contrib/tcsh-6/sh.exec.c

   1 /* $Header: /p/tcsh/cvsroot/tcsh/sh.exec.c,v 3.80 2014/07/11 14:57:55 christos Exp $ */
   2 /*
   3  * sh.exec.c: Search, find, and execute a command!
   4  */
   5 /*-
   6  * Copyright (c) 1980, 1991 The Regents of the University of California.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33 #include "sh.h"
  34
  35 RCSID("$tcsh: sh.exec.c,v 3.80 2014/07/11 14:57:55 christos Exp $")
  36
  37 #include "tc.h"
  38 #include "tw.h"
  39 #ifdef WINNT_NATIVE
  40 #include <nt.const.h>
  41 #endif /*WINNT_NATIVE*/
  42
  43 /*
  44  * C shell
  45  */
  46
  47 #ifndef OLDHASH
  48 # define FASTHASH       /* Fast hashing is the default */
  49 #endif /* OLDHASH */
  50
  51 /*
  52  * System level search and execute of a command.
  53  * We look in each directory for the specified command name.
  54  * If the name contains a '/' then we execute only the full path name.
  55  * If there is no search path then we execute only full path names.
  56  */
  57
  58 /*
  59  * As we search for the command we note the first non-trivial error
  60  * message for presentation to the user.  This allows us often
  61  * to show that a file has the wrong mode/no access when the file
  62  * is not in the last component of the search path, so we must
  63  * go on after first detecting the error.
  64  */
  65 static char *exerr;             /* Execution error message */
  66 static Char *expath;            /* Path for exerr */
  67
  68 /*
  69  * The two part hash function is designed to let texec() call the
  70  * more expensive hashname() only once and the simple hash() several
  71  * times (once for each path component checked).
  72  * Byte size is assumed to be 8.
  73  */
  74 #define BITS_PER_BYTE   8
  75
  76 #ifdef FASTHASH
  77 /*
  78  * xhash is an array of hash buckets which are used to hash execs.  If
  79  * it is allocated (havhash true), then to tell if ``name'' is
  80  * (possibly) present in the i'th component of the variable path, look
  81  * at the [hashname(name)] bucket of size [hashwidth] bytes, in the [i
  82  * mod size*8]'th bit.  The cache size is defaults to a length of 1024
  83  * buckets, each 1 byte wide.  This implementation guarantees that
  84  * objects n bytes wide will be aligned on n byte boundaries.
  85  */
  86 # define HSHMUL         241
  87
  88 static unsigned long *xhash = NULL;
  89 static unsigned int hashlength = 0, uhashlength = 0;
  90 static unsigned int hashwidth = 0, uhashwidth = 0;
  91 static int hashdebug = 0;
  92
  93 # define hash(a, b)     (((a) * HSHMUL + (b)) % (hashlength))
  94 # define widthof(t)     (sizeof(t) * BITS_PER_BYTE)
  95 # define tbit(f, i, t)  (((t *) xhash)[(f)] &  \
  96                          (1UL << (i & (widthof(t) - 1))))
  97 # define tbis(f, i, t)  (((t *) xhash)[(f)] |= \
  98                          (1UL << (i & (widthof(t) - 1))))
  99 # define cbit(f, i)     tbit(f, i, unsigned char)
 100 # define cbis(f, i)     tbis(f, i, unsigned char)
 101 # define sbit(f, i)     tbit(f, i, unsigned short)
 102 # define sbis(f, i)     tbis(f, i, unsigned short)
 103 # define ibit(f, i)     tbit(f, i, unsigned int)
 104 # define ibis(f, i)     tbis(f, i, unsigned int)
 105 # define lbit(f, i)     tbit(f, i, unsigned long)
 106 # define lbis(f, i)     tbis(f, i, unsigned long)
 107
 108 # define bit(f, i) (hashwidth==sizeof(unsigned char)  ? cbit(f,i) : \
 109                     ((hashwidth==sizeof(unsigned short) ? sbit(f,i) : \
 110                      ((hashwidth==sizeof(unsigned int)   ? ibit(f,i) : \
 111                      lbit(f,i))))))
 112 # define bis(f, i) (hashwidth==sizeof(unsigned char)  ? cbis(f,i) : \
 113                     ((hashwidth==sizeof(unsigned short) ? sbis(f,i) : \
 114                      ((hashwidth==sizeof(unsigned int)   ? ibis(f,i) : \
 115                      lbis(f,i))))))
 116 #else /* OLDHASH */
 117 /*
 118  * Xhash is an array of HSHSIZ bits (HSHSIZ / 8 chars), which are used
 119  * to hash execs.  If it is allocated (havhash true), then to tell
 120  * whether ``name'' is (possibly) present in the i'th component
 121  * of the variable path, you look at the bit in xhash indexed by
 122  * hash(hashname("name"), i).  This is setup automatically
 123  * after .login is executed, and recomputed whenever ``path'' is
 124  * changed.
 125  */
 126 # define HSHSIZ         8192    /* 1k bytes */
 127 # define HSHMASK                (HSHSIZ - 1)
 128 # define HSHMUL         243
 129 static char xhash[HSHSIZ / BITS_PER_BYTE];
 130
 131 # define hash(a, b)     (((a) * HSHMUL + (b)) & HSHMASK)
 132 # define bit(h, b)      ((h)[(b) >> 3] & 1 << ((b) & 7))        /* bit test */
 133 # define bis(h, b)      ((h)[(b) >> 3] |= 1 << ((b) & 7))       /* bit set */
 134
 135 #endif /* FASTHASH */
 136
 137 #ifdef VFORK
 138 static int hits, misses;
 139 #endif /* VFORK */
 140
 141 /* Dummy search path for just absolute search when no path */
 142 static Char *justabs[] = {STRNULL, 0};
 143
 144 static  void    pexerr          (void) __attribute__((__noreturn__));
 145 static  void    texec           (Char *, Char **);
 146 int     hashname        (Char *);
 147 static  int     iscommand       (Char *);
 148
 149 void
 150 doexec(struct command *t, int do_glob)
 151 {
 152     Char *dp, **pv, **opv, **av, *sav;
 153     struct varent *v;
 154     int slash, gflag, rehashed;
 155     int hashval, i;
 156     Char   *blk[2];
 157
 158     /*
 159      * Glob the command name. We will search $path even if this does something,
 160      * as in sh but not in csh.  One special case: if there is no PATH, then we
 161      * execute only commands which start with '/'.
 162      */
 163     blk[0] = t->t_dcom[0];
 164     blk[1] = 0;
 165     gflag = 0;
 166     if (do_glob)
 167         gflag = tglob(blk);
 168     if (gflag) {
 169         pv = globall(blk, gflag);
 170         if (pv == 0) {
 171             setname(short2str(blk[0]));
 172             stderror(ERR_NAME | ERR_NOMATCH);
 173         }
 174     }
 175     else
 176         pv = saveblk(blk);
 177     cleanup_push(pv, blk_cleanup);
 178
 179     trim(pv);
 180
 181     exerr = 0;
 182     expath = Strsave(pv[0]);
 183 #ifdef VFORK
 184     Vexpath = expath;
 185 #endif /* VFORK */
 186
 187     v = adrof(STRpath);
 188     if (v == 0 && expath[0] != '/' && expath[0] != '.')
 189         pexerr();
 190     slash = any(short2str(expath), '/');
 191
 192     /*
 193      * Glob the argument list, if necessary. Otherwise trim off the quote bits.
 194      */
 195     gflag = 0;
 196     av = &t->t_dcom[1];
 197     if (do_glob)
 198         gflag = tglob(av);
 199     if (gflag) {
 200         av = globall(av, gflag);
 201         if (av == 0) {
 202             setname(short2str(expath));
 203             stderror(ERR_NAME | ERR_NOMATCH);
 204         }
 205     }
 206     else
 207         av = saveblk(av);
 208
 209     blkfree(t->t_dcom);
 210     cleanup_ignore(pv);
 211     cleanup_until(pv);
 212     t->t_dcom = blkspl(pv, av);
 213     xfree(pv);
 214     xfree(av);
 215     av = t->t_dcom;
 216     trim(av);
 217
 218     if (*av == NULL || **av == '\0')
 219         pexerr();
 220
 221     xechoit(av);                /* Echo command if -x */
 222 #ifdef CLOSE_ON_EXEC
 223     /*
 224      * Since all internal file descriptors are set to close on exec, we don't
 225      * need to close them explicitly here.  Just reorient ourselves for error
 226      * messages.
 227      */
 228     SHIN = 0;
 229     SHOUT = 1;
 230     SHDIAG = 2;
 231     OLDSTD = 0;
 232     isoutatty = isatty(SHOUT);
 233     isdiagatty = isatty(SHDIAG);
 234 #else
 235     closech();                  /* Close random fd's */
 236 #endif
 237     /*
 238      * We must do this AFTER any possible forking (like `foo` in glob) so that
 239      * this shell can still do subprocesses.
 240      */
 241     {
 242         sigset_t set;
 243         sigemptyset(&set);
 244         sigaddset(&set, SIGINT);
 245         sigaddset(&set, SIGCHLD);
 246         sigprocmask(SIG_UNBLOCK, &set, NULL);
 247     }
 248     pintr_disabled = 0;
 249     pchild_disabled = 0;
 250
 251     /*
 252      * If no path, no words in path, or a / in the filename then restrict the
 253      * command search.
 254      */
 255     if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
 256         opv = justabs;
 257     else
 258         opv = v->vec;
 259     sav = Strspl(STRslash, *av);/* / command name for postpending */
 260 #ifndef VFORK
 261     cleanup_push(sav, xfree);
 262 #else /* VFORK */
 263     Vsav = sav;
 264 #endif /* VFORK */
 265     hashval = havhash ? hashname(*av) : 0;
 266
 267     rehashed = 0;
 268 retry:
 269     pv = opv;
 270     i = 0;
 271 #ifdef VFORK
 272     hits++;
 273 #endif /* VFORK */
 274     do {
 275         /*
 276          * Try to save time by looking at the hash table for where this command
 277          * could be.  If we are doing delayed hashing, then we put the names in
 278          * one at a time, as the user enters them.  This is kinda like Korn
 279          * Shell's "tracked aliases".
 280          */
 281         if (!slash && ABSOLUTEP(pv[0]) && havhash) {
 282 #ifdef FASTHASH
 283             if (!bit(hashval, i))
 284                 goto cont;
 285 #else /* OLDHASH */
 286             int hashval1 = hash(hashval, i);
 287             if (!bit(xhash, hashval1))
 288                 goto cont;
 289 #endif /* FASTHASH */
 290         }
 291         if (pv[0][0] == 0 || eq(pv[0], STRdot)) /* don't make ./xxx */
 292             texec(*av, av);
 293         else {
 294             dp = Strspl(*pv, sav);
 295 #ifndef VFORK
 296             cleanup_push(dp, xfree);
 297 #else /* VFORK */
 298             Vdp = dp;
 299 #endif /* VFORK */
 300
 301             texec(dp, av);
 302 #ifndef VFORK
 303             cleanup_until(dp);
 304 #else /* VFORK */
 305             Vdp = 0;
 306             xfree(dp);
 307 #endif /* VFORK */
 308         }
 309 #ifdef VFORK
 310         misses++;
 311 #endif /* VFORK */
 312 cont:
 313         pv++;
 314         i++;
 315     } while (*pv);
 316 #ifdef VFORK
 317     hits--;
 318 #endif /* VFORK */
 319     if (adrof(STRautorehash) && !rehashed && havhash && opv != justabs) {
 320         dohash(NULL, NULL);
 321         rehashed = 1;
 322         goto retry;
 323     }
 324 #ifndef VFORK
 325     cleanup_until(sav);
 326 #else /* VFORK */
 327     Vsav = 0;
 328     xfree(sav);
 329 #endif /* VFORK */
 330     pexerr();
 331 }
 332
 333 static void
 334 pexerr(void)
 335 {
 336     /* Couldn't find the damn thing */
 337     if (expath) {
 338         setname(short2str(expath));
 339 #ifdef VFORK
 340         Vexpath = 0;
 341 #endif /* VFORK */
 342         xfree(expath);
 343         expath = 0;
 344     }
 345     else
 346         setname("");
 347     if (exerr)
 348         stderror(ERR_NAME | ERR_STRING, exerr);
 349     stderror(ERR_NAME | ERR_COMMAND);
 350 }
 351
 352 /*
 353  * Execute command f, arg list t.
 354  * Record error message if not found.
 355  * Also do shell scripts here.
 356  */
 357 static void
 358 texec(Char *sf, Char **st)
 359 {
 360     char **t;
 361     char *f;
 362     struct varent *v;
 363     Char  **vp;
 364     Char   *lastsh[2];
 365     char    pref[2];
 366     int     fd;
 367     Char   *st0, **ost;
 368
 369     /* The order for the conversions is significant */
 370     t = short2blk(st);
 371     f = short2str(sf);
 372 #ifdef VFORK
 373     Vt = t;
 374 #endif /* VFORK */
 375     errno = 0;                  /* don't use a previous error */
 376 #ifdef apollo
 377     /*
 378      * If we try to execute an nfs mounted directory on the apollo, we
 379      * hang forever. So until apollo fixes that..
 380      */
 381     {
 382         struct stat stb;
 383         if (stat(f, &stb) == 0 && S_ISDIR(stb.st_mode))
 384             errno = EISDIR;
 385     }
 386     if (errno == 0)
 387 #endif /* apollo */
 388     {
 389 #ifdef ISC_POSIX_EXEC_BUG
 390         __setostype(0);         /* "0" is "__OS_SYSV" in <sys/user.h> */
 391 #endif /* ISC_POSIX_EXEC_BUG */
 392         (void) execv(f, t);
 393 #ifdef ISC_POSIX_EXEC_BUG
 394         __setostype(1);         /* "1" is "__OS_POSIX" in <sys/user.h> */
 395 #endif /* ISC_POSIX_EXEC_BUG */
 396     }
 397 #ifdef VFORK
 398     Vt = 0;
 399 #endif /* VFORK */
 400     blkfree((Char **) t);
 401     switch (errno) {
 402
 403     case ENOEXEC:
 404 #ifdef WINNT_NATIVE
 405                 nt_feed_to_cmd(f,t);
 406 #endif /* WINNT_NATIVE */
 407         /*
 408          * From: casper@fwi.uva.nl (Casper H.S. Dik) If we could not execute
 409          * it, don't feed it to the shell if it looks like a binary!
 410          */
 411         if ((fd = xopen(f, O_RDONLY|O_LARGEFILE)) != -1) {
 412             int nread;
 413             if ((nread = xread(fd, pref, 2)) == 2) {
 414                 if (!isprint((unsigned char)pref[0]) &&
 415                     (pref[0] != '\n' && pref[0] != '\t')) {
 416                     int err;
 417
 418                     err = errno;
 419                     xclose(fd);
 420                     /*
 421                      * We *know* what ENOEXEC means.
 422                      */
 423                     stderror(ERR_ARCH, f, strerror(err));
 424                 }
 425             }
 426             else if (nread < 0) {
 427 #ifdef convex
 428                 int err;
 429
 430                 err = errno;
 431                 xclose(fd);
 432                 /* need to print error incase the file is migrated */
 433                 stderror(ERR_SYSTEM, f, strerror(err));
 434 #endif
 435             }
 436 #ifdef _PATH_BSHELL
 437             else {
 438                 pref[0] = '#';
 439                 pref[1] = '\0';
 440             }
 441 #endif
 442         }
 443 #ifdef HASHBANG
 444         if (fd == -1 ||
 445             pref[0] != '#' || pref[1] != '!' || hashbang(fd, &vp) == -1) {
 446 #endif /* HASHBANG */
 447         /*
 448          * If there is an alias for shell, then put the words of the alias in
 449          * front of the argument list replacing the command name. Note no
 450          * interpretation of the words at this point.
 451          */
 452             v = adrof1(STRshell, &aliases);
 453             if (v == NULL || v->vec == NULL) {
 454                 vp = lastsh;
 455                 vp[0] = adrof(STRshell) ? varval(STRshell) : STR_SHELLPATH;
 456                 vp[1] = NULL;
 457 #ifdef _PATH_BSHELL
 458                 if (fd != -1
 459 # ifndef ISC    /* Compatible with ISC's /bin/csh */
 460                     && pref[0] != '#'
 461 # endif /* ISC */
 462                     )
 463                     vp[0] = STR_BSHELL;
 464 #endif
 465                 vp = saveblk(vp);
 466             }
 467             else
 468                 vp = saveblk(v->vec);
 469 #ifdef HASHBANG
 470         }
 471 #endif /* HASHBANG */
 472         if (fd != -1)
 473             xclose(fd);
 474
 475         st0 = st[0];
 476         st[0] = sf;
 477         ost = st;
 478         st = blkspl(vp, st);    /* Splice up the new arglst */
 479         ost[0] = st0;
 480         sf = *st;
 481         /* The order for the conversions is significant */
 482         t = short2blk(st);
 483         f = short2str(sf);
 484         xfree(st);
 485         blkfree((Char **) vp);
 486 #ifdef VFORK
 487         Vt = t;
 488 #endif /* VFORK */
 489 #ifdef ISC_POSIX_EXEC_BUG
 490         __setostype(0);         /* "0" is "__OS_SYSV" in <sys/user.h> */
 491 #endif /* ISC_POSIX_EXEC_BUG */
 492         (void) execv(f, t);
 493 #ifdef ISC_POSIX_EXEC_BUG
 494         __setostype(1);         /* "1" is "__OS_POSIX" in <sys/user.h> */
 495 #endif /* ISC_POSIX_EXEC_BUG */
 496 #ifdef VFORK
 497         Vt = 0;
 498 #endif /* VFORK */
 499         blkfree((Char **) t);
 500         /* The sky is falling, the sky is falling! */
 501         stderror(ERR_SYSTEM, f, strerror(errno));
 502         break;
 503
 504     case ENOMEM:
 505         stderror(ERR_SYSTEM, f, strerror(errno));
 506         break;
 507
 508 #ifdef _IBMR2
 509     case 0:                     /* execv fails and returns 0! */
 510 #endif /* _IBMR2 */
 511     case ENOENT:
 512         break;
 513
 514     default:
 515         if (exerr == 0) {
 516             exerr = strerror(errno);
 517             xfree(expath);
 518             expath = Strsave(sf);
 519 #ifdef VFORK
 520             Vexpath = expath;
 521 #endif /* VFORK */
 522         }
 523         break;
 524     }
 525 }
 526
 527 struct execash_state
 528 {
 529     int saveIN, saveOUT, saveDIAG, saveSTD;
 530     int SHIN, SHOUT, SHDIAG, OLDSTD;
 531     int didfds;
 532 #ifndef CLOSE_ON_EXEC
 533     int didcch;
 534 #endif
 535     struct sigaction sigint, sigquit, sigterm;
 536 };
 537
 538 static void
 539 execash_cleanup(void *xstate)
 540 {
 541     struct execash_state *state;
 542
 543     state = xstate;
 544     sigaction(SIGINT, &state->sigint, NULL);
 545     sigaction(SIGQUIT, &state->sigquit, NULL);
 546     sigaction(SIGTERM, &state->sigterm, NULL);
 547
 548     doneinp = 0;
 549 #ifndef CLOSE_ON_EXEC
 550     didcch = state->didcch;
 551 #endif /* CLOSE_ON_EXEC */
 552     didfds = state->didfds;
 553     xclose(SHIN);
 554     xclose(SHOUT);
 555     xclose(SHDIAG);
 556     xclose(OLDSTD);
 557     close_on_exec(SHIN = dmove(state->saveIN, state->SHIN), 1);
 558     close_on_exec(SHOUT = dmove(state->saveOUT, state->SHOUT), 1);
 559     close_on_exec(SHDIAG = dmove(state->saveDIAG, state->SHDIAG), 1);
 560     close_on_exec(OLDSTD = dmove(state->saveSTD, state->OLDSTD), 1);
 561 }
 562
 563 /*ARGSUSED*/
 564 void
 565 execash(Char **t, struct command *kp)
 566 {
 567     struct execash_state state;
 568
 569     USE(t);
 570     if (chkstop == 0 && setintr)
 571         panystop(0);
 572     /*
 573      * Hmm, we don't really want to do that now because we might
 574      * fail, but what is the choice
 575      */
 576     rechist(NULL, adrof(STRsavehist) != NULL);
 577
 578
 579     sigaction(SIGINT, &parintr, &state.sigint);
 580     sigaction(SIGQUIT, &parintr, &state.sigquit);
 581     sigaction(SIGTERM, &parterm, &state.sigterm);
 582
 583     state.didfds = didfds;
 584 #ifndef CLOSE_ON_EXEC
 585     state.didcch = didcch;
 586 #endif /* CLOSE_ON_EXEC */
 587     state.SHIN = SHIN;
 588     state.SHOUT = SHOUT;
 589     state.SHDIAG = SHDIAG;
 590     state.OLDSTD = OLDSTD;
 591
 592     (void)close_on_exec (state.saveIN = dcopy(SHIN, -1), 1);
 593     (void)close_on_exec (state.saveOUT = dcopy(SHOUT, -1), 1);
 594     (void)close_on_exec (state.saveDIAG = dcopy(SHDIAG, -1), 1);
 595     (void)close_on_exec (state.saveSTD = dcopy(OLDSTD, -1), 1);
 596
 597     lshift(kp->t_dcom, 1);
 598
 599     (void)close_on_exec (SHIN = dcopy(0, -1), 1);
 600     (void)close_on_exec (SHOUT = dcopy(1, -1), 1);
 601     (void)close_on_exec (SHDIAG = dcopy(2, -1), 1);
 602 #ifndef CLOSE_ON_EXEC
 603     didcch = 0;
 604 #endif /* CLOSE_ON_EXEC */
 605     didfds = 0;
 606     cleanup_push(&state, execash_cleanup);
 607
 608     /*
 609      * Decrement the shell level
 610      */
 611     shlvl(-1);
 612 #ifdef WINNT_NATIVE
 613     __nt_really_exec=1;
 614 #endif /* WINNT_NATIVE */
 615     doexec(kp, 1);
 616
 617     cleanup_until(&state);
 618 }
 619
 620 void
 621 xechoit(Char **t)
 622 {
 623     if (adrof(STRecho)) {
 624         int odidfds = didfds;
 625         flush();
 626         haderr = 1;
 627         didfds = 0;
 628         blkpr(t), xputchar('\n');
 629         flush();
 630         didfds = odidfds;
 631         haderr = 0;
 632     }
 633 }
 634
 635 /*ARGSUSED*/
 636 void
 637 dohash(Char **vv, struct command *c)
 638 {
 639 #ifdef COMMENT
 640     struct stat stb;
 641 #endif
 642     DIR    *dirp;
 643     struct dirent *dp;
 644     int     i = 0;
 645     struct varent *v = adrof(STRpath);
 646     Char  **pv;
 647     int hashval;
 648 #ifdef WINNT_NATIVE
 649     int is_windir; /* check if it is the windows directory */
 650     USE(hashval);
 651 #endif /* WINNT_NATIVE */
 652
 653     USE(c);
 654 #ifdef FASTHASH
 655     if (vv && vv[1]) {
 656         uhashlength = atoi(short2str(vv[1]));
 657         if (vv[2]) {
 658             uhashwidth = atoi(short2str(vv[2]));
 659             if ((uhashwidth != sizeof(unsigned char)) &&
 660                 (uhashwidth != sizeof(unsigned short)) &&
 661                 (uhashwidth != sizeof(unsigned long)))
 662                 uhashwidth = 0;
 663             if (vv[3])
 664                 hashdebug = atoi(short2str(vv[3]));
 665         }
 666     }
 667
 668     if (uhashwidth)
 669         hashwidth = uhashwidth;
 670     else {
 671         hashwidth = 0;
 672         if (v == NULL)
 673             return;
 674         for (pv = v->vec; pv && *pv; pv++, hashwidth++)
 675             continue;
 676         if (hashwidth <= widthof(unsigned char))
 677             hashwidth = sizeof(unsigned char);
 678         else if (hashwidth <= widthof(unsigned short))
 679             hashwidth = sizeof(unsigned short);
 680         else if (hashwidth <= widthof(unsigned int))
 681             hashwidth = sizeof(unsigned int);
 682         else
 683             hashwidth = sizeof(unsigned long);
 684     }
 685
 686     if (uhashlength)
 687         hashlength = uhashlength;
 688     else
 689         hashlength = hashwidth * (8*64);/* "average" files per dir in path */
 690
 691     xfree(xhash);
 692     xhash = xcalloc(hashlength * hashwidth, 1);
 693 #endif /* FASTHASH */
 694
 695     (void) getusername(NULL);   /* flush the tilde cashe */
 696     tw_cmd_free();
 697     havhash = 1;
 698     if (v == NULL)
 699         return;
 700     for (pv = v->vec; pv && *pv; pv++, i++) {
 701         if (!ABSOLUTEP(pv[0]))
 702             continue;
 703         dirp = opendir(short2str(*pv));
 704         if (dirp == NULL)
 705             continue;
 706         cleanup_push(dirp, opendir_cleanup);
 707 #ifdef COMMENT                  /* this isn't needed.  opendir won't open
 708                                  * non-dirs */
 709         if (fstat(dirp->dd_fd, &stb) < 0 || !S_ISDIR(stb.st_mode)) {
 710             cleanup_until(dirp);
 711             continue;
 712         }
 713 #endif
 714 #ifdef WINNT_NATIVE
 715         is_windir = nt_check_if_windir(short2str(*pv));
 716 #endif /* WINNT_NATIVE */
 717         while ((dp = readdir(dirp)) != NULL) {
 718             if (dp->d_ino == 0)
 719                 continue;
 720             if (dp->d_name[0] == '.' &&
 721                 (dp->d_name[1] == '\0' ||
 722                  (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
 723                 continue;
 724 #ifdef WINNT_NATIVE
 725             nt_check_name_and_hash(is_windir, dp->d_name, i);
 726 #else /* !WINNT_NATIVE*/
 727 #if defined(_UWIN) || defined(__CYGWIN__)
 728             /* Turn foo.{exe,com,bat} into foo since UWIN's readdir returns
 729              * the file with the .exe, .com, .bat extension
 730              *
 731              * Same for Cygwin, but only for .exe and .com extension.
 732              */
 733             {
 734                 ssize_t ext = strlen(dp->d_name) - 4;
 735                 if ((ext > 0) && (strcasecmp(&dp->d_name[ext], ".exe") == 0 ||
 736 #ifndef __CYGWIN__
 737                                   strcasecmp(&dp->d_name[ext], ".bat") == 0 ||
 738 #endif
 739                                   strcasecmp(&dp->d_name[ext], ".com") == 0)) {
 740 #ifdef __CYGWIN__
 741                     /* Also store the variation with extension. */
 742                     hashval = hashname(str2short(dp->d_name));
 743                     bis(hashval, i);
 744 #endif /* __CYGWIN__ */
 745                     dp->d_name[ext] = '\0';
 746                 }
 747             }
 748 #endif /* _UWIN || __CYGWIN__ */
 749 # ifdef FASTHASH
 750             hashval = hashname(str2short(dp->d_name));
 751             bis(hashval, i);
 752             if (hashdebug & 1)
 753                 xprintf(CGETS(13, 1, "hash=%-4d dir=%-2d prog=%s\n"),
 754                         hashname(str2short(dp->d_name)), i, dp->d_name);
 755 # else /* OLD HASH */
 756             hashval = hash(hashname(str2short(dp->d_name)), i);
 757             bis(xhash, hashval);
 758 # endif /* FASTHASH */
 759             /* tw_add_comm_name (dp->d_name); */
 760 #endif /* WINNT_NATIVE */
 761         }
 762         cleanup_until(dirp);
 763     }
 764 }
 765
 766 /*ARGSUSED*/
 767 void
 768 dounhash(Char **v, struct command *c)
 769 {
 770     USE(c);
 771     USE(v);
 772     havhash = 0;
 773 #ifdef FASTHASH
 774     xfree(xhash);
 775     xhash = NULL;
 776 #endif /* FASTHASH */
 777 }
 778
 779 /*ARGSUSED*/
 780 void
 781 hashstat(Char **v, struct command *c)
 782 {
 783     USE(c);
 784     USE(v);
 785 #ifdef FASTHASH
 786    if (havhash && hashlength && hashwidth)
 787       xprintf(CGETS(13, 2, "%d hash buckets of %d bits each\n"),
 788               hashlength, hashwidth*8);
 789    if (hashdebug)
 790       xprintf(CGETS(13, 3, "debug mask = 0x%08x\n"), hashdebug);
 791 #endif /* FASTHASH */
 792 #ifdef VFORK
 793    if (hits + misses)
 794       xprintf(CGETS(13, 4, "%d hits, %d misses, %d%%\n"),
 795               hits, misses, 100 * hits / (hits + misses));
 796 #endif
 797 }
 798
 799
 800 /*
 801  * Hash a command name.
 802  */
 803 int
 804 hashname(Char *cp)
 805 {
 806     unsigned long h;
 807
 808     for (h = 0; *cp; cp++)
 809         h = hash(h, *cp);
 810     return ((int) h);
 811 }
 812
 813 static int
 814 iscommand(Char *name)
 815 {
 816     Char **opv, **pv;
 817     Char *sav;
 818     struct varent *v;
 819     int slash = any(short2str(name), '/');
 820     int hashval, rehashed, i;
 821
 822     v = adrof(STRpath);
 823     if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
 824         opv = justabs;
 825     else
 826         opv = v->vec;
 827     sav = Strspl(STRslash, name);       /* / command name for postpending */
 828     hashval = havhash ? hashname(name) : 0;
 829
 830     rehashed = 0;
 831 retry:
 832     pv = opv;
 833     i = 0;
 834     do {
 835         if (!slash && ABSOLUTEP(pv[0]) && havhash) {
 836 #ifdef FASTHASH
 837             if (!bit(hashval, i))
 838                 goto cont;
 839 #else /* OLDHASH */
 840             int hashval1 = hash(hashval, i);
 841             if (!bit(xhash, hashval1))
 842                 goto cont;
 843 #endif /* FASTHASH */
 844         }
 845         if (pv[0][0] == 0 || eq(pv[0], STRdot)) {       /* don't make ./xxx */
 846             if (executable(NULL, name, 0)) {
 847                 xfree(sav);
 848                 return i + 1;
 849             }
 850         }
 851         else {
 852             if (executable(*pv, sav, 0)) {
 853                 xfree(sav);
 854                 return i + 1;
 855             }
 856         }
 857 cont:
 858         pv++;
 859         i++;
 860     } while (*pv);
 861     if (adrof(STRautorehash) && !rehashed && havhash && opv != justabs) {
 862         dohash(NULL, NULL);
 863         rehashed = 1;
 864         goto retry;
 865     }
 866     xfree(sav);
 867     return 0;
 868 }
 869
 870 /* Also by:
 871  *  Andreas Luik <luik@isaak.isa.de>
 872  *  I S A  GmbH - Informationssysteme fuer computerintegrierte Automatisierung
 873  *  Azenberstr. 35
 874  *  D-7000 Stuttgart 1
 875  *  West-Germany
 876  * is the executable() routine below and changes to iscommand().
 877  * Thanks again!!
 878  */
 879
 880 #ifndef WINNT_NATIVE
 881 /*
 882  * executable() examines the pathname obtained by concatenating dir and name
 883  * (dir may be NULL), and returns 1 either if it is executable by us, or
 884  * if dir_ok is set and the pathname refers to a directory.
 885  * This is a bit kludgy, but in the name of optimization...
 886  */
 887 int
 888 executable(const Char *dir, const Char *name, int dir_ok)
 889 {
 890     struct stat stbuf;
 891     char   *strname;
 892
 893     if (dir && *dir) {
 894         Char *path;
 895
 896         path = Strspl(dir, name);
 897         strname = short2str(path);
 898         xfree(path);
 899     }
 900     else
 901         strname = short2str(name);
 902
 903     return (stat(strname, &stbuf) != -1 &&
 904             ((dir_ok && S_ISDIR(stbuf.st_mode)) ||
 905              (S_ISREG(stbuf.st_mode) &&
 906     /* save time by not calling access() in the hopeless case */
 907               (stbuf.st_mode & (S_IXOTH | S_IXGRP | S_IXUSR)) &&
 908               access(strname, X_OK) == 0
 909         )));
 910 }
 911 #endif /*!WINNT_NATIVE*/
 912
 913 struct tellmewhat_s0_cleanup
 914 {
 915     Char **dest, *val;
 916 };
 917
 918 static void
 919 tellmewhat_s0_cleanup(void *xstate)
 920 {
 921     struct tellmewhat_s0_cleanup *state;
 922
 923     state = xstate;
 924     *state->dest = state->val;
 925 }
 926
 927 int
 928 tellmewhat(struct wordent *lexp, Char **str)
 929 {
 930     struct tellmewhat_s0_cleanup s0;
 931     int i;
 932     const struct biltins *bptr;
 933     struct wordent *sp = lexp->next;
 934     int    aliased = 0, found;
 935     Char   *s1, *s2, *cmd;
 936     Char    qc;
 937
 938     if (adrof1(sp->word, &aliases)) {
 939         alias(lexp);
 940         sp = lexp->next;
 941         aliased = 1;
 942     }
 943
 944     s0.dest = &sp->word;        /* to get the memory freeing right... */
 945     s0.val = sp->word;
 946     cleanup_push(&s0, tellmewhat_s0_cleanup);
 947
 948     /* handle quoted alias hack */
 949     if ((*(sp->word) & (QUOTE | TRIM)) == QUOTE)
 950         (sp->word)++;
 951
 952     /* do quoting, if it hasn't been done */
 953     s1 = s2 = sp->word;
 954     while (*s2)
 955         switch (*s2) {
 956         case '\'':
 957         case '"':
 958             qc = *s2++;
 959             while (*s2 && *s2 != qc)
 960                 *s1++ = *s2++ | QUOTE;
 961             if (*s2)
 962                 s2++;
 963             break;
 964         case '\\':
 965             if (*++s2)
 966                 *s1++ = *s2++ | QUOTE;
 967             break;
 968         default:
 969             *s1++ = *s2++;
 970         }
 971     *s1 = '\0';
 972
 973     for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
 974         if (eq(sp->word, str2short(bptr->bname))) {
 975             if (str == NULL) {
 976                 if (aliased)
 977                     prlex(lexp);
 978                 xprintf(CGETS(13, 5, "%S: shell built-in command.\n"),
 979                               sp->word);
 980                 flush();
 981             }
 982             else
 983                 *str = Strsave(sp->word);
 984             cleanup_until(&s0);
 985             return TRUE;
 986         }
 987     }
 988 #ifdef WINNT_NATIVE
 989     for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
 990         if (eq(sp->word, str2short(bptr->bname))) {
 991             if (str == NULL) {
 992                 if (aliased)
 993                     prlex(lexp);
 994                 xprintf(CGETS(13, 5, "%S: shell built-in command.\n"),
 995                               sp->word);
 996                 flush();
 997             }
 998             else
 999                 *str = Strsave(sp->word);
1000             cleanup_until(&s0);
1001             return TRUE;
1002         }
1003     }
1004 #endif /* WINNT_NATIVE*/
1005
1006     sp->word = cmd = globone(sp->word, G_IGNORE);
1007     cleanup_push(cmd, xfree);
1008
1009     if ((i = iscommand(sp->word)) != 0) {
1010         Char **pv;
1011         struct varent *v;
1012         int    slash = any(short2str(sp->word), '/');
1013
1014         v = adrof(STRpath);
1015         if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
1016             pv = justabs;
1017         else
1018             pv = v->vec;
1019
1020         pv += i - 1;
1021         if (pv[0][0] == 0 || eq(pv[0], STRdot)) {
1022             if (!slash) {
1023                 sp->word = Strspl(STRdotsl, sp->word);
1024                 cleanup_push(sp->word, xfree);
1025                 prlex(lexp);
1026                 cleanup_until(sp->word);
1027             }
1028             else
1029                 prlex(lexp);
1030         }
1031         else {
1032             s1 = Strspl(*pv, STRslash);
1033             sp->word = Strspl(s1, sp->word);
1034             xfree(s1);
1035             cleanup_push(sp->word, xfree);
1036             if (str == NULL)
1037                 prlex(lexp);
1038             else
1039                 *str = Strsave(sp->word);
1040             cleanup_until(sp->word);
1041         }
1042         found = 1;
1043     }
1044     else {
1045         if (str == NULL) {
1046             if (aliased)
1047                 prlex(lexp);
1048             xprintf(CGETS(13, 6, "%S: Command not found.\n"), sp->word);
1049             flush();
1050         }
1051         else
1052             *str = Strsave(sp->word);
1053         found = 0;
1054     }
1055     cleanup_until(&s0);
1056     return found;
1057 }
1058
1059 /*
1060  * Builtin to look at and list all places a command may be defined:
1061  * aliases, shell builtins, and the path.
1062  *
1063  * Marc Horowitz <marc@mit.edu>
1064  * MIT Student Information Processing Board
1065  */
1066
1067 /*ARGSUSED*/
1068 void
1069 dowhere(Char **v, struct command *c)
1070 {
1071     int found = 1;
1072     USE(c);
1073
1074     if (adrof(STRautorehash))
1075         dohash(NULL, NULL);
1076     for (v++; *v; v++)
1077         found &= find_cmd(*v, 1);
1078     /* Make status nonzero if any command is not found. */
1079     if (!found)
1080         setcopy(STRstatus, STR1, VAR_READWRITE);
1081 }
1082
1083 int
1084 find_cmd(Char *cmd, int prt)
1085 {
1086     struct varent *var;
1087     const struct biltins *bptr;
1088     Char **pv;
1089     Char *sv;
1090     int hashval, rehashed, i, ex, rval = 0;
1091
1092     if (prt && any(short2str(cmd), '/')) {
1093         xprintf("%s", CGETS(13, 7, "where: / in command makes no sense\n"));
1094         return rval;
1095     }
1096
1097     /* first, look for an alias */
1098
1099     if (prt && adrof1(cmd, &aliases)) {
1100         if ((var = adrof1(cmd, &aliases)) != NULL) {
1101             xprintf(CGETS(13, 8, "%S is aliased to "), cmd);
1102             if (var->vec != NULL)
1103                 blkpr(var->vec);
1104             xputchar('\n');
1105             rval = 1;
1106         }
1107     }
1108
1109     /* next, look for a shell builtin */
1110
1111     for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
1112         if (eq(cmd, str2short(bptr->bname))) {
1113             rval = 1;
1114             if (prt)
1115                 xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1116             else
1117                 return rval;
1118         }
1119     }
1120 #ifdef WINNT_NATIVE
1121     for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
1122         if (eq(cmd, str2short(bptr->bname))) {
1123             rval = 1;
1124             if (prt)
1125                 xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1126             else
1127                 return rval;
1128         }
1129     }
1130 #endif /* WINNT_NATIVE*/
1131
1132     /* last, look through the path for the command */
1133
1134     if ((var = adrof(STRpath)) == NULL)
1135         return rval;
1136
1137     hashval = havhash ? hashname(cmd) : 0;
1138
1139     sv = Strspl(STRslash, cmd);
1140     cleanup_push(sv, xfree);
1141
1142     rehashed = 0;
1143 retry:
1144     for (pv = var->vec, i = 0; pv && *pv; pv++, i++) {
1145         if (havhash && !eq(*pv, STRdot)) {
1146 #ifdef FASTHASH
1147             if (!bit(hashval, i))
1148                 continue;
1149 #else /* OLDHASH */
1150             int hashval1 = hash(hashval, i);
1151             if (!bit(xhash, hashval1))
1152                 continue;
1153 #endif /* FASTHASH */
1154         }
1155         ex = executable(*pv, sv, 0);
1156 #ifdef FASTHASH
1157         if (!ex && (hashdebug & 2)) {
1158             xprintf("%s", CGETS(13, 10, "hash miss: "));
1159             ex = 1;     /* Force printing */
1160         }
1161 #endif /* FASTHASH */
1162         if (ex) {
1163             rval = 1;
1164             if (prt) {
1165                 xprintf("%S/", *pv);
1166                 xprintf("%S\n", cmd);
1167             }
1168             else
1169                 return rval;
1170         }
1171     }
1172     /*
1173      * If we are printing, we are being called from dowhere() which it
1174      * has rehashed already
1175      */
1176     if (!prt && adrof(STRautorehash) && !rehashed && havhash) {
1177         dohash(NULL, NULL);
1178         rehashed = 1;
1179         goto retry;
1180     }
1181     cleanup_until(sv);
1182     return rval;
1183 }
1184 #ifdef WINNT_NATIVE
1185 int hashval_extern(cp)
1186         Char *cp;
1187 {
1188         return havhash?hashname(cp):0;
1189 }
1190 int bit_extern(val,i)
1191         int val;
1192         int i;
1193 {
1194         return bit(val,i);
1195 }
1196 void bis_extern(val,i)
1197         int val;
1198         int i;
1199 {
1200         bis(val,i);
1201 }
1202 #endif /* WINNT_NATIVE */
1203