if JOBS
4038                 retval = WSTOPSIG(status);
4039                 if (!WIFSTOPPED(status))
4040 #endif
4041                 {
4042                         /* XXX: limits number of signals */
4043                         retval = WTERMSIG(status);
4044 #if JOBS
4045                         if (retval == SIGINT)
4046                                 job->sigint = 1;
4047 #endif
4048                 }
4049                 retval += 128;
4050         }
4051         TRACE(("getstatus: job %d, nproc %d, status %x, retval %x\n",
4052                 jobno(job), job->nprocs, status, retval));
4053         return retval;
4054 }
4055
4056 static int
4057 waitcmd(int argc UNUSED_PARAM, char **argv)
4058 {
4059         struct job *job;
4060         int retval;
4061         struct job *jp;
4062
4063 //      exsig++;
4064 //      xbarrier();
4065         if (pendingsig)
4066                 raise_exception(EXSIG);
4067
4068         nextopt(nullstr);
4069         retval = 0;
4070
4071         argv = argptr;
4072         if (!*argv) {
4073                 /* wait for all jobs */
4074                 for (;;) {
4075                         jp = curjob;
4076                         while (1) {
4077                                 if (!jp) /* no running procs */
4078                                         goto ret;
4079                                 if (jp->state == JOBRUNNING)
4080                                         break;
4081                                 jp->waited = 1;
4082                                 jp = jp->prev_job;
4083                         }
4084         /* man bash:
4085          * "When bash is waiting for an asynchronous command via
4086          * the wait builtin, the reception of a signal for which a trap
4087          * has been set will cause the wait builtin to return immediately
4088          * with an exit status greater than 128, immediately after which
4089          * the trap is executed."
4090          * Do we do it that way? */
4091                         blocking_wait_with_raise_on_sig(NULL);
4092                 }
4093         }
4094
4095         retval = 127;
4096         do {
4097                 if (**argv != '%') {
4098                         pid_t pid = number(*argv);
4099                         job = curjob;
4100                         while (1) {
4101                                 if (!job)
4102                                         goto repeat;
4103                                 if (job->ps[job->nprocs - 1].pid == pid)
4104                                         break;
4105                                 job = job->prev_job;
4106                         }
4107                 } else
4108                         job = getjob(*argv, 0);
4109                 /* loop until process terminated or stopped */
4110                 while (job->state == JOBRUNNING)
4111                         blocking_wait_with_raise_on_sig(NULL);
4112                 job->waited = 1;
4113                 retval = getstatus(job);
4114  repeat: ;
4115         } while (*++argv);
4116
4117  ret:
4118         return retval;
4119 }
4120
4121 static struct job *
4122 growjobtab(void)
4123 {
4124         size_t len;
4125         ptrdiff_t offset;
4126         struct job *jp, *jq;
4127
4128         len = njobs * sizeof(*jp);
4129         jq = jobtab;
4130         jp = ckrealloc(jq, len + 4 * sizeof(*jp));
4131
4132         offset = (char *)jp - (char *)jq;
4133         if (offset) {
4134                 /* Relocate pointers */
4135                 size_t l = len;
4136
4137                 jq = (struct job *)((char *)jq + l);
4138                 while (l) {
4139                         l -= sizeof(*jp);
4140                         jq--;
4141 #define joff(p) ((struct job *)((char *)(p) + l))
4142 #define jmove(p) (p) = (void *)((char *)(p) + offset)
4143                         if (joff(jp)->ps == &jq->ps0)
4144                                 jmove(joff(jp)->ps);
4145                         if (joff(jp)->prev_job)
4146                                 jmove(joff(jp)->prev_job);
4147                 }
4148                 if (curjob)
4149                         jmove(curjob);
4150 #undef joff
4151 #undef jmove
4152         }
4153
4154         njobs += 4;
4155         jobtab = jp;
4156         jp = (struct job *)((char *)jp + len);
4157         jq = jp + 3;
4158         do {
4159                 jq->used = 0;
4160         } while (--jq >= jp);
4161         return jp;
4162 }
4163
4164 /*
4165  * Return a new job structure.
4166  * Called with interrupts off.
4167  */
4168 static struct job *
4169 makejob(/*union node *node,*/ int nprocs)
4170 {
4171         int i;
4172         struct job *jp;
4173
4174         for (i = njobs, jp = jobtab; ; jp++) {
4175                 if (--i < 0) {
4176                         jp = growjobtab();
4177                         break;
4178                 }
4179                 if (jp->used == 0)
4180                         break;
4181                 if (jp->state != JOBDONE || !jp->waited)
4182                         continue;
4183 #if JOBS
4184                 if (doing_jobctl)
4185                         continue;
4186 #endif
4187                 freejob(jp);
4188                 break;
4189         }
4190         memset(jp, 0, sizeof(*jp));
4191 #if JOBS
4192         /* jp->jobctl is a bitfield.
4193          * "jp->jobctl |= jobctl" likely to give awful code */
4194         if (doing_jobctl)
4195                 jp->jobctl = 1;
4196 #endif
4197         jp->prev_job = curjob;
4198         curjob = jp;
4199         jp->used = 1;
4200         jp->ps = &jp->ps0;
4201         if (nprocs > 1) {
4202                 jp->ps = ckmalloc(nprocs * sizeof(struct procstat));
4203         }
4204         TRACE(("makejob(%d) returns %%%d\n", nprocs,
4205                                 jobno(jp)));
4206         return jp;
4207 }
4208
4209 #if JOBS
4210 /*
4211  * Return a string identifying a command (to be printed by the
4212  * jobs command).
4213  */
4214 static char *cmdnextc;
4215
4216 static void
4217 cmdputs(const char *s)
4218 {
4219         static const char vstype[VSTYPE + 1][3] = {
4220                 "", "}", "-", "+", "?", "=",
4221                 "%", "%%", "#", "##"
4222                 USE_ASH_BASH_COMPAT(, ":", "/", "//")
4223         };
4224
4225         const char *p, *str;
4226         char c, cc[2] = " ";
4227         char *nextc;
4228         int subtype = 0;
4229         int quoted = 0;
4230
4231         nextc = makestrspace((strlen(s) + 1) * 8, cmdnextc);
4232         p = s;
4233         while ((c = *p++) != 0) {
4234                 str = NULL;
4235                 switch (c) {
4236                 case CTLESC:
4237                         c = *p++;
4238                         break;
4239                 case CTLVAR:
4240                         subtype = *p++;
4241                         if ((subtype & VSTYPE) == VSLENGTH)
4242                                 str = "${#";
4243                         else
4244                                 str = "${";
4245                         if (!(subtype & VSQUOTE) == !(quoted & 1))
4246                                 goto dostr;
4247                         quoted ^= 1;
4248                         c = '"';
4249                         break;
4250                 case CTLENDVAR:
4251                         str = "\"}" + !(quoted & 1);
4252                         quoted >>= 1;
4253                         subtype = 0;
4254                         goto dostr;
4255                 case CTLBACKQ:
4256                         str = "$(...)";
4257                         goto dostr;
4258                 case CTLBACKQ+CTLQUOTE:
4259                         str = "\"$(...)\"";
4260                         goto dostr;
4261 #if ENABLE_SH_MATH_SUPPORT
4262                 case CTLARI:
4263                         str = "$((";
4264                         goto dostr;
4265                 case CTLENDARI:
4266                         str = "))";
4267                         goto dostr;
4268 #endif
4269                 case CTLQUOTEMARK:
4270                         quoted ^= 1;
4271                         c = '"';
4272                         break;
4273                 case '=':
4274                         if (subtype == 0)
4275                                 break;
4276                         if ((subtype & VSTYPE) != VSNORMAL)
4277                                 quoted <<= 1;
4278                         str = vstype[subtype & VSTYPE];
4279                         if (subtype & VSNUL)
4280                                 c = ':';
4281                         else
4282                                 goto checkstr;
4283                         break;
4284                 case '\'':
4285                 case '\\':
4286                 case '"':
4287                 case '$':
4288                         /* These can only happen inside quotes */
4289                         cc[0] = c;
4290                         str = cc;
4291                         c = '\\';
4292                         break;
4293                 default:
4294                         break;
4295                 }
4296                 USTPUTC(c, nextc);
4297  checkstr:
4298                 if (!str)
4299                         continue;
4300  dostr:
4301                 while ((c = *str++)) {
4302                         USTPUTC(c, nextc);
4303                 }
4304         }
4305         if (quoted & 1) {
4306                 USTPUTC('"', nextc);
4307         }
4308         *nextc = 0;
4309         cmdnextc = nextc;
4310 }
4311
4312 /* cmdtxt() and cmdlist() call each other */
4313 static void cmdtxt(union node *n);
4314
4315 static void
4316 cmdlist(union node *np, int sep)
4317 {
4318         for (; np; np = np->narg.next) {
4319                 if (!sep)
4320                         cmdputs(" ");
4321                 cmdtxt(np);
4322                 if (sep && np->narg.next)
4323                         cmdputs(" ");
4324         }
4325 }
4326
4327 static void
4328 cmdtxt(union node *n)
4329 {
4330         union node *np;
4331         struct nodelist *lp;
4332         const char *p;
4333
4334         if (!n)
4335                 return;
4336         switch (n->type) {
4337         default:
4338 #if DEBUG
4339                 abort();
4340 #endif
4341         case NPIPE:
4342                 lp = n->npipe.cmdlist;
4343                 for (;;) {
4344                         cmdtxt(lp->n);
4345                         lp = lp->next;
4346                         if (!lp)
4347                                 break;
4348                         cmdputs(" | ");
4349                 }
4350                 break;
4351         case NSEMI:
4352                 p = "; ";
4353                 goto binop;
4354         case NAND:
4355                 p = " && ";
4356                 goto binop;
4357         case NOR:
4358                 p = " || ";
4359  binop:
4360                 cmdtxt(n->nbinary.ch1);
4361                 cmdputs(p);
4362                 n = n->nbinary.ch2;
4363                 goto donode;
4364         case NREDIR:
4365         case NBACKGND:
4366                 n = n->nredir.n;
4367                 goto donode;
4368         case NNOT:
4369                 cmdputs("!");
4370                 n = n->nnot.com;
4371  donode:
4372                 cmdtxt(n);
4373                 break;
4374         case NIF:
4375                 cmdputs("if ");
4376                 cmdtxt(n->nif.test);
4377                 cmdputs("; then ");
4378                 n = n->nif.ifpart;
4379                 if (n->nif.elsepart) {
4380                         cmdtxt(n);
4381                         cmdputs("; else ");
4382                         n = n->nif.elsepart;
4383                 }
4384                 p = "; fi";
4385                 goto dotail;
4386         case NSUBSHELL:
4387                 cmdputs("(");
4388                 n = n->nredir.n;
4389                 p = ")";
4390                 goto dotail;
4391         case NWHILE:
4392                 p = "while ";
4393                 goto until;
4394         case NUNTIL:
4395                 p = "until ";
4396  until:
4397                 cmdputs(p);
4398                 cmdtxt(n->nbinary.ch1);
4399                 n = n->nbinary.ch2;
4400                 p = "; done";
4401  dodo:
4402                 cmdputs("; do ");
4403  dotail:
4404                 cmdtxt(n);
4405                 goto dotail2;
4406         case NFOR:
4407                 cmdputs("for ");
4408                 cmdputs(n->nfor.var);
4409                 cmdputs(" in ");
4410                 cmdlist(n->nfor.args, 1);
4411                 n = n->nfor.body;
4412                 p = "; done";
4413                 goto dodo;
4414         case NDEFUN:
4415                 cmdputs(n->narg.text);
4416                 p = "() { ... }";
4417                 goto dotail2;
4418         case NCMD:
4419                 cmdlist(n->ncmd.args, 1);
4420                 cmdlist(n->ncmd.redirect, 0);
4421                 break;
4422         case NARG:
4423                 p = n->narg.text;
4424  dotail2:
4425                 cmdputs(p);
4426                 break;
4427         case NHERE:
4428         case NXHERE:
4429                 p = "<<...";
4430                 goto dotail2;
4431         case NCASE:
4432                 cmdputs("case ");
4433                 cmdputs(n->ncase.expr->narg.text);
4434                 cmdputs(" in ");
4435                 for (np = n->ncase.cases; np; np = np->nclist.next) {
4436                         cmdtxt(np->nclist.pattern);
4437                         cmdputs(") ");
4438                         cmdtxt(np->nclist.body);
4439                         cmdputs(";; ");
4440                 }
4441                 p = "esac";
4442                 goto dotail2;
4443         case NTO:
4444                 p = ">";
4445                 goto redir;
4446         case NCLOBBER:
4447                 p = ">|";
4448                 goto redir;
4449         case NAPPEND:
4450                 p = ">>";
4451                 goto redir;
4452 #if ENABLE_ASH_BASH_COMPAT
4453         case NTO2:
4454 #endif
4455         case NTOFD:
4456                 p = ">&";
4457                 goto redir;
4458         case NFROM:
4459                 p = "<";
4460                 goto redir;
4461         case NFROMFD:
4462                 p = "<&";
4463                 goto redir;
4464         case NFROMTO:
4465                 p = "<>";
4466  redir:
4467                 cmdputs(utoa(n->nfile.fd));
4468                 cmdputs(p);
4469                 if (n->type == NTOFD || n->type == NFROMFD) {
4470                         cmdputs(utoa(n->ndup.dupfd));
4471                         break;
4472                 }
4473                 n = n->nfile.fname;
4474                 goto donode;
4475         }
4476 }
4477
4478 static char *
4479 commandtext(union node *n)
4480 {
4481         char *name;
4482
4483         STARTSTACKSTR(cmdnextc);
4484         cmdtxt(n);
4485         name = stackblock();
4486         TRACE(("commandtext: name %p, end %p\n\t\"%s\"\n",
4487                         name, cmdnextc, cmdnextc));
4488         return ckstrdup(name);
4489 }
4490 #endif /* JOBS */
4491
4492 /*
4493  * Fork off a subshell.  If we are doing job control, give the subshell its
4494  * own process group.  Jp is a job structure that the job is to be added to.
4495  * N is the command that will be evaluated by the child.  Both jp and n may
4496  * be NULL.  The mode parameter can be one of the following:
4497  *      FORK_FG - Fork off a foreground process.
4498  *      FORK_BG - Fork off a background process.
4499  *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
4500  *                   process group even if job control is on.
4501  *
4502  * When job control is turned off, background processes have their standard
4503  * input redirected to /dev/null (except for the second and later processes
4504  * in a pipeline).
4505  *
4506  * Called with interrupts off.
4507  */
4508 /*
4509  * Clear traps on a fork.
4510  */
4511 static void
4512 clear_traps(void)
4513 {
4514         char **tp;
4515
4516         for (tp = trap; tp < &trap[NSIG]; tp++) {
4517                 if (*tp && **tp) {      /* trap not NULL or "" (SIG_IGN) */
4518                         INT_OFF;
4519                         free(*tp);
4520                         *tp = NULL;
4521                         if (tp != &trap[0])
4522                                 setsignal(tp - trap);
4523                         INT_ON;
4524                 }
4525         }
4526 }
4527
4528 /* Lives far away from here, needed for forkchild */
4529 static void closescript(void);
4530
4531 /* Called after fork(), in child */
4532 static void
4533 forkchild(struct job *jp, /*union node *n,*/ int mode)
4534 {
4535         int oldlvl;
4536
4537         TRACE(("Child shell %d\n", getpid()));
4538         oldlvl = shlvl;
4539         shlvl++;
4540
4541         /* man bash: "Non-builtin commands run by bash have signal handlers
4542          * set to the values inherited by the shell from its parent".
4543          * Do we do it correctly? */
4544
4545         closescript();
4546         clear_traps();
4547 #if JOBS
4548         /* do job control only in root shell */
4549         doing_jobctl = 0;
4550         if (mode != FORK_NOJOB && jp->jobctl && !oldlvl) {
4551                 pid_t pgrp;
4552
4553                 if (jp->nprocs == 0)
4554                         pgrp = getpid();
4555                 else
4556                         pgrp = jp->ps[0].pid;
4557                 /* this can fail because we are doing it in the parent also */
4558                 setpgid(0, pgrp);
4559                 if (mode == FORK_FG)
4560                         xtcsetpgrp(ttyfd, pgrp);
4561                 setsignal(SIGTSTP);
4562                 setsignal(SIGTTOU);
4563         } else
4564 #endif
4565         if (mode == FORK_BG) {
4566                 /* man bash: "When job control is not in effect,
4567                  * asynchronous commands ignore SIGINT and SIGQUIT" */
4568                 ignoresig(SIGINT);
4569                 ignoresig(SIGQUIT);
4570                 if (jp->nprocs == 0) {
4571                         close(0);
4572                         if (open(bb_dev_null, O_RDONLY) != 0)
4573                                 ash_msg_and_raise_error("can't open '%s'", bb_dev_null);
4574                 }
4575         }
4576         if (!oldlvl) {
4577                 if (iflag) { /* why if iflag only? */
4578                         setsignal(SIGINT);
4579                         setsignal(SIGTERM);
4580                 }
4581                 /* man bash:
4582                  * "In all cases, bash ignores SIGQUIT. Non-builtin
4583                  * commands run by bash have signal handlers
4584                  * set to the values inherited by the shell
4585                  * from its parent".
4586                  * Take care of the second rule: */
4587                 setsignal(SIGQUIT);
4588         }
4589         for (jp = curjob; jp; jp = jp->prev_job)
4590                 freejob(jp);
4591         jobless = 0;
4592 }
4593
4594 /* Called after fork(), in parent */
4595 #if !JOBS
4596 #define forkparent(jp, n, mode, pid) forkparent(jp, mode, pid)
4597 #endif
4598 static void
4599 forkparent(struct job *jp, union node *n, int mode, pid_t pid)
4600 {
4601         TRACE(("In parent shell: child = %d\n", pid));
4602         if (!jp) {
4603                 while (jobless && dowait(DOWAIT_NONBLOCK, NULL) > 0)
4604                         continue;
4605                 jobless++;
4606                 return;
4607         }
4608 #if JOBS
4609         if (mode != FORK_NOJOB && jp->jobctl) {
4610                 int pgrp;
4611
4612                 if (jp->nprocs == 0)
4613                         pgrp = pid;
4614                 else
4615                         pgrp = jp->ps[0].pid;
4616                 /* This can fail because we are doing it in the child also */
4617                 setpgid(pid, pgrp);
4618         }
4619 #endif
4620         if (mode == FORK_BG) {
4621                 backgndpid = pid;               /* set $! */
4622                 set_curjob(jp, CUR_RUNNING);
4623         }
4624         if (jp) {
4625                 struct procstat *ps = &jp->ps[jp->nprocs++];
4626                 ps->pid = pid;
4627                 ps->status = -1;
4628                 ps->cmd = nullstr;
4629 #if JOBS
4630                 if (doing_jobctl && n)
4631                         ps->cmd = commandtext(n);
4632 #endif
4633         }
4634 }
4635
4636 static int
4637 forkshell(struct job *jp, union node *n, int mode)
4638 {
4639         int pid;
4640
4641         TRACE(("forkshell(%%%d, %p, %d) called\n", jobno(jp), n, mode));
4642         pid = fork();
4643         if (pid < 0) {
4644                 TRACE(("Fork failed, errno=%d", errno));
4645                 if (jp)
4646                         freejob(jp);
4647                 ash_msg_and_raise_error("can't fork");
4648         }
4649         if (pid == 0)
4650                 forkchild(jp, /*n,*/ mode);
4651         else
4652                 forkparent(jp, n, mode, pid);
4653         return pid;
4654 }
4655
4656 /*
4657  * Wait for job to finish.
4658  *
4659  * Under job control we have the problem that while a child process
4660  * is running interrupts generated by the user are sent to the child
4661  * but not to the shell.  This means that an infinite loop started by
4662  * an interactive user may be hard to kill.  With job control turned off,
4663  * an interactive user may place an interactive program inside a loop.
4664  * If the interactive program catches interrupts, the user doesn't want
4665  * these interrupts to also abort the loop.  The approach we take here
4666  * is to have the shell ignore interrupt signals while waiting for a
4667  * foreground process to terminate, and then send itself an interrupt
4668  * signal if the child process was terminated by an interrupt signal.
4669  * Unfortunately, some programs want to do a bit of cleanup and then
4670  * exit on interrupt; unless these processes terminate themselves by
4671  * sending a signal to themselves (instead of calling exit) they will
4672  * confuse this approach.
4673  *
4674  * Called with interrupts off.
4675  */
4676 static int
4677 waitforjob(struct job *jp)
4678 {
4679         int st;
4680
4681         TRACE(("waitforjob(%%%d) called\n", jobno(jp)));
4682
4683         INT_OFF;
4684         while (jp->state == JOBRUNNING) {
4685                 /* In non-interactive shells, we _can_ get
4686                  * a keyboard signal here and be EINTRed,
4687                  * but we just loop back, waiting for command to complete.
4688                  *
4689                  * man bash:
4690                  * "If bash is waiting for a command to complete and receives
4691                  * a signal for which a trap has been set, the trap
4692                  * will not be executed until the command completes."
4693                  *
4694                  * Reality is that even if trap is not set, bash
4695                  * will not act on the signal until command completes.
4696                  * Try this. sleep5intoff.c:
4697                  * #include <signal.h>
4698                  * #include <unistd.h>
4699                  * int main() {
4700                  *         sigset_t set;
4701                  *         sigemptyset(&set);
4702                  *         sigaddset(&set, SIGINT);
4703                  *         sigaddset(&set, SIGQUIT);
4704                  *         sigprocmask(SIG_BLOCK, &set, NULL);
4705                  *         sleep(5);
4706                  *         return 0;
4707                  * }
4708                  * $ bash -c './sleep5intoff; echo hi'
4709                  * ^C^C^C^C <--- pressing ^C once a second
4710                  * $ _
4711                  * $ bash -c './sleep5intoff; echo hi'
4712                  * ^\^\^\^\hi <--- pressing ^\ (SIGQUIT)
4713                  * $ _
4714                  */
4715                 dowait(DOWAIT_BLOCK, jp);
4716         }
4717         INT_ON;
4718
4719         st = getstatus(jp);
4720 #if JOBS
4721         if (jp->jobctl) {
4722                 xtcsetpgrp(ttyfd, rootpid);
4723                 /*
4724                  * This is truly gross.
4725                  * If we're doing job control, then we did a TIOCSPGRP which
4726                  * caused us (the shell) to no longer be in the controlling
4727                  * session -- so we wouldn't have seen any ^C/SIGINT.  So, we
4728                  * intuit from the subprocess exit status whether a SIGINT
4729                  * occurred, and if so interrupt ourselves.  Yuck.  - mycroft
4730                  */
4731                 if (jp->sigint) /* TODO: do the same with all signals */
4732                         raise(SIGINT); /* ... by raise(jp->sig) instead? */
4733         }
4734         if (jp->state == JOBDONE)
4735 #endif
4736                 freejob(jp);
4737         return st;
4738 }
4739
4740 /*
4741  * return 1 if there are stopped jobs, otherwise 0
4742  */
4743 static int
4744 stoppedjobs(void)
4745 {
4746         struct job *jp;
4747         int retval;
4748
4749         retval = 0;
4750         if (job_warning)
4751                 goto out;
4752         jp = curjob;
4753         if (jp && jp->state == JOBSTOPPED) {
4754                 out2str("You have stopped jobs.\n");
4755                 job_warning = 2;
4756                 retval++;
4757         }
4758  out:
4759         return retval;
4760 }
4761
4762
4763 /* ============ redir.c
4764  *
4765  * Code for dealing with input/output redirection.
4766  */
4767
4768 #define EMPTY -2                /* marks an unused slot in redirtab */
4769 #define CLOSED -3               /* marks a slot of previously-closed fd */
4770
4771 /*
4772  * Open a file in noclobber mode.
4773  * The code was copied from bash.
4774  */
4775 static int
4776 noclobberopen(const char *fname)
4777 {
4778         int r, fd;
4779         struct stat finfo, finfo2;
4780
4781         /*
4782          * If the file exists and is a regular file, return an error
4783          * immediately.
4784          */
4785         r = stat(fname, &finfo);
4786         if (r == 0 && S_ISREG(finfo.st_mode)) {
4787                 errno = EEXIST;
4788                 return -1;
4789         }
4790
4791         /*
4792          * If the file was not present (r != 0), make sure we open it
4793          * exclusively so that if it is created before we open it, our open
4794          * will fail.  Make sure that we do not truncate an existing file.
4795          * Note that we don't turn on O_EXCL unless the stat failed -- if the
4796          * file was not a regular file, we leave O_EXCL off.
4797          */
4798         if (r != 0)
4799                 return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
4800         fd = open(fname, O_WRONLY|O_CREAT, 0666);
4801
4802         /* If the open failed, return the file descriptor right away. */
4803         if (fd < 0)
4804                 return fd;
4805
4806         /*
4807          * OK, the open succeeded, but the file may have been changed from a
4808          * non-regular file to a regular file between the stat and the open.
4809          * We are assuming that the O_EXCL open handles the case where FILENAME
4810          * did not exist and is symlinked to an existing file between the stat
4811          * and open.
4812          */
4813
4814         /*
4815          * If we can open it and fstat the file descriptor, and neither check
4816          * revealed that it was a regular file, and the file has not been
4817          * replaced, return the file descriptor.
4818          */
4819         if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode)
4820          && finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino)
4821                 return fd;
4822
4823         /* The file has been replaced.  badness. */
4824         close(fd);
4825         errno = EEXIST;
4826         return -1;
4827 }
4828
4829 /*
4830  * Handle here documents.  Normally we fork off a process to write the
4831  * data to a pipe.  If the document is short, we can stuff the data in
4832  * the pipe without forking.
4833  */
4834 /* openhere needs this forward reference */
4835 static void expandhere(union node *arg, int fd);
4836 static int
4837 openhere(union node *redir)
4838 {
4839         int pip[2];
4840         size_t len = 0;
4841
4842         if (pipe(pip) < 0)
4843                 ash_msg_and_raise_error("pipe call failed");
4844         if (redir->type == NHERE) {
4845                 len = strlen(redir->nhere.doc->narg.text);
4846                 if (len <= PIPE_BUF) {
4847                         full_write(pip[1], redir->nhere.doc->narg.text, len);
4848                         goto out;
4849                 }
4850         }
4851         if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
4852                 /* child */
4853                 close(pip[0]);
4854                 ignoresig(SIGINT);  //signal(SIGINT, SIG_IGN);
4855                 ignoresig(SIGQUIT); //signal(SIGQUIT, SIG_IGN);
4856                 ignoresig(SIGHUP);  //signal(SIGHUP, SIG_IGN);
4857                 ignoresig(SIGTSTP); //signal(SIGTSTP, SIG_IGN);
4858                 signal(SIGPIPE, SIG_DFL);
4859                 if (redir->type == NHERE)
4860                         full_write(pip[1], redir->nhere.doc->narg.text, len);
4861                 else /* NXHERE */
4862                         expandhere(redir->nhere.doc, pip[1]);
4863                 _exit(EXIT_SUCCESS);
4864         }
4865  out:
4866         close(pip[1]);
4867         return pip[0];
4868 }
4869
4870 static int
4871 openredirect(union node *redir)
4872 {
4873         char *fname;
4874         int f;
4875
4876         switch (redir->nfile.type) {
4877         case NFROM:
4878                 fname = redir->nfile.expfname;
4879                 f = open(fname, O_RDONLY);
4880                 if (f < 0)
4881                         goto eopen;
4882                 break;
4883         case NFROMTO:
4884                 fname = redir->nfile.expfname;
4885                 f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
4886                 if (f < 0)
4887                         goto ecreate;
4888                 break;
4889         case NTO:
4890 #if ENABLE_ASH_BASH_COMPAT
4891         case NTO2:
4892 #endif
4893                 /* Take care of noclobber mode. */
4894                 if (Cflag) {
4895                         fname = redir->nfile.expfname;
4896                         f = noclobberopen(fname);
4897                         if (f < 0)
4898                                 goto ecreate;
4899                         break;
4900                 }
4901                 /* FALLTHROUGH */
4902         case NCLOBBER:
4903                 fname = redir->nfile.expfname;
4904                 f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
4905                 if (f < 0)
4906                         goto ecreate;
4907                 break;
4908         case NAPPEND:
4909                 fname = redir->nfile.expfname;
4910                 f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666);
4911                 if (f < 0)
4912                         goto ecreate;
4913                 break;
4914         default:
4915 #if DEBUG
4916                 abort();
4917 #endif
4918                 /* Fall through to eliminate warning. */
4919 /* Our single caller does this itself */
4920 //      case NTOFD:
4921 //      case NFROMFD:
4922 //              f = -1;
4923 //              break;
4924         case NHERE:
4925         case NXHERE:
4926                 f = openhere(redir);
4927                 break;
4928         }
4929
4930         return f;
4931  ecreate:
4932         ash_msg_and_raise_error("can't create %s: %s", fname, errmsg(errno, "nonexistent directory"));
4933  eopen:
4934         ash_msg_and_raise_error("can't open %s: %s", fname, errmsg(errno, "no such file"));
4935 }
4936
4937 /*
4938  * Copy a file descriptor to be >= to.  Returns -1
4939  * if the source file descriptor is closed, EMPTY if there are no unused
4940  * file descriptors left.
4941  */
4942 /* 0x800..00: bit to set in "to" to request dup2 instead of fcntl(F_DUPFD).
4943  * old code was doing close(to) prior to copyfd() to achieve the same */
4944 enum {
4945         COPYFD_EXACT   = (int)~(INT_MAX),
4946         COPYFD_RESTORE = (int)((unsigned)COPYFD_EXACT >> 1),
4947 };
4948 static int
4949 copyfd(int from, int to)
4950 {
4951         int newfd;
4952
4953         if (to & COPYFD_EXACT) {
4954                 to &= ~COPYFD_EXACT;
4955                 /*if (from != to)*/
4956                         newfd = dup2(from, to);
4957         } else {
4958                 newfd = fcntl(from, F_DUPFD, to);
4959         }
4960         if (newfd < 0) {
4961                 if (errno == EMFILE)
4962                         return EMPTY;
4963                 /* Happens when source fd is not open: try "echo >&99" */
4964                 ash_msg_and_raise_error("%d: %m", from);
4965         }
4966         return newfd;
4967 }
4968
4969 /* Struct def and variable are moved down to the first usage site */
4970 struct two_fd_t {
4971         int orig, copy;
4972 };
4973 struct redirtab {
4974         struct redirtab *next;
4975         int nullredirs;
4976         int pair_count;
4977         struct two_fd_t two_fd[0];
4978 };
4979 #define redirlist (G_var.redirlist)
4980
4981 static int need_to_remember(struct redirtab *rp, int fd)
4982 {
4983         int i;
4984
4985         if (!rp) /* remembering was not requested */
4986                 return 0;
4987
4988         for (i = 0; i < rp->pair_count; i++) {
4989                 if (rp->two_fd[i].orig == fd) {
4990                         /* already remembered */
4991                         return 0;
4992                 }
4993         }
4994         return 1;
4995 }
4996
4997 /* "hidden" fd is a fd used to read scripts, or a copy of such */
4998 static int is_hidden_fd(struct redirtab *rp, int fd)
4999 {
5000         int i;
5001         struct parsefile *pf;
5002
5003         if (fd == -1)
5004                 return 0;
5005         pf = g_parsefile;
5006         while (pf) {
5007                 if (fd == pf->fd) {
5008                         return 1;
5009                 }
5010                 pf = pf->prev;
5011         }
5012         if (!rp)
5013                 return 0;
5014         fd |= COPYFD_RESTORE;
5015         for (i = 0; i < rp->pair_count; i++) {
5016                 if (rp->two_fd[i].copy == fd) {
5017                         return 1;
5018                 }
5019         }
5020         return 0;
5021 }
5022
5023 /*
5024  * Process a list of redirection commands.  If the REDIR_PUSH flag is set,
5025  * old file descriptors are stashed away so that the redirection can be
5026  * undone by calling popredir.  If the REDIR_BACKQ flag is set, then the
5027  * standard output, and the standard error if it becomes a duplicate of
5028  * stdout, is saved in memory.
5029  */
5030 /* flags passed to redirect */
5031 #define REDIR_PUSH    01        /* save previous values of file descriptors */
5032 #define REDIR_SAVEFD2 03        /* set preverrout */
5033 static void
5034 redirect(union node *redir, int flags)
5035 {
5036         struct redirtab *sv;
5037         int sv_pos;
5038         int i;
5039         int fd;
5040         int newfd;
5041         int copied_fd2 = -1;
5042
5043         g_nullredirs++;
5044         if (!redir) {
5045                 return;
5046         }
5047
5048         sv = NULL;
5049         sv_pos = 0;
5050         INT_OFF;
5051         if (flags & REDIR_PUSH) {
5052                 union node *tmp = redir;
5053                 do {
5054                         sv_pos++;
5055 #if ENABLE_ASH_BASH_COMPAT
5056                         if (redir->nfile.type == NTO2)
5057                                 sv_pos++;
5058 #endif
5059                         tmp = tmp->nfile.next;
5060                 } while (tmp);
5061                 sv = ckmalloc(sizeof(*sv) + sv_pos * sizeof(sv->two_fd[0]));
5062                 sv->next = redirlist;
5063                 sv->pair_count = sv_pos;
5064                 redirlist = sv;
5065                 sv->nullredirs = g_nullredirs - 1;
5066                 g_nullredirs = 0;
5067                 while (sv_pos > 0) {
5068                         sv_pos--;
5069                         sv->two_fd[sv_pos].orig = sv->two_fd[sv_pos].copy = EMPTY;
5070                 }
5071         }
5072
5073         do {
5074                 fd = redir->nfile.fd;
5075                 if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
5076                         int right_fd = redir->ndup.dupfd;
5077                         /* redirect from/to same file descriptor? */
5078                         if (right_fd == fd)
5079                                 continue;
5080                         /* echo >&10 and 10 is a fd opened to the sh script? */
5081                         if (is_hidden_fd(sv, right_fd)) {
5082                                 errno = EBADF; /* as if it is closed */
5083                                 ash_msg_and_raise_error("%d: %m", right_fd);
5084                         }
5085                         newfd = -1;
5086                 } else {
5087                         newfd = openredirect(redir); /* always >= 0 */
5088                         if (fd == newfd) {
5089                                 /* Descriptor wasn't open before redirect.
5090                                  * Mark it for close in the future */
5091                                 if (need_to_remember(sv, fd)) {
5092                                         goto remember_to_close;
5093                                 }
5094                                 continue;
5095                         }
5096                 }
5097 #if ENABLE_ASH_BASH_COMPAT
5098  redirect_more:
5099 #endif
5100                 if (need_to_remember(sv, fd)) {
5101                         /* Copy old descriptor */
5102                         i = fcntl(fd, F_DUPFD, 10);
5103 /* You'd expect copy to be CLOEXECed. Currently these extra "saved" fds
5104  * are closed in popredir() in the child, preventing them from leaking
5105  * into child. (popredir() also cleans up the mess in case of failures)
5106  */
5107                         if (i == -1) {
5108                                 i = errno;
5109                                 if (i != EBADF) {
5110                                         /* Strange error (e.g. "too many files" EMFILE?) */
5111                                         if (newfd >= 0)
5112                                                 close(newfd);
5113                                         errno = i;
5114                                         ash_msg_and_raise_error("%d: %m", fd);
5115                                         /* NOTREACHED */
5116                                 }
5117                                 /* EBADF: it is not open - good, remember to close it */
5118  remember_to_close:
5119                                 i = CLOSED;
5120                         } else { /* fd is open, save its copy */
5121                                 /* "exec fd>&-" should not close fds
5122                                  * which point to script file(s).
5123                                  * Force them to be restored afterwards */
5124                                 if (is_hidden_fd(sv, fd))
5125                                         i |= COPYFD_RESTORE;
5126                         }
5127                         if (fd == 2)
5128                                 copied_fd2 = i;
5129                         sv->two_fd[sv_pos].orig = fd;
5130                         sv->two_fd[sv_pos].copy = i;
5131                         sv_pos++;
5132                 }
5133                 if (newfd < 0) {
5134                         /* NTOFD/NFROMFD: copy redir->ndup.dupfd to fd */
5135                         if (redir->ndup.dupfd < 0) { /* "fd>&-" */
5136                                 /* Don't want to trigger debugging */
5137                                 if (fd != -1)
5138                                         close(fd);
5139                         } else {
5140                                 copyfd(redir->ndup.dupfd, fd | COPYFD_EXACT);
5141                         }
5142                 } else if (fd != newfd) { /* move newfd to fd */
5143                         copyfd(newfd, fd | COPYFD_EXACT);
5144 #if ENABLE_ASH_BASH_COMPAT
5145                         if (!(redir->nfile.type == NTO2 && fd == 2))
5146 #endif
5147                                 close(newfd);
5148                 }
5149 #if ENABLE_ASH_BASH_COMPAT
5150                 if (redir->nfile.type == NTO2 && fd == 1) {
5151                         /* We already redirected it to fd 1, now copy it to 2 */
5152                         newfd = 1;
5153                         fd = 2;
5154                         goto redirect_more;
5155                 }
5156 #endif
5157         } while ((redir = redir->nfile.next) != NULL);
5158
5159         INT_ON;
5160         if ((flags & REDIR_SAVEFD2) && copied_fd2 >= 0)
5161                 preverrout_fd = copied_fd2;
5162 }
5163
5164 /*
5165  * Undo the effects of the last redirection.
5166  */
5167 static void
5168 popredir(int drop, int restore)
5169 {
5170         struct redirtab *rp;
5171         int i;
5172
5173         if (--g_nullredirs >= 0)
5174                 return;
5175         INT_OFF;
5176         rp = redirlist;
5177         for (i = 0; i < rp->pair_count; i++) {
5178                 int fd = rp->two_fd[i].orig;
5179                 int copy = rp->two_fd[i].copy;
5180                 if (copy == CLOSED) {
5181                         if (!drop)
5182                                 close(fd);
5183                         continue;
5184                 }
5185                 if (copy != EMPTY) {
5186                         if (!drop || (restore && (copy & COPYFD_RESTORE))) {
5187                                 copy &= ~COPYFD_RESTORE;
5188                                 /*close(fd);*/
5189                                 copyfd(copy, fd | COPYFD_EXACT);
5190                         }
5191                         close(copy & ~COPYFD_RESTORE);
5192                 }
5193         }
5194         redirlist = rp->next;
5195         g_nullredirs = rp->nullredirs;
5196         free(rp);
5197         INT_ON;
5198 }
5199
5200 /*
5201  * Undo all redirections.  Called on error or interrupt.
5202  */
5203
5204 /*
5205  * Discard all saved file descriptors.
5206  */
5207 static void
5208 clearredir(int drop)
5209 {
5210         for (;;) {
5211                 g_nullredirs = 0;
5212                 if (!redirlist)
5213                         break;
5214                 popredir(drop, /*restore:*/ 0);
5215         }
5216 }
5217
5218 static int
5219 redirectsafe(union node *redir, int flags)
5220 {
5221         int err;
5222         volatile int saveint;
5223         struct jmploc *volatile savehandler = exception_handler;
5224         struct jmploc jmploc;
5225
5226         SAVE_INT(saveint);
5227         /* "echo 9>/dev/null; echo >&9; echo result: $?" - result should be 1, not 2! */
5228         err = setjmp(jmploc.loc); // huh?? was = setjmp(jmploc.loc) * 2;
5229         if (!err) {
5230                 exception_handler = &jmploc;
5231                 redirect(redir, flags);
5232         }
5233         exception_handler = savehandler;
5234         if (err && exception_type != EXERROR)
5235                 longjmp(exception_handler->loc, 1);
5236         RESTORE_INT(saveint);
5237         return err;
5238 }
5239
5240
5241 /* ============ Routines to expand arguments to commands
5242  *
5243  * We have to deal with backquotes, shell variables, and file metacharacters.
5244  */
5245
5246 #if ENABLE_SH_MATH_SUPPORT
5247 static arith_t
5248 ash_arith(const char *s)
5249 {
5250         arith_eval_hooks_t math_hooks;
5251         arith_t result;
5252         int errcode = 0;
5253
5254         math_hooks.lookupvar = lookupvar;
5255         math_hooks.setvar = setvar;
5256         math_hooks.endofname = endofname;
5257
5258         INT_OFF;
5259         result = arith(s, &errcode, &math_hooks);
5260         if (errcode < 0) {
5261                 if (errcode == -3)
5262                         ash_msg_and_raise_error("exponent less than 0");
5263                 if (errcode == -2)
5264                         ash_msg_and_raise_error("divide by zero");
5265                 if (errcode == -5)
5266                         ash_msg_and_raise_error("expression recursion loop detected");
5267                 raise_error_syntax(s);
5268         }
5269         INT_ON;
5270
5271         return result;
5272 }
5273 #endif
5274
5275 /*
5276  * expandarg flags
5277  */
5278 #define EXP_FULL        0x1     /* perform word splitting & file globbing */
5279 #define EXP_TILDE       0x2     /* do normal tilde expansion */
5280 #define EXP_VARTILDE    0x4     /* expand tildes in an assignment */
5281 #define EXP_REDIR       0x8     /* file glob for a redirection (1 match only) */
5282 #define EXP_CASE        0x10    /* keeps quotes around for CASE pattern */
5283 #define EXP_RECORD      0x20    /* need to record arguments for ifs breakup */
5284 #define EXP_VARTILDE2   0x40    /* expand tildes after colons only */
5285 #define EXP_WORD        0x80    /* expand word in parameter expansion */
5286 #define EXP_QWORD       0x100   /* expand word in quoted parameter expansion */
5287 /*
5288  * _rmescape() flags
5289  */
5290 #define RMESCAPE_ALLOC  0x1     /* Allocate a new string */
5291 #define RMESCAPE_GLOB   0x2     /* Add backslashes for glob */
5292 #define RMESCAPE_QUOTED 0x4     /* Remove CTLESC unless in quotes */
5293 #define RMESCAPE_GROW   0x8     /* Grow strings instead of stalloc */
5294 #define RMESCAPE_HEAP   0x10    /* Malloc strings instead of stalloc */
5295
5296 /*
5297  * Structure specifying which parts of the string should be searched
5298  * for IFS characters.
5299  */
5300 struct ifsregion {
5301         struct ifsregion *next; /* next region in list */
5302         int begoff;             /* offset of start of region */
5303         int endoff;             /* offset of end of region */
5304         int nulonly;            /* search for nul bytes only */
5305 };
5306
5307 struct arglist {
5308         struct strlist *list;
5309         struct strlist **lastp;
5310 };
5311
5312 /* output of current string */
5313 static char *expdest;
5314 /* list of back quote expressions */
5315 static struct nodelist *argbackq;
5316 /* first struct in list of ifs regions */
5317 static struct ifsregion ifsfirst;
5318 /* last struct in list */
5319 static struct ifsregion *ifslastp;
5320 /* holds expanded arg list */
5321 static struct arglist exparg;
5322
5323 /*
5324  * Our own itoa().
5325  */
5326 static int
5327 cvtnum(arith_t num)
5328 {
5329         int len;
5330
5331         expdest = makestrspace(32, expdest);
5332         len = fmtstr(expdest, 32, arith_t_fmt, num);
5333         STADJUST(len, expdest);
5334         return len;
5335 }
5336
5337 static size_t
5338 esclen(const char *start, const char *p)
5339 {
5340         size_t esc = 0;
5341
5342         while (p > start && *--p == CTLESC) {
5343                 esc++;
5344         }
5345         return esc;
5346 }
5347
5348 /*
5349  * Remove any CTLESC characters from a string.
5350  */
5351 static char *
5352 _rmescapes(char *str, int flag)
5353 {
5354         static const char qchars[] ALIGN1 = { CTLESC, CTLQUOTEMARK, '\0' };
5355
5356         char *p, *q, *r;
5357         unsigned inquotes;
5358         int notescaped;
5359         int globbing;
5360
5361         p = strpbrk(str, qchars);
5362         if (!p) {
5363                 return str;
5364         }
5365         q = p;
5366         r = str;
5367         if (flag & RMESCAPE_ALLOC) {
5368                 size_t len = p - str;
5369                 size_t fulllen = len + strlen(p) + 1;
5370
5371                 if (flag & RMESCAPE_GROW) {
5372                         r = makestrspace(fulllen, expdest);
5373                 } else if (flag & RMESCAPE_HEAP) {
5374                         r = ckmalloc(fulllen);
5375                 } else {
5376                         r = stalloc(fulllen);
5377                 }
5378                 q = r;
5379                 if (len > 0) {
5380                         q = (char *)memcpy(q, str, len) + len;
5381                 }
5382         }
5383         inquotes = (flag & RMESCAPE_QUOTED) ^ RMESCAPE_QUOTED;
5384         globbing = flag & RMESCAPE_GLOB;
5385         notescaped = globbing;
5386         while (*p) {
5387                 if (*p == CTLQUOTEMARK) {
5388                         inquotes = ~inquotes;
5389                         p++;
5390                         notescaped = globbing;
5391                         continue;
5392                 }
5393                 if (*p == '\\') {
5394                         /* naked back slash */
5395                         notescaped = 0;
5396                         goto copy;
5397                 }
5398                 if (*p == CTLESC) {
5399                         p++;
5400                         if (notescaped && inquotes && *p != '/') {
5401                                 *q++ = '\\';
5402                         }
5403                 }
5404                 notescaped = globbing;
5405  copy:
5406                 *q++ = *p++;
5407         }
5408         *q = '\0';
5409         if (flag & RMESCAPE_GROW) {
5410                 expdest = r;
5411                 STADJUST(q - r + 1, expdest);
5412         }
5413         return r;
5414 }
5415 #define rmescapes(p) _rmescapes((p), 0)
5416
5417 #define pmatch(a, b) !fnmatch((a), (b), 0)
5418
5419 /*
5420  * Prepare a pattern for a expmeta (internal glob(3)) call.
5421  *
5422  * Returns an stalloced string.
5423  */
5424 static char *
5425 preglob(const char *pattern, int quoted, int flag)
5426 {
5427         flag |= RMESCAPE_GLOB;
5428         if (quoted) {
5429                 flag |= RMESCAPE_QUOTED;
5430         }
5431         return _rmescapes((char *)pattern, flag);
5432 }
5433
5434 /*
5435  * Put a string on the stack.
5436  */
5437 static void
5438 memtodest(const char *p, size_t len, int syntax, int quotes)
5439 {
5440         char *q = expdest;
5441
5442         q = makestrspace(len * 2, q);
5443
5444         while (len--) {
5445                 int c = signed_char2int(*p++);
5446                 if (!c)
5447                         continue;
5448                 if (quotes && (SIT(c, syntax) == CCTL || SIT(c, syntax) == CBACK))
5449                         USTPUTC(CTLESC, q);
5450                 USTPUTC(c, q);
5451         }
5452
5453         expdest = q;
5454 }
5455
5456 static void
5457 strtodest(const char *p, int syntax, int quotes)
5458 {
5459         memtodest(p, strlen(p), syntax, quotes);
5460 }
5461
5462 /*
5463  * Record the fact that we have to scan this region of the
5464  * string for IFS characters.
5465  */
5466 static void
5467 recordregion(int start, int end, int nulonly)
5468 {
5469         struct ifsregion *ifsp;
5470
5471         if (ifslastp == NULL) {
5472                 ifsp = &ifsfirst;
5473         } else {
5474                 INT_OFF;
5475                 ifsp = ckzalloc(sizeof(*ifsp));
5476                 /*ifsp->next = NULL; - ckzalloc did it */
5477                 ifslastp->next = ifsp;
5478                 INT_ON;
5479         }
5480         ifslastp = ifsp;
5481         ifslastp->begoff = start;
5482         ifslastp->endoff = end;
5483         ifslastp->nulonly = nulonly;
5484 }
5485
5486 static void
5487 removerecordregions(int endoff)
5488 {
5489         if (ifslastp == NULL)
5490                 return;
5491
5492         if (ifsfirst.endoff > endoff) {
5493                 while (ifsfirst.next != NULL) {
5494                         struct ifsregion *ifsp;
5495                         INT_OFF;
5496                         ifsp = ifsfirst.next->next;
5497                         free(ifsfirst.next);
5498                         ifsfirst.next = ifsp;
5499                         INT_ON;
5500                 }
5501                 if (ifsfirst.begoff > endoff)
5502                         ifslastp = NULL;
5503                 else {
5504                         ifslastp = &ifsfirst;
5505                         ifsfirst.endoff = endoff;
5506                 }
5507                 return;
5508         }
5509
5510         ifslastp = &ifsfirst;
5511         while (ifslastp->next && ifslastp->next->begoff < endoff)
5512                 ifslastp=ifslastp->next;
5513         while (ifslastp->next != NULL) {
5514                 struct ifsregion *ifsp;
5515                 INT_OFF;
5516                 ifsp = ifslastp->next->next;
5517                 free(ifslastp->next);
5518                 ifslastp->next = ifsp;
5519                 INT_ON;
5520         }
5521         if (ifslastp->endoff > endoff)
5522                 ifslastp->endoff = endoff;
5523 }
5524
5525 static char *
5526 exptilde(char *startp, char *p, int flag)
5527 {
5528         char c;
5529         char *name;
5530         struct passwd *pw;
5531         const char *home;
5532         int quotes = flag & (EXP_FULL | EXP_CASE);
5533         int startloc;
5534
5535         name = p + 1;
5536
5537         while ((c = *++p) != '\0') {
5538                 switch (c) {
5539                 case CTLESC:
5540                         return startp;
5541                 case CTLQUOTEMARK:
5542                         return startp;
5543                 case ':':
5544                         if (flag & EXP_VARTILDE)
5545                                 goto done;
5546                         break;
5547                 case '/':
5548                 case CTLENDVAR:
5549                         goto done;
5550                 }
5551         }
5552  done:
5553         *p = '\0';
5554         if (*name == '\0') {
5555                 home = lookupvar(homestr);
5556         } else {
5557                 pw = getpwnam(name);
5558                 if (pw == NULL)
5559                         goto lose;
5560                 home = pw->pw_dir;
5561         }
5562         if (!home || !*home)
5563                 goto lose;
5564         *p = c;
5565         startloc = expdest - (char *)stackblock();
5566         strtodest(home, SQSYNTAX, quotes);
5567         recordregion(startloc, expdest - (char *)stackblock(), 0);
5568         return p;
5569  lose:
5570         *p = c;
5571         return startp;
5572 }
5573
5574 /*
5575  * Execute a command inside back quotes.  If it's a builtin command, we
5576  * want to save its output in a block obtained from malloc.  Otherwise
5577  * we fork off a subprocess and get the output of the command via a pipe.
5578  * Should be called with interrupts off.
5579  */
5580 struct backcmd {                /* result of evalbackcmd */
5581         int fd;                 /* file descriptor to read from */
5582         int nleft;              /* number of chars in buffer */
5583         char *buf;              /* buffer */
5584         struct job *jp;         /* job structure for command */
5585 };
5586
5587 /* These forward decls are needed to use "eval" code for backticks handling: */
5588 static uint8_t back_exitstatus; /* exit status of backquoted command */
5589 #define EV_EXIT 01              /* exit after evaluating tree */
5590 static void evaltree(union node *, int);
5591
5592 static void
5593 evalbackcmd(union node *n, struct backcmd *result)
5594 {
5595         int saveherefd;
5596
5597         result->fd = -1;
5598         result->buf = NULL;
5599         result->nleft = 0;
5600         result->jp = NULL;
5601         if (n == NULL)
5602                 goto out;
5603
5604         saveherefd = herefd;
5605         herefd = -1;
5606
5607         {
5608                 int pip[2];
5609                 struct job *jp;
5610
5611                 if (pipe(pip) < 0)
5612                         ash_msg_and_raise_error("pipe call failed");
5613                 jp = makejob(/*n,*/ 1);
5614                 if (forkshell(jp, n, FORK_NOJOB) == 0) {
5615                         FORCE_INT_ON;
5616                         close(pip[0]);
5617                         if (pip[1] != 1) {
5618                                 /*close(1);*/
5619                                 copyfd(pip[1], 1 | COPYFD_EXACT);
5620                                 close(pip[1]);
5621                         }
5622                         eflag = 0;
5623                         evaltree(n, EV_EXIT); /* actually evaltreenr... */
5624                         /* NOTREACHED */
5625                 }
5626                 close(pip[1]);
5627                 result->fd = pip[0];
5628                 result->jp = jp;
5629         }
5630         herefd = saveherefd;
5631  out:
5632         TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
5633                 result->fd, result->buf, result->nleft, result->jp));
5634 }
5635
5636 /*
5637  * Expand stuff in backwards quotes.
5638  */
5639 static void
5640 expbackq(union node *cmd, int quoted, int quotes)
5641 {
5642         struct backcmd in;
5643         int i;
5644         char buf[128];
5645         char *p;
5646         char *dest;
5647         int startloc;
5648         int syntax = quoted ? DQSYNTAX : BASESYNTAX;
5649         struct stackmark smark;
5650
5651         INT_OFF;
5652         setstackmark(&smark);
5653         dest = expdest;
5654         startloc = dest - (char *)stackblock();
5655         grabstackstr(dest);
5656         evalbackcmd(cmd, &in);
5657         popstackmark(&smark);
5658
5659         p = in.buf;
5660         i = in.nleft;
5661         if (i == 0)
5662                 goto read;
5663         for (;;) {
5664                 memtodest(p, i, syntax, quotes);
5665  read:
5666                 if (in.fd < 0)
5667                         break;
5668                 i = nonblock_safe_read(in.fd, buf, sizeof(buf));
5669                 TRACE(("expbackq: read returns %d\n", i));
5670                 if (i <= 0)
5671                         break;
5672                 p = buf;
5673         }
5674
5675         free(in.buf);
5676         if (in.fd >= 0) {
5677                 close(in.fd);
5678                 back_exitstatus = waitforjob(in.jp);
5679         }
5680         INT_ON;
5681
5682         /* Eat all trailing newlines */
5683         dest = expdest;
5684         for (; dest > (char *)stackblock() && dest[-1] == '\n';)
5685                 STUNPUTC(dest);
5686         expdest = dest;
5687
5688         if (quoted == 0)
5689                 recordregion(startloc, dest - (char *)stackblock(), 0);
5690         TRACE(("evalbackq: size=%d: \"%.*s\"\n",
5691                 (dest - (char *)stackblock()) - startloc,
5692                 (dest - (char *)stackblock()) - startloc,
5693                 stackblock() + startloc));
5694 }
5695
5696 #if ENABLE_SH_MATH_SUPPORT
5697 /*
5698  * Expand arithmetic expression.  Backup to start of expression,
5699  * evaluate, place result in (backed up) result, adjust string position.
5700  */
5701 static void
5702 expari(int quotes)
5703 {
5704         char *p, *start;
5705         int begoff;
5706         int flag;
5707         int len;
5708
5709         /* ifsfree(); */
5710
5711         /*
5712          * This routine is slightly over-complicated for
5713          * efficiency.  Next we scan backwards looking for the
5714          * start of arithmetic.
5715          */
5716         start = stackblock();
5717         p = expdest - 1;
5718         *p = '\0';
5719         p--;
5720         do {
5721                 int esc;
5722
5723                 while (*p != CTLARI) {
5724                         p--;
5725 #if DEBUG
5726                         if (p < start) {
5727                                 ash_msg_and_raise_error("missing CTLARI (shouldn't happen)");
5728                         }
5729 #endif
5730                 }
5731
5732                 esc = esclen(start, p);
5733                 if (!(esc % 2)) {
5734                         break;
5735                 }
5736
5737                 p -= esc + 1;
5738         } while (1);
5739
5740         begoff = p - start;
5741
5742         removerecordregions(begoff);
5743
5744         flag = p[1];
5745
5746         expdest = p;
5747
5748         if (quotes)
5749                 rmescapes(p + 2);
5750
5751         len = cvtnum(ash_arith(p + 2));
5752
5753         if (flag != '"')
5754                 recordregion(begoff, begoff + len, 0);
5755 }
5756 #endif
5757
5758 /* argstr needs it */
5759 static char *evalvar(char *p, int flag, struct strlist *var_str_list);
5760
5761 /*
5762  * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
5763  * characters to allow for further processing.  Otherwise treat
5764  * $@ like $* since no splitting will be performed.
5765  *
5766  * var_str_list (can be NULL) is a list of "VAR=val" strings which take precedence
5767  * over shell varables. Needed for "A=a B=$A; echo $B" case - we use it
5768  * for correct expansion of "B=$A" word.
5769  */
5770 static void
5771 argstr(char *p, int flag, struct strlist *var_str_list)
5772 {
5773         static const char spclchars[] ALIGN1 = {
5774                 '=',
5775                 ':',
5776                 CTLQUOTEMARK,
5777                 CTLENDVAR,
5778                 CTLESC,
5779                 CTLVAR,
5780                 CTLBACKQ,
5781                 CTLBACKQ | CTLQUOTE,
5782 #if ENABLE_SH_MATH_SUPPORT
5783                 CTLENDARI,
5784 #endif
5785                 0
5786         };
5787         const char *reject = spclchars;
5788         int c;
5789         int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */
5790         int breakall = flag & EXP_WORD;
5791         int inquotes;
5792         size_t length;
5793         int startloc;
5794
5795         if (!(flag & EXP_VARTILDE)) {
5796                 reject += 2;
5797         } else if (flag & EXP_VARTILDE2) {
5798                 reject++;
5799         }
5800         inquotes = 0;
5801         length = 0;
5802         if (flag & EXP_TILDE) {
5803                 char *q;
5804
5805                 flag &= ~EXP_TILDE;
5806  tilde:
5807                 q = p;
5808                 if (*q == CTLESC && (flag & EXP_QWORD))
5809                         q++;
5810                 if (*q == '~')
5811                         p = exptilde(p, q, flag);
5812         }
5813  start:
5814         startloc = expdest - (char *)stackblock();
5815         for (;;) {
5816                 length += strcspn(p + length, reject);
5817                 c = p[length];
5818                 if (c && (!(c & 0x80)
5819 #if ENABLE_SH_MATH_SUPPORT
5820                                         || c == CTLENDARI
5821 #endif
5822                    )) {
5823                         /* c == '=' || c == ':' || c == CTLENDARI */
5824                         length++;
5825                 }
5826                 if (length > 0) {
5827                         int newloc;
5828                         expdest = stack_nputstr(p, length, expdest);
5829                         newloc = expdest - (char *)stackblock();
5830                         if (breakall && !inquotes && newloc > startloc) {
5831                                 recordregion(startloc, newloc, 0);
5832                         }
5833                         startloc = newloc;
5834                 }
5835                 p += length + 1;
5836                 length = 0;
5837
5838                 switch (c) {
5839                 case '\0':
5840                         goto breakloop;
5841                 case '=':
5842                         if (flag & EXP_VARTILDE2) {
5843                                 p--;
5844                                 continue;
5845                         }
5846                         flag |= EXP_VARTILDE2;
5847                         reject++;
5848                         /* fall through */
5849                 case ':':
5850                         /*
5851                          * sort of a hack - expand tildes in variable
5852                          * assignments (after the first '=' and after ':'s).
5853                          */
5854                         if (*--p == '~') {
5855                                 goto tilde;
5856                         }
5857                         continue;
5858                 }
5859
5860                 switch (c) {
5861                 case CTLENDVAR: /* ??? */
5862                         goto breakloop;
5863                 case CTLQUOTEMARK:
5864                         /* "$@" syntax adherence hack */
5865                         if (
5866                                 !inquotes &&
5867                                 !memcmp(p, dolatstr, 4) &&
5868                                 (p[4] == CTLQUOTEMARK || (
5869                                         p[4] == CTLENDVAR &&
5870                                         p[5] == CTLQUOTEMARK
5871                                 ))
5872                         ) {
5873                                 p = evalvar(p + 1, flag, /* var_str_list: */ NULL) + 1;
5874                                 goto start;
5875                         }
5876                         inquotes = !inquotes;
5877  addquote:
5878                         if (quotes) {
5879                                 p--;
5880                                 length++;
5881                                 startloc++;
5882                         }
5883                         break;
5884                 case CTLESC:
5885                         startloc++;
5886                         length++;
5887                         goto addquote;
5888                 case CTLVAR:
5889                         p = evalvar(p, flag, var_str_list);
5890                         goto start;
5891                 case CTLBACKQ:
5892                         c = 0;
5893                 case CTLBACKQ|CTLQUOTE:
5894                         expbackq(argbackq->n, c, quotes);
5895                         argbackq = argbackq->next;
5896                         goto start;
5897 #if ENABLE_SH_MATH_SUPPORT
5898                 case CTLENDARI:
5899                         p--;
5900                         expari(quotes);
5901                         goto start;
5902 #endif
5903                 }
5904         }
5905  breakloop:
5906         ;
5907 }
5908
5909 static char *
5910 scanleft(char *startp, char *rmesc, char *rmescend UNUSED_PARAM, char *str, int quotes,
5911         int zero)
5912 {
5913 // This commented out code was added by James Simmons <jsimmons@infradead.org>
5914 // as part of a larger change when he added support for ${var/a/b}.
5915 // However, it broke # and % operators:
5916 //
5917 //var=ababcdcd
5918 //                 ok       bad
5919 //echo ${var#ab}   abcdcd   abcdcd
5920 //echo ${var##ab}  abcdcd   abcdcd
5921 //echo ${var#a*b}  abcdcd   ababcdcd  (!)
5922 //echo ${var##a*b} cdcd     cdcd
5923 //echo ${var#?}    babcdcd  ababcdcd  (!)
5924 //echo ${var##?}   babcdcd  babcdcd
5925 //echo ${var#*}    ababcdcd babcdcd   (!)
5926 //echo ${var##*}
5927 //echo ${var%cd}   ababcd   ababcd
5928 //echo ${var%%cd}  ababcd   abab      (!)
5929 //echo ${var%c*d}  ababcd   ababcd
5930 //echo ${var%%c*d} abab     ababcdcd  (!)
5931 //echo ${var%?}    ababcdc  ababcdc
5932 //echo ${var%%?}   ababcdc  ababcdcd  (!)
5933 //echo ${var%*}    ababcdcd ababcdcd
5934 //echo ${var%%*}
5935 //
5936 // Commenting it back out helped. Remove it completely if it really
5937 // is not needed.
5938
5939         char *loc, *loc2; //, *full;
5940         char c;
5941
5942         loc = startp;
5943         loc2 = rmesc;
5944         do {
5945                 int match; // = strlen(str);
5946                 const char *s = loc2;
5947
5948                 c = *loc2;
5949                 if (zero) {
5950                         *loc2 = '\0';
5951                         s = rmesc;
5952                 }
5953                 match = pmatch(str, s); // this line was deleted
5954
5955 //              // chop off end if its '*'
5956 //              full = strrchr(str, '*');
5957 //              if (full && full != str)
5958 //                      match--;
5959 //
5960 //              // If str starts with '*' replace with s.
5961 //              if ((*str == '*') && strlen(s) >= match) {
5962 //                      full = xstrdup(s);
5963 //                      strncpy(full+strlen(s)-match+1, str+1, match-1);
5964 //              } else
5965 //                      full = xstrndup(str, match);
5966 //              match = strncmp(s, full, strlen(full));
5967 //              free(full);
5968 //
5969                 *loc2 = c;
5970                 if (match) // if (!match)
5971                         return loc;
5972                 if (quotes && *loc == CTLESC)
5973                         loc++;
5974                 loc++;
5975                 loc2++;
5976         } while (c);
5977         return 0;
5978 }
5979
5980 static char *
5981 scanright(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
5982         int zero)
5983 {
5984         int esc = 0;
5985         char *loc;
5986         char *loc2;
5987
5988         for (loc = str - 1, loc2 = rmescend; loc >= startp; loc2--) {
5989                 int match;
5990                 char c = *loc2;
5991                 const char *s = loc2;
5992                 if (zero) {
5993                         *loc2 = '\0';
5994                         s = rmesc;
5995                 }
5996                 match = pmatch(str, s);
5997                 *loc2 = c;
5998                 if (match)
5999                         return loc;
6000                 loc--;
6001                 if (quotes) {
6002                         if (--esc < 0) {
6003                                 esc = esclen(startp, loc);
6004                         }
6005                         if (esc % 2) {
6006                                 esc--;
6007                                 loc--;
6008                         }
6009                 }
6010         }
6011         return 0;
6012 }
6013
6014 static void varunset(const char *, const char *, const char *, int) NORETURN;
6015 static void
6016 varunset(const char *end, const char *var, const char *umsg, int varflags)
6017 {
6018         const char *msg;
6019         const char *tail;
6020
6021         tail = nullstr;
6022         msg = "parameter not set";
6023         if (umsg) {
6024                 if (*end == CTLENDVAR) {
6025                         if (varflags & VSNUL)
6026                                 tail = " or null";
6027                 } else {
6028                         msg = umsg;
6029                 }
6030         }
6031         ash_msg_and_raise_error("%.*s: %s%s", end - var - 1, var, msg, tail);
6032 }
6033
6034 #if ENABLE_ASH_BASH_COMPAT
6035 static char *
6036 parse_sub_pattern(char *arg, int inquotes)
6037 {
6038         char *idx, *repl = NULL;
6039         unsigned char c;
6040
6041         idx = arg;
6042         while (1) {
6043                 c = *arg;
6044                 if (!c)
6045                         break;
6046                 if (c == '/') {
6047                         /* Only the first '/' seen is our separator */
6048                         if (!repl) {
6049                                 repl = idx + 1;
6050                                 c = '\0';
6051                         }
6052                 }
6053                 *idx++ = c;
6054                 if (!inquotes && c == '\\' && arg[1] == '\\')
6055                         arg++; /* skip both \\, not just first one */
6056                 arg++;
6057         }
6058         *idx = c; /* NUL */
6059
6060         return repl;
6061 }
6062 #endif /* ENABLE_ASH_BASH_COMPAT */
6063
6064 static const char *
6065 subevalvar(char *p, char *str, int strloc, int subtype,
6066                 int startloc, int varflags, int quotes, struct strlist *var_str_list)
6067 {
6068         struct nodelist *saveargbackq = argbackq;
6069         char *startp;
6070         char *loc;
6071         char *rmesc, *rmescend;
6072         USE_ASH_BASH_COMPAT(char *repl = NULL;)
6073         USE_ASH_BASH_COMPAT(char null = '\0';)
6074         USE_ASH_BASH_COMPAT(int pos, len, orig_len;)
6075         int saveherefd = herefd;
6076         int amount, workloc, resetloc;
6077         int zero;
6078         char *(*scan)(char*, char*, char*, char*, int, int);
6079
6080         herefd = -1;
6081         argstr(p, (subtype != VSASSIGN && subtype != VSQUESTION) ? EXP_CASE : 0,
6082                         var_str_list);
6083         STPUTC('\0', expdest);
6084         herefd = saveherefd;
6085         argbackq = saveargbackq;
6086         startp = (char *)stackblock() + startloc;
6087
6088         switch (subtype) {
6089         case VSASSIGN:
6090                 setvar(str, startp, 0);
6091                 amount = startp - expdest;
6092                 STADJUST(amount, expdest);
6093                 return startp;
6094
6095 #if ENABLE_ASH_BASH_COMPAT
6096         case VSSUBSTR:
6097                 loc = str = stackblock() + strloc;
6098 // TODO: number() instead? It does error checking...
6099                 pos = atoi(loc);
6100                 len = str - startp - 1;
6101
6102                 /* *loc != '\0', guaranteed by parser */
6103                 if (quotes) {
6104                         char *ptr;
6105
6106                         /* We must adjust the length by the number of escapes we find. */
6107                         for (ptr = startp; ptr < (str - 1); ptr++) {
6108                                 if (*ptr == CTLESC) {
6109                                         len--;
6110                                         ptr++;
6111                                 }
6112                         }
6113                 }
6114                 orig_len = len;
6115
6116                 if (*loc++ == ':') {
6117 // TODO: number() instead? It does error checking...
6118                         len = atoi(loc);
6119                 } else {
6120                         len = orig_len;
6121                         while (*loc && *loc != ':')
6122                                 loc++;
6123                         if (*loc++ == ':')
6124 // TODO: number() instead? It does error checking...
6125                                 len = atoi(loc);
6126                 }
6127                 if (pos >= orig_len) {
6128                         pos = 0;
6129                         len = 0;
6130                 }
6131                 if (len > (orig_len - pos))
6132                         len = orig_len - pos;
6133
6134                 for (str = startp; pos; str++, pos--) {
6135                         if (quotes && *str == CTLESC)
6136                                 str++;
6137                 }
6138                 for (loc = startp; len; len--) {
6139                         if (quotes && *str == CTLESC)
6140                                 *loc++ = *str++;
6141                         *loc++ = *str++;
6142                 }
6143                 *loc = '\0';
6144                 amount = loc - expdest;
6145                 STADJUST(amount, expdest);
6146                 return loc;
6147 #endif
6148
6149         case VSQUESTION:
6150                 varunset(p, str, startp, varflags);
6151                 /* NOTREACHED */
6152         }
6153         resetloc = expdest - (char *)stackblock();
6154
6155         /* We'll comeback here if we grow the stack while handling
6156          * a VSREPLACE or VSREPLACEALL, since our pointers into the
6157          * stack will need rebasing, and we'll need to remove our work
6158          * areas each time
6159          */
6160  USE_ASH_BASH_COMPAT(restart:)
6161
6162         amount = expdest - ((char *)stackblock() + resetloc);
6163         STADJUST(-amount, expdest);
6164         startp = (char *)stackblock() + startloc;
6165
6166         rmesc = startp;
6167         rmescend = (char *)stackblock() + strloc;
6168         if (quotes) {
6169                 rmesc = _rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
6170                 if (rmesc != startp) {
6171                         rmescend = expdest;
6172                         startp = (char *)stackblock() + startloc;
6173                 }
6174         }
6175         rmescend--;
6176         str = (char *)stackblock() + strloc;
6177         preglob(str, varflags & VSQUOTE, 0);
6178         workloc = expdest - (char *)stackblock();
6179
6180 #if ENABLE_ASH_BASH_COMPAT
6181         if (subtype == VSREPLACE || subtype == VSREPLACEALL) {
6182                 char *idx, *end, *restart_detect;
6183
6184                 if (!repl) {
6185                         repl = parse_sub_pattern(str, varflags & VSQUOTE);
6186                         if (!repl)
6187                                 repl = &null;
6188                 }
6189
6190                 /* If there's no pattern to match, return the expansion unmolested */
6191                 if (*str == '\0')
6192                         return 0;
6193
6194                 len = 0;
6195                 idx = startp;
6196                 end = str - 1;
6197                 while (idx < end) {
6198                         loc = scanright(idx, rmesc, rmescend, str, quotes, 1);
6199                         if (!loc) {
6200                                 /* No match, advance */
6201                                 restart_detect = stackblock();
6202                                 STPUTC(*idx, expdest);
6203                                 if (quotes && *idx == CTLESC) {
6204                                         idx++;
6205                                         len++;
6206                                         STPUTC(*idx, expdest);
6207                                 }
6208                                 if (stackblock() != restart_detect)
6209                                         goto restart;
6210                                 idx++;
6211                                 len++;
6212                                 rmesc++;
6213                                 continue;
6214                         }
6215
6216                         if (subtype == VSREPLACEALL) {
6217                                 while (idx < loc) {
6218                                         if (quotes && *idx == CTLESC)
6219                                                 idx++;
6220                                         idx++;
6221                                         rmesc++;
6222                                 }
6223                         } else {
6224                                 idx = loc;
6225                         }
6226
6227                         for (loc = repl; *loc; loc++) {
6228                                 restart_detect = stackblock();
6229                                 STPUTC(*loc, expdest);
6230                                 if (stackblock() != restart_detect)
6231                                         goto restart;
6232                                 len++;
6233                         }
6234
6235                         if (subtype == VSREPLACE) {
6236                                 while (*idx) {
6237                                         restart_detect = stackblock();
6238                                         STPUTC(*idx, expdest);
6239                                         if (stackblock() != restart_detect)
6240                                                 goto restart;
6241                                         len++;
6242                                         idx++;
6243                                 }
6244                                 break;
6245                         }
6246                 }
6247
6248                 /* We've put the replaced text into a buffer at workloc, now
6249                  * move it to the right place and adjust the stack.
6250                  */
6251                 startp = stackblock() + startloc;
6252                 STPUTC('\0', expdest);
6253                 memmove(startp, stackblock() + workloc, len);
6254                 startp[len++] = '\0';
6255                 amount = expdest - ((char *)stackblock() + startloc + len - 1);
6256                 STADJUST(-amount, expdest);
6257                 return startp;
6258         }
6259 #endif /* ENABLE_ASH_BASH_COMPAT */
6260
6261         subtype -= VSTRIMRIGHT;
6262 #if DEBUG
6263         if (subtype < 0 || subtype > 7)
6264                 abort();
6265 #endif
6266         /* zero = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX */
6267         zero = subtype >> 1;
6268         /* VSTRIMLEFT/VSTRIMRIGHTMAX -> scanleft */
6269         scan = (subtype & 1) ^ zero ? scanleft : scanright;
6270
6271         loc = scan(startp, rmesc, rmescend, str, quotes, zero);
6272         if (loc) {
6273                 if (zero) {
6274                         memmove(startp, loc, str - loc);
6275                         loc = startp + (str - loc) - 1;
6276                 }
6277                 *loc = '\0';
6278                 amount = loc - expdest;
6279                 STADJUST(amount, expdest);
6280         }
6281         return loc;
6282 }
6283
6284 /*
6285  * Add the value of a specialized variable to the stack string.
6286  */
6287 static ssize_t
6288 varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
6289 {
6290         int num;
6291         const char *p;
6292         int i;
6293         int sep = 0;
6294         int sepq = 0;
6295         ssize_t len = 0;
6296         char **ap;
6297         int syntax;
6298         int quoted = varflags & VSQUOTE;
6299         int subtype = varflags & VSTYPE;
6300         int quotes = flags & (EXP_FULL | EXP_CASE);
6301
6302         if (quoted && (flags & EXP_FULL))
6303                 sep = 1 << CHAR_BIT;
6304
6305         syntax = quoted ? DQSYNTAX : BASESYNTAX;
6306         switch (*name) {
6307         case '$':
6308                 num = rootpid;
6309                 goto numvar;
6310         case '?':
6311                 num = exitstatus;
6312                 goto numvar;
6313         case '#':
6314                 num = shellparam.nparam;
6315                 goto numvar;
6316         case '!':
6317                 num = backgndpid;
6318                 if (num == 0)
6319                         return -1;
6320  numvar:
6321                 len = cvtnum(num);
6322                 break;
6323         case '-':
6324                 expdest = makestrspace(NOPTS, expdest);
6325                 for (i = NOPTS - 1; i >= 0; i--) {
6326                         if (optlist[i]) {
6327                                 USTPUTC(optletters(i), expdest);
6328                                 len++;
6329                         }
6330                 }
6331                 break;
6332         case '@':
6333                 if (sep)
6334                         goto param;
6335                 /* fall through */
6336         case '*':
6337                 sep = ifsset() ? signed_char2int(ifsval()[0]) : ' ';
6338                 if (quotes && (SIT(sep, syntax) == CCTL || SIT(sep, syntax) == CBACK))
6339                         sepq = 1;
6340  param:
6341                 ap = shellparam.p;
6342                 if (!ap)
6343                         return -1;
6344                 while ((p = *ap++)) {
6345                         size_t partlen;
6346
6347                         partlen = strlen(p);
6348                         len += partlen;
6349
6350                         if (!(subtype == VSPLUS || subtype == VSLENGTH))
6351                                 memtodest(p, partlen, syntax, quotes);
6352
6353                         if (*ap && sep) {
6354                                 char *q;
6355
6356                                 len++;
6357                                 if (subtype == VSPLUS || subtype == VSLENGTH) {
6358                                         continue;
6359                                 }
6360                                 q = expdest;
6361                                 if (sepq)
6362                                         STPUTC(CTLESC, q);
6363                                 STPUTC(sep, q);
6364                                 expdest = q;
6365                         }
6366                 }
6367                 return len;
6368         case '0':
6369         case '1':
6370         case '2':
6371         case '3':
6372         case '4':
6373         case '5':
6374         case '6':
6375         case '7':
6376         case '8':
6377         case '9':
6378 // TODO: number() instead? It does error checking...
6379                 num = atoi(name);
6380                 if (num < 0 || num > shellparam.nparam)
6381                         return -1;
6382                 p = num ? shellparam.p[num - 1] : arg0;
6383                 goto value;
6384         default:
6385                 /* NB: name has form "VAR=..." */
6386
6387                 /* "A=a B=$A" case: var_str_list is a list of "A=a" strings
6388                  * which should be considered before we check variables. */
6389                 if (var_str_list) {
6390                         unsigned name_len = (strchrnul(name, '=') - name) + 1;
6391                         p = NULL;
6392                         do {
6393                                 char *str, *eq;
6394                                 str = var_str_list->text;
6395                                 eq = strchr(str, '=');
6396                                 if (!eq) /* stop at first non-assignment */
6397                                         break;
6398                                 eq++;
6399                                 if (name_len == (unsigned)(eq - str)
6400                                  && strncmp(str, name, name_len) == 0) {
6401                                         p = eq;
6402                                         /* goto value; - WRONG! */
6403                                         /* think "A=1 A=2 B=$A" */
6404                                 }
6405                                 var_str_list = var_str_list->next;
6406                         } while (var_str_list);
6407                         if (p)
6408                                 goto value;
6409                 }
6410                 p = lookupvar(name);
6411  value:
6412                 if (!p)
6413                         return -1;
6414
6415                 len = strlen(p);
6416                 if (!(subtype == VSPLUS || subtype == VSLENGTH))
6417                         memtodest(p, len, syntax, quotes);
6418                 return len;
6419         }
6420
6421         if (subtype == VSPLUS || subtype == VSLENGTH)
6422                 STADJUST(-len, expdest);
6423         return len;
6424 }
6425
6426 /*
6427  * Expand a variable, and return a pointer to the next character in the
6428  * input string.
6429  */
6430 static char *
6431 evalvar(char *p, int flag, struct strlist *var_str_list)
6432 {
6433         char varflags;
6434         char subtype;
6435         char quoted;
6436         char easy;
6437         char *var;
6438         int patloc;
6439         int startloc;
6440         ssize_t varlen;
6441
6442         varflags = *p++;
6443         subtype = varflags & VSTYPE;
6444         quoted = varflags & VSQUOTE;
6445         var = p;
6446         easy = (!quoted || (*var == '@' && shellparam.nparam));
6447         startloc = expdest - (char *)stackblock();
6448         p = strchr(p, '=') + 1;
6449
6450  again:
6451         varlen = varvalue(var, varflags, flag, var_str_list);
6452         if (varflags & VSNUL)
6453                 varlen--;
6454
6455         if (subtype == VSPLUS) {
6456                 varlen = -1 - varlen;
6457                 goto vsplus;
6458         }
6459
6460         if (subtype == VSMINUS) {
6461  vsplus:
6462                 if (varlen < 0) {
6463                         argstr(
6464                                 p, flag | EXP_TILDE |
6465                                         (quoted ?  EXP_QWORD : EXP_WORD),
6466                                 var_str_list
6467                         );
6468                         goto end;
6469                 }
6470                 if (easy)
6471                         goto record;
6472                 goto end;
6473         }
6474
6475         if (subtype == VSASSIGN || subtype == VSQUESTION) {
6476                 if (varlen < 0) {
6477                         if (subevalvar(p, var, /* strloc: */ 0,
6478                                         subtype, startloc, varflags,
6479                                         /* quotes: */ 0,
6480                                         var_str_list)
6481                         ) {
6482                                 varflags &= ~VSNUL;
6483                                 /*
6484                                  * Remove any recorded regions beyond
6485                                  * start of variable
6486                                  */
6487                                 removerecordregions(startloc);
6488                                 goto again;
6489                         }
6490                         goto end;
6491                 }
6492                 if (easy)
6493                         goto record;
6494                 goto end;
6495         }
6496
6497         if (varlen < 0 && uflag)
6498                 varunset(p, var, 0, 0);
6499
6500         if (subtype == VSLENGTH) {
6501                 cvtnum(varlen > 0 ? varlen : 0);
6502                 goto record;
6503         }
6504
6505         if (subtype == VSNORMAL) {
6506                 if (easy)
6507                         goto record;
6508                 goto end;
6509         }
6510
6511 #if DEBUG
6512         switch (subtype) {
6513         case VSTRIMLEFT:
6514         case VSTRIMLEFTMAX:
6515         case VSTRIMRIGHT:
6516         case VSTRIMRIGHTMAX:
6517 #if ENABLE_ASH_BASH_COMPAT
6518         case VSSUBSTR:
6519         case VSREPLACE:
6520         case VSREPLACEALL:
6521 #endif
6522                 break;
6523         default:
6524                 abort();
6525         }
6526 #endif
6527
6528         if (varlen >= 0) {
6529                 /*
6530                  * Terminate the string and start recording the pattern
6531                  * right after it
6532                  */
6533                 STPUTC('\0', expdest);
6534                 patloc = expdest - (char *)stackblock();
6535                 if (0 == subevalvar(p, /* str: */ NULL, patloc, subtype,
6536                                 startloc, varflags,
6537                                 /* quotes: */ flag & (EXP_FULL | EXP_CASE),
6538                                 var_str_list)
6539                 ) {
6540                         int amount = expdest - (
6541                                 (char *)stackblock() + patloc - 1
6542                         );
6543                         STADJUST(-amount, expdest);
6544                 }
6545                 /* Remove any recorded regions beyond start of variable */
6546                 removerecordregions(startloc);
6547  record:
6548                 recordregion(startloc, expdest - (char *)stackblock(), quoted);
6549         }
6550
6551  end:
6552         if (subtype != VSNORMAL) {      /* skip to end of alternative */
6553                 int nesting = 1;
6554                 for (;;) {
6555                         char c = *p++;
6556                         if (c == CTLESC)
6557                                 p++;
6558                         else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
6559                                 if (varlen >= 0)
6560                                         argbackq = argbackq->next;
6561                         } else if (c == CTLVAR) {
6562                                 if ((*p++ & VSTYPE) != VSNORMAL)
6563                                         nesting++;
6564                         } else if (c == CTLENDVAR) {
6565                                 if (--nesting == 0)
6566                                         break;
6567                         }
6568                 }
6569         }
6570         return p;
6571 }
6572
6573 /*
6574  * Break the argument string into pieces based upon IFS and add the
6575  * strings to the argument list.  The regions of the string to be
6576  * searched for IFS characters have been stored by recordregion.
6577  */
6578 static void
6579 ifsbreakup(char *string, struct arglist *arglist)
6580 {
6581         struct ifsregion *ifsp;
6582         struct strlist *sp;
6583         char *start;
6584         char *p;
6585         char *q;
6586         const char *ifs, *realifs;
6587         int ifsspc;
6588         int nulonly;
6589
6590         start = string;
6591         if (ifslastp != NULL) {
6592                 ifsspc = 0;
6593                 nulonly = 0;
6594                 realifs = ifsset() ? ifsval() : defifs;
6595                 ifsp = &ifsfirst;
6596                 do {
6597                         p = string + ifsp->begoff;
6598                         nulonly = ifsp->nulonly;
6599                         ifs = nulonly ? nullstr : realifs;
6600                         ifsspc = 0;
6601                         while (p < string + ifsp->endoff) {
6602                                 q = p;
6603                                 if (*p == CTLESC)
6604                                         p++;
6605                                 if (!strchr(ifs, *p)) {
6606                                         p++;
6607                                         continue;
6608                                 }
6609                                 if (!nulonly)
6610                                         ifsspc = (strchr(defifs, *p) != NULL);
6611                                 /* Ignore IFS whitespace at start */
6612                                 if (q == start && ifsspc) {
6613                                         p++;
6614                                         start = p;
6615                                         continue;
6616                                 }
6617                                 *q = '\0';
6618                                 sp = stzalloc(sizeof(*sp));
6619                                 sp->text = start;
6620                                 *arglist->lastp = sp;
6621                                 arglist->lastp = &sp->next;
6622                                 p++;
6623                                 if (!nulonly) {
6624                                         for (;;) {
6625                                                 if (p >= string + ifsp->endoff) {
6626                                                         break;
6627                                                 }
6628                                                 q = p;
6629                                                 if (*p == CTLESC)
6630                                                         p++;
6631                                                 if (strchr(ifs, *p) == NULL) {
6632                                                         p = q;
6633                                                         break;
6634                                                 }
6635                                                 if (strchr(defifs, *p) == NULL) {
6636                                                         if (ifsspc) {
6637                                                                 p++;
6638                                                                 ifsspc = 0;
6639                                                         } else {
6640                                                                 p = q;
6641                                                                 break;
6642                                                         }
6643                                                 } else
6644                                                         p++;
6645                                         }
6646                                 }
6647                                 start = p;
6648                         } /* while */
6649                         ifsp = ifsp->next;
6650                 } while (ifsp != NULL);
6651                 if (nulonly)
6652                         goto add;
6653         }
6654
6655         if (!*start)
6656                 return;
6657
6658  add:
6659         sp = stzalloc(sizeof(*sp));
6660         sp->text = start;
6661         *arglist->lastp = sp;
6662         arglist->lastp = &sp->next;
6663 }
6664
6665 static void
6666 ifsfree(void)
6667 {
6668         struct ifsregion *p;
6669
6670         INT_OFF;
6671         p = ifsfirst.next;
6672         do {
6673                 struct ifsregion *ifsp;
6674                 ifsp = p->next;
6675                 free(p);
6676                 p = ifsp;
6677         } while (p);
6678         ifslastp = NULL;
6679         ifsfirst.next = NULL;
6680         INT_ON;
6681 }
6682
6683 /*
6684  * Add a file name to the list.
6685  */
6686 static void
6687 addfname(const char *name)
6688 {
6689         struct strlist *sp;
6690
6691         sp = stzalloc(sizeof(*sp));
6692         sp->text = ststrdup(name);
6693         *exparg.lastp = sp;
6694         exparg.lastp = &sp->next;
6695 }
6696
6697 static char *expdir;
6698
6699 /*
6700  * Do metacharacter (i.e. *, ?, [...]) expansion.
6701  */
6702 static void
6703 expmeta(char *enddir, char *name)
6704 {
6705         char *p;
6706         const char *cp;
6707         char *start;
6708         char *endname;
6709         int metaflag;
6710         struct stat statb;
6711         DIR *dirp;
6712         struct dirent *dp;
6713         int atend;
6714         int matchdot;
6715
6716         metaflag = 0;
6717         start = name;
6718         for (p = name; *p; p++) {
6719                 if (*p == '*' || *p == '?')
6720                         metaflag = 1;
6721                 else if (*p == '[') {
6722                         char *q = p + 1;
6723                         if (*q == '!')
6724                                 q++;
6725                         for (;;) {
6726                                 if (*q == '\\')
6727                                         q++;
6728                                 if (*q == '/' || *q == '\0')
6729                                         break;
6730                                 if (*++q == ']') {
6731                                         metaflag = 1;
6732                                         break;
6733                                 }
6734                         }
6735                 } else if (*p == '\\')
6736                         p++;
6737                 else if (*p == '/') {
6738                         if (metaflag)
6739                                 goto out;
6740                         start = p + 1;
6741                 }
6742         }
6743  out:
6744         if (metaflag == 0) {    /* we've reached the end of the file name */
6745                 if (enddir != expdir)
6746                         metaflag++;
6747                 p = name;
6748                 do {
6749                         if (*p == '\\')
6750                                 p++;
6751                         *enddir++ = *p;
6752                 } while (*p++);
6753                 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
6754                         addfname(expdir);
6755                 return;
6756         }
6757         endname = p;
6758         if (name < start) {
6759                 p = name;
6760                 do {
6761                         if (*p == '\\')
6762                                 p++;
6763                         *enddir++ = *p++;
6764                 } while (p < start);
6765         }
6766         if (enddir == expdir) {
6767                 cp = ".";
6768         } else if (enddir == expdir + 1 && *expdir == '/') {
6769                 cp = "/";
6770         } else {
6771                 cp = expdir;
6772                 enddir[-1] = '\0';
6773         }
6774         dirp = opendir(cp);
6775         if (dirp == NULL)
6776                 return;
6777         if (enddir != expdir)
6778                 enddir[-1] = '/';
6779         if (*endname == 0) {
6780                 atend = 1;
6781         } else {
6782                 atend = 0;
6783                 *endname++ = '\0';
6784         }
6785         matchdot = 0;
6786         p = start;
6787         if (*p == '\\')
6788                 p++;
6789         if (*p == '.')
6790                 matchdot++;
6791         while (!intpending && (dp = readdir(dirp)) != NULL) {
6792                 if (dp->d_name[0] == '.' && !matchdot)
6793                         continue;
6794                 if (pmatch(start, dp->d_name)) {
6795                         if (atend) {
6796                                 strcpy(enddir, dp->d_name);
6797                                 addfname(expdir);
6798                         } else {
6799                                 for (p = enddir, cp = dp->d_name; (*p++ = *cp++) != '\0';)
6800                                         continue;
6801                                 p[-1] = '/';
6802                                 expmeta(p, endname);
6803                         }
6804                 }
6805         }
6806         closedir(dirp);
6807         if (!atend)
6808                 endname[-1] = '/';
6809 }
6810
6811 static struct strlist *
6812 msort(struct strlist *list, int len)
6813 {
6814         struct strlist *p, *q = NULL;
6815         struct strlist **lpp;
6816         int half;
6817         int n;
6818
6819         if (len <= 1)
6820                 return list;
6821         half = len >> 1;
6822         p = list;
6823         for (n = half; --n >= 0;) {
6824                 q = p;
6825                 p = p->next;
6826         }
6827         q->next = NULL;                 /* terminate first half of list */
6828         q = msort(list, half);          /* sort first half of list */
6829         p = msort(p, len - half);               /* sort second half */
6830         lpp = &list;
6831         for (;;) {
6832 #if ENABLE_LOCALE_SUPPORT
6833                 if (strcoll(p->text, q->text) < 0)
6834 #else
6835                 if (strcmp(p->text, q->text) < 0)
6836 #endif
6837                                                 {
6838                         *lpp = p;
6839                         lpp = &p->next;
6840                         p = *lpp;
6841                         if (p == NULL) {
6842                                 *lpp = q;
6843                                 break;
6844                         }
6845                 } else {
6846                         *lpp = q;
6847                         lpp = &q->next;
6848                         q = *lpp;
6849                         if (q == NULL) {
6850                                 *lpp = p;
6851                                 break;
6852                         }
6853                 }
6854         }
6855         return list;
6856 }
6857
6858 /*
6859  * Sort the results of file name expansion.  It calculates the number of
6860  * strings to sort and then calls msort (short for merge sort) to do the
6861  * work.
6862  */
6863 static struct strlist *
6864 expsort(struct strlist *str)
6865 {
6866         int len;
6867         struct strlist *sp;
6868
6869         len = 0;
6870         for (sp = str; sp; sp = sp->next)
6871                 len++;
6872         return msort(str, len);
6873 }
6874
6875 static void
6876 expandmeta(struct strlist *str /*, int flag*/)
6877 {
6878         static const char metachars[] ALIGN1 = {
6879                 '*', '?', '[', 0
6880         };
6881         /* TODO - EXP_REDIR */
6882
6883         while (str) {
6884                 struct strlist **savelastp;
6885                 struct strlist *sp;
6886                 char *p;
6887
6888                 if (fflag)
6889                         goto nometa;
6890                 if (!strpbrk(str->text, metachars))
6891                         goto nometa;
6892                 savelastp = exparg.lastp;
6893
6894                 INT_OFF;
6895                 p = preglob(str->text, 0, RMESCAPE_ALLOC | RMESCAPE_HEAP);
6896                 {
6897                         int i = strlen(str->text);
6898                         expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
6899                 }
6900
6901                 expmeta(expdir, p);
6902                 free(expdir);
6903                 if (p != str->text)
6904                         free(p);
6905                 INT_ON;
6906                 if (exparg.lastp == savelastp) {
6907                         /*
6908                          * no matches
6909                          */
6910  nometa:
6911                         *exparg.lastp = str;
6912                         rmescapes(str->text);
6913                         exparg.lastp = &str->next;
6914                 } else {
6915                         *exparg.lastp = NULL;
6916                         *savelastp = sp = expsort(*savelastp);
6917                         while (sp->next != NULL)
6918                                 sp = sp->next;
6919                         exparg.lastp = &sp->next;
6920                 }
6921                 str = str->next;
6922         }
6923 }
6924
6925 /*
6926  * Perform variable substitution and command substitution on an argument,
6927  * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
6928  * perform splitting and file name expansion.  When arglist is NULL, perform
6929  * here document expansion.
6930  */
6931 static void
6932 expandarg(union node *arg, struct arglist *arglist, int flag)
6933 {
6934         struct strlist *sp;
6935         char *p;
6936
6937         argbackq = arg->narg.backquote;
6938         STARTSTACKSTR(expdest);
6939         ifsfirst.next = NULL;
6940         ifslastp = NULL;
6941         argstr(arg->narg.text, flag,
6942                         /* var_str_list: */ arglist ? arglist->list : NULL);
6943         p = _STPUTC('\0', expdest);
6944         expdest = p - 1;
6945         if (arglist == NULL) {
6946                 return;                 /* here document expanded */
6947         }
6948         p = grabstackstr(p);
6949         exparg.lastp = &exparg.list;
6950         /*
6951          * TODO - EXP_REDIR
6952          */
6953         if (flag & EXP_FULL) {
6954                 ifsbreakup(p, &exparg);
6955                 *exparg.lastp = NULL;
6956                 exparg.lastp = &exparg.list;
6957                 expandmeta(exparg.list /*, flag*/);
6958         } else {
6959                 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
6960                         rmescapes(p);
6961                 sp = stzalloc(sizeof(*sp));
6962                 sp->text = p;
6963                 *exparg.lastp = sp;
6964                 exparg.lastp = &sp->next;
6965         }
6966         if (ifsfirst.next)
6967                 ifsfree();
6968         *exparg.lastp = NULL;
6969         if (exparg.list) {
6970                 *arglist->lastp = exparg.list;
6971                 arglist->lastp = exparg.lastp;
6972         }
6973 }
6974
6975 /*
6976  * Expand shell variables and backquotes inside a here document.
6977  */
6978 static void
6979 expandhere(union node *arg, int fd)
6980 {
6981         herefd = fd;
6982         expandarg(arg, (struct arglist *)NULL, 0);
6983         full_write(fd, stackblock(), expdest - (char *)stackblock());
6984 }
6985
6986 /*
6987  * Returns true if the pattern matches the string.
6988  */
6989 static int
6990 patmatch(char *pattern, const char *string)
6991 {
6992         return pmatch(preglob(pattern, 0, 0), string);
6993 }
6994
6995 /*
6996  * See if a pattern matches in a case statement.
6997  */
6998 static int
6999 casematch(union node *pattern, char *val)
7000 {
7001         struct stackmark smark;
7002         int result;
7003
7004         setstackmark(&smark);
7005         argbackq = pattern->narg.backquote;
7006         STARTSTACKSTR(expdest);
7007         ifslastp = NULL;
7008         argstr(pattern->narg.text, EXP_TILDE | EXP_CASE,
7009                         /* var_str_list: */ NULL);
7010         STACKSTRNUL(expdest);
7011         result = patmatch(stackblock(), val);
7012         popstackmark(&smark);
7013         return result;
7014 }
7015
7016
7017 /* ============ find_command */
7018
7019 struct builtincmd {
7020         const char *name;
7021         int (*builtin)(int, char **);
7022         /* unsigned flags; */
7023 };
7024 #define IS_BUILTIN_SPECIAL(b) ((b)->name[0] & 1)
7025 /* "regular" builtins always take precedence over commands,
7026  * regardless of PATH=....%builtin... position */
7027 #define IS_BUILTIN_REGULAR(b) ((b)->name[0] & 2)
7028 #define IS_BUILTIN_ASSIGN(b)  ((b)->name[0] & 4)
7029
7030 struct cmdentry {
7031         smallint cmdtype;       /* CMDxxx */
7032         union param {
7033                 int index;
7034                 /* index >= 0 for commands without path (slashes) */
7035                 /* (TODO: what exactly does the value mean? PATH position?) */
7036                 /* index == -1 for commands with slashes */
7037                 /* index == (-2 - applet_no) for NOFORK applets */
7038                 const struct builtincmd *cmd;
7039                 struct funcnode *func;
7040         } u;
7041 };
7042 /* values of cmdtype */
7043 #define CMDUNKNOWN      -1      /* no entry in table for command */
7044 #define CMDNORMAL       0       /* command is an executable program */
7045 #define CMDFUNCTION     1       /* command is a shell function */
7046 #define CMDBUILTIN      2       /* command is a shell builtin */
7047
7048 /* action to find_command() */
7049 #define DO_ERR          0x01    /* prints errors */
7050 #define DO_ABS          0x02    /* checks absolute paths */
7051 #define DO_NOFUNC       0x04    /* don't return shell functions, for command */
7052 #define DO_ALTPATH      0x08    /* using alternate path */
7053 #define DO_ALTBLTIN     0x20    /* %builtin in alt. path */
7054
7055 static void find_command(char *, struct cmdentry *, int, const char *);
7056
7057
7058 /* ============ Hashing commands */
7059
7060 /*
7061  * When commands are first encountered, they are entered in a hash table.
7062  * This ensures that a full path search will not have to be done for them
7063  * on each invocation.
7064  *
7065  * We should investigate converting to a linear search, even though that
7066  * would make the command name "hash" a misnomer.
7067  */
7068
7069 struct tblentry {
7070         struct tblentry *next;  /* next entry in hash chain */
7071         union param param;      /* definition of builtin function */
7072         smallint cmdtype;       /* CMDxxx */
7073         char rehash;            /* if set, cd done since entry created */
7074         char cmdname[1];        /* name of command */
7075 };
7076
7077 static struct tblentry **cmdtable;
7078 #define INIT_G_cmdtable() do { \
7079         cmdtable = xzalloc(CMDTABLESIZE * sizeof(cmdtable[0])); \
7080 } while (0)
7081
7082 static int builtinloc = -1;     /* index in path of %builtin, or -1 */
7083
7084
7085 static void
7086 tryexec(USE_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **envp)
7087 {
7088         int repeated = 0;
7089
7090 #if ENABLE_FEATURE_SH_STANDALONE
7091         if (applet_no >= 0) {
7092                 if (APPLET_IS_NOEXEC(applet_no)) {
7093                         while (*envp)
7094                                 putenv(*envp++);
7095                         run_applet_no_and_exit(applet_no, argv);
7096                 }
7097                 /* re-exec ourselves with the new arguments */
7098                 execve(bb_busybox_exec_path, argv, envp);
7099                 /* If they called chroot or otherwise made the binary no longer
7100                  * executable, fall through */
7101         }
7102 #endif
7103
7104  repeat:
7105 #ifdef SYSV
7106         do {
7107                 execve(cmd, argv, envp);
7108         } while (errno == EINTR);
7109 #else
7110         execve(cmd, argv, envp);
7111 #endif
7112         if (repeated) {
7113                 free(argv);
7114                 return;
7115         }
7116         if (errno == ENOEXEC) {
7117                 char **ap;
7118                 char **new;
7119
7120                 for (ap = argv; *ap; ap++)
7121                         continue;
7122                 ap = new = ckmalloc((ap - argv + 2) * sizeof(ap[0]));
7123                 ap[1] = cmd;
7124                 ap[0] = cmd = (char *)DEFAULT_SHELL;
7125                 ap += 2;
7126                 argv++;
7127                 while ((*ap++ = *argv++) != NULL)
7128                         continue;
7129                 argv = new;
7130                 repeated++;
7131                 goto repeat;
7132         }
7133 }
7134
7135 /*
7136  * Exec a program.  Never returns.  If you change this routine, you may
7137  * have to change the find_command routine as well.
7138  */
7139 static void shellexec(char **, const char *, int) NORETURN;
7140 static void
7141 shellexec(char **argv, const char *path, int idx)
7142 {
7143         char *cmdname;
7144         int e;
7145         char **envp;
7146         int exerrno;
7147 #if ENABLE_FEATURE_SH_STANDALONE
7148         int applet_no = -1;
7149 #endif
7150
7151         clearredir(/*drop:*/ 1);
7152         envp = listvars(VEXPORT, VUNSET, 0);
7153         if (strchr(argv[0], '/') != NULL
7154 #if ENABLE_FEATURE_SH_STANDALONE
7155          || (applet_no = find_applet_by_name(argv[0])) >= 0
7156 #endif
7157         ) {
7158                 tryexec(USE_FEATURE_SH_STANDALONE(applet_no,) argv[0], argv, envp);
7159                 e = errno;
7160         } else {
7161                 e = ENOENT;
7162                 while ((cmdname = padvance(&path, argv[0])) != NULL) {
7163                         if (--idx < 0 && pathopt == NULL) {
7164                                 tryexec(USE_FEATURE_SH_STANDALONE(-1,) cmdname, argv, envp);
7165                                 if (errno != ENOENT && errno != ENOTDIR)
7166                                         e = errno;
7167                         }
7168                         stunalloc(cmdname);
7169                 }
7170         }
7171
7172         /* Map to POSIX errors */
7173         switch (e) {
7174         case EACCES:
7175                 exerrno = 126;
7176                 break;
7177         case ENOENT:
7178                 exerrno = 127;
7179                 break;
7180         default:
7181                 exerrno = 2;
7182                 break;
7183         }
7184         exitstatus = exerrno;
7185         TRACE(("shellexec failed for %s, errno %d, suppressint %d\n",
7186                 argv[0], e, suppressint));
7187         ash_msg_and_raise(EXEXEC, "%s: %s", argv[0], errmsg(e, "not found"));
7188         /* NOTREACHED */
7189 }
7190
7191 static void
7192 printentry(struct tblentry *cmdp)
7193 {
7194         int idx;
7195         const char *path;
7196         char *name;
7197
7198         idx = cmdp->param.index;
7199         path = pathval();
7200         do {
7201                 name = padvance(&path, cmdp->cmdname);
7202                 stunalloc(name);
7203         } while (--idx >= 0);
7204         out1fmt("%s%s\n", name, (cmdp->rehash ? "*" : nullstr));
7205 }
7206
7207 /*
7208  * Clear out command entries.  The argument specifies the first entry in
7209  * PATH which has changed.
7210  */
7211 static void
7212 clearcmdentry(int firstchange)
7213 {
7214         struct tblentry **tblp;
7215         struct tblentry **pp;
7216         struct tblentry *cmdp;
7217
7218         INT_OFF;
7219         for (tblp = cmdtable; tblp < &cmdtable[CMDTABLESIZE]; tblp++) {
7220                 pp = tblp;
7221                 while ((cmdp = *pp) != NULL) {
7222                         if ((cmdp->cmdtype == CMDNORMAL &&
7223                              cmdp->param.index >= firstchange)
7224                          || (cmdp->cmdtype == CMDBUILTIN &&
7225                              builtinloc >= firstchange)
7226                         ) {
7227                                 *pp = cmdp->next;
7228                                 free(cmdp);
7229                         } else {
7230                                 pp = &cmdp->next;
7231                         }
7232                 }
7233         }
7234         INT_ON;
7235 }
7236
7237 /*
7238  * Locate a command in the command hash table.  If "add" is nonzero,
7239  * add the command to the table if it is not already present.  The
7240  * variable "lastcmdentry" is set to point to the address of the link
7241  * pointing to the entry, so that delete_cmd_entry can delete the
7242  * entry.
7243  *
7244  * Interrupts must be off if called with add != 0.
7245  */
7246 static struct tblentry **lastcmdentry;
7247
7248 static struct tblentry *
7249 cmdlookup(const char *name, int add)
7250 {
7251         unsigned int hashval;
7252         const char *p;
7253         struct tblentry *cmdp;
7254         struct tblentry **pp;
7255
7256         p = name;
7257         hashval = (unsigned char)*p << 4;
7258         while (*p)
7259                 hashval += (unsigned char)*p++;
7260         hashval &= 0x7FFF;
7261         pp = &cmdtable[hashval % CMDTABLESIZE];
7262         for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
7263                 if (strcmp(cmdp->cmdname, name) == 0)
7264                         break;
7265                 pp = &cmdp->next;
7266         }
7267         if (add && cmdp == NULL) {
7268                 cmdp = *pp = ckzalloc(sizeof(struct tblentry)
7269                                 + strlen(name)
7270                                 /* + 1 - already done because
7271                                  * tblentry::cmdname is char[1] */);
7272                 /*cmdp->next = NULL; - ckzalloc did it */
7273                 cmdp->cmdtype = CMDUNKNOWN;
7274                 strcpy(cmdp->cmdname, name);
7275         }
7276         lastcmdentry = pp;
7277         return cmdp;
7278 }
7279
7280 /*
7281  * Delete the command entry returned on the last lookup.
7282  */
7283 static void
7284 delete_cmd_entry(void)
7285 {
7286         struct tblentry *cmdp;
7287
7288         INT_OFF;
7289         cmdp = *lastcmdentry;
7290         *lastcmdentry = cmdp->next;
7291         if (cmdp->cmdtype == CMDFUNCTION)
7292                 freefunc(cmdp->param.func);
7293         free(cmdp);
7294         INT_ON;
7295 }
7296
7297 /*
7298  * Add a new command entry, replacing any existing command entry for
7299  * the same name - except special builtins.
7300  */
7301 static void
7302 addcmdentry(char *name, struct cmdentry *entry)
7303 {
7304         struct tblentry *cmdp;
7305
7306         cmdp = cmdlookup(name, 1);
7307         if (cmdp->cmdtype == CMDFUNCTION) {
7308                 freefunc(cmdp->param.func);
7309         }
7310         cmdp->cmdtype = entry->cmdtype;
7311         cmdp->param = entry->u;
7312         cmdp->rehash = 0;
7313 }
7314
7315 static int
7316 hashcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
7317 {
7318         struct tblentry **pp;
7319         struct tblentry *cmdp;
7320         int c;
7321         struct cmdentry entry;
7322         char *name;
7323
7324         if (nextopt("r") != '\0') {
7325                 clearcmdentry(0);
7326                 return 0;
7327         }
7328
7329         if (*argptr == NULL) {
7330                 for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) {
7331                         for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
7332                                 if (cmdp->cmdtype == CMDNORMAL)
7333                                         printentry(cmdp);
7334                         }
7335                 }
7336                 return 0;
7337         }
7338
7339         c = 0;
7340         while ((name = *argptr) != NULL) {
7341                 cmdp = cmdlookup(name, 0);
7342                 if (cmdp != NULL
7343                  && (cmdp->cmdtype == CMDNORMAL
7344                      || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
7345                 ) {
7346                         delete_cmd_entry();
7347                 }
7348                 find_command(name, &entry, DO_ERR, pathval());
7349                 if (entry.cmdtype == CMDUNKNOWN)
7350                         c = 1;
7351                 argptr++;
7352         }
7353         return c;
7354 }
7355
7356 /*
7357  * Called when a cd is done.  Marks all commands so the next time they
7358  * are executed they will be rehashed.
7359  */
7360 static void
7361 hashcd(void)
7362 {
7363         struct tblentry **pp;
7364         struct tblentry *cmdp;
7365
7366         for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) {
7367                 for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
7368                         if (cmdp->cmdtype == CMDNORMAL
7369                          || (cmdp->cmdtype == CMDBUILTIN
7370                              && !IS_BUILTIN_REGULAR(cmdp->param.cmd)
7371                              && builtinloc > 0)
7372                         ) {
7373                                 cmdp->rehash = 1;
7374                         }
7375                 }
7376         }
7377 }
7378
7379 /*
7380  * Fix command hash table when PATH changed.
7381  * Called before PATH is changed.  The argument is the new value of PATH;
7382  * pathval() still returns the old value at this point.
7383  * Called with interrupts off.
7384  */
7385 static void
7386 changepath(const char *new)
7387 {
7388         const char *old;
7389         int firstchange;
7390         int idx;
7391         int idx_bltin;
7392
7393         old = pathval();
7394         firstchange = 9999;     /* assume no change */
7395         idx = 0;
7396         idx_bltin = -1;
7397         for (;;) {
7398                 if (*old != *new) {
7399                         firstchange = idx;
7400                         if ((*old == '\0' && *new == ':')
7401                          || (*old == ':' && *new == '\0'))
7402                                 firstchange++;
7403                         old = new;      /* ignore subsequent differences */
7404                 }
7405                 if (*new == '\0')
7406                         break;
7407                 if (*new == '%' && idx_bltin < 0 && prefix(new + 1, "builtin"))
7408                         idx_bltin = idx;
7409                 if (*new == ':')
7410                         idx++;
7411                 new++, old++;
7412         }
7413         if (builtinloc < 0 && idx_bltin >= 0)
7414                 builtinloc = idx_bltin;             /* zap builtins */
7415         if (builtinloc >= 0 && idx_bltin < 0)
7416                 firstchange = 0;
7417         clearcmdentry(firstchange);
7418         builtinloc = idx_bltin;
7419 }
7420
7421 #define TEOF 0
7422 #define TNL 1
7423 #define TREDIR 2
7424 #define TWORD 3
7425 #define TSEMI 4
7426 #define TBACKGND 5
7427 #define TAND 6
7428 #define TOR 7
7429 #define TPIPE 8
7430 #define TLP 9
7431 #define TRP 10
7432 #define TENDCASE 11
7433 #define TENDBQUOTE 12
7434 #define TNOT 13
7435 #define TCASE 14
7436 #define TDO 15
7437 #define TDONE 16
7438 #define TELIF 17
7439 #define TELSE 18
7440 #define TESAC 19
7441 #define TFI 20
7442 #define TFOR 21
7443 #define TIF 22
7444 #define TIN 23
7445 #define TTHEN 24
7446 #define TUNTIL 25
7447 #define TWHILE 26
7448 #define TBEGIN 27
7449 #define TEND 28
7450 typedef smallint token_id_t;
7451
7452 /* first char is indicating which tokens mark the end of a list */
7453 static const char *const tokname_array[] = {
7454         "\1end of file",
7455         "\0newline",
7456         "\0redirection",
7457         "\0word",
7458         "\0;",
7459         "\0&",
7460         "\0&&",
7461         "\0||",
7462         "\0|",
7463         "\0(",
7464         "\1)",
7465         "\1;;",
7466         "\1`",
7467 #define KWDOFFSET 13
7468         /* the following are keywords */
7469         "\0!",
7470         "\0case",
7471         "\1do",
7472         "\1done",
7473         "\1elif",
7474         "\1else",
7475         "\1esac",
7476         "\1fi",
7477         "\0for",
7478         "\0if",
7479         "\0in",
7480         "\1then",
7481         "\0until",
7482         "\0while",
7483         "\0{",
7484         "\1}",
7485 };
7486
7487 static const char *
7488 tokname(int tok)
7489 {
7490         static char buf[16];
7491
7492 //try this:
7493 //if (tok < TSEMI) return tokname_array[tok] + 1;
7494 //sprintf(buf, "\"%s\"", tokname_array[tok] + 1);
7495 //return buf;
7496
7497         if (tok >= TSEMI)
7498                 buf[0] = '"';
7499         sprintf(buf + (tok >= TSEMI), "%s%c",
7500                         tokname_array[tok] + 1, (tok >= TSEMI ? '"' : 0));
7501         return buf;
7502 }
7503
7504 /* Wrapper around strcmp for qsort/bsearch/... */
7505 static int
7506 pstrcmp(const void *a, const void *b)
7507 {
7508         return strcmp((char*) a, (*(char**) b) + 1);
7509 }
7510
7511 static const char *const *
7512 findkwd(const char *s)
7513 {
7514         return bsearch(s, tokname_array + KWDOFFSET,
7515                         ARRAY_SIZE(tokname_array) - KWDOFFSET,
7516                         sizeof(tokname_array[0]), pstrcmp);
7517 }
7518
7519 /*
7520  * Locate and print what a word is...
7521  */
7522 static int
7523 describe_command(char *command, int describe_command_verbose)
7524 {
7525         struct cmdentry entry;
7526         struct tblentry *cmdp;
7527 #if ENABLE_ASH_ALIAS
7528         const struct alias *ap;
7529 #endif
7530         const char *path = pathval();
7531
7532         if (describe_command_verbose) {
7533                 out1str(command);
7534         }
7535
7536         /* First look at the keywords */
7537         if (findkwd(command)) {
7538                 out1str(describe_command_verbose ? " is a shell keyword" : command);
7539                 goto out;
7540         }
7541
7542 #if ENABLE_ASH_ALIAS
7543         /* Then look at the aliases */
7544         ap = lookupalias(command, 0);
7545         if (ap != NULL) {
7546                 if (!describe_command_verbose) {
7547                         out1str("alias ");
7548                         printalias(ap);
7549                         return 0;
7550                 }
7551                 out1fmt(" is an alias for %s", ap->val);
7552                 goto out;
7553         }
7554 #endif
7555         /* Then check if it is a tracked alias */
7556         cmdp = cmdlookup(command, 0);
7557         if (cmdp != NULL) {
7558                 entry.cmdtype = cmdp->cmdtype;
7559                 entry.u = cmdp->param;
7560         } else {
7561                 /* Finally use brute force */
7562                 find_command(command, &entry, DO_ABS, path);
7563         }
7564
7565         switch (entry.cmdtype) {
7566         case CMDNORMAL: {
7567                 int j = entry.u.index;
7568                 char *p;
7569                 if (j < 0) {
7570                         p = command;
7571                 } else {
7572                         do {
7573                                 p = padvance(&path, command);
7574                                 stunalloc(p);
7575                         } while (--j >= 0);
7576                 }
7577                 if (describe_command_verbose) {
7578                         out1fmt(" is%s %s",
7579                                 (cmdp ? " a tracked alias for" : nullstr), p
7580                         );
7581                 } else {
7582                         out1str(p);
7583                 }
7584                 break;
7585         }
7586
7587         case CMDFUNCTION:
7588                 if (describe_command_verbose) {
7589                         out1str(" is a shell function");
7590                 } else {
7591                         out1str(command);
7592                 }
7593                 break;
7594
7595         case CMDBUILTIN:
7596                 if (describe_command_verbose) {
7597                         out1fmt(" is a %sshell builtin",
7598                                 IS_BUILTIN_SPECIAL(entry.u.cmd) ?
7599                                         "special " : nullstr
7600                         );
7601                 } else {
7602                         out1str(command);
7603                 }
7604                 break;
7605
7606         default:
7607                 if (describe_command_verbose) {
7608                         out1str(": not found\n");
7609                 }
7610                 return 127;
7611         }
7612  out:
7613         outstr("\n", stdout);
7614         return 0;
7615 }
7616
7617 static int
7618 typecmd(int argc UNUSED_PARAM, char **argv)
7619 {
7620         int i = 1;
7621         int err = 0;
7622         int verbose = 1;
7623
7624         /* type -p ... ? (we don't bother checking for 'p') */
7625         if (argv[1] && argv[1][0] == '-') {
7626                 i++;
7627                 verbose = 0;
7628         }
7629         while (argv[i]) {
7630                 err |= describe_command(argv[i++], verbose);
7631         }
7632         return err;
7633 }
7634
7635 #if ENABLE_ASH_CMDCMD
7636 static int
7637 commandcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
7638 {
7639         int c;
7640         enum {
7641                 VERIFY_BRIEF = 1,
7642                 VERIFY_VERBOSE = 2,
7643         } verify = 0;
7644
7645         while ((c = nextopt("pvV")) != '\0')
7646                 if (c == 'V')
7647                         verify |= VERIFY_VERBOSE;
7648                 else if (c == 'v')
7649                         verify |= VERIFY_BRIEF;
7650 #if DEBUG
7651                 else if (c != 'p')
7652                         abort();
7653 #endif
7654         /* Mimic bash: just "command -v" doesn't complain, it's a nop */
7655         if (verify && (*argptr != NULL)) {
7656                 return describe_command(*argptr, verify - VERIFY_BRIEF);
7657         }
7658
7659         return 0;
7660 }
7661 #endif
7662
7663
7664 /* ============ eval.c */
7665
7666 static int funcblocksize;       /* size of structures in function */
7667 static int funcstringsize;      /* size of strings in node */
7668 static void *funcblock;         /* block to allocate function from */
7669 static char *funcstring;        /* block to allocate strings from */
7670
7671 /* flags in argument to evaltree */
7672 #define EV_EXIT    01           /* exit after evaluating tree */
7673 #define EV_TESTED  02           /* exit status is checked; ignore -e flag */
7674 #define EV_BACKCMD 04           /* command executing within back quotes */
7675
7676 static const short nodesize[N_NUMBER] = {
7677         [NCMD     ] = SHELL_ALIGN(sizeof(struct ncmd)),
7678         [NPIPE    ] = SHELL_ALIGN(sizeof(struct npipe)),
7679         [NREDIR   ] = SHELL_ALIGN(sizeof(struct nredir)),
7680         [NBACKGND ] = SHELL_ALIGN(sizeof(struct nredir)),
7681         [NSUBSHELL] = SHELL_ALIGN(sizeof(struct nredir)),
7682         [NAND     ] = SHELL_ALIGN(sizeof(struct nbinary)),
7683         [NOR      ] = SHELL_ALIGN(sizeof(struct nbinary)),
7684         [NSEMI    ] = SHELL_ALIGN(sizeof(struct nbinary)),
7685         [NIF      ] = SHELL_ALIGN(sizeof(struct nif)),
7686         [NWHILE   ] = SHELL_ALIGN(sizeof(struct nbinary)),
7687         [NUNTIL   ] = SHELL_ALIGN(sizeof(struct nbinary)),
7688         [NFOR     ] = SHELL_ALIGN(sizeof(struct nfor)),
7689         [NCASE    ] = SHELL_ALIGN(sizeof(struct ncase)),
7690         [NCLIST   ] = SHELL_ALIGN(sizeof(struct nclist)),
7691         [NDEFUN   ] = SHELL_ALIGN(sizeof(struct narg)),
7692         [NARG     ] = SHELL_ALIGN(sizeof(struct narg)),
7693         [NTO      ] = SHELL_ALIGN(sizeof(struct nfile)),
7694 #if ENABLE_ASH_BASH_COMPAT
7695         [NTO2     ] = SHELL_ALIGN(sizeof(struct nfile)),
7696 #endif
7697         [NCLOBBER ] = SHELL_ALIGN(sizeof(struct nfile)),
7698         [NFROM    ] = SHELL_ALIGN(sizeof(struct nfile)),
7699         [NFROMTO  ] = SHELL_ALIGN(sizeof(struct nfile)),
7700         [NAPPEND  ] = SHELL_ALIGN(sizeof(struct nfile)),
7701         [NTOFD    ] = SHELL_ALIGN(sizeof(struct ndup)),
7702         [NFROMFD  ] = SHELL_ALIGN(sizeof(struct ndup)),
7703         [NHERE    ] = SHELL_ALIGN(sizeof(struct nhere)),
7704         [NXHERE   ] = SHELL_ALIGN(sizeof(struct nhere)),
7705         [NNOT     ] = SHELL_ALIGN(sizeof(struct nnot)),
7706 };
7707
7708 static void calcsize(union node *n);
7709
7710 static void
7711 sizenodelist(struct nodelist *lp)
7712 {
7713         while (lp) {
7714                 funcblocksize += SHELL_ALIGN(sizeof(struct nodelist));
7715                 calcsize(lp->n);
7716                 lp = lp->next;
7717         }
7718 }
7719
7720 static void
7721 calcsize(union node *n)
7722 {
7723         if (n == NULL)
7724                 return;
7725         funcblocksize += nodesize[n->type];
7726         switch (n->type) {
7727         case NCMD:
7728                 calcsize(n->ncmd.redirect);
7729                 calcsize(n->ncmd.args);
7730                 calcsize(n->ncmd.assign);
7731                 break;
7732         case NPIPE:
7733                 sizenodelist(n->npipe.cmdlist);
7734                 break;
7735         case NREDIR:
7736         case NBACKGND:
7737         case NSUBSHELL:
7738                 calcsize(n->nredir.redirect);
7739                 calcsize(n->nredir.n);
7740                 break;
7741         case NAND:
7742         case NOR:
7743         case NSEMI:
7744         case NWHILE:
7745         case NUNTIL:
7746                 calcsize(n->nbinary.ch2);
7747                 calcsize(n->nbinary.ch1);
7748                 break;
7749         case NIF:
7750                 calcsize(n->nif.elsepart);
7751                 calcsize(n->nif.ifpart);
7752                 calcsize(n->nif.test);
7753                 break;
7754         case NFOR:
7755                 funcstringsize += strlen(n->nfor.var) + 1;
7756                 calcsize(n->nfor.body);
7757                 calcsize(n->nfor.args);
7758                 break;
7759         case NCASE:
7760                 calcsize(n->ncase.cases);
7761                 calcsize(n->ncase.expr);
7762                 break;
7763         case NCLIST:
7764                 calcsize(n->nclist.body);
7765                 calcsize(n->nclist.pattern);
7766                 calcsize(n->nclist.next);
7767                 break;
7768         case NDEFUN:
7769         case NARG:
7770                 sizenodelist(n->narg.backquote);
7771                 funcstringsize += strlen(n->narg.text) + 1;
7772                 calcsize(n->narg.next);
7773                 break;
7774         case NTO:
7775 #if ENABLE_ASH_BASH_COMPAT
7776         case NTO2:
7777 #endif
7778         case NCLOBBER:
7779         case NFROM:
7780         case NFROMTO:
7781         case NAPPEND:
7782                 calcsize(n->nfile.fname);
7783                 calcsize(n->nfile.next);
7784                 break;
7785         case NTOFD:
7786         case NFROMFD:
7787                 calcsize(n->ndup.vname);
7788                 calcsize(n->ndup.next);
7789         break;
7790         case NHERE:
7791         case NXHERE:
7792                 calcsize(n->nhere.doc);
7793                 calcsize(n->nhere.next);
7794                 break;
7795         case NNOT:
7796                 calcsize(n->nnot.com);
7797                 break;
7798         };
7799 }
7800
7801 static char *
7802 nodeckstrdup(char *s)
7803 {
7804         char *rtn = funcstring;
7805
7806         strcpy(funcstring, s);
7807         funcstring += strlen(s) + 1;
7808         return rtn;
7809 }
7810
7811 static union node *copynode(union node *);
7812
7813 static struct nodelist *
7814 copynodelist(struct nodelist *lp)
7815 {
7816         struct nodelist *start;
7817         struct nodelist **lpp;
7818
7819         lpp = &start;
7820         while (lp) {
7821                 *lpp = funcblock;
7822                 funcblock = (char *) funcblock + SHELL_ALIGN(sizeof(struct nodelist));
7823                 (*lpp)->n = copynode(lp->n);
7824                 lp = lp->next;
7825                 lpp = &(*lpp)->next;
7826         }
7827         *lpp = NULL;
7828         return start;
7829 }
7830
7831 static union node *
7832 copynode(union node *n)
7833 {
7834         union node *new;
7835
7836         if (n == NULL)
7837                 return NULL;
7838         new = funcblock;
7839         funcblock = (char *) funcblock + nodesize[n->type];
7840
7841         switch (n->type) {
7842         case NCMD:
7843                 new->ncmd.redirect = copynode(n->ncmd.redirect);
7844                 new->ncmd.args = copynode(n->ncmd.args);
7845                 new->ncmd.assign = copynode(n->ncmd.assign);
7846                 break;
7847         case NPIPE:
7848                 new->npipe.cmdlist = copynodelist(n->npipe.cmdlist);
7849                 new->npipe.pipe_backgnd = n->npipe.pipe_backgnd;
7850                 break;
7851         case NREDIR:
7852         case NBACKGND:
7853         case NSUBSHELL:
7854                 new->nredir.redirect = copynode(n->nredir.redirect);
7855                 new->nredir.n = copynode(n->nredir.n);
7856                 break;
7857         case NAND:
7858         case NOR:
7859         case NSEMI:
7860         case NWHILE:
7861         case NUNTIL:
7862                 new->nbinary.ch2 = copynode(n->nbinary.ch2);
7863                 new->nbinary.ch1 = copynode(n->nbinary.ch1);
7864                 break;
7865         case NIF:
7866                 new->nif.elsepart = copynode(n->nif.elsepart);
7867                 new->nif.ifpart = copynode(n->nif.ifpart);
7868                 new->nif.test = copynode(n->nif.test);
7869                 break;
7870         case NFOR:
7871                 new->nfor.var = nodeckstrdup(n->nfor.var);
7872                 new->nfor.body = copynode(n->nfor.body);
7873                 new->nfor.args = copynode(n->nfor.args);
7874                 break;
7875         case NCASE:
7876                 new->ncase.cases = copynode(n->ncase.cases);
7877                 new->ncase.expr = copynode(n->ncase.expr);
7878                 break;
7879         case NCLIST:
7880                 new->nclist.body = copynode(n->nclist.body);
7881                 new->nclist.pattern = copynode(n->nclist.pattern);
7882                 new->nclist.next = copynode(n->nclist.next);
7883                 break;
7884         case NDEFUN:
7885         case NARG:
7886                 new->narg.backquote = copynodelist(n->narg.backquote);
7887                 new->narg.text = nodeckstrdup(n->narg.text);
7888                 new->narg.next = copynode(n->narg.next);
7889                 break;
7890         case NTO:
7891 #if ENABLE_ASH_BASH_COMPAT
7892         case NTO2:
7893 #endif
7894         case NCLOBBER:
7895         case NFROM:
7896         case NFROMTO:
7897         case NAPPEND:
7898                 new->nfile.fname = copynode(n->nfile.fname);
7899                 new->nfile.fd = n->nfile.fd;
7900                 new->nfile.next = copynode(n->nfile.next);
7901                 break;
7902         case NTOFD:
7903         case NFROMFD:
7904                 new->ndup.vname = copynode(n->ndup.vname);
7905                 new->ndup.dupfd = n->ndup.dupfd;
7906                 new->ndup.fd = n->ndup.fd;
7907                 new->ndup.next = copynode(n->ndup.next);
7908                 break;
7909         case NHERE:
7910         case NXHERE:
7911                 new->nhere.doc = copynode(n->nhere.doc);
7912                 new->nhere.fd = n->nhere.fd;
7913                 new->nhere.next = copynode(n->nhere.next);
7914                 break;
7915         case NNOT:
7916                 new->nnot.com = copynode(n->nnot.com);
7917                 break;
7918         };
7919         new->type = n->type;
7920         return new;
7921 }
7922
7923 /*
7924  * Make a copy of a parse tree.
7925  */
7926 static struct funcnode *
7927 copyfunc(union node *n)
7928 {
7929         struct funcnode *f;
7930         size_t blocksize;
7931
7932         funcblocksize = offsetof(struct funcnode, n);
7933         funcstringsize = 0;
7934         calcsize(n);
7935         blocksize = funcblocksize;
7936         f = ckmalloc(blocksize + funcstringsize);
7937         funcblock = (char *) f + offsetof(struct funcnode, n);
7938         funcstring = (char *) f + blocksize;
7939         copynode(n);
7940         f->count = 0;
7941         return f;
7942 }
7943
7944 /*
7945  * Define a shell function.
7946  */
7947 static void
7948 defun(char *name, union node *func)
7949 {
7950         struct cmdentry entry;
7951
7952         INT_OFF;
7953         entry.cmdtype = CMDFUNCTION;
7954         entry.u.func = copyfunc(func);
7955         addcmdentry(name, &entry);
7956         INT_ON;
7957 }
7958
7959 /* Reasons for skipping commands (see comment on breakcmd routine) */
7960 #define SKIPBREAK      (1 << 0)
7961 #define SKIPCONT       (1 << 1)
7962 #define SKIPFUNC       (1 << 2)
7963 #define SKIPFILE       (1 << 3)
7964 #define SKIPEVAL       (1 << 4)
7965 static smallint evalskip;       /* set to SKIPxxx if we are skipping commands */
7966 static int skipcount;           /* number of levels to skip */
7967 static int funcnest;            /* depth of function calls */
7968 static int loopnest;            /* current loop nesting level */
7969
7970 /* Forward decl way out to parsing code - dotrap needs it */
7971 static int evalstring(char *s, int mask);
7972
7973 /* Called to execute a trap.
7974  * Single callsite - at the end of evaltree().
7975  * If we return non-zero, exaltree raises EXEXIT exception.
7976  *
7977  * Perhaps we should avoid entering new trap handlers
7978  * while we are executing a trap handler. [is it a TODO?]
7979  */
7980 static int
7981 dotrap(void)
7982 {
7983         uint8_t *g;
7984         int sig;
7985         uint8_t savestatus;
7986
7987         savestatus = exitstatus;
7988         pendingsig = 0;
7989         xbarrier();
7990
7991         TRACE(("dotrap entered\n"));
7992         for (sig = 1, g = gotsig; sig < NSIG; sig++, g++) {
7993                 int want_exexit;
7994                 char *t;
7995
7996                 if (*g == 0)
7997                         continue;
7998                 t = trap[sig];
7999                 /* non-trapped SIGINT is handled separately by raise_interrupt,
8000                  * don't upset it by resetting gotsig[SIGINT-1] */
8001                 if (sig == SIGINT && !t)
8002                         continue;
8003
8004                 TRACE(("sig %d is active, will run handler '%s'\n", sig, t));
8005                 *g = 0;
8006                 if (!t)
8007                         continue;
8008                 want_exexit = evalstring(t, SKIPEVAL);
8009                 exitstatus = savestatus;
8010                 if (want_exexit) {
8011                         TRACE(("dotrap returns %d\n", want_exexit));
8012                         return want_exexit;
8013                 }
8014         }
8015
8016         TRACE(("dotrap returns 0\n"));
8017         return 0;
8018 }
8019
8020 /* forward declarations - evaluation is fairly recursive business... */
8021 static void evalloop(union node *, int);
8022 static void evalfor(union node *, int);
8023 static void evalcase(union node *, int);
8024 static void evalsubshell(union node *, int);
8025 static void expredir(union node *);
8026 static void evalpipe(union node *, int);
8027 static void evalcommand(union node *, int);
8028 static int evalbltin(const struct builtincmd *, int, char **);
8029 static void prehash(union node *);
8030
8031 /*
8032  * Evaluate a parse tree.  The value is left in the global variable
8033  * exitstatus.
8034  */
8035 static void
8036 evaltree(union node *n, int flags)
8037 {
8038         struct jmploc *volatile savehandler = exception_handler;
8039         struct jmploc jmploc;
8040         int checkexit = 0;
8041         void (*evalfn)(union node *, int);
8042         int status;
8043         int int_level;
8044
8045         SAVE_INT(int_level);
8046
8047         if (n == NULL) {
8048                 TRACE(("evaltree(NULL) called\n"));
8049                 goto out1;
8050         }
8051         TRACE(("evaltree(%p: %d, %d) called\n", n, n->type, flags));
8052
8053         exception_handler = &jmploc;
8054         {
8055                 int err = setjmp(jmploc.loc);
8056                 if (err) {
8057                         /* if it was a signal, check for trap handlers */
8058                         if (exception_type == EXSIG) {
8059                                 TRACE(("exception %d (EXSIG) in evaltree, err=%d\n",
8060                                                 exception_type, err));
8061                                 goto out;
8062                         }
8063                         /* continue on the way out */
8064                         TRACE(("exception %d in evaltree, propagating err=%d\n",
8065                                         exception_type, err));
8066                         exception_handler = savehandler;
8067                         longjmp(exception_handler->loc, err);
8068                 }
8069         }
8070
8071         switch (n->type) {
8072         default:
8073 #if DEBUG
8074                 out1fmt("Node type = %d\n", n->type);
8075                 fflush(stdout);
8076                 break;
8077 #endif
8078         case NNOT:
8079                 evaltree(n->nnot.com, EV_TESTED);
8080                 status = !exitstatus;
8081                 goto setstatus;
8082         case NREDIR:
8083                 expredir(n->nredir.redirect);
8084                 status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
8085                 if (!status) {
8086                         evaltree(n->nredir.n, flags & EV_TESTED);
8087                         status = exitstatus;
8088                 }
8089                 popredir(/*drop:*/ 0, /*restore:*/ 0 /* not sure */);
8090                 goto setstatus;
8091         case NCMD:
8092                 evalfn = evalcommand;
8093  checkexit:
8094                 if (eflag && !(flags & EV_TESTED))
8095                         checkexit = ~0;
8096                 goto calleval;
8097         case NFOR:
8098                 evalfn = evalfor;
8099                 goto calleval;
8100         case NWHILE:
8101         case NUNTIL:
8102                 evalfn = evalloop;
8103                 goto calleval;
8104         case NSUBSHELL:
8105         case NBACKGND:
8106                 evalfn = evalsubshell;
8107                 goto calleval;
8108         case NPIPE:
8109                 evalfn = evalpipe;
8110                 goto checkexit;
8111         case NCASE:
8112                 evalfn = evalcase;
8113                 goto calleval;
8114         case NAND:
8115         case NOR:
8116         case NSEMI: {
8117
8118 #if NAND + 1 != NOR
8119 #error NAND + 1 != NOR
8120 #endif
8121 #if NOR + 1 != NSEMI
8122 #error NOR + 1 != NSEMI
8123 #endif
8124                 unsigned is_or = n->type - NAND;
8125                 evaltree(
8126                         n->nbinary.ch1,
8127                         (flags | ((is_or >> 1) - 1)) & EV_TESTED
8128                 );
8129                 if (!exitstatus == is_or)
8130                         break;
8131                 if (!evalskip) {
8132                         n = n->nbinary.ch2;
8133  evaln:
8134                         evalfn = evaltree;
8135  calleval:
8136                         evalfn(n, flags);
8137                         break;
8138                 }
8139                 break;
8140         }
8141         case NIF:
8142                 evaltree(n->nif.test, EV_TESTED);
8143                 if (evalskip)
8144                         break;
8145                 if (exitstatus == 0) {
8146                         n = n->nif.ifpart;
8147                         goto evaln;
8148                 }
8149                 if (n->nif.elsepart) {
8150                         n = n->nif.elsepart;
8151                         goto evaln;
8152                 }
8153                 goto success;
8154         case NDEFUN:
8155                 defun(n->narg.text, n->narg.next);
8156  success:
8157                 status = 0;
8158  setstatus:
8159                 exitstatus = status;
8160                 break;
8161         }
8162
8163  out:
8164         exception_handler = savehandler;
8165  out1:
8166         if (checkexit & exitstatus)
8167                 evalskip |= SKIPEVAL;
8168         else if (pendingsig && dotrap())
8169                 goto exexit;
8170
8171         if (flags & EV_EXIT) {
8172  exexit:
8173                 raise_exception(EXEXIT);
8174         }
8175
8176         RESTORE_INT(int_level);
8177         TRACE(("leaving evaltree (no interrupts)\n"));
8178 }
8179
8180 #if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
8181 static
8182 #endif
8183 void evaltreenr(union node *, int) __attribute__ ((alias("evaltree"),__noreturn__));
8184
8185 static void
8186 evalloop(union node *n, int flags)
8187 {
8188         int status;
8189
8190         loopnest++;
8191         status = 0;
8192         flags &= EV_TESTED;
8193         for (;;) {
8194                 int i;
8195
8196                 evaltree(n->nbinary.ch1, EV_TESTED);
8197                 if (evalskip) {
8198  skipping:
8199                         if (evalskip == SKIPCONT && --skipcount <= 0) {
8200                                 evalskip = 0;
8201                                 continue;
8202                         }
8203                         if (evalskip == SKIPBREAK && --skipcount <= 0)
8204                                 evalskip = 0;
8205                         break;
8206                 }
8207                 i = exitstatus;
8208                 if (n->type != NWHILE)
8209                         i = !i;
8210                 if (i != 0)
8211                         break;
8212                 evaltree(n->nbinary.ch2, flags);
8213                 status = exitstatus;
8214                 if (evalskip)
8215                         goto skipping;
8216         }
8217         loopnest--;
8218         exitstatus = status;
8219 }
8220
8221 static void
8222 evalfor(union node *n, int flags)
8223 {
8224         struct arglist arglist;
8225         union node *argp;
8226         struct strlist *sp;
8227         struct stackmark smark;
8228
8229         setstackmark(&smark);
8230         arglist.list = NULL;
8231         arglist.lastp = &arglist.list;
8232         for (argp = n->nfor.args; argp; argp = argp->narg.next) {
8233                 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE | EXP_RECORD);
8234                 /* XXX */
8235                 if (evalskip)
8236                         goto out;
8237         }
8238         *arglist.lastp = NULL;
8239
8240         exitstatus = 0;
8241         loopnest++;
8242         flags &= EV_TESTED;
8243         for (sp = arglist.list; sp; sp = sp->next) {
8244                 setvar(n->nfor.var, sp->text, 0);
8245                 evaltree(n->nfor.body, flags);
8246                 if (evalskip) {
8247                         if (evalskip == SKIPCONT && --skipcount <= 0) {
8248                                 evalskip = 0;
8249                                 continue;
8250                         }
8251                         if (evalskip == SKIPBREAK && --skipcount <= 0)
8252                                 evalskip = 0;
8253                         break;
8254                 }
8255         }
8256         loopnest--;
8257  out:
8258         popstackmark(&smark);
8259 }
8260
8261 static void
8262 evalcase(union node *n, int flags)
8263 {
8264         union node *cp;
8265         union node *patp;
8266         struct arglist arglist;
8267         struct stackmark smark;
8268
8269         setstackmark(&smark);
8270         arglist.list = NULL;
8271         arglist.lastp = &arglist.list;
8272         expandarg(n->ncase.expr, &arglist, EXP_TILDE);
8273         exitstatus = 0;
8274         for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) {
8275                 for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) {
8276                         if (casematch(patp, arglist.list->text)) {
8277                                 if (evalskip == 0) {
8278                                         evaltree(cp->nclist.body, flags);
8279                                 }
8280                                 goto out;
8281                         }
8282                 }
8283         }
8284  out:
8285         popstackmark(&smark);
8286 }
8287
8288 /*
8289  * Kick off a subshell to evaluate a tree.
8290  */
8291 static void
8292 evalsubshell(union node *n, int flags)
8293 {
8294         struct job *jp;
8295         int backgnd = (n->type == NBACKGND);
8296         int status;
8297
8298         expredir(n->nredir.redirect);
8299         if (!backgnd && flags & EV_EXIT && !trap[0])
8300                 goto nofork;
8301         INT_OFF;
8302         jp = makejob(/*n,*/ 1);
8303         if (forkshell(jp, n, backgnd) == 0) {
8304                 INT_ON;
8305                 flags |= EV_EXIT;
8306                 if (backgnd)
8307                         flags &=~ EV_TESTED;
8308  nofork:
8309                 redirect(n->nredir.redirect, 0);
8310                 evaltreenr(n->nredir.n, flags);
8311                 /* never returns */
8312         }
8313         status = 0;
8314         if (!backgnd)
8315                 status = waitforjob(jp);
8316         exitstatus = status;
8317         INT_ON;
8318 }
8319
8320 /*
8321  * Compute the names of the files in a redirection list.
8322  */
8323 static void fixredir(union node *, const char *, int);
8324 static void
8325 expredir(union node *n)
8326 {
8327         union node *redir;
8328
8329         for (redir = n; redir; redir = redir->nfile.next) {
8330                 struct arglist fn;
8331
8332                 fn.list = NULL;
8333                 fn.lastp = &fn.list;
8334                 switch (redir->type) {
8335                 case NFROMTO:
8336                 case NFROM:
8337                 case NTO:
8338 #if ENABLE_ASH_BASH_COMPAT
8339                 case NTO2:
8340 #endif
8341                 case NCLOBBER:
8342                 case NAPPEND:
8343                         expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
8344 #if ENABLE_ASH_BASH_COMPAT
8345  store_expfname:
8346 #endif
8347                         redir->nfile.expfname = fn.list->text;
8348                         break;
8349                 case NFROMFD:
8350                 case NTOFD: /* >& */
8351                         if (redir->ndup.vname) {
8352                                 expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
8353                                 if (fn.list == NULL)
8354                                         ash_msg_and_raise_error("redir error");
8355 #if ENABLE_ASH_BASH_COMPAT
8356 //FIXME: we used expandarg with different args!
8357                                 if (!isdigit_str9(fn.list->text)) {
8358                                         /* >&file, not >&fd */
8359                                         if (redir->nfile.fd != 1) /* 123>&file - BAD */
8360                                                 ash_msg_and_raise_error("redir error");
8361                                         redir->type = NTO2;
8362                                         goto store_expfname;
8363                                 }
8364 #endif
8365                                 fixredir(redir, fn.list->text, 1);
8366                         }
8367                         break;
8368                 }
8369         }
8370 }
8371
8372 /*
8373  * Evaluate a pipeline.  All the processes in the pipeline are children
8374  * of the process creating the pipeline.  (This differs from some versions
8375  * of the shell, which make the last process in a pipeline the parent
8376  * of all the rest.)
8377  */
8378 static void
8379 evalpipe(union node *n, int flags)
8380 {
8381         struct job *jp;
8382         struct nodelist *lp;
8383         int pipelen;
8384         int prevfd;
8385         int pip[2];
8386
8387         TRACE(("evalpipe(0x%lx) called\n", (long)n));
8388         pipelen = 0;
8389         for (lp = n->npipe.cmdlist; lp; lp = lp->next)
8390                 pipelen++;
8391         flags |= EV_EXIT;
8392         INT_OFF;
8393         jp = makejob(/*n,*/ pipelen);
8394         prevfd = -1;
8395         for (lp = n->npipe.cmdlist; lp; lp = lp->next) {
8396                 prehash(lp->n);
8397                 pip[1] = -1;
8398                 if (lp->next) {
8399                         if (pipe(pip) < 0) {
8400                                 close(prevfd);
8401                                 ash_msg_and_raise_error("pipe call failed");
8402                         }
8403                 }
8404                 if (forkshell(jp, lp->n, n->npipe.pipe_backgnd) == 0) {
8405                         INT_ON;
8406                         if (pip[1] >= 0) {
8407                                 close(pip[0]);
8408                         }
8409                         if (prevfd > 0) {
8410                                 dup2(prevfd, 0);
8411                                 close(prevfd);
8412                         }
8413                         if (pip[1] > 1) {
8414                                 dup2(pip[1], 1);
8415                                 close(pip[1]);
8416                         }
8417                         evaltreenr(lp->n, flags);
8418                         /* never returns */
8419                 }
8420                 if (prevfd >= 0)
8421                         close(prevfd);
8422                 prevfd = pip[0];
8423                 /* Don't want to trigger debugging */
8424                 if (pip[1] != -1)
8425                         close(pip[1]);
8426         }
8427         if (n->npipe.pipe_backgnd == 0) {
8428                 exitstatus = waitforjob(jp);
8429                 TRACE(("evalpipe:  job done exit status %d\n", exitstatus));
8430         }
8431         INT_ON;
8432 }
8433
8434 /*
8435  * Controls whether the shell is interactive or not.
8436  */
8437 static void
8438 setinteractive(int on)
8439 {
8440         static smallint is_interactive;
8441
8442         if (++on == is_interactive)
8443                 return;
8444         is_interactive = on;
8445         setsignal(SIGINT);
8446         setsignal(SIGQUIT);
8447         setsignal(SIGTERM);
8448 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
8449         if (is_interactive > 1) {
8450                 /* Looks like they want an interactive shell */
8451                 static smallint did_banner;
8452
8453                 if (!did_banner) {
8454                         out1fmt(
8455                                 "\n\n"
8456                                 "%s built-in shell (ash)\n"
8457                                 "Enter 'help' for a list of built-in commands."
8458                                 "\n\n",
8459                                 bb_banner);
8460                         did_banner = 1;
8461                 }
8462         }
8463 #endif
8464 }
8465
8466 static void
8467 optschanged(void)
8468 {
8469 #if DEBUG
8470         opentrace();
8471 #endif
8472         setinteractive(iflag);
8473         setjobctl(mflag);
8474 #if ENABLE_FEATURE_EDITING_VI
8475         if (viflag)
8476                 line_input_state->flags |= VI_MODE;
8477         else
8478                 line_input_state->flags &= ~VI_MODE;
8479 #else
8480         viflag = 0; /* forcibly keep the option off */
8481 #endif
8482 }
8483
8484 static struct localvar *localvars;
8485
8486 /*
8487  * Called after a function returns.
8488  * Interrupts must be off.
8489  */
8490 static void
8491 poplocalvars(void)
8492 {
8493         struct localvar *lvp;
8494         struct var *vp;
8495
8496         while ((lvp = localvars) != NULL) {
8497                 localvars = lvp->next;
8498                 vp = lvp->vp;
8499                 TRACE(("poplocalvar %s", vp ? vp->text : "-"));
8500                 if (vp == NULL) {       /* $- saved */
8501                         memcpy(optlist, lvp->text, sizeof(optlist));
8502                         free((char*)lvp->text);
8503                         optschanged();
8504                 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
8505                         unsetvar(vp->text);
8506                 } else {
8507                         if (vp->func)
8508                                 (*vp->func)(strchrnul(lvp->text, '=') + 1);
8509                         if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
8510                                 free((char*)vp->text);
8511                         vp->flags = lvp->flags;
8512                         vp->text = lvp->text;
8513                 }
8514                 free(lvp);
8515         }
8516 }
8517
8518 static int
8519 evalfun(struct funcnode *func, int argc, char **argv, int flags)
8520 {
8521         volatile struct shparam saveparam;
8522         struct localvar *volatile savelocalvars;
8523         struct jmploc *volatile savehandler;
8524         struct jmploc jmploc;
8525         int e;
8526
8527         saveparam = shellparam;
8528         savelocalvars = localvars;
8529         e = setjmp(jmploc.loc);
8530         if (e) {
8531                 goto funcdone;
8532         }
8533         INT_OFF;
8534         savehandler = exception_handler;
8535         exception_handler = &jmploc;
8536         localvars = NULL;
8537         shellparam.malloced = 0;
8538         func->count++;
8539         funcnest++;
8540         INT_ON;
8541         shellparam.nparam = argc - 1;
8542         shellparam.p = argv + 1;
8543 #if ENABLE_ASH_GETOPTS
8544         shellparam.optind = 1;
8545         shellparam.optoff = -1;
8546 #endif
8547         evaltree(&func->n, flags & EV_TESTED);
8548  funcdone:
8549         INT_OFF;
8550         funcnest--;
8551         freefunc(func);
8552         poplocalvars();
8553         localvars = savelocalvars;
8554         freeparam(&shellparam);
8555         shellparam = saveparam;
8556         exception_handler = savehandler;
8557         INT_ON;
8558         evalskip &= ~SKIPFUNC;
8559         return e;
8560 }
8561
8562 #if ENABLE_ASH_CMDCMD
8563 static char **
8564 parse_command_args(char **argv, const char **path)
8565 {
8566         char *cp, c;
8567
8568         for (;;) {
8569                 cp = *++argv;
8570                 if (!cp)
8571                         return 0;
8572                 if (*cp++ != '-')
8573                         break;
8574                 c = *cp++;
8575                 if (!c)
8576                         break;
8577                 if (c == '-' && !*cp) {
8578                         argv++;
8579                         break;
8580                 }
8581                 do {
8582                         switch (c) {
8583                         case 'p':
8584                                 *path = bb_default_path;
8585                                 break;
8586                         default:
8587                                 /* run 'typecmd' for other options */
8588                                 return 0;
8589                         }
8590                         c = *cp++;
8591                 } while (c);
8592         }
8593         return argv;
8594 }
8595 #endif
8596
8597 /*
8598  * Make a variable a local variable.  When a variable is made local, it's
8599  * value and flags are saved in a localvar structure.  The saved values
8600  * will be restored when the shell function returns.  We handle the name
8601  * "-" as a special case.
8602  */
8603 static void
8604 mklocal(char *name)
8605 {
8606         struct localvar *lvp;
8607         struct var **vpp;
8608         struct var *vp;
8609
8610         INT_OFF;
8611         lvp = ckzalloc(sizeof(struct localvar));
8612         if (LONE_DASH(name)) {
8613                 char *p;
8614                 p = ckmalloc(sizeof(optlist));
8615                 lvp->text = memcpy(p, optlist, sizeof(optlist));
8616                 vp = NULL;
8617         } else {
8618                 char *eq;
8619
8620                 vpp = hashvar(name);
8621                 vp = *findvar(vpp, name);
8622                 eq = strchr(name, '=');
8623                 if (vp == NULL) {
8624                         if (eq)
8625                                 setvareq(name, VSTRFIXED);
8626                         else
8627                                 setvar(name, NULL, VSTRFIXED);
8628                         vp = *vpp;      /* the new variable */
8629                         lvp->flags = VUNSET;
8630                 } else {
8631                         lvp->text = vp->text;
8632                         lvp->flags = vp->flags;
8633                         vp->flags |= VSTRFIXED|VTEXTFIXED;
8634                         if (eq)
8635                                 setvareq(name, 0);
8636                 }
8637         }
8638         lvp->vp = vp;
8639         lvp->next = localvars;
8640         localvars = lvp;
8641         INT_ON;
8642 }
8643
8644 /*
8645  * The "local" command.
8646  */
8647 static int
8648 localcmd(int argc UNUSED_PARAM, char **argv)
8649 {
8650         char *name;
8651
8652         argv = argptr;
8653         while ((name = *argv++) != NULL) {
8654                 mklocal(name);
8655         }
8656         return 0;
8657 }
8658
8659 static int
8660 falsecmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
8661 {
8662         return 1;
8663 }
8664
8665 static int
8666 truecmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
8667 {
8668         return 0;
8669 }
8670
8671 static int
8672 execcmd(int argc UNUSED_PARAM, char **argv)
8673 {
8674         if (argv[1]) {
8675                 iflag = 0;              /* exit on error */
8676                 mflag = 0;
8677                 optschanged();
8678                 shellexec(argv + 1, pathval(), 0);
8679         }
8680         return 0;
8681 }
8682
8683 /*
8684  * The return command.
8685  */
8686 static int
8687 returncmd(int argc UNUSED_PARAM, char **argv)
8688 {
8689         /*
8690          * If called outside a function, do what ksh does;
8691          * skip the rest of the file.
8692          */
8693         evalskip = funcnest ? SKIPFUNC : SKIPFILE;
8694         return argv[1] ? number(argv[1]) : exitstatus;
8695 }
8696
8697 /* Forward declarations for builtintab[] */
8698 static int breakcmd(int, char **);
8699 static int dotcmd(int, char **);
8700 static int evalcmd(int, char **);
8701 static int exitcmd(int, char **);
8702 static int exportcmd(int, char **);
8703 #if ENABLE_ASH_GETOPTS
8704 static int getoptscmd(int, char **);
8705 #endif
8706 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
8707 static int helpcmd(int, char **);
8708 #endif
8709 #if ENABLE_SH_MATH_SUPPORT
8710 static int letcmd(int, char **);
8711 #endif
8712 static int readcmd(int, char **);
8713 static int setcmd(int, char **);
8714 static int shiftcmd(int, char **);
8715 static int timescmd(int, char **);
8716 static int trapcmd(int, char **);
8717 static int umaskcmd(int, char **);
8718 static int unsetcmd(int, char **);
8719 static int ulimitcmd(int, char **);
8720
8721 #define BUILTIN_NOSPEC          "0"
8722 #define BUILTIN_SPECIAL         "1"
8723 #define BUILTIN_REGULAR         "2"
8724 #define BUILTIN_SPEC_REG        "3"
8725 #define BUILTIN_ASSIGN          "4"
8726 #define BUILTIN_SPEC_ASSG       "5"
8727 #define BUILTIN_REG_ASSG        "6"
8728 #define BUILTIN_SPEC_REG_ASSG   "7"
8729
8730 /* We do not handle [[ expr ]] bashism bash-compatibly,
8731  * we make it a synonym of [ expr ].
8732  * Basically, word splitting and pathname expansion should NOT be performed
8733  * Examples:
8734  * no word splitting:     a="a b"; [[ $a = "a b" ]]; echo $? should print "0"
8735  * no pathname expansion: [[ /bin/m* = "/bin/m*" ]]; echo $? should print "0"
8736  * Additional operators:
8737  * || and && should work as -o and -a
8738  * =~ regexp match
8739  * Apart from the above, [[ expr ]] should work as [ expr ]
8740  */
8741
8742 #define echocmd   echo_main
8743 #define printfcmd printf_main
8744 #define testcmd   test_main
8745
8746 /* Keep these in proper order since it is searched via bsearch() */
8747 static const struct builtincmd builtintab[] = {
8748         { BUILTIN_SPEC_REG      ".", dotcmd },
8749         { BUILTIN_SPEC_REG      ":", truecmd },
8750 #if ENABLE_ASH_BUILTIN_TEST
8751         { BUILTIN_REGULAR       "[", testcmd },
8752 #if ENABLE_ASH_BASH_COMPAT
8753         { BUILTIN_REGULAR       "[[", testcmd },
8754 #endif
8755 #endif
8756 #if ENABLE_ASH_ALIAS
8757         { BUILTIN_REG_ASSG      "alias", aliascmd },
8758 #endif
8759 #if JOBS
8760         { BUILTIN_REGULAR       "bg", fg_bgcmd },
8761 #endif
8762         { BUILTIN_SPEC_REG      "break", breakcmd },
8763         { BUILTIN_REGULAR       "cd", cdcmd },
8764         { BUILTIN_NOSPEC        "chdir", cdcmd },
8765 #if ENABLE_ASH_CMDCMD
8766         { BUILTIN_REGULAR       "command", commandcmd },
8767 #endif
8768         { BUILTIN_SPEC_REG      "continue", breakcmd },
8769 #if ENABLE_ASH_BUILTIN_ECHO
8770         { BUILTIN_REGULAR       "echo", echocmd },
8771 #endif
8772         { BUILTIN_SPEC_REG      "eval", evalcmd },
8773         { BUILTIN_SPEC_REG      "exec", execcmd },
8774         { BUILTIN_SPEC_REG      "exit", exitcmd },
8775         { BUILTIN_SPEC_REG_ASSG "export", exportcmd },
8776         { BUILTIN_REGULAR       "false", falsecmd },
8777 #if JOBS
8778         { BUILTIN_REGULAR       "fg", fg_bgcmd },
8779 #endif
8780 #if ENABLE_ASH_GETOPTS
8781         { BUILTIN_REGULAR       "getopts", getoptscmd },
8782 #endif
8783         { BUILTIN_NOSPEC        "hash", hashcmd },
8784 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
8785         { BUILTIN_NOSPEC        "help", helpcmd },
8786 #endif
8787 #if JOBS
8788         { BUILTIN_REGULAR       "jobs", jobscmd },
8789         { BUILTIN_REGULAR       "kill", killcmd },
8790 #endif
8791 #if ENABLE_SH_MATH_SUPPORT
8792         { BUILTIN_NOSPEC        "let", letcmd },
8793 #endif
8794         { BUILTIN_ASSIGN        "local", localcmd },
8795 #if ENABLE_ASH_BUILTIN_PRINTF
8796         { BUILTIN_REGULAR       "printf", printfcmd },
8797 #endif
8798         { BUILTIN_NOSPEC        "pwd", pwdcmd },
8799         { BUILTIN_REGULAR       "read", readcmd },
8800         { BUILTIN_SPEC_REG_ASSG "readonly", exportcmd },
8801         { BUILTIN_SPEC_REG      "return", returncmd },
8802         { BUILTIN_SPEC_REG      "set", setcmd },
8803         { BUILTIN_SPEC_REG      "shift", shiftcmd },
8804         { BUILTIN_SPEC_REG      "source", dotcmd },
8805 #if ENABLE_ASH_BUILTIN_TEST
8806         { BUILTIN_REGULAR       "test", testcmd },
8807 #endif
8808         { BUILTIN_SPEC_REG      "times", timescmd },
8809         { BUILTIN_SPEC_REG      "trap", trapcmd },
8810         { BUILTIN_REGULAR       "true", truecmd },
8811         { BUILTIN_NOSPEC        "type", typecmd },
8812         { BUILTIN_NOSPEC        "ulimit", ulimitcmd },
8813         { BUILTIN_REGULAR       "umask", umaskcmd },
8814 #if ENABLE_ASH_ALIAS
8815         { BUILTIN_REGULAR       "unalias", unaliascmd },
8816 #endif
8817         { BUILTIN_SPEC_REG      "unset", unsetcmd },
8818         { BUILTIN_REGULAR       "wait", waitcmd },
8819 };
8820
8821 /* Should match the above table! */
8822 #define COMMANDCMD (builtintab + \
8823         2 + \
8824         1 * ENABLE_ASH_BUILTIN_TEST + \
8825         1 * ENABLE_ASH_BUILTIN_TEST * ENABLE_ASH_BASH_COMPAT + \
8826         1 * ENABLE_ASH_ALIAS + \
8827         1 * ENABLE_ASH_JOB_CONTROL + \
8828         3)
8829 #define EXECCMD (builtintab + \
8830         2 + \
8831         1 * ENABLE_ASH_BUILTIN_TEST + \
8832         1 * ENABLE_ASH_BUILTIN_TEST * ENABLE_ASH_BASH_COMPAT + \
8833         1 * ENABLE_ASH_ALIAS + \
8834         1 * ENABLE_ASH_JOB_CONTROL + \
8835         3 + \
8836         1 * ENABLE_ASH_CMDCMD + \
8837         1 + \
8838         ENABLE_ASH_BUILTIN_ECHO + \
8839         1)
8840
8841 /*
8842  * Search the table of builtin commands.
8843  */
8844 static struct builtincmd *
8845 find_builtin(const char *name)
8846 {
8847         struct builtincmd *bp;
8848
8849         bp = bsearch(
8850                 name, builtintab, ARRAY_SIZE(builtintab), sizeof(builtintab[0]),
8851                 pstrcmp
8852         );
8853         return bp;
8854 }
8855
8856 /*
8857  * Execute a simple command.
8858  */
8859 static int
8860 isassignment(const char *p)
8861 {
8862         const char *q = endofname(p);
8863         if (p == q)
8864                 return 0;
8865         return *q == '=';
8866 }
8867 static int
8868 bltincmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
8869 {
8870         /* Preserve exitstatus of a previous possible redirection
8871          * as POSIX mandates */
8872         return back_exitstatus;
8873 }
8874 static void
8875 evalcommand(union node *cmd, int flags)
8876 {
8877         static const struct builtincmd null_bltin = {
8878                 "\0\0", bltincmd /* why three NULs? */
8879         };
8880         struct stackmark smark;
8881         union node *argp;
8882         struct arglist arglist;
8883         struct arglist varlist;
8884         char **argv;
8885         int argc;
8886         const struct strlist *sp;
8887         struct cmdentry cmdentry;
8888         struct job *jp;
8889         char *lastarg;
8890         const char *path;
8891         int spclbltin;
8892         int status;
8893         char **nargv;
8894         struct builtincmd *bcmd;
8895         smallint cmd_is_exec;
8896         smallint pseudovarflag = 0;
8897
8898         /* First expand the arguments. */
8899         TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
8900         setstackmark(&smark);
8901         back_exitstatus = 0;
8902
8903         cmdentry.cmdtype = CMDBUILTIN;
8904         cmdentry.u.cmd = &null_bltin;
8905         varlist.lastp = &varlist.list;
8906         *varlist.lastp = NULL;
8907         arglist.lastp = &arglist.list;
8908         *arglist.lastp = NULL;
8909
8910         argc = 0;
8911         if (cmd->ncmd.args) {
8912                 bcmd = find_builtin(cmd->ncmd.args->narg.text);
8913                 pseudovarflag = bcmd && IS_BUILTIN_ASSIGN(bcmd);
8914         }
8915
8916         for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) {
8917                 struct strlist **spp;
8918
8919                 spp = arglist.lastp;
8920                 if (pseudovarflag && isassignment(argp->narg.text))
8921                         expandarg(argp, &arglist, EXP_VARTILDE);
8922                 else
8923                         expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
8924
8925                 for (sp = *spp; sp; sp = sp->next)
8926                         argc++;
8927         }
8928
8929         argv = nargv = stalloc(sizeof(char *) * (argc + 1));
8930         for (sp = arglist.list; sp; sp = sp->next) {
8931                 TRACE(("evalcommand arg: %s\n", sp->text));
8932                 *nargv++ = sp->text;
8933         }
8934         *nargv = NULL;
8935
8936         lastarg = NULL;
8937         if (iflag && funcnest == 0 && argc > 0)
8938                 lastarg = nargv[-1];
8939
8940         preverrout_fd = 2;
8941         expredir(cmd->ncmd.redirect);
8942         status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2);
8943
8944         path = vpath.text;
8945         for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
8946                 struct strlist **spp;
8947                 char *p;
8948
8949                 spp = varlist.lastp;
8950                 expandarg(argp, &varlist, EXP_VARTILDE);
8951
8952                 /*
8953                  * Modify the command lookup path, if a PATH= assignment
8954                  * is present
8955                  */
8956                 p = (*spp)->text;
8957                 if (varequal(p, path))
8958                         path = p;
8959         }
8960
8961         /* Print the command if xflag is set. */
8962         if (xflag) {
8963                 int n;
8964                 const char *p = " %s";
8965
8966                 p++;
8967                 fdprintf(preverrout_fd, p, expandstr(ps4val()));
8968
8969                 sp = varlist.list;
8970                 for (n = 0; n < 2; n++) {
8971                         while (sp) {
8972                                 fdprintf(preverrout_fd, p, sp->text);
8973                                 sp = sp->next;
8974                                 if (*p == '%') {
8975                                         p--;
8976                                 }
8977                         }
8978                         sp = arglist.list;
8979                 }
8980                 safe_write(preverrout_fd, "\n", 1);
8981         }
8982
8983         cmd_is_exec = 0;
8984         spclbltin = -1;
8985
8986         /* Now locate the command. */
8987         if (argc) {
8988                 const char *oldpath;
8989                 int cmd_flag = DO_ERR;
8990
8991                 path += 5;
8992                 oldpath = path;
8993                 for (;;) {
8994                         find_command(argv[0], &cmdentry, cmd_flag, path);
8995                         if (cmdentry.cmdtype == CMDUNKNOWN) {
8996                                 flush_stderr();
8997                                 status = 127;
8998                                 goto bail;
8999                         }
9000
9001                         /* implement bltin and command here */
9002                         if (cmdentry.cmdtype != CMDBUILTIN)
9003                                 break;
9004                         if (spclbltin < 0)
9005                                 spclbltin = IS_BUILTIN_SPECIAL(cmdentry.u.cmd);
9006                         if (cmdentry.u.cmd == EXECCMD)
9007                                 cmd_is_exec = 1;
9008 #if ENABLE_ASH_CMDCMD
9009                         if (cmdentry.u.cmd == COMMANDCMD) {
9010                                 path = oldpath;
9011                                 nargv = parse_command_args(argv, &path);
9012                                 if (!nargv)
9013                                         break;
9014                                 argc -= nargv - argv;
9015                                 argv = nargv;
9016                                 cmd_flag |= DO_NOFUNC;
9017                         } else
9018 #endif
9019                                 break;
9020                 }
9021         }
9022
9023         if (status) {
9024                 /* We have a redirection error. */
9025                 if (spclbltin > 0)
9026                         raise_exception(EXERROR);
9027  bail:
9028                 exitstatus = status;
9029                 goto out;
9030         }
9031
9032         /* Execute the command. */
9033         switch (cmdentry.cmdtype) {
9034         default:
9035
9036 #if ENABLE_FEATURE_SH_NOFORK
9037 /* Hmmm... shouldn't it happen somewhere in forkshell() instead?
9038  * Why "fork off a child process if necessary" doesn't apply to NOFORK? */
9039         {
9040                 /* find_command() encodes applet_no as (-2 - applet_no) */
9041                 int applet_no = (- cmdentry.u.index - 2);
9042                 if (applet_no >= 0 && APPLET_IS_NOFORK(applet_no)) {
9043                         listsetvar(varlist.list, VEXPORT|VSTACK);
9044                         /* run <applet>_main() */
9045                         exitstatus = run_nofork_applet(applet_no, argv);
9046                         break;
9047                 }
9048         }
9049 #endif
9050                 /* Fork off a child process if necessary. */
9051                 if (!(flags & EV_EXIT) || trap[0]) {
9052                         INT_OFF;
9053                         jp = makejob(/*cmd,*/ 1);
9054                         if (forkshell(jp, cmd, FORK_FG) != 0) {
9055                                 exitstatus = waitforjob(jp);
9056                                 INT_ON;
9057                                 TRACE(("forked child exited with %d\n", exitstatus));
9058                                 break;
9059                         }
9060                         FORCE_INT_ON;
9061                 }
9062                 listsetvar(varlist.list, VEXPORT|VSTACK);
9063                 shellexec(argv, path, cmdentry.u.index);
9064                 /* NOTREACHED */
9065
9066         case CMDBUILTIN:
9067                 cmdenviron = varlist.list;
9068                 if (cmdenviron) {
9069                         struct strlist *list = cmdenviron;
9070                         int i = VNOSET;
9071                         if (spclbltin > 0 || argc == 0) {
9072                                 i = 0;
9073                                 if (cmd_is_exec && argc > 1)
9074                                         i = VEXPORT;
9075                         }
9076                         listsetvar(list, i);
9077                 }
9078                 /* Tight loop with builtins only:
9079                  * "while kill -0 $child; do true; done"
9080                  * will never exit even if $child died, unless we do this
9081                  * to reap the zombie and make kill detect that it's gone: */
9082                 dowait(DOWAIT_NONBLOCK, NULL);
9083
9084                 if (evalbltin(cmdentry.u.cmd, argc, argv)) {
9085                         int exit_status;
9086                         int i = exception_type;
9087                         if (i == EXEXIT)
9088                                 goto raise;
9089                         exit_status = 2;
9090                         if (i == EXINT)
9091                                 exit_status = 128 + SIGINT;
9092                         if (i == EXSIG)
9093                                 exit_status = 128 + pendingsig;
9094                         exitstatus = exit_status;
9095                         if (i == EXINT || spclbltin > 0) {
9096  raise:
9097                                 longjmp(exception_handler->loc, 1);
9098                         }
9099                         FORCE_INT_ON;
9100                 }
9101                 break;
9102
9103         case CMDFUNCTION:
9104                 listsetvar(varlist.list, 0);
9105                 /* See above for the rationale */
9106                 dowait(DOWAIT_NONBLOCK, NULL);
9107                 if (evalfun(cmdentry.u.func, argc, argv, flags))
9108                         goto raise;
9109                 break;
9110         }
9111
9112  out:
9113         popredir(/*drop:*/ cmd_is_exec, /*restore:*/ cmd_is_exec);
9114         if (lastarg) {
9115                 /* dsl: I think this is intended to be used to support
9116                  * '_' in 'vi' command mode during line editing...
9117                  * However I implemented that within libedit itself.
9118                  */
9119                 setvar("_", lastarg, 0);
9120         }
9121         popstackmark(&smark);
9122 }
9123
9124 static int
9125 evalbltin(const struct builtincmd *cmd, int argc, char **argv)
9126 {
9127         char *volatile savecmdname;
9128         struct jmploc *volatile savehandler;
9129         struct jmploc jmploc;
9130         int i;
9131
9132         savecmdname = commandname;
9133         i = setjmp(jmploc.loc);
9134         if (i)
9135                 goto cmddone;
9136         savehandler = exception_handler;
9137         exception_handler = &jmploc;
9138         commandname = argv[0];
9139         argptr = argv + 1;
9140         optptr = NULL;                  /* initialize nextopt */
9141         exitstatus = (*cmd->builtin)(argc, argv);
9142         flush_stdout_stderr();
9143  cmddone:
9144         exitstatus |= ferror(stdout);
9145         clearerr(stdout);
9146         commandname = savecmdname;
9147 //      exsig = 0;
9148         exception_handler = savehandler;
9149
9150         return i;
9151 }
9152
9153 static int
9154 goodname(const char *p)
9155 {
9156         return !*endofname(p);
9157 }
9158
9159
9160 /*
9161  * Search for a command.  This is called before we fork so that the
9162  * location of the command will be available in the parent as well as
9163  * the child.  The check for "goodname" is an overly conservative
9164  * check that the name will not be subject to expansion.
9165  */
9166 static void
9167 prehash(union node *n)
9168 {
9169         struct cmdentry entry;
9170
9171         if (n->type == NCMD && n->ncmd.args && goodname(n->ncmd.args->narg.text))
9172                 find_command(n->ncmd.args->narg.text, &entry, 0, pathval());
9173 }
9174
9175
9176 /* ============ Builtin commands
9177  *
9178  * Builtin commands whose functions are closely tied to evaluation
9179  * are implemented here.
9180  */
9181
9182 /*
9183  * Handle break and continue commands.  Break, continue, and return are
9184  * all handled by setting the evalskip flag.  The evaluation routines
9185  * above all check this flag, and if it is set they start skipping
9186  * commands rather than executing them.  The variable skipcount is
9187  * the number of loops to break/continue, or the number of function
9188  * levels to return.  (The latter is always 1.)  It should probably
9189  * be an error to break out of more loops than exist, but it isn't
9190  * in the standard shell so we don't make it one here.
9191  */
9192 static int
9193 breakcmd(int argc UNUSED_PARAM, char **argv)
9194 {
9195         int n = argv[1] ? number(argv[1]) : 1;
9196
9197         if (n <= 0)
9198                 ash_msg_and_raise_error(illnum, argv[1]);
9199         if (n > loopnest)
9200                 n = loopnest;
9201         if (n > 0) {
9202                 evalskip = (**argv == 'c') ? SKIPCONT : SKIPBREAK;
9203                 skipcount = n;
9204         }
9205         return 0;
9206 }
9207
9208
9209 /* ============ input.c
9210  *
9211  * This implements the input routines used by the parser.
9212  */
9213
9214 enum {
9215         INPUT_PUSH_FILE = 1,
9216         INPUT_NOFILE_OK = 2,
9217 };
9218
9219 static smallint checkkwd;
9220 /* values of checkkwd variable */
9221 #define CHKALIAS        0x1
9222 #define CHKKWD          0x2
9223 #define CHKNL           0x4
9224
9225 /*
9226  * Push a string back onto the input at this current parsefile level.
9227  * We handle aliases this way.
9228  */
9229 #if !ENABLE_ASH_ALIAS
9230 #define pushstring(s, ap) pushstring(s)
9231 #endif
9232 static void
9233 pushstring(char *s, struct alias *ap)
9234 {
9235         struct strpush *sp;
9236         int len;
9237
9238         len = strlen(s);
9239         INT_OFF;
9240         if (g_parsefile->strpush) {
9241                 sp = ckzalloc(sizeof(*sp));
9242                 sp->prev = g_parsefile->strpush;
9243         } else {
9244                 sp = &(g_parsefile->basestrpush);
9245         }
9246         g_parsefile->strpush = sp;
9247         sp->prev_string = g_parsefile->next_to_pgetc;
9248         sp->prev_left_in_line = g_parsefile->left_in_line;
9249 #if ENABLE_ASH_ALIAS
9250         sp->ap = ap;
9251         if (ap) {
9252                 ap->flag |= ALIASINUSE;
9253                 sp->string = s;
9254         }
9255 #endif
9256         g_parsefile->next_to_pgetc = s;
9257         g_parsefile->left_in_line = len;
9258         INT_ON;
9259 }
9260
9261 static void
9262 popstring(void)
9263 {
9264         struct strpush *sp = g_parsefile->strpush;
9265
9266         INT_OFF;
9267 #if ENABLE_ASH_ALIAS
9268         if (sp->ap) {
9269                 if (g_parsefile->next_to_pgetc[-1] == ' '
9270                  || g_parsefile->next_to_pgetc[-1] == '\t'
9271                 ) {
9272                         checkkwd |= CHKALIAS;
9273                 }
9274                 if (sp->string != sp->ap->val) {
9275                         free(sp->string);
9276                 }
9277                 sp->ap->flag &= ~ALIASINUSE;
9278                 if (sp->ap->flag & ALIASDEAD) {
9279                         unalias(sp->ap->name);
9280                 }
9281         }
9282 #endif
9283         g_parsefile->next_to_pgetc = sp->prev_string;
9284         g_parsefile->left_in_line = sp->prev_left_in_line;
9285         g_parsefile->strpush = sp->prev;
9286         if (sp != &(g_parsefile->basestrpush))
9287                 free(sp);
9288         INT_ON;
9289 }
9290
9291 //FIXME: BASH_COMPAT with "...&" does TWO pungetc():
9292 //it peeks whether it is &>, and then pushes back both chars.
9293 //This function needs to save last *next_to_pgetc to buf[0]
9294 //to make two pungetc() reliable. Currently,
9295 // pgetc (out of buf: does preadfd), pgetc, pungetc, pungetc won't work...
9296 static int
9297 preadfd(void)
9298 {
9299         int nr;
9300         char *buf = g_parsefile->buf;
9301
9302         g_parsefile->next_to_pgetc = buf;
9303 #if ENABLE_FEATURE_EDITING
9304  retry:
9305         if (!iflag || g_parsefile->fd != STDIN_FILENO)
9306                 nr = nonblock_safe_read(g_parsefile->fd, buf, BUFSIZ - 1);
9307         else {
9308 #if ENABLE_FEATURE_TAB_COMPLETION
9309                 line_input_state->path_lookup = pathval();
9310 #endif
9311                 nr = read_line_input(cmdedit_prompt, buf, BUFSIZ, line_input_state);
9312                 if (nr == 0) {
9313                         /* Ctrl+C pressed */
9314                         if (trap[SIGINT]) {
9315                                 buf[0] = '\n';
9316                                 buf[1] = '\0';
9317                                 raise(SIGINT);
9318                                 return 1;
9319                         }
9320                         goto retry;
9321                 }
9322                 if (nr < 0 && errno == 0) {
9323                         /* Ctrl+D pressed */
9324                         nr = 0;
9325                 }
9326         }
9327 #else
9328         nr = nonblock_safe_read(g_parsefile->fd, buf, BUFSIZ - 1);
9329 #endif
9330
9331 #if 0
9332 /* nonblock_safe_read() handles this problem */
9333         if (nr < 0) {
9334                 if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
9335                         int flags = fcntl(0, F_GETFL);
9336                         if (flags >= 0 && (flags & O_NONBLOCK)) {
9337                                 flags &= ~O_NONBLOCK;
9338                                 if (fcntl(0, F_SETFL, flags) >= 0) {
9339                                         out2str("sh: turning off NDELAY mode\n");
9340                                         goto retry;
9341                                 }
9342                         }
9343                 }
9344         }
9345 #endif
9346         return nr;
9347 }
9348
9349 /*
9350  * Refill the input buffer and return the next input character:
9351  *
9352  * 1) If a string was pushed back on the input, pop it;
9353  * 2) If an EOF was pushed back (g_parsefile->left_in_line < -BIGNUM)
9354  *    or we are reading from a string so we can't refill the buffer,
9355  *    return EOF.
9356  * 3) If the is more stuff in this buffer, use it else call read to fill it.
9357  * 4) Process input up to the next newline, deleting nul characters.
9358  */
9359 //#define pgetc_debug(...) bb_error_msg(__VA_ARGS__)
9360 #define pgetc_debug(...) ((void)0)
9361 /*
9362  * NB: due to SIT(c) internals (syntax_index_table[] vector),
9363  * pgetc() and related functions must return chars SIGN-EXTENDED into ints,
9364  * not zero-extended. Seems fragile to me. Affects only !USE_SIT_FUNCTION case,
9365  * so we can fix it by ditching !USE_SIT_FUNCTION if Unicode requires that.
9366  */
9367 static int
9368 preadbuffer(void)
9369 {
9370         char *q;
9371         int more;
9372
9373         while (g_parsefile->strpush) {
9374 #if ENABLE_ASH_ALIAS
9375                 if (g_parsefile->left_in_line == -1
9376                  && g_parsefile->strpush->ap
9377                  && g_parsefile->next_to_pgetc[-1] != ' '
9378                  && g_parsefile->next_to_pgetc[-1] != '\t'
9379                 ) {
9380                         pgetc_debug("preadbuffer PEOA");
9381                         return PEOA;
9382                 }
9383 #endif
9384                 popstring();
9385                 /* try "pgetc" now: */
9386                 pgetc_debug("preadbuffer internal pgetc at %d:%p'%s'",
9387                                 g_parsefile->left_in_line,
9388                                 g_parsefile->next_to_pgetc,
9389                                 g_parsefile->next_to_pgetc);
9390                 if (--g_parsefile->left_in_line >= 0)
9391                         return (unsigned char)(*g_parsefile->next_to_pgetc++);
9392         }
9393         /* on both branches above g_parsefile->left_in_line < 0.
9394          * "pgetc" needs refilling.
9395          */
9396
9397         /* -90 is our -BIGNUM. Below we use -99 to mark "EOF on read",
9398          * pungetc() may increment it a few times.
9399          * Assuming it won't increment it to less than -90.
9400          */
9401         if (g_parsefile->left_in_line < -90 || g_parsefile->buf == NULL) {
9402                 pgetc_debug("preadbuffer PEOF1");
9403                 /* even in failure keep left_in_line and next_to_pgetc
9404                  * in lock step, for correct multi-layer pungetc.
9405                  * left_in_line was decremented before preadbuffer(),
9406                  * must inc next_to_pgetc: */
9407                 g_parsefile->next_to_pgetc++;
9408                 return PEOF;
9409         }
9410
9411         more = g_parsefile->left_in_buffer;
9412         if (more <= 0) {
9413                 flush_stdout_stderr();
9414  again:
9415                 more = preadfd();
9416                 if (more <= 0) {
9417                         /* don't try reading again */
9418                         g_parsefile->left_in_line = -99;
9419                         pgetc_debug("preadbuffer PEOF2");
9420                         g_parsefile->next_to_pgetc++;
9421                         return PEOF;
9422                 }
9423         }
9424
9425         /* Find out where's the end of line.
9426          * Set g_parsefile->left_in_line
9427          * and g_parsefile->left_in_buffer acordingly.
9428          * NUL chars are deleted.
9429          */
9430         q = g_parsefile->next_to_pgetc;
9431         for (;;) {
9432                 char c;
9433
9434                 more--;
9435
9436                 c = *q;
9437                 if (c == '\0') {
9438                         memmove(q, q + 1, more);
9439                 } else {
9440                         q++;
9441                         if (c == '\n') {
9442                                 g_parsefile->left_in_line = q - g_parsefile->next_to_pgetc - 1;
9443                                 break;
9444                         }
9445                 }
9446
9447                 if (more <= 0) {
9448                         g_parsefile->left_in_line = q - g_parsefile->next_to_pgetc - 1;
9449                         if (g_parsefile->left_in_line < 0)
9450                                 goto again;
9451                         break;
9452                 }
9453         }
9454         g_parsefile->left_in_buffer = more;
9455
9456         if (vflag) {
9457                 char save = *q;
9458                 *q = '\0';
9459                 out2str(g_parsefile->next_to_pgetc);
9460                 *q = save;
9461         }
9462
9463         pgetc_debug("preadbuffer at %d:%p'%s'",
9464                         g_parsefile->left_in_line,
9465                         g_parsefile->next_to_pgetc,
9466                         g_parsefile->next_to_pgetc);
9467         return signed_char2int(*g_parsefile->next_to_pgetc++);
9468 }
9469
9470 #define pgetc_as_macro() \
9471         (--g_parsefile->left_in_line >= 0 \
9472         ? signed_char2int(*g_parsefile->next_to_pgetc++) \
9473         : preadbuffer() \
9474         )
9475
9476 static int
9477 pgetc(void)
9478 {
9479         pgetc_debug("pgetc_fast at %d:%p'%s'",
9480                         g_parsefile->left_in_line,
9481                         g_parsefile->next_to_pgetc,
9482                         g_parsefile->next_to_pgetc);
9483         return pgetc_as_macro();
9484 }
9485
9486 #if ENABLE_ASH_OPTIMIZE_FOR_SIZE
9487 #define pgetc_fast() pgetc()
9488 #else
9489 #define pgetc_fast() pgetc_as_macro()
9490 #endif
9491
9492 /*
9493  * Same as pgetc(), but ignores PEOA.
9494  */
9495 #if ENABLE_ASH_ALIAS
9496 static int
9497 pgetc2(void)
9498 {
9499         int c;
9500         do {
9501                 pgetc_debug("pgetc_fast at %d:%p'%s'",
9502                                 g_parsefile->left_in_line,
9503                                 g_parsefile->next_to_pgetc,
9504                                 g_parsefile->next_to_pgetc);
9505                 c = pgetc_fast();
9506         } while (c == PEOA);
9507         return c;
9508 }
9509 #else
9510 #define pgetc2() pgetc()
9511 #endif
9512
9513 /*
9514  * Read a line from the script.
9515  */
9516 static char *
9517 pfgets(char *line, int len)
9518 {
9519         char *p = line;
9520         int nleft = len;
9521         int c;
9522
9523         while (--nleft > 0) {
9524                 c = pgetc2();
9525                 if (c == PEOF) {
9526                         if (p == line)
9527                                 return NULL;
9528                         break;
9529                 }
9530                 *p++ = c;
9531                 if (c == '\n')
9532                         break;
9533         }
9534         *p = '\0';
9535         return line;
9536 }
9537
9538 /*
9539  * Undo the last call to pgetc.  Only one character may be pushed back.
9540  * PEOF may be pushed back.
9541  */
9542 static void
9543 pungetc(void)
9544 {
9545         g_parsefile->left_in_line++;
9546         g_parsefile->next_to_pgetc--;
9547         pgetc_debug("pushed back to %d:%p'%s'",
9548                         g_parsefile->left_in_line,
9549                         g_parsefile->next_to_pgetc,
9550                         g_parsefile->next_to_pgetc);
9551 }
9552
9553 /*
9554  * To handle the "." command, a stack of input files is used.  Pushfile
9555  * adds a new entry to the stack and popfile restores the previous level.
9556  */
9557 static void
9558 pushfile(void)
9559 {
9560         struct parsefile *pf;
9561
9562         pf = ckzalloc(sizeof(*pf));
9563         pf->prev = g_parsefile;
9564         pf->fd = -1;
9565         /*pf->strpush = NULL; - ckzalloc did it */
9566         /*pf->basestrpush.prev = NULL;*/
9567         g_parsefile = pf;
9568 }
9569
9570 static void
9571 popfile(void)
9572 {
9573         struct parsefile *pf = g_parsefile;
9574
9575         INT_OFF;
9576         if (pf->fd >= 0)
9577                 close(pf->fd);
9578         free(pf->buf);
9579         while (pf->strpush)
9580                 popstring();
9581         g_parsefile = pf->prev;
9582         free(pf);
9583         INT_ON;
9584 }
9585
9586 /*
9587  * Return to top level.
9588  */
9589 static void
9590 popallfiles(void)
9591 {
9592         while (g_parsefile != &basepf)
9593                 popfile();
9594 }
9595
9596 /*
9597  * Close the file(s) that the shell is reading commands from.  Called
9598  * after a fork is done.
9599  */
9600 static void
9601 closescript(void)
9602 {
9603         popallfiles();
9604         if (g_parsefile->fd > 0) {
9605                 close(g_parsefile->fd);
9606                 g_parsefile->fd = 0;
9607         }
9608 }
9609
9610 /*
9611  * Like setinputfile, but takes an open file descriptor.  Call this with
9612  * interrupts off.
9613  */
9614 static void
9615 setinputfd(int fd, int push)
9616 {
9617         close_on_exec_on(fd);
9618         if (push) {
9619                 pushfile();
9620                 g_parsefile->buf = NULL;
9621         }
9622         g_parsefile->fd = fd;
9623         if (g_parsefile->buf == NULL)
9624                 g_parsefile->buf = ckmalloc(IBUFSIZ);
9625         g_parsefile->left_in_buffer = 0;
9626         g_parsefile->left_in_line = 0;
9627         g_parsefile->linno = 1;
9628 }
9629
9630 /*
9631  * Set the input to take input from a file.  If push is set, push the
9632  * old input onto the stack first.
9633  */
9634 static int
9635 setinputfile(const char *fname, int flags)
9636 {
9637         int fd;
9638         int fd2;
9639
9640         INT_OFF;
9641         fd = open(fname, O_RDONLY);
9642         if (fd < 0) {
9643                 if (flags & INPUT_NOFILE_OK)
9644                         goto out;
9645                 ash_msg_and_raise_error("can't open '%s'", fname);
9646         }
9647         if (fd < 10) {
9648                 fd2 = copyfd(fd, 10);
9649                 close(fd);
9650                 if (fd2 < 0)
9651                         ash_msg_and_raise_error("out of file descriptors");
9652                 fd = fd2;
9653         }
9654         setinputfd(fd, flags & INPUT_PUSH_FILE);
9655  out:
9656         INT_ON;
9657         return fd;
9658 }
9659
9660 /*
9661  * Like setinputfile, but takes input from a string.
9662  */
9663 static void
9664 setinputstring(char *string)
9665 {
9666         INT_OFF;
9667         pushfile();
9668         g_parsefile->next_to_pgetc = string;
9669         g_parsefile->left_in_line = strlen(string);
9670         g_parsefile->buf = NULL;
9671         g_parsefile->linno = 1;
9672         INT_ON;
9673 }
9674
9675
9676 /* ============ mail.c
9677  *
9678  * Routines to check for mail.
9679  */
9680
9681 #if ENABLE_ASH_MAIL
9682
9683 #define MAXMBOXES 10
9684
9685 /* times of mailboxes */
9686 static time_t mailtime[MAXMBOXES];
9687 /* Set if MAIL or MAILPATH is changed. */
9688 static smallint mail_var_path_changed;
9689
9690 /*
9691  * Print appropriate message(s) if mail has arrived.
9692  * If mail_var_path_changed is set,
9693  * then the value of MAIL has mail_var_path_changed,
9694  * so we just update the values.
9695  */
9696 static void
9697 chkmail(void)
9698 {
9699         const char *mpath;
9700         char *p;
9701         char *q;
9702         time_t *mtp;
9703         struct stackmark smark;
9704         struct stat statb;
9705
9706         setstackmark(&smark);
9707         mpath = mpathset() ? mpathval() : mailval();
9708         for (mtp = mailtime; mtp < mailtime + MAXMBOXES; mtp++) {
9709                 p = padvance(&mpath, nullstr);
9710                 if (p == NULL)
9711                         break;
9712                 if (*p == '\0')
9713                         continue;
9714                 for (q = p; *q; q++)
9715                         continue;
9716 #if DEBUG
9717                 if (q[-1] != '/')
9718                         abort();
9719 #endif
9720                 q[-1] = '\0';                   /* delete trailing '/' */
9721                 if (stat(p, &statb) < 0) {
9722                         *mtp = 0;
9723                         continue;
9724                 }
9725                 if (!mail_var_path_changed && statb.st_mtime != *mtp) {
9726                         fprintf(
9727                                 stderr, snlfmt,
9728                                 pathopt ? pathopt : "you have mail"
9729                         );
9730                 }
9731                 *mtp = statb.st_mtime;
9732         }
9733         mail_var_path_changed = 0;
9734         popstackmark(&smark);
9735 }
9736
9737 static void
9738 changemail(const char *val UNUSED_PARAM)
9739 {
9740         mail_var_path_changed = 1;
9741 }
9742
9743 #endif /* ASH_MAIL */
9744
9745
9746 /* ============ ??? */
9747
9748 /*
9749  * Set the shell parameters.
9750  */
9751 static void
9752 setparam(char **argv)
9753 {
9754         char **newparam;
9755         char **ap;
9756         int nparam;
9757
9758         for (nparam = 0; argv[nparam]; nparam++)
9759                 continue;
9760         ap = newparam = ckmalloc((nparam + 1) * sizeof(*ap));
9761         while (*argv) {
9762                 *ap++ = ckstrdup(*argv++);
9763         }
9764         *ap = NULL;
9765         freeparam(&shellparam);
9766         shellparam.malloced = 1;
9767         shellparam.nparam = nparam;
9768         shellparam.p = newparam;
9769 #if ENABLE_ASH_GETOPTS
9770         shellparam.optind = 1;
9771         shellparam.optoff = -1;
9772 #endif
9773 }
9774
9775 /*
9776  * Process shell options.  The global variable argptr contains a pointer
9777  * to the argument list; we advance it past the options.
9778  *
9779  * SUSv3 section 2.8.1 "Consequences of Shell Errors" says:
9780  * For a non-interactive shell, an error condition encountered
9781  * by a special built-in ... shall cause the shell to write a diagnostic message
9782  * to standard error and exit as shown in the following table:
9783  * Error                                           Special Built-In
9784  * ...
9785  * Utility syntax error (option or operand error)  Shall exit
9786  * ...
9787  * However, in bug 1142 (http://busybox.net/bugs/view.php?id=1142)
9788  * we see that bash does not do that (set "finishes" with error code 1 instead,
9789  * and shell continues), and people rely on this behavior!
9790  * Testcase:
9791  * set -o barfoo 2>/dev/null
9792  * echo $?
9793  *
9794  * Oh well. Let's mimic that.
9795  */
9796 static int
9797 plus_minus_o(char *name, int val)
9798 {
9799         int i;
9800
9801         if (name) {
9802                 for (i = 0; i < NOPTS; i++) {
9803                         if (strcmp(name, optnames(i)) == 0) {
9804                                 optlist[i] = val;
9805                                 return 0;
9806                         }
9807                 }
9808                 ash_msg("illegal option %co %s", val ? '-' : '+', name);
9809                 return 1;
9810         }
9811         for (i = 0; i < NOPTS; i++) {
9812                 if (val) {
9813                         out1fmt("%-16s%s\n", optnames(i), optlist[i] ? "on" : "off");
9814                 } else {
9815                         out1fmt("set %co %s\n", optlist[i] ? '-' : '+', optnames(i));
9816                 }
9817         }
9818         return 0;
9819 }
9820 static void
9821 setoption(int flag, int val)
9822 {
9823         int i;
9824
9825         for (i = 0; i < NOPTS; i++) {
9826                 if (optletters(i) == flag) {
9827                         optlist[i] = val;
9828                         return;
9829                 }
9830         }
9831         ash_msg_and_raise_error("illegal option %c%c", val ? '-' : '+', flag);
9832         /* NOTREACHED */
9833 }
9834 static int
9835 options(int cmdline)
9836 {
9837         char *p;
9838         int val;
9839         int c;
9840
9841         if (cmdline)
9842                 minusc = NULL;
9843         while ((p = *argptr) != NULL) {
9844                 c = *p++;
9845                 if (c != '-' && c != '+')
9846                         break;
9847                 argptr++;
9848                 val = 0; /* val = 0 if c == '+' */
9849                 if (c == '-') {
9850                         val = 1;
9851                         if (p[0] == '\0' || LONE_DASH(p)) {
9852                                 if (!cmdline) {
9853                                         /* "-" means turn off -x and -v */
9854                                         if (p[0] == '\0')
9855                                                 xflag = vflag = 0;
9856                                         /* "--" means reset params */
9857                                         else if (*argptr == NULL)
9858                                                 setparam(argptr);
9859                                 }
9860                                 break;    /* "-" or  "--" terminates options */
9861                         }
9862                 }
9863                 /* first char was + or - */
9864                 while ((c = *p++) != '\0') {
9865                         /* bash 3.2 indeed handles -c CMD and +c CMD the same */
9866                         if (c == 'c' && cmdline) {
9867                                 minusc = p;     /* command is after shell args */
9868                         } else if (c == 'o') {
9869                                 if (plus_minus_o(*argptr, val)) {
9870                                         /* it already printed err message */
9871                                         return 1; /* error */
9872                                 }
9873                                 if (*argptr)
9874                                         argptr++;
9875                         } else if (cmdline && (c == 'l')) { /* -l or +l == --login */
9876                                 isloginsh = 1;
9877                         /* bash does not accept +-login, we also won't */
9878                         } else if (cmdline && val && (c == '-')) { /* long options */
9879                                 if (strcmp(p, "login") == 0)
9880                                         isloginsh = 1;
9881                                 break;
9882                         } else {
9883                                 setoption(c, val);
9884                         }
9885                 }
9886         }
9887         return 0;
9888 }
9889
9890 /*
9891  * The shift builtin command.
9892  */
9893 static int
9894 shiftcmd(int argc UNUSED_PARAM, char **argv)
9895 {
9896         int n;
9897         char **ap1, **ap2;
9898
9899         n = 1;
9900         if (argv[1])
9901                 n = number(argv[1]);
9902         if (n > shellparam.nparam)
9903                 n = 0; /* bash compat, was = shellparam.nparam; */
9904         INT_OFF;
9905         shellparam.nparam -= n;
9906         for (ap1 = shellparam.p; --n >= 0; ap1++) {
9907                 if (shellparam.malloced)
9908                         free(*ap1);
9909         }
9910         ap2 = shellparam.p;
9911         while ((*ap2++ = *ap1++) != NULL)
9912                 continue;
9913 #if ENABLE_ASH_GETOPTS
9914         shellparam.optind = 1;
9915         shellparam.optoff = -1;
9916 #endif
9917         INT_ON;
9918         return 0;
9919 }
9920
9921 /*
9922  * POSIX requires that 'set' (but not export or readonly) output the
9923  * variables in lexicographic order - by the locale's collating order (sigh).
9924  * Maybe we could keep them in an ordered balanced binary tree
9925  * instead of hashed lists.
9926  * For now just roll 'em through qsort for printing...
9927  */
9928 static int
9929 showvars(const char *sep_prefix, int on, int off)
9930 {
9931         const char *sep;
9932         char **ep, **epend;
9933
9934         ep = listvars(on, off, &epend);
9935         qsort(ep, epend - ep, sizeof(char *), vpcmp);
9936
9937         sep = *sep_prefix ? " " : sep_prefix;
9938
9939         for (; ep < epend; ep++) {
9940                 const char *p;
9941                 const char *q;
9942
9943                 p = strchrnul(*ep, '=');
9944                 q = nullstr;
9945                 if (*p)
9946                         q = single_quote(++p);
9947                 out1fmt("%s%s%.*s%s\n", sep_prefix, sep, (int)(p - *ep), *ep, q);
9948         }
9949         return 0;
9950 }
9951
9952 /*
9953  * The set command builtin.
9954  */
9955 static int
9956 setcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
9957 {
9958         int retval;
9959
9960         if (!argv[1])
9961                 return showvars(nullstr, 0, VUNSET);
9962         INT_OFF;
9963         retval = 1;
9964         if (!options(0)) { /* if no parse error... */
9965                 retval = 0;
9966                 optschanged();
9967                 if (*argptr != NULL) {
9968                         setparam(argptr);
9969                 }
9970         }
9971         INT_ON;
9972         return retval;
9973 }
9974
9975 #if ENABLE_ASH_RANDOM_SUPPORT
9976 static void
9977 change_random(const char *value)
9978 {
9979         /* Galois LFSR parameter */
9980         /* Taps at 32 31 29 1: */
9981         enum { MASK = 0x8000000b };
9982         /* Another example - taps at 32 31 30 10: */
9983         /* MASK = 0x00400007 */
9984
9985         if (value == NULL) {
9986                 /* "get", generate */
9987                 uint32_t t;
9988
9989                 /* LCG has period of 2^32 and alternating lowest bit */
9990                 random_LCG = 1664525 * random_LCG + 1013904223;
9991                 /* Galois LFSR has period of 2^32-1 = 3 * 5 * 17 * 257 * 65537 */
9992                 t = (random_galois_LFSR << 1);
9993                 if (random_galois_LFSR < 0) /* if we just shifted 1 out of msb... */
9994                         t ^= MASK;
9995                 random_galois_LFSR = t;
9996                 /* Both are weak, combining them gives better randomness
9997                  * and ~2^64 period. & 0x7fff is probably bash compat
9998                  * for $RANDOM range. Combining with subtraction is
9999                  * just for fun. + and ^ would work equally well. */
10000                 t = (t - random_LCG) & 0x7fff;
10001                 /* set without recursion */
10002                 setvar(vrandom.text, utoa(t), VNOFUNC);
10003                 vrandom.flags &= ~VNOFUNC;
10004         } else {
10005                 /* set/reset */
10006                 random_galois_LFSR = random_LCG = strtoul(value, (char **)NULL, 10);
10007         }
10008 }
10009 #endif
10010
10011 #if ENABLE_ASH_GETOPTS
10012 static int
10013 getopts(char *optstr, char *optvar, char **optfirst, int *param_optind, int *optoff)
10014 {
10015         char *p, *q;
10016         char c = '?';
10017         int done = 0;
10018         int err = 0;
10019         char s[12];
10020         char **optnext;
10021
10022         if (*param_optind < 1)
10023                 return 1;
10024         optnext = optfirst + *param_optind - 1;
10025
10026         if (*param_optind <= 1 || *optoff < 0 || (int)strlen(optnext[-1]) < *optoff)
10027                 p = NULL;
10028         else
10029                 p = optnext[-1] + *optoff;
10030         if (p == NULL || *p == '\0') {
10031                 /* Current word is done, advance */
10032                 p = *optnext;
10033                 if (p == NULL || *p != '-' || *++p == '\0') {
10034  atend:
10035                         p = NULL;
10036                         done = 1;
10037                         goto out;
10038                 }
10039                 optnext++;
10040                 if (LONE_DASH(p))        /* check for "--" */
10041                         goto atend;
10042         }
10043
10044         c = *p++;
10045         for (q = optstr; *q != c;) {
10046                 if (*q == '\0') {
10047                         if (optstr[0] == ':') {
10048                                 s[0] = c;
10049                                 s[1] = '\0';
10050                                 err |= setvarsafe("OPTARG", s, 0);
10051                         } else {
10052                                 fprintf(stderr, "Illegal option -%c\n", c);
10053                                 unsetvar("OPTARG");
10054                         }
10055                         c = '?';
10056                         goto out;
10057                 }
10058                 if (*++q == ':')
10059                         q++;
10060         }
10061
10062         if (*++q == ':') {
10063                 if (*p == '\0' && (p = *optnext) == NULL) {
10064                         if (optstr[0] == ':') {
10065                                 s[0] = c;
10066                                 s[1] = '\0';
10067                                 err |= setvarsafe("OPTARG", s, 0);
10068                                 c = ':';
10069                         } else {
10070                                 fprintf(stderr, "No arg for -%c option\n", c);
10071                                 unsetvar("OPTARG");
10072                                 c = '?';
10073                         }
10074                         goto out;
10075                 }
10076
10077                 if (p == *optnext)
10078                         optnext++;
10079                 err |= setvarsafe("OPTARG", p, 0);
10080                 p = NULL;
10081         } else
10082                 err |= setvarsafe("OPTARG", nullstr, 0);
10083  out:
10084         *optoff = p ? p - *(optnext - 1) : -1;
10085         *param_optind = optnext - optfirst + 1;
10086         fmtstr(s, sizeof(s), "%d", *param_optind);
10087         err |= setvarsafe("OPTIND", s, VNOFUNC);
10088         s[0] = c;
10089         s[1] = '\0';
10090         err |= setvarsafe(optvar, s, 0);
10091         if (err) {
10092                 *param_optind = 1;
10093                 *optoff = -1;
10094                 flush_stdout_stderr();
10095                 raise_exception(EXERROR);
10096         }
10097         return done;
10098 }
10099
10100 /*
10101  * The getopts builtin.  Shellparam.optnext points to the next argument
10102  * to be processed.  Shellparam.optptr points to the next character to
10103  * be processed in the current argument.  If shellparam.optnext is NULL,
10104  * then it's the first time getopts has been called.
10105  */
10106 static int
10107 getoptscmd(int argc, char **argv)
10108 {
10109         char **optbase;
10110
10111         if (argc < 3)
10112                 ash_msg_and_raise_error("usage: getopts optstring var [arg]");
10113         if (argc == 3) {
10114                 optbase = shellparam.p;
10115                 if (shellparam.optind > shellparam.nparam + 1) {
10116                         shellparam.optind = 1;
10117                         shellparam.optoff = -1;
10118                 }
10119         } else {
10120                 optbase = &argv[3];
10121                 if (shellparam.optind > argc - 2) {
10122                         shellparam.optind = 1;
10123                         shellparam.optoff = -1;
10124                 }
10125         }
10126
10127         return getopts(argv[1], argv[2], optbase, &shellparam.optind,
10128                         &shellparam.optoff);
10129 }
10130 #endif /* ASH_GETOPTS */
10131
10132
10133 /* ============ Shell parser */
10134
10135 struct heredoc {
10136         struct heredoc *next;   /* next here document in list */
10137         union node *here;       /* redirection node */
10138         char *eofmark;          /* string indicating end of input */
10139         smallint striptabs;     /* if set, strip leading tabs */
10140 };
10141
10142 static smallint tokpushback;           /* last token pushed back */
10143 static smallint parsebackquote;        /* nonzero if we are inside backquotes */
10144 static smallint quoteflag;             /* set if (part of) last token was quoted */
10145 static token_id_t lasttoken;           /* last token read (integer id Txxx) */
10146 static struct heredoc *heredoclist;    /* list of here documents to read */
10147 static char *wordtext;                 /* text of last word returned by readtoken */
10148 static struct nodelist *backquotelist;
10149 static union node *redirnode;
10150 static struct heredoc *heredoc;
10151 /*
10152  * NEOF is returned by parsecmd when it encounters an end of file.  It
10153  * must be distinct from NULL, so we use the address of a variable that
10154  * happens to be handy.
10155  */
10156 #define NEOF ((union node *)&tokpushback)
10157
10158 /*
10159  * Called when an unexpected token is read during the parse.  The argument
10160  * is the token that is expected, or -1 if more than one type of token can
10161  * occur at this point.
10162  */
10163 static void raise_error_unexpected_syntax(int) NORETURN;
10164 static void
10165 raise_error_unexpected_syntax(int token)
10166 {
10167         char msg[64];
10168         int l;
10169
10170         l = sprintf(msg, "unexpected %s", tokname(lasttoken));
10171         if (token >= 0)
10172                 sprintf(msg + l, " (expecting %s)", tokname(token));
10173         raise_error_syntax(msg);
10174         /* NOTREACHED */
10175 }
10176
10177 #define EOFMARKLEN 79
10178
10179 /* parsing is heavily cross-recursive, need these forward decls */
10180 static union node *andor(void);
10181 static union node *pipeline(void);
10182 static union node *parse_command(void);
10183 static void parseheredoc(void);
10184 static char peektoken(void);
10185 static int readtoken(void);
10186
10187 static union node *
10188 list(int nlflag)
10189 {
10190         union node *n1, *n2, *n3;
10191         int tok;
10192
10193         checkkwd = CHKNL | CHKKWD | CHKALIAS;
10194         if (nlflag == 2 && peektoken())
10195                 return NULL;
10196         n1 = NULL;
10197         for (;;) {
10198                 n2 = andor();
10199                 tok = readtoken();
10200                 if (tok == TBACKGND) {
10201                         if (n2->type == NPIPE) {
10202                                 n2->npipe.pipe_backgnd = 1;
10203                         } else {
10204                                 if (n2->type != NREDIR) {
10205                                         n3 = stzalloc(sizeof(struct nredir));
10206                                         n3->nredir.n = n2;
10207                                         /*n3->nredir.redirect = NULL; - stzalloc did it */
10208                                         n2 = n3;
10209                                 }
10210                                 n2->type = NBACKGND;
10211                         }
10212                 }
10213                 if (n1 == NULL) {
10214                         n1 = n2;
10215                 } else {
10216                         n3 = stzalloc(sizeof(struct nbinary));
10217                         n3->type = NSEMI;
10218                         n3->nbinary.ch1 = n1;
10219                         n3->nbinary.ch2 = n2;
10220                         n1 = n3;
10221                 }
10222                 switch (tok) {
10223                 case TBACKGND:
10224                 case TSEMI:
10225                         tok = readtoken();
10226                         /* fall through */
10227                 case TNL:
10228                         if (tok == TNL) {
10229                                 parseheredoc();
10230                                 if (nlflag == 1)
10231                                         return n1;
10232                         } else {
10233                                 tokpushback = 1;
10234                         }
10235                         checkkwd = CHKNL | CHKKWD | CHKALIAS;
10236                         if (peektoken())
10237                                 return n1;
10238                         break;
10239                 case TEOF:
10240                         if (heredoclist)
10241                                 parseheredoc();
10242                         else
10243                                 pungetc();              /* push back EOF on input */
10244                         return n1;
10245                 default:
10246                         if (nlflag == 1)
10247                                 raise_error_unexpected_syntax(-1);
10248                         tokpushback = 1;
10249                         return n1;
10250                 }
10251         }
10252 }
10253
10254 static union node *
10255 andor(void)
10256 {
10257         union node *n1, *n2, *n3;
10258         int t;
10259
10260         n1 = pipeline();
10261         for (;;) {
10262                 t = readtoken();
10263                 if (t == TAND) {
10264                         t = NAND;
10265                 } else if (t == TOR) {
10266                         t = NOR;
10267                 } else {
10268                         tokpushback = 1;
10269                         return n1;
10270                 }
10271                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
10272                 n2 = pipeline();
10273                 n3 = stzalloc(sizeof(struct nbinary));
10274                 n3->type = t;
10275                 n3->nbinary.ch1 = n1;
10276                 n3->nbinary.ch2 = n2;
10277                 n1 = n3;
10278         }
10279 }
10280
10281 static union node *
10282 pipeline(void)
10283 {
10284         union node *n1, *n2, *pipenode;
10285         struct nodelist *lp, *prev;
10286         int negate;
10287
10288         negate = 0;
10289         TRACE(("pipeline: entered\n"));
10290         if (readtoken() == TNOT) {
10291                 negate = !negate;
10292                 checkkwd = CHKKWD | CHKALIAS;
10293         } else
10294                 tokpushback = 1;
10295         n1 = parse_command();
10296         if (readtoken() == TPIPE) {
10297                 pipenode = stzalloc(sizeof(struct npipe));
10298                 pipenode->type = NPIPE;
10299                 /*pipenode->npipe.pipe_backgnd = 0; - stzalloc did it */
10300                 lp = stzalloc(sizeof(struct nodelist));
10301                 pipenode->npipe.cmdlist = lp;
10302                 lp->n = n1;
10303                 do {
10304                         prev = lp;
10305                         lp = stzalloc(sizeof(struct nodelist));
10306                         checkkwd = CHKNL | CHKKWD | CHKALIAS;
10307                         lp->n = parse_command();
10308                         prev->next = lp;
10309                 } while (readtoken() == TPIPE);
10310                 lp->next = NULL;
10311                 n1 = pipenode;
10312         }
10313         tokpushback = 1;
10314         if (negate) {
10315                 n2 = stzalloc(sizeof(struct nnot));
10316                 n2->type = NNOT;
10317                 n2->nnot.com = n1;
10318                 return n2;
10319         }
10320         return n1;
10321 }
10322
10323 static union node *
10324 makename(void)
10325 {
10326         union node *n;
10327
10328         n = stzalloc(sizeof(struct narg));
10329         n->type = NARG;
10330         /*n->narg.next = NULL; - stzalloc did it */
10331         n->narg.text = wordtext;
10332         n->narg.backquote = backquotelist;
10333         return n;
10334 }
10335
10336 static void
10337 fixredir(union node *n, const char *text, int err)
10338 {
10339         int fd;
10340
10341         TRACE(("Fix redir %s %d\n", text, err));
10342         if (!err)
10343                 n->ndup.vname = NULL;
10344
10345         fd = bb_strtou(text, NULL, 10);
10346         if (!errno && fd >= 0)
10347                 n->ndup.dupfd = fd;
10348         else if (LONE_DASH(text))
10349                 n->ndup.dupfd = -1;
10350         else {
10351                 if (err)
10352                         raise_error_syntax("bad fd number");
10353                 n->ndup.vname = makename();
10354         }
10355 }
10356
10357 /*
10358  * Returns true if the text contains nothing to expand (no dollar signs
10359  * or backquotes).
10360  */
10361 static int
10362 noexpand(const char *text)
10363 {
10364         const char *p;
10365         char c;
10366
10367         p = text;
10368         while ((c = *p++) != '\0') {
10369                 if (c == CTLQUOTEMARK)
10370                         continue;
10371                 if (c == CTLESC)
10372                         p++;
10373                 else if (SIT((signed char)c, BASESYNTAX) == CCTL)
10374                         return 0;
10375         }
10376         return 1;
10377 }
10378
10379 static void
10380 parsefname(void)
10381 {
10382         union node *n = redirnode;
10383
10384         if (readtoken() != TWORD)
10385                 raise_error_unexpected_syntax(-1);
10386         if (n->type == NHERE) {
10387                 struct heredoc *here = heredoc;
10388                 struct heredoc *p;
10389                 int i;
10390
10391                 if (quoteflag == 0)
10392                         n->type = NXHERE;
10393                 TRACE(("Here document %d\n", n->type));
10394                 if (!noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
10395                         raise_error_syntax("illegal eof marker for << redirection");
10396                 rmescapes(wordtext);
10397                 here->eofmark = wordtext;
10398                 here->next = NULL;
10399                 if (heredoclist == NULL)
10400                         heredoclist = here;
10401                 else {
10402                         for (p = heredoclist; p->next; p = p->next)
10403                                 continue;
10404                         p->next = here;
10405                 }
10406         } else if (n->type == NTOFD || n->type == NFROMFD) {
10407                 fixredir(n, wordtext, 0);
10408         } else {
10409                 n->nfile.fname = makename();
10410         }
10411 }
10412
10413 static union node *
10414 simplecmd(void)
10415 {
10416         union node *args, **app;
10417         union node *n = NULL;
10418         union node *vars, **vpp;
10419         union node **rpp, *redir;
10420         int savecheckkwd;
10421 #if ENABLE_ASH_BASH_COMPAT
10422         smallint double_brackets_flag = 0;
10423 #endif
10424
10425         args = NULL;
10426         app = &args;
10427         vars = NULL;
10428         vpp = &vars;
10429         redir = NULL;
10430         rpp = &redir;
10431
10432         savecheckkwd = CHKALIAS;
10433         for (;;) {
10434                 int t;
10435                 checkkwd = savecheckkwd;
10436                 t = readtoken();
10437                 switch (t) {
10438 #if ENABLE_ASH_BASH_COMPAT
10439                 case TAND: /* "&&" */
10440                 case TOR: /* "||" */
10441                         if (!double_brackets_flag) {
10442                                 tokpushback = 1;
10443                                 goto out;
10444                         }
10445                         wordtext = (char *) (t == TAND ? "-a" : "-o");
10446 #endif
10447                 case TWORD:
10448                         n = stzalloc(sizeof(struct narg));
10449                         n->type = NARG;
10450                         /*n->narg.next = NULL; - stzalloc did it */
10451                         n->narg.text = wordtext;
10452 #if ENABLE_ASH_BASH_COMPAT
10453                         if (strcmp("[[", wordtext) == 0)
10454                                 double_brackets_flag = 1;
10455                         else if (strcmp("]]", wordtext) == 0)
10456                                 double_brackets_flag = 0;
10457 #endif
10458                         n->narg.backquote = backquotelist;
10459                         if (savecheckkwd && isassignment(wordtext)) {
10460                                 *vpp = n;
10461                                 vpp = &n->narg.next;
10462                         } else {
10463                                 *app = n;
10464                                 app = &n->narg.next;
10465                                 savecheckkwd = 0;
10466                         }
10467                         break;
10468                 case TREDIR:
10469                         *rpp = n = redirnode;
10470                         rpp = &n->nfile.next;
10471                         parsefname();   /* read name of redirection file */
10472                         break;
10473                 case TLP:
10474                         if (args && app == &args->narg.next
10475                          && !vars && !redir
10476                         ) {
10477                                 struct builtincmd *bcmd;
10478                                 const char *name;
10479
10480                                 /* We have a function */
10481                                 if (readtoken() != TRP)
10482                                         raise_error_unexpected_syntax(TRP);
10483                                 name = n->narg.text;
10484                                 if (!goodname(name)
10485                                  || ((bcmd = find_builtin(name)) && IS_BUILTIN_SPECIAL(bcmd))
10486                                 ) {
10487                                         raise_error_syntax("bad function name");
10488                                 }
10489                                 n->type = NDEFUN;
10490                                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
10491                                 n->narg.next = parse_command();
10492                                 return n;
10493                         }
10494                         /* fall through */
10495                 default:
10496                         tokpushback = 1;
10497                         goto out;
10498                 }
10499         }
10500  out:
10501         *app = NULL;
10502         *vpp = NULL;
10503         *rpp = NULL;
10504         n = stzalloc(sizeof(struct ncmd));
10505         n->type = NCMD;
10506         n->ncmd.args = args;
10507         n->ncmd.assign = vars;
10508         n->ncmd.redirect = redir;
10509         return n;
10510 }
10511
10512 static union node *
10513 parse_command(void)
10514 {
10515         union node *n1, *n2;
10516         union node *ap, **app;
10517         union node *cp, **cpp;
10518         union node *redir, **rpp;
10519         union node **rpp2;
10520         int t;
10521
10522         redir = NULL;
10523         rpp2 = &redir;
10524
10525         switch (readtoken()) {
10526         default:
10527                 raise_error_unexpected_syntax(-1);
10528                 /* NOTREACHED */
10529         case TIF:
10530                 n1 = stzalloc(sizeof(struct nif));
10531                 n1->type = NIF;
10532                 n1->nif.test = list(0);
10533                 if (readtoken() != TTHEN)
10534                         raise_error_unexpected_syntax(TTHEN);
10535                 n1->nif.ifpart = list(0);
10536                 n2 = n1;
10537                 while (readtoken() == TELIF) {
10538                         n2->nif.elsepart = stzalloc(sizeof(struct nif));
10539                         n2 = n2->nif.elsepart;
10540                         n2->type = NIF;
10541                         n2->nif.test = list(0);
10542                         if (readtoken() != TTHEN)
10543                                 raise_error_unexpected_syntax(TTHEN);
10544                         n2->nif.ifpart = list(0);
10545                 }
10546                 if (lasttoken == TELSE)
10547                         n2->nif.elsepart = list(0);
10548                 else {
10549                         n2->nif.elsepart = NULL;
10550                         tokpushback = 1;
10551                 }
10552                 t = TFI;
10553                 break;
10554         case TWHILE:
10555         case TUNTIL: {
10556                 int got;
10557                 n1 = stzalloc(sizeof(struct nbinary));
10558                 n1->type = (lasttoken == TWHILE) ? NWHILE : NUNTIL;
10559                 n1->nbinary.ch1 = list(0);
10560                 got = readtoken();
10561                 if (got != TDO) {
10562                         TRACE(("expecting DO got %s %s\n", tokname(got),
10563                                         got == TWORD ? wordtext : ""));
10564                         raise_error_unexpected_syntax(TDO);
10565                 }
10566                 n1->nbinary.ch2 = list(0);
10567                 t = TDONE;
10568                 break;
10569         }
10570         case TFOR:
10571                 if (readtoken() != TWORD || quoteflag || !goodname(wordtext))
10572                         raise_error_syntax("bad for loop variable");
10573                 n1 = stzalloc(sizeof(struct nfor));
10574                 n1->type = NFOR;
10575                 n1->nfor.var = wordtext;
10576                 checkkwd = CHKKWD | CHKALIAS;
10577                 if (readtoken() == TIN) {
10578                         app = &ap;
10579                         while (readtoken() == TWORD) {
10580                                 n2 = stzalloc(sizeof(struct narg));
10581                                 n2->type = NARG;
10582                                 /*n2->narg.next = NULL; - stzalloc did it */
10583                                 n2->narg.text = wordtext;
10584                                 n2->narg.backquote = backquotelist;
10585                                 *app = n2;
10586                                 app = &n2->narg.next;
10587                         }
10588                         *app = NULL;
10589                         n1->nfor.args = ap;
10590                         if (lasttoken != TNL && lasttoken != TSEMI)
10591                                 raise_error_unexpected_syntax(-1);
10592                 } else {
10593                         n2 = stzalloc(sizeof(struct narg));
10594                         n2->type = NARG;
10595                         /*n2->narg.next = NULL; - stzalloc did it */
10596                         n2->narg.text = (char *)dolatstr;
10597                         /*n2->narg.backquote = NULL;*/
10598                         n1->nfor.args = n2;
10599                         /*
10600                          * Newline or semicolon here is optional (but note
10601                          * that the original Bourne shell only allowed NL).
10602                          */
10603                         if (lasttoken != TNL && lasttoken != TSEMI)
10604                                 tokpushback = 1;
10605                 }
10606                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
10607                 if (readtoken() != TDO)
10608                         raise_error_unexpected_syntax(TDO);
10609                 n1->nfor.body = list(0);
10610                 t = TDONE;
10611                 break;
10612         case TCASE:
10613                 n1 = stzalloc(sizeof(struct ncase));
10614                 n1->type = NCASE;
10615                 if (readtoken() != TWORD)
10616                         raise_error_unexpected_syntax(TWORD);
10617                 n1->ncase.expr = n2 = stzalloc(sizeof(struct narg));
10618                 n2->type = NARG;
10619                 /*n2->narg.next = NULL; - stzalloc did it */
10620                 n2->narg.text = wordtext;
10621                 n2->narg.backquote = backquotelist;
10622                 do {
10623                         checkkwd = CHKKWD | CHKALIAS;
10624                 } while (readtoken() == TNL);
10625                 if (lasttoken != TIN)
10626                         raise_error_unexpected_syntax(TIN);
10627                 cpp = &n1->ncase.cases;
10628  next_case:
10629                 checkkwd = CHKNL | CHKKWD;
10630                 t = readtoken();
10631                 while (t != TESAC) {
10632                         if (lasttoken == TLP)
10633                                 readtoken();
10634                         *cpp = cp = stzalloc(sizeof(struct nclist));
10635                         cp->type = NCLIST;
10636                         app = &cp->nclist.pattern;
10637                         for (;;) {
10638                                 *app = ap = stzalloc(sizeof(struct narg));
10639                                 ap->type = NARG;
10640                                 /*ap->narg.next = NULL; - stzalloc did it */
10641                                 ap->narg.text = wordtext;
10642                                 ap->narg.backquote = backquotelist;
10643                                 if (readtoken() != TPIPE)
10644                                         break;
10645                                 app = &ap->narg.next;
10646                                 readtoken();
10647                         }
10648                         //ap->narg.next = NULL;
10649                         if (lasttoken != TRP)
10650                                 raise_error_unexpected_syntax(TRP);
10651                         cp->nclist.body = list(2);
10652
10653                         cpp = &cp->nclist.next;
10654
10655                         checkkwd = CHKNL | CHKKWD;
10656                         t = readtoken();
10657                         if (t != TESAC) {
10658                                 if (t != TENDCASE)
10659                                         raise_error_unexpected_syntax(TENDCASE);
10660                                 goto next_case;
10661                         }
10662                 }
10663                 *cpp = NULL;
10664                 goto redir;
10665         case TLP:
10666                 n1 = stzalloc(sizeof(struct nredir));
10667                 n1->type = NSUBSHELL;
10668                 n1->nredir.n = list(0);
10669                 /*n1->nredir.redirect = NULL; - stzalloc did it */
10670                 t = TRP;
10671                 break;
10672         case TBEGIN:
10673                 n1 = list(0);
10674                 t = TEND;
10675                 break;
10676         case TWORD:
10677         case TREDIR:
10678                 tokpushback = 1;
10679                 return simplecmd();
10680         }
10681
10682         if (readtoken() != t)
10683                 raise_error_unexpected_syntax(t);
10684
10685  redir:
10686         /* Now check for redirection which may follow command */
10687         checkkwd = CHKKWD | CHKALIAS;
10688         rpp = rpp2;
10689         while (readtoken() == TREDIR) {
10690                 *rpp = n2 = redirnode;
10691                 rpp = &n2->nfile.next;
10692                 parsefname();
10693         }
10694         tokpushback = 1;
10695         *rpp = NULL;
10696         if (redir) {
10697                 if (n1->type != NSUBSHELL) {
10698                         n2 = stzalloc(sizeof(struct nredir));
10699                         n2->type = NREDIR;
10700                         n2->nredir.n = n1;
10701                         n1 = n2;
10702                 }
10703                 n1->nredir.redirect = redir;
10704         }
10705         return n1;
10706 }
10707
10708 #if ENABLE_ASH_BASH_COMPAT
10709 static int decode_dollar_squote(void)
10710 {
10711         static const char C_escapes[] ALIGN1 = "nrbtfav""x\\01234567";
10712         int c, cnt;
10713         char *p;
10714         char buf[4];
10715
10716         c = pgetc();
10717         p = strchr(C_escapes, c);
10718         if (p) {
10719                 buf[0] = c;
10720                 p = buf;
10721                 cnt = 3;
10722                 if ((unsigned char)(c - '0') <= 7) { /* \ooo */
10723                         do {
10724                                 c = pgetc();
10725                                 *++p = c;
10726                         } while ((unsigned char)(c - '0') <= 7 && --cnt);
10727                         pungetc();
10728                 } else if (c == 'x') { /* \xHH */
10729                         do {
10730                                 c = pgetc();
10731                                 *++p = c;
10732                         } while (isxdigit(c) && --cnt);
10733                         pungetc();
10734                         if (cnt == 3) { /* \x but next char is "bad" */
10735                                 c = 'x';
10736                                 goto unrecognized;
10737                         }
10738                 } else { /* simple seq like \\ or \t */
10739                         p++;
10740                 }
10741                 *p = '\0';
10742                 p = buf;
10743                 c = bb_process_escape_sequence((void*)&p);
10744         } else { /* unrecognized "\z": print both chars unless ' or " */
10745                 if (c != '\'' && c != '"') {
10746  unrecognized:
10747                         c |= 0x100; /* "please encode \, then me" */
10748                 }
10749         }
10750         return c;
10751 }
10752 #endif
10753
10754 /*
10755  * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
10756  * is not NULL, read a here document.  In the latter case, eofmark is the
10757  * word which marks the end of the document and striptabs is true if
10758  * leading tabs should be stripped from the document.  The argument firstc
10759  * is the first character of the input token or document.
10760  *
10761  * Because C does not have internal subroutines, I have simulated them
10762  * using goto's to implement the subroutine linkage.  The following macros
10763  * will run code that appears at the end of readtoken1.
10764  */
10765 #define CHECKEND()      {goto checkend; checkend_return:;}
10766 #define PARSEREDIR()    {goto parseredir; parseredir_return:;}
10767 #define PARSESUB()      {goto parsesub; parsesub_return:;}
10768 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
10769 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
10770 #define PARSEARITH()    {goto parsearith; parsearith_return:;}
10771 static int
10772 readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
10773 {
10774         /* NB: syntax parameter fits into smallint */
10775         int c = firstc;
10776         char *out;
10777         int len;
10778         char line[EOFMARKLEN + 1];
10779         struct nodelist *bqlist;
10780         smallint quotef;
10781         smallint dblquote;
10782         smallint oldstyle;
10783         smallint prevsyntax; /* syntax before arithmetic */
10784 #if ENABLE_ASH_EXPAND_PRMT
10785         smallint pssyntax;   /* we are expanding a prompt string */
10786 #endif
10787         int varnest;         /* levels of variables expansion */
10788         int arinest;         /* levels of arithmetic expansion */
10789         int parenlevel;      /* levels of parens in arithmetic */
10790         int dqvarnest;       /* levels of variables expansion within double quotes */
10791
10792         USE_ASH_BASH_COMPAT(smallint bash_dollar_squote = 0;)
10793
10794 #if __GNUC__
10795         /* Avoid longjmp clobbering */
10796         (void) &out;
10797         (void) &quotef;
10798         (void) &dblquote;
10799         (void) &varnest;
10800         (void) &arinest;
10801         (void) &parenlevel;
10802         (void) &dqvarnest;
10803         (void) &oldstyle;
10804         (void) &prevsyntax;
10805         (void) &syntax;
10806 #endif
10807         startlinno = g_parsefile->linno;
10808         bqlist = NULL;
10809         quotef = 0;
10810         oldstyle = 0;
10811         prevsyntax = 0;
10812 #if ENABLE_ASH_EXPAND_PRMT
10813         pssyntax = (syntax == PSSYNTAX);
10814         if (pssyntax)
10815                 syntax = DQSYNTAX;
10816 #endif
10817         dblquote = (syntax == DQSYNTAX);
10818         varnest = 0;
10819         arinest = 0;
10820         parenlevel = 0;
10821         dqvarnest = 0;
10822
10823         STARTSTACKSTR(out);
10824  loop:
10825         /* For each line, until end of word */
10826         {
10827                 CHECKEND();     /* set c to PEOF if at end of here document */
10828                 for (;;) {      /* until end of line or end of word */
10829                         CHECKSTRSPACE(4, out);  /* permit 4 calls to USTPUTC */
10830                         switch (SIT(c, syntax)) {
10831                         case CNL:       /* '\n' */
10832                                 if (syntax == BASESYNTAX)
10833                                         goto endword;   /* exit outer loop */
10834                                 USTPUTC(c, out);
10835                                 g_parsefile->linno++;
10836                                 if (doprompt)
10837                                         setprompt(2);
10838                                 c = pgetc();
10839                                 goto loop;              /* continue outer loop */
10840                         case CWORD:
10841                                 USTPUTC(c, out);
10842                                 break;
10843                         case CCTL:
10844                                 if (eofmark == NULL || dblquote)
10845                                         USTPUTC(CTLESC, out);
10846 #if ENABLE_ASH_BASH_COMPAT
10847                                 if (c == '\\' && bash_dollar_squote) {
10848                                         c = decode_dollar_squote();
10849                                         if (c & 0x100) {
10850                                                 USTPUTC('\\', out);
10851                                                 c = (unsigned char)c;
10852                                         }
10853                                 }
10854 #endif
10855                                 USTPUTC(c, out);
10856                                 break;
10857                         case CBACK:     /* backslash */
10858                                 c = pgetc2();
10859                                 if (c == PEOF) {
10860                                         USTPUTC(CTLESC, out);
10861                                         USTPUTC('\\', out);
10862                                         pungetc();
10863                                 } else if (c == '\n') {
10864                                         if (doprompt)
10865                                                 setprompt(2);
10866                                 } else {
10867 #if ENABLE_ASH_EXPAND_PRMT
10868                                         if (c == '$' && pssyntax) {
10869                                                 USTPUTC(CTLESC, out);
10870                                                 USTPUTC('\\', out);
10871                                         }
10872 #endif
10873                                         if (dblquote && c != '\\'
10874                                          && c != '`' && c != '$'
10875                                          && (c != '"' || eofmark != NULL)
10876                                         ) {
10877                                                 USTPUTC(CTLESC, out);
10878                                                 USTPUTC('\\', out);
10879                                         }
10880                                         if (SIT(c, SQSYNTAX) == CCTL)
10881                                                 USTPUTC(CTLESC, out);
10882                                         USTPUTC(c, out);
10883                                         quotef = 1;
10884                                 }
10885                                 break;
10886                         case CSQUOTE:
10887                                 syntax = SQSYNTAX;
10888  quotemark:
10889                                 if (eofmark == NULL) {
10890                                         USTPUTC(CTLQUOTEMARK, out);
10891                                 }
10892                                 break;
10893                         case CDQUOTE:
10894                                 syntax = DQSYNTAX;
10895                                 dblquote = 1;
10896                                 goto quotemark;
10897                         case CENDQUOTE:
10898                                 USE_ASH_BASH_COMPAT(bash_dollar_squote = 0;)
10899                                 if (eofmark != NULL && arinest == 0
10900                                  && varnest == 0
10901                                 ) {
10902                                         USTPUTC(c, out);
10903                                 } else {
10904                                         if (dqvarnest == 0) {
10905                                                 syntax = BASESYNTAX;
10906                                                 dblquote = 0;
10907                                         }
10908                                         quotef = 1;
10909                                         goto quotemark;
10910                                 }
10911                                 break;
10912                         case CVAR:      /* '$' */
10913                                 PARSESUB();             /* parse substitution */
10914                                 break;
10915                         case CENDVAR:   /* '}' */
10916                                 if (varnest > 0) {
10917                                         varnest--;
10918                                         if (dqvarnest > 0) {
10919                                                 dqvarnest--;
10920                                         }
10921                                         USTPUTC(CTLENDVAR, out);
10922                                 } else {
10923                                         USTPUTC(c, out);
10924                                 }
10925                                 break;
10926 #if ENABLE_SH_MATH_SUPPORT
10927                         case CLP:       /* '(' in arithmetic */
10928                                 parenlevel++;
10929                                 USTPUTC(c, out);
10930                                 break;
10931                         case CRP:       /* ')' in arithmetic */
10932                                 if (parenlevel > 0) {
10933                                         USTPUTC(c, out);
10934                                         --parenlevel;
10935                                 } else {
10936                                         if (pgetc() == ')') {
10937                                                 if (--arinest == 0) {
10938                                                         USTPUTC(CTLENDARI, out);
10939                                                         syntax = prevsyntax;
10940                                                         dblquote = (syntax == DQSYNTAX);
10941                                                 } else
10942                                                         USTPUTC(')', out);
10943                                         } else {
10944                                                 /*
10945                                                  * unbalanced parens
10946                                                  *  (don't 2nd guess - no error)
10947                                                  */
10948                                                 pungetc();
10949                                                 USTPUTC(')', out);
10950                                         }
10951                                 }
10952                                 break;
10953 #endif
10954                         case CBQUOTE:   /* '`' */
10955                                 PARSEBACKQOLD();
10956                                 break;
10957                         case CENDFILE:
10958                                 goto endword;           /* exit outer loop */
10959                         case CIGN:
10960                                 break;
10961                         default:
10962                                 if (varnest == 0) {
10963 #if ENABLE_ASH_BASH_COMPAT
10964                                         if (c == '&') {
10965                                                 if (pgetc() == '>')
10966                                                         c = 0x100 + '>'; /* flag &> */
10967                                                 pungetc();
10968                                         }
10969 #endif
10970                                         goto endword;   /* exit outer loop */
10971                                 }
10972 #if ENABLE_ASH_ALIAS
10973                                 if (c != PEOA)
10974 #endif
10975                                         USTPUTC(c, out);
10976
10977                         }
10978                         c = pgetc_fast();
10979                 } /* for (;;) */
10980         }
10981  endword:
10982 #if ENABLE_SH_MATH_SUPPORT
10983         if (syntax == ARISYNTAX)
10984                 raise_error_syntax("missing '))'");
10985 #endif
10986         if (syntax != BASESYNTAX && !parsebackquote && eofmark == NULL)
10987                 raise_error_syntax("unterminated quoted string");
10988         if (varnest != 0) {
10989                 startlinno = g_parsefile->linno;
10990                 /* { */
10991                 raise_error_syntax("missing '}'");
10992         }
10993         USTPUTC('\0', out);
10994         len = out - (char *)stackblock();
10995         out = stackblock();
10996         if (eofmark == NULL) {
10997                 if ((c == '>' || c == '<' USE_ASH_BASH_COMPAT( || c == 0x100 + '>'))
10998                  && quotef == 0
10999                 ) {
11000                         if (isdigit_str9(out)) {
11001                                 PARSEREDIR(); /* passed as params: out, c */
11002                                 lasttoken = TREDIR;
11003                                 return lasttoken;
11004                         }
11005                         /* else: non-number X seen, interpret it
11006                          * as "NNNX>file" = "NNNX >file" */
11007                 }
11008                 pungetc();
11009         }
11010         quoteflag = quotef;
11011         backquotelist = bqlist;
11012         grabstackblock(len);
11013         wordtext = out;
11014         lasttoken = TWORD;
11015         return lasttoken;
11016 /* end of readtoken routine */
11017
11018 /*
11019  * Check to see whether we are at the end of the here document.  When this
11020  * is called, c is set to the first character of the next input line.  If
11021  * we are at the end of the here document, this routine sets the c to PEOF.
11022  */
11023 checkend: {
11024         if (eofmark) {
11025 #if ENABLE_ASH_ALIAS
11026                 if (c == PEOA) {
11027                         c = pgetc2();
11028                 }
11029 #endif
11030                 if (striptabs) {
11031                         while (c == '\t') {
11032                                 c = pgetc2();
11033                         }
11034                 }
11035                 if (c == *eofmark) {
11036                         if (pfgets(line, sizeof(line)) != NULL) {
11037                                 char *p, *q;
11038
11039                                 p = line;
11040                                 for (q = eofmark + 1; *q && *p == *q; p++, q++)
11041                                         continue;
11042                                 if (*p == '\n' && *q == '\0') {
11043                                         c = PEOF;
11044                                         g_parsefile->linno++;
11045                                         needprompt = doprompt;
11046                                 } else {
11047                                         pushstring(line, NULL);
11048                                 }
11049                         }
11050                 }
11051         }
11052         goto checkend_return;
11053 }
11054
11055 /*
11056  * Parse a redirection operator.  The variable "out" points to a string
11057  * specifying the fd to be redirected.  The variable "c" contains the
11058  * first character of the redirection operator.
11059  */
11060 parseredir: {
11061         /* out is already checked to be a valid number or "" */
11062         int fd = (*out == '\0' ? -1 : atoi(out));
11063         union node *np;
11064
11065         np = stzalloc(sizeof(struct nfile));
11066         if (c == '>') {
11067                 np->nfile.fd = 1;
11068                 c = pgetc();
11069                 if (c == '>')
11070                         np->type = NAPPEND;
11071                 else if (c == '|')
11072                         np->type = NCLOBBER;
11073                 else if (c == '&')
11074                         np->type = NTOFD;
11075                         /* it also can be NTO2 (>&file), but we can't figure it out yet */
11076                 else {
11077                         np->type = NTO;
11078                         pungetc();
11079                 }
11080         }
11081 #if ENABLE_ASH_BASH_COMPAT
11082         else if (c == 0x100 + '>') { /* this flags &> redirection */
11083                 np->nfile.fd = 1;
11084                 pgetc(); /* this is '>', no need to check */
11085                 np->type = NTO2;
11086         }
11087 #endif
11088         else { /* c == '<' */
11089                 /*np->nfile.fd = 0; - stzalloc did it */
11090                 c = pgetc();
11091                 switch (c) {
11092                 case '<':
11093                         if (sizeof(struct nfile) != sizeof(struct nhere)) {
11094                                 np = stzalloc(sizeof(struct nhere));
11095                                 /*np->nfile.fd = 0; - stzalloc did it */
11096                         }
11097                         np->type = NHERE;
11098                         heredoc = stzalloc(sizeof(struct heredoc));
11099                         heredoc->here = np;
11100                         c = pgetc();
11101                         if (c == '-') {
11102                                 heredoc->striptabs = 1;
11103                         } else {
11104                                 /*heredoc->striptabs = 0; - stzalloc did it */
11105                                 pungetc();
11106                         }
11107                         break;
11108
11109                 case '&':
11110                         np->type = NFROMFD;
11111                         break;
11112
11113                 case '>':
11114                         np->type = NFROMTO;
11115                         break;
11116
11117                 default:
11118                         np->type = NFROM;
11119                         pungetc();
11120                         break;
11121                 }
11122         }
11123         if (fd >= 0)
11124                 np->nfile.fd = fd;
11125         redirnode = np;
11126         goto parseredir_return;
11127 }
11128
11129 /*
11130  * Parse a substitution.  At this point, we have read the dollar sign
11131  * and nothing else.
11132  */
11133
11134 /* is_special(c) evaluates to 1 for c in "!#$*-0123456789?@"; 0 otherwise
11135  * (assuming ascii char codes, as the original implementation did) */
11136 #define is_special(c) \
11137         (((unsigned)(c) - 33 < 32) \
11138                         && ((0xc1ff920dU >> ((unsigned)(c) - 33)) & 1))
11139 parsesub: {
11140         int subtype;
11141         int typeloc;
11142         int flags;
11143         char *p;
11144         static const char types[] ALIGN1 = "}-+?=";
11145
11146         c = pgetc();
11147         if (c <= PEOA_OR_PEOF
11148          || (c != '(' && c != '{' && !is_name(c) && !is_special(c))
11149         ) {
11150 #if ENABLE_ASH_BASH_COMPAT
11151                 if (c == '\'')
11152                         bash_dollar_squote = 1;
11153                 else
11154 #endif
11155                         USTPUTC('$', out);
11156                 pungetc();
11157         } else if (c == '(') {  /* $(command) or $((arith)) */
11158                 if (pgetc() == '(') {
11159 #if ENABLE_SH_MATH_SUPPORT
11160                         PARSEARITH();
11161 #else
11162                         raise_error_syntax("you disabled math support for $((arith)) syntax");
11163 #endif
11164                 } else {
11165                         pungetc();
11166                         PARSEBACKQNEW();
11167                 }
11168         } else {
11169                 USTPUTC(CTLVAR, out);
11170                 typeloc = out - (char *)stackblock();
11171                 USTPUTC(VSNORMAL, out);
11172                 subtype = VSNORMAL;
11173                 if (c == '{') {
11174                         c = pgetc();
11175                         if (c == '#') {
11176                                 c = pgetc();
11177                                 if (c == '}')
11178                                         c = '#';
11179                                 else
11180                                         subtype = VSLENGTH;
11181                         } else
11182                                 subtype = 0;
11183                 }
11184                 if (c > PEOA_OR_PEOF && is_name(c)) {
11185                         do {
11186                                 STPUTC(c, out);
11187                                 c = pgetc();
11188                         } while (c > PEOA_OR_PEOF && is_in_name(c));
11189                 } else if (isdigit(c)) {
11190                         do {
11191                                 STPUTC(c, out);
11192                                 c = pgetc();
11193                         } while (isdigit(c));
11194                 } else if (is_special(c)) {
11195                         USTPUTC(c, out);
11196                         c = pgetc();
11197                 } else {
11198  badsub:
11199                         raise_error_syntax("bad substitution");
11200                 }
11201
11202                 STPUTC('=', out);
11203                 flags = 0;
11204                 if (subtype == 0) {
11205                         switch (c) {
11206                         case ':':
11207                                 c = pgetc();
11208 #if ENABLE_ASH_BASH_COMPAT
11209                                 if (c == ':' || c == '$' || isdigit(c)) {
11210                                         pungetc();
11211                                         subtype = VSSUBSTR;
11212                                         break;
11213                                 }
11214 #endif
11215                                 flags = VSNUL;
11216                                 /*FALLTHROUGH*/
11217                         default:
11218                                 p = strchr(types, c);
11219                                 if (p == NULL)
11220                                         goto badsub;
11221                                 subtype = p - types + VSNORMAL;
11222                                 break;
11223                         case '%':
11224                         case '#': {
11225                                 int cc = c;
11226                                 subtype = c == '#' ? VSTRIMLEFT : VSTRIMRIGHT;
11227                                 c = pgetc();
11228                                 if (c == cc)
11229                                         subtype++;
11230                                 else
11231                                         pungetc();
11232                                 break;
11233                         }
11234 #if ENABLE_ASH_BASH_COMPAT
11235                         case '/':
11236                                 subtype = VSREPLACE;
11237                                 c = pgetc();
11238                                 if (c == '/')
11239                                         subtype++; /* VSREPLACEALL */
11240                                 else
11241                                         pungetc();
11242                                 break;
11243 #endif
11244                         }
11245                 } else {
11246                         pungetc();
11247                 }
11248                 if (dblquote || arinest)
11249                         flags |= VSQUOTE;
11250                 *((char *)stackblock() + typeloc) = subtype | flags;
11251                 if (subtype != VSNORMAL) {
11252                         varnest++;
11253                         if (dblquote || arinest) {
11254                                 dqvarnest++;
11255                         }
11256                 }
11257         }
11258         goto parsesub_return;
11259 }
11260
11261 /*
11262  * Called to parse command substitutions.  Newstyle is set if the command
11263  * is enclosed inside $(...); nlpp is a pointer to the head of the linked
11264  * list of commands (passed by reference), and savelen is the number of
11265  * characters on the top of the stack which must be preserved.
11266  */
11267 parsebackq: {
11268         struct nodelist **nlpp;
11269         smallint savepbq;
11270         union node *n;
11271         char *volatile str;
11272         struct jmploc jmploc;
11273         struct jmploc *volatile savehandler;
11274         size_t savelen;
11275         smallint saveprompt = 0;
11276
11277 #ifdef __GNUC__
11278         (void) &saveprompt;
11279 #endif
11280         savepbq = parsebackquote;
11281         if (setjmp(jmploc.loc)) {
11282                 free(str);
11283                 parsebackquote = 0;
11284                 exception_handler = savehandler;
11285                 longjmp(exception_handler->loc, 1);
11286         }
11287         INT_OFF;
11288         str = NULL;
11289         savelen = out - (char *)stackblock();
11290         if (savelen > 0) {
11291                 str = ckmalloc(savelen);
11292                 memcpy(str, stackblock(), savelen);
11293         }
11294         savehandler = exception_handler;
11295         exception_handler = &jmploc;
11296         INT_ON;
11297         if (oldstyle) {
11298                 /* We must read until the closing backquote, giving special
11299                    treatment to some slashes, and then push the string and
11300                    reread it as input, interpreting it normally.  */
11301                 char *pout;
11302                 int pc;
11303                 size_t psavelen;
11304                 char *pstr;
11305
11306
11307                 STARTSTACKSTR(pout);
11308                 for (;;) {
11309                         if (needprompt) {
11310                                 setprompt(2);
11311                         }
11312                         pc = pgetc();
11313                         switch (pc) {
11314                         case '`':
11315                                 goto done;
11316
11317                         case '\\':
11318                                 pc = pgetc();
11319                                 if (pc == '\n') {
11320                                         g_parsefile->linno++;
11321                                         if (doprompt)
11322                                                 setprompt(2);
11323                                         /*
11324                                          * If eating a newline, avoid putting
11325                                          * the newline into the new character
11326                                          * stream (via the STPUTC after the
11327                                          * switch).
11328                                          */
11329                                         continue;
11330                                 }
11331                                 if (pc != '\\' && pc != '`' && pc != '$'
11332                                  && (!dblquote || pc != '"'))
11333                                         STPUTC('\\', pout);
11334                                 if (pc > PEOA_OR_PEOF) {
11335                                         break;
11336                                 }
11337                                 /* fall through */
11338
11339                         case PEOF:
11340 #if ENABLE_ASH_ALIAS
11341                         case PEOA:
11342 #endif
11343                                 startlinno = g_parsefile->linno;
11344                                 raise_error_syntax("EOF in backquote substitution");
11345
11346                         case '\n':
11347                                 g_parsefile->linno++;
11348                                 needprompt = doprompt;
11349                                 break;
11350
11351                         default:
11352                                 break;
11353                         }
11354                         STPUTC(pc, pout);
11355                 }
11356  done:
11357                 STPUTC('\0', pout);
11358                 psavelen = pout - (char *)stackblock();
11359                 if (psavelen > 0) {
11360                         pstr = grabstackstr(pout);
11361                         setinputstring(pstr);
11362                 }
11363         }
11364         nlpp = &bqlist;
11365         while (*nlpp)
11366                 nlpp = &(*nlpp)->next;
11367         *nlpp = stzalloc(sizeof(**nlpp));
11368         /* (*nlpp)->next = NULL; - stzalloc did it */
11369         parsebackquote = oldstyle;
11370
11371         if (oldstyle) {
11372                 saveprompt = doprompt;
11373                 doprompt = 0;
11374         }
11375
11376         n = list(2);
11377
11378         if (oldstyle)
11379                 doprompt = saveprompt;
11380         else if (readtoken() != TRP)
11381                 raise_error_unexpected_syntax(TRP);
11382
11383         (*nlpp)->n = n;
11384         if (oldstyle) {
11385                 /*
11386                  * Start reading from old file again, ignoring any pushed back
11387                  * tokens left from the backquote parsing
11388                  */
11389                 popfile();
11390                 tokpushback = 0;
11391         }
11392         while (stackblocksize() <= savelen)
11393                 growstackblock();
11394         STARTSTACKSTR(out);
11395         if (str) {
11396                 memcpy(out, str, savelen);
11397                 STADJUST(savelen, out);
11398                 INT_OFF;
11399                 free(str);
11400                 str = NULL;
11401                 INT_ON;
11402         }
11403         parsebackquote = savepbq;
11404         exception_handler = savehandler;
11405         if (arinest || dblquote)
11406                 USTPUTC(CTLBACKQ | CTLQUOTE, out);
11407         else
11408                 USTPUTC(CTLBACKQ, out);
11409         if (oldstyle)
11410                 goto parsebackq_oldreturn;
11411         goto parsebackq_newreturn;
11412 }
11413
11414 #if ENABLE_SH_MATH_SUPPORT
11415 /*
11416  * Parse an arithmetic expansion (indicate start of one and set state)
11417  */
11418 parsearith: {
11419         if (++arinest == 1) {
11420                 prevsyntax = syntax;
11421                 syntax = ARISYNTAX;
11422                 USTPUTC(CTLARI, out);
11423                 if (dblquote)
11424                         USTPUTC('"', out);
11425                 else
11426                         USTPUTC(' ', out);
11427         } else {
11428                 /*
11429                  * we collapse embedded arithmetic expansion to
11430                  * parenthesis, which should be equivalent
11431                  */
11432                 USTPUTC('(', out);
11433         }
11434         goto parsearith_return;
11435 }
11436 #endif
11437
11438 } /* end of readtoken */
11439
11440 /*
11441  * Read the next input token.
11442  * If the token is a word, we set backquotelist to the list of cmds in
11443  *      backquotes.  We set quoteflag to true if any part of the word was
11444  *      quoted.
11445  * If the token is TREDIR, then we set redirnode to a structure containing
11446  *      the redirection.
11447  * In all cases, the variable startlinno is set to the number of the line
11448  *      on which the token starts.
11449  *
11450  * [Change comment:  here documents and internal procedures]
11451  * [Readtoken shouldn't have any arguments.  Perhaps we should make the
11452  *  word parsing code into a separate routine.  In this case, readtoken
11453  *  doesn't need to have any internal procedures, but parseword does.
11454  *  We could also make parseoperator in essence the main routine, and
11455  *  have parseword (readtoken1?) handle both words and redirection.]
11456  */
11457 #define NEW_xxreadtoken
11458 #ifdef NEW_xxreadtoken
11459 /* singles must be first! */
11460 static const char xxreadtoken_chars[7] ALIGN1 = {
11461         '\n', '(', ')', /* singles */
11462         '&', '|', ';',  /* doubles */
11463         0
11464 };
11465
11466 #define xxreadtoken_singles 3
11467 #define xxreadtoken_doubles 3
11468
11469 static const char xxreadtoken_tokens[] ALIGN1 = {
11470         TNL, TLP, TRP,          /* only single occurrence allowed */
11471         TBACKGND, TPIPE, TSEMI, /* if single occurrence */
11472         TEOF,                   /* corresponds to trailing nul */
11473         TAND, TOR, TENDCASE     /* if double occurrence */
11474 };
11475
11476 static int
11477 xxreadtoken(void)
11478 {
11479         int c;
11480
11481         if (tokpushback) {
11482                 tokpushback = 0;
11483                 return lasttoken;
11484         }
11485         if (needprompt) {
11486                 setprompt(2);
11487         }
11488         startlinno = g_parsefile->linno;
11489         for (;;) {                      /* until token or start of word found */
11490                 c = pgetc_fast();
11491                 if (c == ' ' || c == '\t' USE_ASH_ALIAS( || c == PEOA))
11492                         continue;
11493
11494                 if (c == '#') {
11495                         while ((c = pgetc()) != '\n' && c != PEOF)
11496                                 continue;
11497                         pungetc();
11498                 } else if (c == '\\') {
11499                         if (pgetc() != '\n') {
11500                                 pungetc();
11501                                 break; /* return readtoken1(...) */
11502                         }
11503                         startlinno = ++g_parsefile->linno;
11504                         if (doprompt)
11505                                 setprompt(2);
11506                 } else {
11507                         const char *p;
11508
11509                         p = xxreadtoken_chars + sizeof(xxreadtoken_chars) - 1;
11510                         if (c != PEOF) {
11511                                 if (c == '\n') {
11512                                         g_parsefile->linno++;
11513                                         needprompt = doprompt;
11514                                 }
11515
11516                                 p = strchr(xxreadtoken_chars, c);
11517                                 if (p == NULL)
11518                                         break; /* return readtoken1(...) */
11519
11520                                 if ((int)(p - xxreadtoken_chars) >= xxreadtoken_singles) {
11521                                         int cc = pgetc();
11522                                         if (cc == c) {    /* double occurrence? */
11523                                                 p += xxreadtoken_doubles + 1;
11524                                         } else {
11525                                                 pungetc();
11526 #if ENABLE_ASH_BASH_COMPAT
11527                                                 if (c == '&' && cc == '>') /* &> */
11528                                                         break; /* return readtoken1(...) */
11529 #endif
11530                                         }
11531                                 }
11532                         }
11533                         lasttoken = xxreadtoken_tokens[p - xxreadtoken_chars];
11534                         return lasttoken;
11535                 }
11536         } /* for (;;) */
11537
11538         return readtoken1(c, BASESYNTAX, (char *) NULL, 0);
11539 }
11540 #else /* old xxreadtoken */
11541 #define RETURN(token)   return lasttoken = token
11542 static int
11543 xxreadtoken(void)
11544 {
11545         int c;
11546
11547         if (tokpushback) {
11548                 tokpushback = 0;
11549                 return lasttoken;
11550         }
11551         if (needprompt) {
11552                 setprompt(2);
11553         }
11554         startlinno = g_parsefile->linno;
11555         for (;;) {      /* until token or start of word found */
11556                 c = pgetc_fast();
11557                 switch (c) {
11558                 case ' ': case '\t':
11559 #if ENABLE_ASH_ALIAS
11560                 case PEOA:
11561 #endif
11562                         continue;
11563                 case '#':
11564                         while ((c = pgetc()) != '\n' && c != PEOF)
11565                                 continue;
11566                         pungetc();
11567                         continue;
11568                 case '\\':
11569                         if (pgetc() == '\n') {
11570                                 startlinno = ++g_parsefile->linno;
11571                                 if (doprompt)
11572                                         setprompt(2);
11573                                 continue;
11574                         }
11575                         pungetc();
11576                         goto breakloop;
11577                 case '\n':
11578                         g_parsefile->linno++;
11579                         needprompt = doprompt;
11580                         RETURN(TNL);
11581                 case PEOF:
11582                         RETURN(TEOF);
11583                 case '&':
11584                         if (pgetc() == '&')
11585                                 RETURN(TAND);
11586                         pungetc();
11587                         RETURN(TBACKGND);
11588                 case '|':
11589                         if (pgetc() == '|')
11590                                 RETURN(TOR);
11591                         pungetc();
11592                         RETURN(TPIPE);
11593                 case ';':
11594                         if (pgetc() == ';')
11595                                 RETURN(TENDCASE);
11596                         pungetc();
11597                         RETURN(TSEMI);
11598                 case '(':
11599                         RETURN(TLP);
11600                 case ')':
11601                         RETURN(TRP);
11602                 default:
11603                         goto breakloop;
11604                 }
11605         }
11606  breakloop:
11607         return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
11608 #undef RETURN
11609 }
11610 #endif /* old xxreadtoken */
11611
11612 static int
11613 readtoken(void)
11614 {
11615         int t;
11616 #if DEBUG
11617         smallint alreadyseen = tokpushback;
11618 #endif
11619
11620 #if ENABLE_ASH_ALIAS
11621  top:
11622 #endif
11623
11624         t = xxreadtoken();
11625
11626         /*
11627          * eat newlines
11628          */
11629         if (checkkwd & CHKNL) {
11630                 while (t == TNL) {
11631                         parseheredoc();
11632                         t = xxreadtoken();
11633                 }
11634         }
11635
11636         if (t != TWORD || quoteflag) {
11637                 goto out;
11638         }
11639
11640         /*
11641          * check for keywords
11642          */
11643         if (checkkwd & CHKKWD) {
11644                 const char *const *pp;
11645
11646                 pp = findkwd(wordtext);
11647                 if (pp) {
11648                         lasttoken = t = pp - tokname_array;
11649                         TRACE(("keyword %s recognized\n", tokname(t)));
11650                         goto out;
11651                 }
11652         }
11653
11654         if (checkkwd & CHKALIAS) {
11655 #if ENABLE_ASH_ALIAS
11656                 struct alias *ap;
11657                 ap = lookupalias(wordtext, 1);
11658                 if (ap != NULL) {
11659                         if (*ap->val) {
11660                                 pushstring(ap->val, ap);
11661                         }
11662                         goto top;
11663                 }
11664 #endif
11665         }
11666  out:
11667         checkkwd = 0;
11668 #if DEBUG
11669         if (!alreadyseen)
11670                 TRACE(("token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
11671         else
11672                 TRACE(("reread token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
11673 #endif
11674         return t;
11675 }
11676
11677 static char
11678 peektoken(void)
11679 {
11680         int t;
11681
11682         t = readtoken();
11683         tokpushback = 1;
11684         return tokname_array[t][0];
11685 }
11686
11687 /*
11688  * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
11689  * valid parse tree indicating a blank line.)
11690  */
11691 static union node *
11692 parsecmd(int interact)
11693 {
11694         int t;
11695
11696         tokpushback = 0;
11697         doprompt = interact;
11698         if (doprompt)
11699                 setprompt(doprompt);
11700         needprompt = 0;
11701         t = readtoken();
11702         if (t == TEOF)
11703                 return NEOF;
11704         if (t == TNL)
11705                 return NULL;
11706         tokpushback = 1;
11707         return list(1);
11708 }
11709
11710 /*
11711  * Input any here documents.
11712  */
11713 static void
11714 parseheredoc(void)
11715 {
11716         struct heredoc *here;
11717         union node *n;
11718
11719         here = heredoclist;
11720         heredoclist = NULL;
11721
11722         while (here) {
11723                 if (needprompt) {
11724                         setprompt(2);
11725                 }
11726                 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
11727                                 here->eofmark, here->striptabs);
11728                 n = stzalloc(sizeof(struct narg));
11729                 n->narg.type = NARG;
11730                 /*n->narg.next = NULL; - stzalloc did it */
11731                 n->narg.text = wordtext;
11732                 n->narg.backquote = backquotelist;
11733                 here->here->nhere.doc = n;
11734                 here = here->next;
11735         }
11736 }
11737
11738
11739 /*
11740  * called by editline -- any expansions to the prompt should be added here.
11741  */
11742 #if ENABLE_ASH_EXPAND_PRMT
11743 static const char *
11744 expandstr(const char *ps)
11745 {
11746         union node n;
11747
11748         /* XXX Fix (char *) cast. It _is_ a bug. ps is variable's value,
11749          * and token processing _can_ alter it (delete NULs etc). */
11750         setinputstring((char *)ps);
11751         readtoken1(pgetc(), PSSYNTAX, nullstr, 0);
11752         popfile();
11753
11754         n.narg.type = NARG;
11755         n.narg.next = NULL;
11756         n.narg.text = wordtext;
11757         n.narg.backquote = backquotelist;
11758
11759         expandarg(&n, NULL, 0);
11760         return stackblock();
11761 }
11762 #endif
11763
11764 /*
11765  * Execute a command or commands contained in a string.
11766  */
11767 static int
11768 evalstring(char *s, int mask)
11769 {
11770         union node *n;
11771         struct stackmark smark;
11772         int skip;
11773
11774         setinputstring(s);
11775         setstackmark(&smark);
11776
11777         skip = 0;
11778         while ((n = parsecmd(0)) != NEOF) {
11779                 evaltree(n, 0);
11780                 popstackmark(&smark);
11781                 skip = evalskip;
11782                 if (skip)
11783                         break;
11784         }
11785         popfile();
11786
11787         skip &= mask;
11788         evalskip = skip;
11789         return skip;
11790 }
11791
11792 /*
11793  * The eval command.
11794  */
11795 static int
11796 evalcmd(int argc UNUSED_PARAM, char **argv)
11797 {
11798         char *p;
11799         char *concat;
11800
11801         if (argv[1]) {
11802                 p = argv[1];
11803                 argv += 2;
11804                 if (argv[0]) {
11805                         STARTSTACKSTR(concat);
11806                         for (;;) {
11807                                 concat = stack_putstr(p, concat);
11808                                 p = *argv++;
11809                                 if (p == NULL)
11810                                         break;
11811                                 STPUTC(' ', concat);
11812                         }
11813                         STPUTC('\0', concat);
11814                         p = grabstackstr(concat);
11815                 }
11816                 evalstring(p, ~SKIPEVAL);
11817
11818         }
11819         return exitstatus;
11820 }
11821
11822 /*
11823  * Read and execute commands.  "Top" is nonzero for the top level command
11824  * loop; it turns on prompting if the shell is interactive.
11825  */
11826 static int
11827 cmdloop(int top)
11828 {
11829         union node *n;
11830         struct stackmark smark;
11831         int inter;
11832         int numeof = 0;
11833
11834         TRACE(("cmdloop(%d) called\n", top));
11835         for (;;) {
11836                 int skip;
11837
11838                 setstackmark(&smark);
11839 #if JOBS
11840                 if (doing_jobctl)
11841                         showjobs(stderr, SHOW_CHANGED);
11842 #endif
11843                 inter = 0;
11844                 if (iflag && top) {
11845                         inter++;
11846 #if ENABLE_ASH_MAIL
11847                         chkmail();
11848 #endif
11849                 }
11850                 n = parsecmd(inter);
11851 #if DEBUG
11852                 showtree(n);
11853 #endif
11854                 if (n == NEOF) {
11855                         if (!top || numeof >= 50)
11856                                 break;
11857                         if (!stoppedjobs()) {
11858                                 if (!Iflag)
11859                                         break;
11860                                 out2str("\nUse \"exit\" to leave shell.\n");
11861                         }
11862                         numeof++;
11863                 } else if (nflag == 0) {
11864                         /* job_warning can only be 2,1,0. Here 2->1, 1/0->0 */
11865                         job_warning >>= 1;
11866                         numeof = 0;
11867                         evaltree(n, 0);
11868                 }
11869                 popstackmark(&smark);
11870                 skip = evalskip;
11871
11872                 if (skip) {
11873                         evalskip = 0;
11874                         return skip & SKIPEVAL;
11875                 }
11876         }
11877         return 0;
11878 }
11879
11880 /*
11881  * Take commands from a file.  To be compatible we should do a path
11882  * search for the file, which is necessary to find sub-commands.
11883  */
11884 static char *
11885 find_dot_file(char *name)
11886 {
11887         char *fullname;
11888         const char *path = pathval();
11889         struct stat statb;
11890
11891         /* don't try this for absolute or relative paths */
11892         if (strchr(name, '/'))
11893                 return name;
11894
11895         /* IIRC standards do not say whether . is to be searched.
11896          * And it is even smaller this way, making it unconditional for now:
11897          */
11898         if (1) { /* ENABLE_ASH_BASH_COMPAT */
11899                 fullname = name;
11900                 goto try_cur_dir;
11901         }
11902
11903         while ((fullname = padvance(&path, name)) != NULL) {
11904  try_cur_dir:
11905                 if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
11906                         /*
11907                          * Don't bother freeing here, since it will
11908                          * be freed by the caller.
11909                          */
11910                         return fullname;
11911                 }
11912                 if (fullname != name)
11913                         stunalloc(fullname);
11914         }
11915
11916         /* not found in the PATH */
11917         ash_msg_and_raise_error("%s: not found", name);
11918         /* NOTREACHED */
11919 }
11920
11921 static int
11922 dotcmd(int argc, char **argv)
11923 {
11924         struct strlist *sp;
11925         volatile struct shparam saveparam;
11926         int status = 0;
11927
11928         for (sp = cmdenviron; sp; sp = sp->next)
11929                 setvareq(ckstrdup(sp->text), VSTRFIXED | VTEXTFIXED);
11930
11931         if (argv[1]) {        /* That's what SVR2 does */
11932                 char *fullname = find_dot_file(argv[1]);
11933                 argv += 2;
11934                 argc -= 2;
11935                 if (argc) { /* argc > 0, argv[0] != NULL */
11936                         saveparam = shellparam;
11937                         shellparam.malloced = 0;
11938                         shellparam.nparam = argc;
11939                         shellparam.p = argv;
11940                 };
11941
11942                 setinputfile(fullname, INPUT_PUSH_FILE);
11943                 commandname = fullname;
11944                 cmdloop(0);
11945                 popfile();
11946
11947                 if (argc) {
11948                         freeparam(&shellparam);
11949                         shellparam = saveparam;
11950                 };
11951                 status = exitstatus;
11952         }
11953         return status;
11954 }
11955
11956 static int
11957 exitcmd(int argc UNUSED_PARAM, char **argv)
11958 {
11959         if (stoppedjobs())
11960                 return 0;
11961         if (argv[1])
11962                 exitstatus = number(argv[1]);
11963         raise_exception(EXEXIT);
11964         /* NOTREACHED */
11965 }
11966
11967 /*
11968  * Read a file containing shell functions.
11969  */
11970 static void
11971 readcmdfile(char *name)
11972 {
11973         setinputfile(name, INPUT_PUSH_FILE);
11974         cmdloop(0);
11975         popfile();
11976 }
11977
11978
11979 /* ============ find_command inplementation */
11980
11981 /*
11982  * Resolve a command name.  If you change this routine, you may have to
11983  * change the shellexec routine as well.
11984  */
11985 static void
11986 find_command(char *name, struct cmdentry *entry, int act, const char *path)
11987 {
11988         struct tblentry *cmdp;
11989         int idx;
11990         int prev;
11991         char *fullname;
11992         struct stat statb;
11993         int e;
11994         int updatetbl;
11995         struct builtincmd *bcmd;
11996
11997         /* If name contains a slash, don't use PATH or hash table */
11998         if (strchr(name, '/') != NULL) {
11999                 entry->u.index = -1;
12000                 if (act & DO_ABS) {
12001                         while (stat(name, &statb) < 0) {
12002 #ifdef SYSV
12003                                 if (errno == EINTR)
12004                                         continue;
12005 #endif
12006                                 entry->cmdtype = CMDUNKNOWN;
12007                                 return;
12008                         }
12009                 }
12010                 entry->cmdtype = CMDNORMAL;
12011                 return;
12012         }
12013
12014 /* #if ENABLE_FEATURE_SH_STANDALONE... moved after builtin check */
12015
12016         updatetbl = (path == pathval());
12017         if (!updatetbl) {
12018                 act |= DO_ALTPATH;
12019                 if (strstr(path, "%builtin") != NULL)
12020                         act |= DO_ALTBLTIN;
12021         }
12022
12023         /* If name is in the table, check answer will be ok */
12024         cmdp = cmdlookup(name, 0);
12025         if (cmdp != NULL) {
12026                 int bit;
12027
12028                 switch (cmdp->cmdtype) {
12029                 default:
12030 #if DEBUG
12031                         abort();
12032 #endif
12033                 case CMDNORMAL:
12034                         bit = DO_ALTPATH;
12035                         break;
12036                 case CMDFUNCTION:
12037                         bit = DO_NOFUNC;
12038                         break;
12039                 case CMDBUILTIN:
12040                         bit = DO_ALTBLTIN;
12041                         break;
12042                 }
12043                 if (act & bit) {
12044                         updatetbl = 0;
12045                         cmdp = NULL;
12046                 } else if (cmdp->rehash == 0)
12047                         /* if not invalidated by cd, we're done */
12048                         goto success;
12049         }
12050
12051         /* If %builtin not in path, check for builtin next */
12052         bcmd = find_builtin(name);
12053         if (bcmd) {
12054                 if (IS_BUILTIN_REGULAR(bcmd))
12055                         goto builtin_success;
12056                 if (act & DO_ALTPATH) {
12057                         if (!(act & DO_ALTBLTIN))
12058                                 goto builtin_success;
12059                 } else if (builtinloc <= 0) {
12060                         goto builtin_success;
12061                 }
12062         }
12063
12064 #if ENABLE_FEATURE_SH_STANDALONE
12065         {
12066                 int applet_no = find_applet_by_name(name);
12067                 if (applet_no >= 0) {
12068                         entry->cmdtype = CMDNORMAL;
12069                         entry->u.index = -2 - applet_no;
12070                         return;
12071                 }
12072         }
12073 #endif
12074
12075         /* We have to search path. */
12076         prev = -1;              /* where to start */
12077         if (cmdp && cmdp->rehash) {     /* doing a rehash */
12078                 if (cmdp->cmdtype == CMDBUILTIN)
12079                         prev = builtinloc;
12080                 else
12081                         prev = cmdp->param.index;
12082         }
12083
12084         e = ENOENT;
12085         idx = -1;
12086  loop:
12087         while ((fullname = padvance(&path, name)) != NULL) {
12088                 stunalloc(fullname);
12089                 /* NB: code below will still use fullname
12090                  * despite it being "unallocated" */
12091                 idx++;
12092                 if (pathopt) {
12093                         if (prefix(pathopt, "builtin")) {
12094                                 if (bcmd)
12095                                         goto builtin_success;
12096                                 continue;
12097                         }
12098                         if ((act & DO_NOFUNC)
12099                          || !prefix(pathopt, "func")
12100                         ) {     /* ignore unimplemented options */
12101                                 continue;
12102                         }
12103                 }
12104                 /* if rehash, don't redo absolute path names */
12105                 if (fullname[0] == '/' && idx <= prev) {
12106                         if (idx < prev)
12107                                 continue;
12108                         TRACE(("searchexec \"%s\": no change\n", name));
12109                         goto success;
12110                 }
12111                 while (stat(fullname, &statb) < 0) {
12112 #ifdef SYSV
12113                         if (errno == EINTR)
12114                                 continue;
12115 #endif
12116                         if (errno != ENOENT && errno != ENOTDIR)
12117                                 e = errno;
12118                         goto loop;
12119                 }
12120                 e = EACCES;     /* if we fail, this will be the error */
12121                 if (!S_ISREG(statb.st_mode))
12122                         continue;
12123                 if (pathopt) {          /* this is a %func directory */
12124                         stalloc(strlen(fullname) + 1);
12125                         /* NB: stalloc will return space pointed by fullname
12126                          * (because we don't have any intervening allocations
12127                          * between stunalloc above and this stalloc) */
12128                         readcmdfile(fullname);
12129                         cmdp = cmdlookup(name, 0);
12130                         if (cmdp == NULL || cmdp->cmdtype != CMDFUNCTION)
12131                                 ash_msg_and_raise_error("%s not defined in %s", name, fullname);
12132                         stunalloc(fullname);
12133                         goto success;
12134                 }
12135                 TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
12136                 if (!updatetbl) {
12137                         entry->cmdtype = CMDNORMAL;
12138                         entry->u.index = idx;
12139                         return;
12140                 }
12141                 INT_OFF;
12142                 cmdp = cmdlookup(name, 1);
12143                 cmdp->cmdtype = CMDNORMAL;
12144                 cmdp->param.index = idx;
12145                 INT_ON;
12146                 goto success;
12147         }
12148
12149         /* We failed.  If there was an entry for this command, delete it */
12150         if (cmdp && updatetbl)
12151                 delete_cmd_entry();
12152         if (act & DO_ERR)
12153                 ash_msg("%s: %s", name, errmsg(e, "not found"));
12154         entry->cmdtype = CMDUNKNOWN;
12155         return;
12156
12157  builtin_success:
12158         if (!updatetbl) {
12159                 entry->cmdtype = CMDBUILTIN;
12160                 entry->u.cmd = bcmd;
12161                 return;
12162         }
12163         INT_OFF;
12164         cmdp = cmdlookup(name, 1);
12165         cmdp->cmdtype = CMDBUILTIN;
12166         cmdp->param.cmd = bcmd;
12167         INT_ON;
12168  success:
12169         cmdp->rehash = 0;
12170         entry->cmdtype = cmdp->cmdtype;
12171         entry->u = cmdp->param;
12172 }
12173
12174
12175 /* ============ trap.c */
12176
12177 /*
12178  * The trap builtin.
12179  */
12180 static int
12181 trapcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
12182 {
12183         char *action;
12184         char **ap;
12185         int signo;
12186
12187         nextopt(nullstr);
12188         ap = argptr;
12189         if (!*ap) {
12190                 for (signo = 0; signo < NSIG; signo++) {
12191                         if (trap[signo] != NULL) {
12192                                 out1fmt("trap -- %s %s\n",
12193                                                 single_quote(trap[signo]),
12194                                                 get_signame(signo));
12195                         }
12196                 }
12197                 return 0;
12198         }
12199         action = NULL;
12200         if (ap[1])
12201                 action = *ap++;
12202         while (*ap) {
12203                 signo = get_signum(*ap);
12204                 if (signo < 0)
12205                         ash_msg_and_raise_error("%s: bad trap", *ap);
12206                 INT_OFF;
12207                 if (action) {
12208                         if (LONE_DASH(action))
12209                                 action = NULL;
12210                         else
12211                                 action = ckstrdup(action);
12212                 }
12213                 free(trap[signo]);
12214                 trap[signo] = action;
12215                 if (signo != 0)
12216                         setsignal(signo);
12217                 INT_ON;
12218                 ap++;
12219         }
12220         return 0;
12221 }
12222
12223
12224 /* ============ Builtins */
12225
12226 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
12227 /*
12228  * Lists available builtins
12229  */
12230 static int
12231 helpcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
12232 {
12233         unsigned col;
12234         unsigned i;
12235
12236         out1fmt("\n"
12237                 "Built-in commands:\n"
12238                 "------------------\n");
12239         for (col = 0, i = 0; i < ARRAY_SIZE(builtintab); i++) {
12240                 col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '),
12241                                         builtintab[i].name + 1);
12242                 if (col > 60) {
12243                         out1fmt("\n");
12244                         col = 0;
12245                 }
12246         }
12247 #if ENABLE_FEATURE_SH_STANDALONE
12248         {
12249                 const char *a = applet_names;
12250                 while (*a) {
12251                         col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '), a);
12252                         if (col > 60) {
12253                                 out1fmt("\n");
12254                                 col = 0;
12255                         }
12256                         a += strlen(a) + 1;
12257                 }
12258         }
12259 #endif
12260         out1fmt("\n\n");
12261         return EXIT_SUCCESS;
12262 }
12263 #endif /* FEATURE_SH_EXTRA_QUIET */
12264
12265 /*
12266  * The export and readonly commands.
12267  */
12268 static int
12269 exportcmd(int argc UNUSED_PARAM, char **argv)
12270 {
12271         struct var *vp;
12272         char *name;
12273         const char *p;
12274         char **aptr;
12275         int flag = argv[0][0] == 'r' ? VREADONLY : VEXPORT;
12276
12277         if (nextopt("p") != 'p') {
12278                 aptr = argptr;
12279                 name = *aptr;
12280                 if (name) {
12281                         do {
12282                                 p = strchr(name, '=');
12283                                 if (p != NULL) {
12284                                         p++;
12285                                 } else {
12286                                         vp = *findvar(hashvar(name), name);
12287                                         if (vp) {
12288                                                 vp->flags |= flag;
12289                                                 continue;
12290                                         }
12291                                 }
12292                                 setvar(name, p, flag);
12293                         } while ((name = *++aptr) != NULL);
12294                         return 0;
12295                 }
12296         }
12297         showvars(argv[0], flag, 0);
12298         return 0;
12299 }
12300
12301 /*
12302  * Delete a function if it exists.
12303  */
12304 static void
12305 unsetfunc(const char *name)
12306 {
12307         struct tblentry *cmdp;
12308
12309         cmdp = cmdlookup(name, 0);
12310         if (cmdp!= NULL && cmdp->cmdtype == CMDFUNCTION)
12311                 delete_cmd_entry();
12312 }
12313
12314 /*
12315  * The unset builtin command.  We unset the function before we unset the
12316  * variable to allow a function to be unset when there is a readonly variable
12317  * with the same name.
12318  */
12319 static int
12320 unsetcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
12321 {
12322         char **ap;
12323         int i;
12324         int flag = 0;
12325         int ret = 0;
12326
12327         while ((i = nextopt("vf")) != '\0') {
12328                 flag = i;
12329         }
12330
12331         for (ap = argptr; *ap; ap++) {
12332                 if (flag != 'f') {
12333                         i = unsetvar(*ap);
12334                         ret |= i;
12335                         if (!(i & 2))
12336                                 continue;
12337                 }
12338                 if (flag != 'v')
12339                         unsetfunc(*ap);
12340         }
12341         return ret & 1;
12342 }
12343
12344
12345 /*      setmode.c      */
12346
12347 #include <sys/times.h>
12348
12349 static const unsigned char timescmd_str[] ALIGN1 = {
12350         ' ',  offsetof(struct tms, tms_utime),
12351         '\n', offsetof(struct tms, tms_stime),
12352         ' ',  offsetof(struct tms, tms_cutime),
12353         '\n', offsetof(struct tms, tms_cstime),
12354         0
12355 };
12356
12357 static int
12358 timescmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
12359 {
12360         long clk_tck, s, t;
12361         const unsigned char *p;
12362         struct tms buf;
12363
12364         clk_tck = sysconf(_SC_CLK_TCK);
12365         times(&buf);
12366
12367         p = timescmd_str;
12368         do {
12369                 t = *(clock_t *)(((char *) &buf) + p[1]);
12370                 s = t / clk_tck;
12371                 out1fmt("%ldm%ld.%.3lds%c",
12372                         s/60, s%60,
12373                         ((t - s * clk_tck) * 1000) / clk_tck,
12374                         p[0]);
12375         } while (*(p += 2));
12376
12377         return 0;
12378 }
12379
12380 #if ENABLE_SH_MATH_SUPPORT
12381 /*
12382  * The let builtin. partial stolen from GNU Bash, the Bourne Again SHell.
12383  * Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
12384  *
12385  * Copyright (C) 2003 Vladimir Oleynik <dzo@simtreas.ru>
12386  */
12387 static int
12388 letcmd(int argc UNUSED_PARAM, char **argv)
12389 {
12390         arith_t i;
12391
12392         argv++;
12393         if (!*argv)
12394                 ash_msg_and_raise_error("expression expected");
12395         do {
12396                 i = ash_arith(*argv);
12397         } while (*++argv);
12398
12399         return !i;
12400 }
12401 #endif /* SH_MATH_SUPPORT */
12402
12403
12404 /* ============ miscbltin.c
12405  *
12406  * Miscellaneous builtins.
12407  */
12408
12409 #undef rflag
12410
12411 #if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 1
12412 typedef enum __rlimit_resource rlim_t;
12413 #endif
12414
12415 /*
12416  * The read builtin. Options:
12417  *      -r              Do not interpret '\' specially
12418  *      -s              Turn off echo (tty only)
12419  *      -n NCHARS       Read NCHARS max
12420  *      -p PROMPT       Display PROMPT on stderr (if input is from tty)
12421  *      -t SECONDS      Timeout after SECONDS (tty or pipe only)
12422  *      -u FD           Read from given FD instead of fd 0
12423  * This uses unbuffered input, which may be avoidable in some cases.
12424  * TODO: bash also has:
12425  *      -a ARRAY        Read into array[0],[1],etc
12426  *      -d DELIM        End on DELIM char, not newline
12427  *      -e              Use line editing (tty only)
12428  */
12429 static int
12430 readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
12431 {
12432         static const char *const arg_REPLY[] = { "REPLY", NULL };
12433
12434         char **ap;
12435         int backslash;
12436         char c;
12437         int rflag;
12438         char *prompt;
12439         const char *ifs;
12440         char *p;
12441         int startword;
12442         int status;
12443         int i;
12444         int fd = 0;
12445 #if ENABLE_ASH_READ_NCHARS
12446         int nchars = 0; /* if != 0, -n is in effect */
12447         int silent = 0;
12448         struct termios tty, old_tty;
12449 #endif
12450 #if ENABLE_ASH_READ_TIMEOUT
12451         unsigned end_ms = 0;
12452         unsigned timeout = 0;
12453 #endif
12454
12455         rflag = 0;
12456         prompt = NULL;
12457         while ((i = nextopt("p:u:r"
12458                 USE_ASH_READ_TIMEOUT("t:")
12459                 USE_ASH_READ_NCHARS("n:s")
12460         )) != '\0') {
12461                 switch (i) {
12462                 case 'p':
12463                         prompt = optionarg;
12464                         break;
12465 #if ENABLE_ASH_READ_NCHARS
12466                 case 'n':
12467                         nchars = bb_strtou(optionarg, NULL, 10);
12468                         if (nchars < 0 || errno)
12469                                 ash_msg_and_raise_error("invalid count");
12470                         /* nchars == 0: off (bash 3.2 does this too) */
12471                         break;
12472                 case 's':
12473                         silent = 1;
12474                         break;
12475 #endif
12476 #if ENABLE_ASH_READ_TIMEOUT
12477                 case 't':
12478                         timeout = bb_strtou(optionarg, NULL, 10);
12479                         if (errno || timeout > UINT_MAX / 2048)
12480                                 ash_msg_and_raise_error("invalid timeout");
12481                         timeout *= 1000;
12482 #if 0 /* even bash have no -t N.NNN support */
12483                         ts.tv_sec = bb_strtou(optionarg, &p, 10);
12484                         ts.tv_usec = 0;
12485                         /* EINVAL means number is ok, but not terminated by NUL */
12486                         if (*p == '.' && errno == EINVAL) {
12487                                 char *p2;
12488                                 if (*++p) {
12489                                         int scale;
12490                                         ts.tv_usec = bb_strtou(p, &p2, 10);
12491                                         if (errno)
12492                                                 ash_msg_and_raise_error("invalid timeout");
12493                                         scale = p2 - p;
12494                                         /* normalize to usec */
12495                                         if (scale > 6)
12496                                                 ash_msg_and_raise_error("invalid timeout");
12497                                         while (scale++ < 6)
12498                                                 ts.tv_usec *= 10;
12499                                 }
12500                         } else if (ts.tv_sec < 0 || errno) {
12501                                 ash_msg_and_raise_error("invalid timeout");
12502                         }
12503                         if (!(ts.tv_sec | ts.tv_usec)) { /* both are 0? */
12504                                 ash_msg_and_raise_error("invalid timeout");
12505                         }
12506 #endif /* if 0 */
12507                         break;
12508 #endif
12509                 case 'r':
12510                         rflag = 1;
12511                         break;
12512                 case 'u':
12513                         fd = bb_strtou(optionarg, NULL, 10);
12514                         if (fd < 0 || errno)
12515                                 ash_msg_and_raise_error("invalid file descriptor");
12516                         break;
12517                 default:
12518                         break;
12519                 }
12520         }
12521         if (prompt && isatty(fd)) {
12522                 out2str(prompt);
12523         }
12524         ap = argptr;
12525         if (*ap == NULL)
12526                 ap = (char**)arg_REPLY;
12527         ifs = bltinlookup("IFS");
12528         if (ifs == NULL)
12529                 ifs = defifs;
12530 #if ENABLE_ASH_READ_NCHARS
12531         tcgetattr(fd, &tty);
12532         old_tty = tty;
12533         if (nchars || silent) {
12534                 if (nchars) {
12535                         tty.c_lflag &= ~ICANON;
12536                         tty.c_cc[VMIN] = nchars < 256 ? nchars : 255;
12537                 }
12538                 if (silent) {
12539                         tty.c_lflag &= ~(ECHO | ECHOK | ECHONL);
12540                 }
12541                 /* if tcgetattr failed, tcsetattr will fail too.
12542                  * Ignoring, it's harmless. */
12543                 tcsetattr(fd, TCSANOW, &tty);
12544         }
12545 #endif
12546
12547         status = 0;
12548         startword = 2;
12549         backslash = 0;
12550 #if ENABLE_ASH_READ_TIMEOUT
12551         if (timeout) /* NB: ensuring end_ms is nonzero */
12552                 end_ms = ((unsigned)(monotonic_us() / 1000) + timeout) | 1;
12553 #endif
12554         STARTSTACKSTR(p);
12555         do {
12556                 const char *is_ifs;
12557
12558 #if ENABLE_ASH_READ_TIMEOUT
12559                 if (end_ms) {
12560                         struct pollfd pfd[1];
12561                         pfd[0].fd = fd;
12562                         pfd[0].events = POLLIN;
12563                         timeout = end_ms - (unsigned)(monotonic_us() / 1000);
12564                         if ((int)timeout <= 0 /* already late? */
12565                          || safe_poll(pfd, 1, timeout) != 1 /* no? wait... */
12566                         ) { /* timed out! */
12567 #if ENABLE_ASH_READ_NCHARS
12568                                 tcsetattr(fd, TCSANOW, &old_tty);
12569 #endif
12570                                 return 1;
12571                         }
12572                 }
12573 #endif
12574                 if (nonblock_safe_read(fd, &c, 1) != 1) {
12575                         status = 1;
12576                         break;
12577                 }
12578                 if (c == '\0')
12579                         continue;
12580                 if (backslash) {
12581                         backslash = 0;
12582                         if (c != '\n')
12583                                 goto put;
12584                         continue;
12585                 }
12586                 if (!rflag && c == '\\') {
12587                         backslash = 1;
12588                         continue;
12589                 }
12590                 if (c == '\n')
12591                         break;
12592                 /* $IFS splitting */
12593 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 */
12594                 is_ifs = strchr(ifs, c);
12595                 if (startword && is_ifs) {
12596                         if (isspace(c))
12597                                 continue;
12598                         /* it is a non-space ifs char */
12599                         startword--;
12600                         if (startword == 1) /* first one? */
12601                                 continue; /* yes, it is not next word yet */
12602                 }
12603                 startword = 0;
12604                 if (ap[1] != NULL && is_ifs) {
12605                         const char *beg;
12606                         STACKSTRNUL(p);
12607                         beg = stackblock();
12608                         setvar(*ap, beg, 0);
12609                         ap++;
12610                         /* can we skip one non-space ifs char? (2: yes) */
12611                         startword = isspace(c) ? 2 : 1;
12612                         STARTSTACKSTR(p);
12613                         continue;
12614                 }
12615  put:
12616                 STPUTC(c, p);
12617         }
12618 /* end of do {} while: */
12619 #if ENABLE_ASH_READ_NCHARS
12620         while (--nchars);
12621 #else
12622         while (1);
12623 #endif
12624
12625 #if ENABLE_ASH_READ_NCHARS
12626         tcsetattr(fd, TCSANOW, &old_tty);
12627 #endif
12628
12629         STACKSTRNUL(p);
12630         /* Remove trailing space ifs chars */
12631         while ((char *)stackblock() <= --p && isspace(*p) && strchr(ifs, *p) != NULL)
12632                 *p = '\0';
12633         setvar(*ap, stackblock(), 0);
12634         while (*++ap != NULL)
12635                 setvar(*ap, nullstr, 0);
12636         return status;
12637 }
12638
12639 static int
12640 umaskcmd(int argc UNUSED_PARAM, char **argv)
12641 {
12642         static const char permuser[3] ALIGN1 = "ugo";
12643         static const char permmode[3] ALIGN1 = "rwx";
12644         static const short permmask[] ALIGN2 = {
12645                 S_IRUSR, S_IWUSR, S_IXUSR,
12646                 S_IRGRP, S_IWGRP, S_IXGRP,
12647                 S_IROTH, S_IWOTH, S_IXOTH
12648         };
12649
12650         char *ap;
12651         mode_t mask;
12652         int i;
12653         int symbolic_mode = 0;
12654
12655         while (nextopt("S") != '\0') {
12656                 symbolic_mode = 1;
12657         }
12658
12659         INT_OFF;
12660         mask = umask(0);
12661         umask(mask);
12662         INT_ON;
12663
12664         ap = *argptr;
12665         if (ap == NULL) {
12666                 if (symbolic_mode) {
12667                         char buf[18];
12668                         char *p = buf;
12669
12670                         for (i = 0; i < 3; i++) {
12671                                 int j;
12672
12673                                 *p++ = permuser[i];
12674                                 *p++ = '=';
12675                                 for (j = 0; j < 3; j++) {
12676                                         if ((mask & permmask[3 * i + j]) == 0) {
12677                                                 *p++ = permmode[j];
12678                                         }
12679                                 }
12680                                 *p++ = ',';
12681                         }
12682                         *--p = 0;
12683                         puts(buf);
12684                 } else {
12685                         out1fmt("%.4o\n", mask);
12686                 }
12687         } else {
12688                 if (isdigit((unsigned char) *ap)) {
12689                         mask = 0;
12690                         do {
12691                                 if (*ap >= '8' || *ap < '0')
12692                                         ash_msg_and_raise_error(illnum, argv[1]);
12693                                 mask = (mask << 3) + (*ap - '0');
12694                         } while (*++ap != '\0');
12695                         umask(mask);
12696                 } else {
12697                         mask = ~mask & 0777;
12698                         if (!bb_parse_mode(ap, &mask)) {
12699                                 ash_msg_and_raise_error("illegal mode: %s", ap);
12700                         }
12701                         umask(~mask & 0777);
12702                 }
12703         }
12704         return 0;
12705 }
12706
12707 /*
12708  * ulimit builtin
12709  *
12710  * This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
12711  * Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
12712  * ash by J.T. Conklin.
12713  *
12714  * Public domain.
12715  */
12716
12717 struct limits {
12718         uint8_t cmd;          /* RLIMIT_xxx fit into it */
12719         uint8_t factor_shift; /* shift by to get rlim_{cur,max} values */
12720         char    option;
12721 };
12722
12723 static const struct limits limits_tbl[] = {
12724 #ifdef RLIMIT_CPU
12725         { RLIMIT_CPU,        0, 't' },
12726 #endif
12727 #ifdef RLIMIT_FSIZE
12728         { RLIMIT_FSIZE,      9, 'f' },
12729 #endif
12730 #ifdef RLIMIT_DATA
12731         { RLIMIT_DATA,      10, 'd' },
12732 #endif
12733 #ifdef RLIMIT_STACK
12734         { RLIMIT_STACK,     10, 's' },
12735 #endif
12736 #ifdef RLIMIT_CORE
12737         { RLIMIT_CORE,       9, 'c' },
12738 #endif
12739 #ifdef RLIMIT_RSS
12740         { RLIMIT_RSS,       10, 'm' },
12741 #endif
12742 #ifdef RLIMIT_MEMLOCK
12743         { RLIMIT_MEMLOCK,   10, 'l' },
12744 #endif
12745 #ifdef RLIMIT_NPROC
12746         { RLIMIT_NPROC,      0, 'p' },
12747 #endif
12748 #ifdef RLIMIT_NOFILE
12749         { RLIMIT_NOFILE,     0, 'n' },
12750 #endif
12751 #ifdef RLIMIT_AS
12752         { RLIMIT_AS,        10, 'v' },
12753 #endif
12754 #ifdef RLIMIT_LOCKS
12755         { RLIMIT_LOCKS,      0, 'w' },
12756 #endif
12757 };
12758 static const char limits_name[] =
12759 #ifdef RLIMIT_CPU
12760         "time(seconds)" "\0"
12761 #endif
12762 #ifdef RLIMIT_FSIZE
12763         "file(blocks)" "\0"
12764 #endif
12765 #ifdef RLIMIT_DATA
12766         "data(kb)" "\0"
12767 #endif
12768 #ifdef RLIMIT_STACK
12769         "stack(kb)" "\0"
12770 #endif
12771 #ifdef RLIMIT_CORE
12772         "coredump(blocks)" "\0"
12773 #endif
12774 #ifdef RLIMIT_RSS
12775         "memory(kb)" "\0"
12776 #endif
12777 #ifdef RLIMIT_MEMLOCK
12778         "locked memory(kb)" "\0"
12779 #endif
12780 #ifdef RLIMIT_NPROC
12781         "process" "\0"
12782 #endif
12783 #ifdef RLIMIT_NOFILE
12784         "nofiles" "\0"
12785 #endif
12786 #ifdef RLIMIT_AS
12787         "vmemory(kb)" "\0"
12788 #endif
12789 #ifdef RLIMIT_LOCKS
12790         "locks" "\0"
12791 #endif
12792 ;
12793
12794 enum limtype { SOFT = 0x1, HARD = 0x2 };
12795
12796 static void
12797 printlim(enum limtype how, const struct rlimit *limit,
12798                         const struct limits *l)
12799 {
12800         rlim_t val;
12801
12802         val = limit->rlim_max;
12803         if (how & SOFT)
12804                 val = limit->rlim_cur;
12805
12806         if (val == RLIM_INFINITY)
12807                 out1fmt("unlimited\n");
12808         else {
12809                 val >>= l->factor_shift;
12810                 out1fmt("%lld\n", (long long) val);
12811         }
12812 }
12813
12814 static int
12815 ulimitcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
12816 {
12817         int c;
12818         rlim_t val = 0;
12819         enum limtype how = SOFT | HARD;
12820         const struct limits *l;
12821         int set, all = 0;
12822         int optc, what;
12823         struct rlimit limit;
12824
12825         what = 'f';
12826         while ((optc = nextopt("HSa"
12827 #ifdef RLIMIT_CPU
12828                                 "t"
12829 #endif
12830 #ifdef RLIMIT_FSIZE
12831                                 "f"
12832 #endif
12833 #ifdef RLIMIT_DATA
12834                                 "d"
12835 #endif
12836 #ifdef RLIMIT_STACK
12837                                 "s"
12838 #endif
12839 #ifdef RLIMIT_CORE
12840                                 "c"
12841 #endif
12842 #ifdef RLIMIT_RSS
12843                                 "m"
12844 #endif
12845 #ifdef RLIMIT_MEMLOCK
12846                                 "l"
12847 #endif
12848 #ifdef RLIMIT_NPROC
12849                                 "p"
12850 #endif
12851 #ifdef RLIMIT_NOFILE
12852                                 "n"
12853 #endif
12854 #ifdef RLIMIT_AS
12855                                 "v"
12856 #endif
12857 #ifdef RLIMIT_LOCKS
12858                                 "w"
12859 #endif
12860                                         )) != '\0')
12861                 switch (optc) {
12862                 case 'H':
12863                         how = HARD;
12864                         break;
12865                 case 'S':
12866                         how = SOFT;
12867                         break;
12868                 case 'a':
12869                         all = 1;
12870                         break;
12871                 default:
12872                         what = optc;
12873                 }
12874
12875         for (l = limits_tbl; l->option != what; l++)
12876                 continue;
12877
12878         set = *argptr ? 1 : 0;
12879         if (set) {
12880                 char *p = *argptr;
12881
12882                 if (all || argptr[1])
12883                         ash_msg_and_raise_error("too many arguments");
12884                 if (strncmp(p, "unlimited\n", 9) == 0)
12885                         val = RLIM_INFINITY;
12886                 else {
12887                         val = (rlim_t) 0;
12888
12889                         while ((c = *p++) >= '0' && c <= '9') {
12890                                 val = (val * 10) + (long)(c - '0');
12891                                 // val is actually 'unsigned long int' and can't get < 0
12892                                 if (val < (rlim_t) 0)
12893                                         break;
12894                         }
12895                         if (c)
12896                                 ash_msg_and_raise_error("bad number");
12897                         val <<= l->factor_shift;
12898                 }
12899         }
12900         if (all) {
12901                 const char *lname = limits_name;
12902                 for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
12903                         getrlimit(l->cmd, &limit);
12904                         out1fmt("%-20s ", lname);
12905                         lname += strlen(lname) + 1;
12906                         printlim(how, &limit, l);
12907                 }
12908                 return 0;
12909         }
12910
12911         getrlimit(l->cmd, &limit);
12912         if (set) {
12913                 if (how & HARD)
12914                         limit.rlim_max = val;
12915                 if (how & SOFT)
12916                         limit.rlim_cur = val;
12917                 if (setrlimit(l->cmd, &limit) < 0)
12918                         ash_msg_and_raise_error("error setting limit (%m)");
12919         } else {
12920                 printlim(how, &limit, l);
12921         }
12922         return 0;
12923 }
12924
12925 /* ============ main() and helpers */
12926
12927 /*
12928  * Called to exit the shell.
12929  */
12930 static void exitshell(void) NORETURN;
12931 static void
12932 exitshell(void)
12933 {
12934         struct jmploc loc;
12935         char *p;
12936         int status;
12937
12938         status = exitstatus;
12939         TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
12940         if (setjmp(loc.loc)) {
12941                 if (exception_type == EXEXIT)
12942 /* dash bug: it just does _exit(exitstatus) here
12943  * but we have to do setjobctl(0) first!
12944  * (bug is still not fixed in dash-0.5.3 - if you run dash
12945  * under Midnight Commander, on exit from dash MC is backgrounded) */
12946                         status = exitstatus;
12947                 goto out;
12948         }
12949         exception_handler = &loc;
12950         p = trap[0];
12951         if (p) {
12952                 trap[0] = NULL;
12953                 evalstring(p, 0);
12954         }
12955         flush_stdout_stderr();
12956  out:
12957         setjobctl(0);
12958         _exit(status);
12959         /* NOTREACHED */
12960 }
12961
12962 static void
12963 init(void)
12964 {
12965         /* from input.c: */
12966         basepf.next_to_pgetc = basepf.buf = basebuf;
12967
12968         /* from trap.c: */
12969         signal(SIGCHLD, SIG_DFL);
12970
12971         /* from var.c: */
12972         {
12973                 char **envp;
12974                 char ppid[sizeof(int)*3 + 1];
12975                 const char *p;
12976                 struct stat st1, st2;
12977
12978                 initvar();
12979                 for (envp = environ; envp && *envp; envp++) {
12980                         if (strchr(*envp, '=')) {
12981                                 setvareq(*envp, VEXPORT|VTEXTFIXED);
12982                         }
12983                 }
12984
12985                 snprintf(ppid, sizeof(ppid), "%u", (unsigned) getppid());
12986                 setvar("PPID", ppid, 0);
12987
12988                 p = lookupvar("PWD");
12989                 if (p)
12990                         if (*p != '/' || stat(p, &st1) || stat(".", &st2)
12991                          || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
12992                                 p = '\0';
12993                 setpwd(p, 0);
12994         }
12995 }
12996
12997 /*
12998  * Process the shell command line arguments.
12999  */
13000 static void
13001 procargs(char **argv)
13002 {
13003         int i;
13004         const char *xminusc;
13005         char **xargv;
13006
13007         xargv = argv;
13008         arg0 = xargv[0];
13009         /* if (xargv[0]) - mmm, this is always true! */
13010                 xargv++;
13011         for (i = 0; i < NOPTS; i++)
13012                 optlist[i] = 2;
13013         argptr = xargv;
13014         if (options(1)) {
13015                 /* it already printed err message */
13016                 raise_exception(EXERROR);
13017         }
13018         xargv = argptr;
13019         xminusc = minusc;
13020         if (*xargv == NULL) {
13021                 if (xminusc)
13022                         ash_msg_and_raise_error(bb_msg_requires_arg, "-c");
13023                 sflag = 1;
13024         }
13025         if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1))
13026                 iflag = 1;
13027         if (mflag == 2)
13028                 mflag = iflag;
13029         for (i = 0; i < NOPTS; i++)
13030                 if (optlist[i] == 2)
13031                         optlist[i] = 0;
13032 #if DEBUG == 2
13033         debug = 1;
13034 #endif
13035         /* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
13036         if (xminusc) {
13037                 minusc = *xargv++;
13038                 if (*xargv)
13039                         goto setarg0;
13040         } else if (!sflag) {
13041                 setinputfile(*xargv, 0);
13042  setarg0:
13043                 arg0 = *xargv++;
13044                 commandname = arg0;
13045         }
13046
13047         shellparam.p = xargv;
13048 #if ENABLE_ASH_GETOPTS
13049         shellparam.optind = 1;
13050         shellparam.optoff = -1;
13051 #endif
13052         /* assert(shellparam.malloced == 0 && shellparam.nparam == 0); */
13053         while (*xargv) {
13054                 shellparam.nparam++;
13055                 xargv++;
13056         }
13057         optschanged();
13058 }
13059
13060 /*
13061  * Read /etc/profile or .profile.
13062  */
13063 static void
13064 read_profile(const char *name)
13065 {
13066         int skip;
13067
13068         if (setinputfile(name, INPUT_PUSH_FILE | INPUT_NOFILE_OK) < 0)
13069                 return;
13070         skip = cmdloop(0);
13071         popfile();
13072         if (skip)
13073                 exitshell();
13074 }
13075
13076 /*
13077  * This routine is called when an error or an interrupt occurs in an
13078  * interactive shell and control is returned to the main command loop.
13079  */
13080 static void
13081 reset(void)
13082 {
13083         /* from eval.c: */
13084         evalskip = 0;
13085         loopnest = 0;
13086         /* from input.c: */
13087         g_parsefile->left_in_buffer = 0;
13088         g_parsefile->left_in_line = 0;      /* clear input buffer */
13089         popallfiles();
13090         /* from parser.c: */
13091         tokpushback = 0;
13092         checkkwd = 0;
13093         /* from redir.c: */
13094         clearredir(/*drop:*/ 0);
13095 }
13096
13097 #if PROFILE
13098 static short profile_buf[16384];
13099 extern int etext();
13100 #endif
13101
13102 /*
13103  * Main routine.  We initialize things, parse the arguments, execute
13104  * profiles if we're a login shell, and then call cmdloop to execute
13105  * commands.  The setjmp call sets up the location to jump to when an
13106  * exception occurs.  When an exception occurs the variable "state"
13107  * is used to figure out how far we had gotten.
13108  */
13109 int ash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
13110 int ash_main(int argc UNUSED_PARAM, char **argv)
13111 {
13112         const char *shinit;
13113         volatile smallint state;
13114         struct jmploc jmploc;
13115         struct stackmark smark;
13116
13117         /* Initialize global data */
13118         INIT_G_misc();
13119         INIT_G_memstack();
13120         INIT_G_var();
13121 #if ENABLE_ASH_ALIAS
13122         INIT_G_alias();
13123 #endif
13124         INIT_G_cmdtable();
13125
13126 #if PROFILE
13127         monitor(4, etext, profile_buf, sizeof(profile_buf), 50);
13128 #endif
13129
13130 #if ENABLE_FEATURE_EDITING
13131         line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
13132 #endif
13133         state = 0;
13134         if (setjmp(jmploc.loc)) {
13135                 smallint e;
13136                 smallint s;
13137
13138                 reset();
13139
13140                 e = exception_type;
13141                 if (e == EXERROR)
13142                         exitstatus = 2;
13143                 s = state;
13144                 if (e == EXEXIT || s == 0 || iflag == 0 || shlvl)
13145                         exitshell();
13146                 if (e == EXINT)
13147                         outcslow('\n', stderr);
13148
13149                 popstackmark(&smark);
13150                 FORCE_INT_ON; /* enable interrupts */
13151                 if (s == 1)
13152                         goto state1;
13153                 if (s == 2)
13154                         goto state2;
13155                 if (s == 3)
13156                         goto state3;
13157                 goto state4;
13158         }
13159         exception_handler = &jmploc;
13160 #if DEBUG
13161         opentrace();
13162         TRACE(("Shell args: "));
13163         trace_puts_args(argv);
13164 #endif
13165         rootpid = getpid();
13166
13167 #if ENABLE_ASH_RANDOM_SUPPORT
13168         /* Can use monotonic_ns() for better randomness but for now it is
13169          * not used anywhere else in busybox... so avoid bloat */
13170         random_galois_LFSR = random_LCG = rootpid + monotonic_us();
13171 #endif
13172         init();
13173         setstackmark(&smark);
13174         procargs(argv);
13175
13176 #if ENABLE_FEATURE_EDITING_SAVEHISTORY
13177         if (iflag) {
13178                 const char *hp = lookupvar("HISTFILE");
13179
13180                 if (hp == NULL) {
13181                         hp = lookupvar("HOME");
13182                         if (hp != NULL) {
13183                                 char *defhp = concat_path_file(hp, ".ash_history");
13184                                 setvar("HISTFILE", defhp, 0);
13185                                 free(defhp);
13186                         }
13187                 }
13188         }
13189 #endif
13190         if (/* argv[0] && */ argv[0][0] == '-')
13191                 isloginsh = 1;
13192         if (isloginsh) {
13193                 state = 1;
13194                 read_profile("/etc/profile");
13195  state1:
13196                 state = 2;
13197                 read_profile(".profile");
13198         }
13199  state2:
13200         state = 3;
13201         if (
13202 #ifndef linux
13203          getuid() == geteuid() && getgid() == getegid() &&
13204 #endif
13205          iflag
13206         ) {
13207                 shinit = lookupvar("ENV");
13208                 if (shinit != NULL && *shinit != '\0') {
13209                         read_profile(shinit);
13210                 }
13211         }
13212  state3:
13213         state = 4;
13214         if (minusc) {
13215                 /* evalstring pushes parsefile stack.
13216                  * Ensure we don't falsely claim that 0 (stdin)
13217                  * is one of stacked source fds.
13218                  * Testcase: ash -c 'exec 1>&0' must not complain. */
13219                 if (!sflag)
13220                         g_parsefile->fd = -1;
13221                 evalstring(minusc, 0);
13222         }
13223
13224         if (sflag || minusc == NULL) {
13225 #if ENABLE_FEATURE_EDITING_SAVEHISTORY
13226                 if (iflag) {
13227                         const char *hp = lookupvar("HISTFILE");
13228                         if (hp)
13229                                 line_input_state->hist_file = hp;
13230                 }
13231 #endif
13232  state4: /* XXX ??? - why isn't this before the "if" statement */
13233                 cmdloop(1);
13234         }
13235 #if PROFILE
13236         monitor(0);
13237 #endif
13238 #ifdef GPROF
13239         {
13240                 extern void _mcleanup(void);
13241                 _mcleanup();
13242         }
13243 #endif
13244         exitshell();
13245         /* NOTREACHED */
13246 }
13247
13248
13249 /*-
13250  * Copyright (c) 1989, 1991, 1993, 1994
13251  *      The Regents of the University of California.  All rights reserved.
13252  *
13253  * This code is derived from software contributed to Berkeley by
13254  * Kenneth Almquist.
13255  *
13256  * Redistribution and use in source and binary forms, with or without
13257  * modification, are permitted provided that the following conditions
13258  * are met:
13259  * 1. Redistributions of source code must retain the above copyright
13260  *    notice, this list of conditions and the following disclaimer.
13261  * 2. Redistributions in binary form must reproduce the above copyright
13262  *    notice, this list of conditions and the following disclaimer in the
13263  *    documentation and/or other materials provided with the distribution.
13264  * 3. Neither the name of the University nor the names of its contributors
13265  *    may be used to endorse or promote products derived from this software
13266  *    without specific prior written permission.
13267  *
13268  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
13269  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
13270  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
13271  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
13272  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
13273  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
13274  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
13275  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
13276  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
13277  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
13278  * SUCH DAMAGE.
13279  */