contrib/tcsh-6/sh.exec.c

   1 /* $Header: /p/tcsh/cvsroot/tcsh/sh.exec.c,v 3.73 2006/08/24 20:56:31 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 3.73 2006/08/24 20:56:31 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) presend 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);
 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, **av, *sav;
 153     struct varent *v;
 154     int slash, gflag;
 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         pv = justabs;
 257     else
 258         pv = 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     i = 0;
 268 #ifdef VFORK
 269     hits++;
 270 #endif /* VFORK */
 271     do {
 272         /*
 273          * Try to save time by looking at the hash table for where this command
 274          * could be.  If we are doing delayed hashing, then we put the names in
 275          * one at a time, as the user enters them.  This is kinda like Korn
 276          * Shell's "tracked aliases".
 277          */
 278         if (!slash && ABSOLUTEP(pv[0]) && havhash) {
 279 #ifdef FASTHASH
 280             if (!bit(hashval, i))
 281                 goto cont;
 282 #else /* OLDHASH */
 283             int hashval1 = hash(hashval, i);
 284             if (!bit(xhash, hashval1))
 285                 goto cont;
 286 #endif /* FASTHASH */
 287         }
 288         if (pv[0][0] == 0 || eq(pv[0], STRdot)) /* don't make ./xxx */
 289             texec(*av, av);
 290         else {
 291             dp = Strspl(*pv, sav);
 292 #ifndef VFORK
 293             cleanup_push(dp, xfree);
 294 #else /* VFORK */
 295             Vdp = dp;
 296 #endif /* VFORK */
 297
 298             texec(dp, av);
 299 #ifndef VFORK
 300             cleanup_until(dp);
 301 #else /* VFORK */
 302             Vdp = 0;
 303             xfree(dp);
 304 #endif /* VFORK */
 305         }
 306 #ifdef VFORK
 307         misses++;
 308 #endif /* VFORK */
 309 cont:
 310         pv++;
 311         i++;
 312     } while (*pv);
 313 #ifdef VFORK
 314     hits--;
 315 #endif /* VFORK */
 316 #ifndef VFORK
 317     cleanup_until(sav);
 318 #else /* VFORK */
 319     Vsav = 0;
 320     xfree(sav);
 321 #endif /* VFORK */
 322     pexerr();
 323 }
 324
 325 static void
 326 pexerr(void)
 327 {
 328     /* Couldn't find the damn thing */
 329     if (expath) {
 330         setname(short2str(expath));
 331 #ifdef VFORK
 332         Vexpath = 0;
 333 #endif /* VFORK */
 334         xfree(expath);
 335         expath = 0;
 336     }
 337     else
 338         setname("");
 339     if (exerr)
 340         stderror(ERR_NAME | ERR_STRING, exerr);
 341     stderror(ERR_NAME | ERR_COMMAND);
 342 }
 343
 344 /*
 345  * Execute command f, arg list t.
 346  * Record error message if not found.
 347  * Also do shell scripts here.
 348  */
 349 static void
 350 texec(Char *sf, Char **st)
 351 {
 352     char **t;
 353     char *f;
 354     struct varent *v;
 355     Char  **vp;
 356     Char   *lastsh[2];
 357     char    pref[2];
 358     int     fd;
 359     Char   *st0, **ost;
 360
 361     /* The order for the conversions is significant */
 362     t = short2blk(st);
 363     f = short2str(sf);
 364 #ifdef VFORK
 365     Vt = t;
 366 #endif /* VFORK */
 367     errno = 0;                  /* don't use a previous error */
 368 #ifdef apollo
 369     /*
 370      * If we try to execute an nfs mounted directory on the apollo, we
 371      * hang forever. So until apollo fixes that..
 372      */
 373     {
 374         struct stat stb;
 375         if (stat(f, &stb) == 0 && S_ISDIR(stb.st_mode))
 376             errno = EISDIR;
 377     }
 378     if (errno == 0)
 379 #endif /* apollo */
 380     {
 381 #ifdef ISC_POSIX_EXEC_BUG
 382         __setostype(0);         /* "0" is "__OS_SYSV" in <sys/user.h> */
 383 #endif /* ISC_POSIX_EXEC_BUG */
 384         (void) execv(f, t);
 385 #ifdef ISC_POSIX_EXEC_BUG
 386         __setostype(1);         /* "1" is "__OS_POSIX" in <sys/user.h> */
 387 #endif /* ISC_POSIX_EXEC_BUG */
 388     }
 389 #ifdef VFORK
 390     Vt = 0;
 391 #endif /* VFORK */
 392     blkfree((Char **) t);
 393     switch (errno) {
 394
 395     case ENOEXEC:
 396 #ifdef WINNT_NATIVE
 397                 nt_feed_to_cmd(f,t);
 398 #endif /* WINNT_NATIVE */
 399         /*
 400          * From: casper@fwi.uva.nl (Casper H.S. Dik) If we could not execute
 401          * it, don't feed it to the shell if it looks like a binary!
 402          */
 403         if ((fd = xopen(f, O_RDONLY|O_LARGEFILE)) != -1) {
 404             int nread;
 405 #ifdef O_TEXT
 406             setmode(fd, O_TEXT);
 407 #endif
 408             if ((nread = xread(fd, pref, 2)) == 2) {
 409                 if (!isprint((unsigned char)pref[0]) &&
 410                     (pref[0] != '\n' && pref[0] != '\t')) {
 411                     int err;
 412
 413                     err = errno;
 414                     xclose(fd);
 415                     /*
 416                      * We *know* what ENOEXEC means.
 417                      */
 418                     stderror(ERR_ARCH, f, strerror(err));
 419                 }
 420             }
 421             else if (nread < 0) {
 422 #ifdef convex
 423                 int err;
 424
 425                 err = errno;
 426                 xclose(fd);
 427                 /* need to print error incase the file is migrated */
 428                 stderror(ERR_SYSTEM, f, strerror(err));
 429 #endif
 430             }
 431 #ifdef _PATH_BSHELL
 432             else {
 433                 pref[0] = '#';
 434                 pref[1] = '\0';
 435             }
 436 #endif
 437         }
 438 #ifdef HASHBANG
 439         if (fd == -1 ||
 440             pref[0] != '#' || pref[1] != '!' || hashbang(fd, &vp) == -1) {
 441 #endif /* HASHBANG */
 442         /*
 443          * If there is an alias for shell, then put the words of the alias in
 444          * front of the argument list replacing the command name. Note no
 445          * interpretation of the words at this point.
 446          */
 447             v = adrof1(STRshell, &aliases);
 448             if (v == NULL || v->vec == NULL) {
 449                 vp = lastsh;
 450                 vp[0] = adrof(STRshell) ? varval(STRshell) : STR_SHELLPATH;
 451                 vp[1] = NULL;
 452 #ifdef _PATH_BSHELL
 453                 if (fd != -1
 454 # ifndef ISC    /* Compatible with ISC's /bin/csh */
 455                     && pref[0] != '#'
 456 # endif /* ISC */
 457                     )
 458                     vp[0] = STR_BSHELL;
 459 #endif
 460                 vp = saveblk(vp);
 461             }
 462             else
 463                 vp = saveblk(v->vec);
 464 #ifdef HASHBANG
 465         }
 466 #endif /* HASHBANG */
 467         if (fd != -1)
 468             xclose(fd);
 469
 470         st0 = st[0];
 471         st[0] = sf;
 472         ost = st;
 473         st = blkspl(vp, st);    /* Splice up the new arglst */
 474         ost[0] = st0;
 475         sf = *st;
 476         /* The order for the conversions is significant */
 477         t = short2blk(st);
 478         f = short2str(sf);
 479         xfree(st);
 480         blkfree((Char **) vp);
 481 #ifdef VFORK
 482         Vt = t;
 483 #endif /* VFORK */
 484 #ifdef ISC_POSIX_EXEC_BUG
 485         __setostype(0);         /* "0" is "__OS_SYSV" in <sys/user.h> */
 486 #endif /* ISC_POSIX_EXEC_BUG */
 487         (void) execv(f, t);
 488 #ifdef ISC_POSIX_EXEC_BUG
 489         __setostype(1);         /* "1" is "__OS_POSIX" in <sys/user.h> */
 490 #endif /* ISC_POSIX_EXEC_BUG */
 491 #ifdef VFORK
 492         Vt = 0;
 493 #endif /* VFORK */
 494         blkfree((Char **) t);
 495         /* The sky is falling, the sky is falling! */
 496         stderror(ERR_SYSTEM, f, strerror(errno));
 497         break;
 498
 499     case ENOMEM:
 500         stderror(ERR_SYSTEM, f, strerror(errno));
 501         break;
 502
 503 #ifdef _IBMR2
 504     case 0:                     /* execv fails and returns 0! */
 505 #endif /* _IBMR2 */
 506     case ENOENT:
 507         break;
 508
 509     default:
 510         if (exerr == 0) {
 511             exerr = strerror(errno);
 512             xfree(expath);
 513             expath = Strsave(sf);
 514 #ifdef VFORK
 515             Vexpath = expath;
 516 #endif /* VFORK */
 517         }
 518         break;
 519     }
 520 }
 521
 522 struct execash_state
 523 {
 524     int saveIN, saveOUT, saveDIAG, saveSTD;
 525     int SHIN, SHOUT, SHDIAG, OLDSTD;
 526     int didfds;
 527 #ifndef CLOSE_ON_EXEC
 528     int didcch;
 529 #endif
 530     struct sigaction sigint, sigquit, sigterm;
 531 };
 532
 533 static void
 534 execash_cleanup(void *xstate)
 535 {
 536     struct execash_state *state;
 537
 538     state = xstate;
 539     sigaction(SIGINT, &state->sigint, NULL);
 540     sigaction(SIGQUIT, &state->sigquit, NULL);
 541     sigaction(SIGTERM, &state->sigterm, NULL);
 542
 543     doneinp = 0;
 544 #ifndef CLOSE_ON_EXEC
 545     didcch = state->didcch;
 546 #endif /* CLOSE_ON_EXEC */
 547     didfds = state->didfds;
 548     xclose(SHIN);
 549     xclose(SHOUT);
 550     xclose(SHDIAG);
 551     xclose(OLDSTD);
 552     close_on_exec(SHIN = dmove(state->saveIN, state->SHIN), 1);
 553     close_on_exec(SHOUT = dmove(state->saveOUT, state->SHOUT), 1);
 554     close_on_exec(SHDIAG = dmove(state->saveDIAG, state->SHDIAG), 1);
 555     close_on_exec(OLDSTD = dmove(state->saveSTD, state->OLDSTD), 1);
 556 }
 557
 558 /*ARGSUSED*/
 559 void
 560 execash(Char **t, struct command *kp)
 561 {
 562     struct execash_state state;
 563
 564     USE(t);
 565     if (chkstop == 0 && setintr)
 566         panystop(0);
 567     /*
 568      * Hmm, we don't really want to do that now because we might
 569      * fail, but what is the choice
 570      */
 571     rechist(NULL, adrof(STRsavehist) != NULL);
 572
 573
 574     sigaction(SIGINT, &parintr, &state.sigint);
 575     sigaction(SIGQUIT, &parintr, &state.sigquit);
 576     sigaction(SIGTERM, &parterm, &state.sigterm);
 577
 578     state.didfds = didfds;
 579 #ifndef CLOSE_ON_EXEC
 580     state.didcch = didcch;
 581 #endif /* CLOSE_ON_EXEC */
 582     state.SHIN = SHIN;
 583     state.SHOUT = SHOUT;
 584     state.SHDIAG = SHDIAG;
 585     state.OLDSTD = OLDSTD;
 586
 587     (void)close_on_exec (state.saveIN = dcopy(SHIN, -1), 1);
 588     (void)close_on_exec (state.saveOUT = dcopy(SHOUT, -1), 1);
 589     (void)close_on_exec (state.saveDIAG = dcopy(SHDIAG, -1), 1);
 590     (void)close_on_exec (state.saveSTD = dcopy(OLDSTD, -1), 1);
 591
 592     lshift(kp->t_dcom, 1);
 593
 594     (void)close_on_exec (SHIN = dcopy(0, -1), 1);
 595     (void)close_on_exec (SHOUT = dcopy(1, -1), 1);
 596     (void)close_on_exec (SHDIAG = dcopy(2, -1), 1);
 597 #ifndef CLOSE_ON_EXEC
 598     didcch = 0;
 599 #endif /* CLOSE_ON_EXEC */
 600     didfds = 0;
 601     cleanup_push(&state, execash_cleanup);
 602
 603     /*
 604      * Decrement the shell level
 605      */
 606     shlvl(-1);
 607 #ifdef WINNT_NATIVE
 608     __nt_really_exec=1;
 609 #endif /* WINNT_NATIVE */
 610     doexec(kp, 1);
 611
 612     cleanup_until(&state);
 613 }
 614
 615 void
 616 xechoit(Char **t)
 617 {
 618     if (adrof(STRecho)) {
 619         int odidfds = didfds;
 620         flush();
 621         haderr = 1;
 622         didfds = 0;
 623         blkpr(t), xputchar('\n');
 624         flush();
 625         didfds = odidfds;
 626         haderr = 0;
 627     }
 628 }
 629
 630 /*ARGSUSED*/
 631 void
 632 dohash(Char **vv, struct command *c)
 633 {
 634 #ifdef COMMENT
 635     struct stat stb;
 636 #endif
 637     DIR    *dirp;
 638     struct dirent *dp;
 639     int     i = 0;
 640     struct varent *v = adrof(STRpath);
 641     Char  **pv;
 642     int hashval;
 643 #ifdef WINNT_NATIVE
 644     int is_windir; /* check if it is the windows directory */
 645     USE(hashval);
 646 #endif /* WINNT_NATIVE */
 647
 648     USE(c);
 649 #ifdef FASTHASH
 650     if (vv && vv[1]) {
 651         uhashlength = atoi(short2str(vv[1]));
 652         if (vv[2]) {
 653             uhashwidth = atoi(short2str(vv[2]));
 654             if ((uhashwidth != sizeof(unsigned char)) &&
 655                 (uhashwidth != sizeof(unsigned short)) &&
 656                 (uhashwidth != sizeof(unsigned long)))
 657                 uhashwidth = 0;
 658             if (vv[3])
 659                 hashdebug = atoi(short2str(vv[3]));
 660         }
 661     }
 662
 663     if (uhashwidth)
 664         hashwidth = uhashwidth;
 665     else {
 666         hashwidth = 0;
 667         if (v == NULL)
 668             return;
 669         for (pv = v->vec; pv && *pv; pv++, hashwidth++)
 670             continue;
 671         if (hashwidth <= widthof(unsigned char))
 672             hashwidth = sizeof(unsigned char);
 673         else if (hashwidth <= widthof(unsigned short))
 674             hashwidth = sizeof(unsigned short);
 675         else if (hashwidth <= widthof(unsigned int))
 676             hashwidth = sizeof(unsigned int);
 677         else
 678             hashwidth = sizeof(unsigned long);
 679     }
 680
 681     if (uhashlength)
 682         hashlength = uhashlength;
 683     else
 684         hashlength = hashwidth * (8*64);/* "average" files per dir in path */
 685
 686     xfree(xhash);
 687     xhash = xcalloc(hashlength * hashwidth, 1);
 688 #endif /* FASTHASH */
 689
 690     (void) getusername(NULL);   /* flush the tilde cashe */
 691     tw_cmd_free();
 692     havhash = 1;
 693     if (v == NULL)
 694         return;
 695     for (pv = v->vec; pv && *pv; pv++, i++) {
 696         if (!ABSOLUTEP(pv[0]))
 697             continue;
 698         dirp = opendir(short2str(*pv));
 699         if (dirp == NULL)
 700             continue;
 701         cleanup_push(dirp, opendir_cleanup);
 702 #ifdef COMMENT                  /* this isn't needed.  opendir won't open
 703                                  * non-dirs */
 704         if (fstat(dirp->dd_fd, &stb) < 0 || !S_ISDIR(stb.st_mode)) {
 705             cleanup_until(dirp);
 706             continue;
 707         }
 708 #endif
 709 #ifdef WINNT_NATIVE
 710         is_windir = nt_check_if_windir(short2str(*pv));
 711 #endif /* WINNT_NATIVE */
 712         while ((dp = readdir(dirp)) != NULL) {
 713             if (dp->d_ino == 0)
 714                 continue;
 715             if (dp->d_name[0] == '.' &&
 716                 (dp->d_name[1] == '\0' ||
 717                  (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
 718                 continue;
 719 #ifdef WINNT_NATIVE
 720             nt_check_name_and_hash(is_windir, dp->d_name, i);
 721 #else /* !WINNT_NATIVE*/
 722 #if defined(_UWIN) || defined(__CYGWIN__)
 723             /* Turn foo.{exe,com,bat} into foo since UWIN's readdir returns
 724              * the file with the .exe, .com, .bat extension
 725              */
 726             {
 727                 ssize_t ext = strlen(dp->d_name) - 4;
 728                 if ((ext > 0) && (strcasecmp(&dp->d_name[ext], ".exe") == 0 ||
 729                                   strcasecmp(&dp->d_name[ext], ".bat") == 0 ||
 730                                   strcasecmp(&dp->d_name[ext], ".com") == 0)) {
 731 #ifdef __CYGWIN__
 732                     /* Also store the variation with extension. */
 733                     hashval = hashname(str2short(dp->d_name));
 734                     bis(hashval, i);
 735 #endif /* __CYGWIN__ */
 736                     dp->d_name[ext] = '\0';
 737                 }
 738             }
 739 #endif /* _UWIN || __CYGWIN__ */
 740 # ifdef FASTHASH
 741             hashval = hashname(str2short(dp->d_name));
 742             bis(hashval, i);
 743             if (hashdebug & 1)
 744                 xprintf(CGETS(13, 1, "hash=%-4d dir=%-2d prog=%s\n"),
 745                         hashname(str2short(dp->d_name)), i, dp->d_name);
 746 # else /* OLD HASH */
 747             hashval = hash(hashname(str2short(dp->d_name)), i);
 748             bis(xhash, hashval);
 749 # endif /* FASTHASH */
 750             /* tw_add_comm_name (dp->d_name); */
 751 #endif /* WINNT_NATIVE */
 752         }
 753         cleanup_until(dirp);
 754     }
 755 }
 756
 757 /*ARGSUSED*/
 758 void
 759 dounhash(Char **v, struct command *c)
 760 {
 761     USE(c);
 762     USE(v);
 763     havhash = 0;
 764 #ifdef FASTHASH
 765     xfree(xhash);
 766     xhash = NULL;
 767 #endif /* FASTHASH */
 768 }
 769
 770 /*ARGSUSED*/
 771 void
 772 hashstat(Char **v, struct command *c)
 773 {
 774     USE(c);
 775     USE(v);
 776 #ifdef FASTHASH
 777    if (havhash && hashlength && hashwidth)
 778       xprintf(CGETS(13, 2, "%d hash buckets of %d bits each\n"),
 779               hashlength, hashwidth*8);
 780    if (hashdebug)
 781       xprintf(CGETS(13, 3, "debug mask = 0x%08x\n"), hashdebug);
 782 #endif /* FASTHASH */
 783 #ifdef VFORK
 784    if (hits + misses)
 785       xprintf(CGETS(13, 4, "%d hits, %d misses, %d%%\n"),
 786               hits, misses, 100 * hits / (hits + misses));
 787 #endif
 788 }
 789
 790
 791 /*
 792  * Hash a command name.
 793  */
 794 int
 795 hashname(Char *cp)
 796 {
 797     unsigned long h;
 798
 799     for (h = 0; *cp; cp++)
 800         h = hash(h, *cp);
 801     return ((int) h);
 802 }
 803
 804 static int
 805 iscommand(Char *name)
 806 {
 807     Char **pv;
 808     Char *sav;
 809     struct varent *v;
 810     int slash = any(short2str(name), '/');
 811     int hashval, i;
 812
 813     v = adrof(STRpath);
 814     if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
 815         pv = justabs;
 816     else
 817         pv = v->vec;
 818     sav = Strspl(STRslash, name);       /* / command name for postpending */
 819     hashval = havhash ? hashname(name) : 0;
 820     i = 0;
 821     do {
 822         if (!slash && ABSOLUTEP(pv[0]) && havhash) {
 823 #ifdef FASTHASH
 824             if (!bit(hashval, i))
 825                 goto cont;
 826 #else /* OLDHASH */
 827             int hashval1 = hash(hashval, i);
 828             if (!bit(xhash, hashval1))
 829                 goto cont;
 830 #endif /* FASTHASH */
 831         }
 832         if (pv[0][0] == 0 || eq(pv[0], STRdot)) {       /* don't make ./xxx */
 833             if (executable(NULL, name, 0)) {
 834                 xfree(sav);
 835                 return i + 1;
 836             }
 837         }
 838         else {
 839             if (executable(*pv, sav, 0)) {
 840                 xfree(sav);
 841                 return i + 1;
 842             }
 843         }
 844 cont:
 845         pv++;
 846         i++;
 847     } while (*pv);
 848     xfree(sav);
 849     return 0;
 850 }
 851
 852 /* Also by:
 853  *  Andreas Luik <luik@isaak.isa.de>
 854  *  I S A  GmbH - Informationssysteme fuer computerintegrierte Automatisierung
 855  *  Azenberstr. 35
 856  *  D-7000 Stuttgart 1
 857  *  West-Germany
 858  * is the executable() routine below and changes to iscommand().
 859  * Thanks again!!
 860  */
 861
 862 #ifndef WINNT_NATIVE
 863 /*
 864  * executable() examines the pathname obtained by concatenating dir and name
 865  * (dir may be NULL), and returns 1 either if it is executable by us, or
 866  * if dir_ok is set and the pathname refers to a directory.
 867  * This is a bit kludgy, but in the name of optimization...
 868  */
 869 int
 870 executable(const Char *dir, const Char *name, int dir_ok)
 871 {
 872     struct stat stbuf;
 873     char   *strname;
 874
 875     if (dir && *dir) {
 876         Char *path;
 877
 878         path = Strspl(dir, name);
 879         strname = short2str(path);
 880         xfree(path);
 881     }
 882     else
 883         strname = short2str(name);
 884
 885     return (stat(strname, &stbuf) != -1 &&
 886             ((dir_ok && S_ISDIR(stbuf.st_mode)) ||
 887              (S_ISREG(stbuf.st_mode) &&
 888     /* save time by not calling access() in the hopeless case */
 889               (stbuf.st_mode & (S_IXOTH | S_IXGRP | S_IXUSR)) &&
 890               access(strname, X_OK) == 0
 891         )));
 892 }
 893 #endif /*!WINNT_NATIVE*/
 894
 895 struct tellmewhat_s0_cleanup
 896 {
 897     Char **dest, *val;
 898 };
 899
 900 static void
 901 tellmewhat_s0_cleanup(void *xstate)
 902 {
 903     struct tellmewhat_s0_cleanup *state;
 904
 905     state = xstate;
 906     *state->dest = state->val;
 907 }
 908
 909 int
 910 tellmewhat(struct wordent *lexp, Char **str)
 911 {
 912     struct tellmewhat_s0_cleanup s0;
 913     int i;
 914     const struct biltins *bptr;
 915     struct wordent *sp = lexp->next;
 916     int    aliased = 0, found;
 917     Char   *s1, *s2, *cmd;
 918     Char    qc;
 919
 920     if (adrof1(sp->word, &aliases)) {
 921         alias(lexp);
 922         sp = lexp->next;
 923         aliased = 1;
 924     }
 925
 926     s0.dest = &sp->word;        /* to get the memory freeing right... */
 927     s0.val = sp->word;
 928     cleanup_push(&s0, tellmewhat_s0_cleanup);
 929
 930     /* handle quoted alias hack */
 931     if ((*(sp->word) & (QUOTE | TRIM)) == QUOTE)
 932         (sp->word)++;
 933
 934     /* do quoting, if it hasn't been done */
 935     s1 = s2 = sp->word;
 936     while (*s2)
 937         switch (*s2) {
 938         case '\'':
 939         case '"':
 940             qc = *s2++;
 941             while (*s2 && *s2 != qc)
 942                 *s1++ = *s2++ | QUOTE;
 943             if (*s2)
 944                 s2++;
 945             break;
 946         case '\\':
 947             if (*++s2)
 948                 *s1++ = *s2++ | QUOTE;
 949             break;
 950         default:
 951             *s1++ = *s2++;
 952         }
 953     *s1 = '\0';
 954
 955     for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
 956         if (eq(sp->word, str2short(bptr->bname))) {
 957             if (str == NULL) {
 958                 if (aliased)
 959                     prlex(lexp);
 960                 xprintf(CGETS(13, 5, "%S: shell built-in command.\n"),
 961                               sp->word);
 962                 flush();
 963             }
 964             else
 965                 *str = Strsave(sp->word);
 966             cleanup_until(&s0);
 967             return TRUE;
 968         }
 969     }
 970 #ifdef WINNT_NATIVE
 971     for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
 972         if (eq(sp->word, str2short(bptr->bname))) {
 973             if (str == NULL) {
 974                 if (aliased)
 975                     prlex(lexp);
 976                 xprintf(CGETS(13, 5, "%S: shell built-in command.\n"),
 977                               sp->word);
 978                 flush();
 979             }
 980             else
 981                 *str = Strsave(sp->word);
 982             cleanup_until(&s0);
 983             return TRUE;
 984         }
 985     }
 986 #endif /* WINNT_NATIVE*/
 987
 988     sp->word = cmd = globone(sp->word, G_IGNORE);
 989     cleanup_push(cmd, xfree);
 990
 991     if ((i = iscommand(sp->word)) != 0) {
 992         Char **pv;
 993         struct varent *v;
 994         int    slash = any(short2str(sp->word), '/');
 995
 996         v = adrof(STRpath);
 997         if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
 998             pv = justabs;
 999         else
1000             pv = v->vec;
1001
1002         pv += i - 1;
1003         if (pv[0][0] == 0 || eq(pv[0], STRdot)) {
1004             if (!slash) {
1005                 sp->word = Strspl(STRdotsl, sp->word);
1006                 cleanup_push(sp->word, xfree);
1007                 prlex(lexp);
1008                 cleanup_until(sp->word);
1009             }
1010             else
1011                 prlex(lexp);
1012         }
1013         else {
1014             s1 = Strspl(*pv, STRslash);
1015             sp->word = Strspl(s1, sp->word);
1016             xfree(s1);
1017             cleanup_push(sp->word, xfree);
1018             if (str == NULL)
1019                 prlex(lexp);
1020             else
1021                 *str = Strsave(sp->word);
1022             cleanup_until(sp->word);
1023         }
1024         found = 1;
1025     }
1026     else {
1027         if (str == NULL) {
1028             if (aliased)
1029                 prlex(lexp);
1030             xprintf(CGETS(13, 6, "%S: Command not found.\n"), sp->word);
1031             flush();
1032         }
1033         else
1034             *str = Strsave(sp->word);
1035         found = 0;
1036     }
1037     cleanup_until(&s0);
1038     return found;
1039 }
1040
1041 /*
1042  * Builtin to look at and list all places a command may be defined:
1043  * aliases, shell builtins, and the path.
1044  *
1045  * Marc Horowitz <marc@mit.edu>
1046  * MIT Student Information Processing Board
1047  */
1048
1049 /*ARGSUSED*/
1050 void
1051 dowhere(Char **v, struct command *c)
1052 {
1053     int found = 1;
1054     USE(c);
1055     for (v++; *v; v++)
1056         found &= find_cmd(*v, 1);
1057     /* Make status nonzero if any command is not found. */
1058     if (!found)
1059         setcopy(STRstatus, STR1, VAR_READWRITE);
1060 }
1061
1062 int
1063 find_cmd(Char *cmd, int prt)
1064 {
1065     struct varent *var;
1066     const struct biltins *bptr;
1067     Char **pv;
1068     Char *sv;
1069     int hashval, i, ex, rval = 0;
1070
1071     if (prt && any(short2str(cmd), '/')) {
1072         xprintf(CGETS(13, 7, "where: / in command makes no sense\n"));
1073         return rval;
1074     }
1075
1076     /* first, look for an alias */
1077
1078     if (prt && adrof1(cmd, &aliases)) {
1079         if ((var = adrof1(cmd, &aliases)) != NULL) {
1080             xprintf(CGETS(13, 8, "%S is aliased to "), cmd);
1081             if (var->vec != NULL)
1082                 blkpr(var->vec);
1083             xputchar('\n');
1084             rval = 1;
1085         }
1086     }
1087
1088     /* next, look for a shell builtin */
1089
1090     for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
1091         if (eq(cmd, str2short(bptr->bname))) {
1092             rval = 1;
1093             if (prt)
1094                 xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1095             else
1096                 return rval;
1097         }
1098     }
1099 #ifdef WINNT_NATIVE
1100     for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
1101         if (eq(cmd, str2short(bptr->bname))) {
1102             rval = 1;
1103             if (prt)
1104                 xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1105             else
1106                 return rval;
1107         }
1108     }
1109 #endif /* WINNT_NATIVE*/
1110
1111     /* last, look through the path for the command */
1112
1113     if ((var = adrof(STRpath)) == NULL)
1114         return rval;
1115
1116     hashval = havhash ? hashname(cmd) : 0;
1117
1118     sv = Strspl(STRslash, cmd);
1119     cleanup_push(sv, xfree);
1120
1121     for (pv = var->vec, i = 0; pv && *pv; pv++, i++) {
1122         if (havhash && !eq(*pv, STRdot)) {
1123 #ifdef FASTHASH
1124             if (!bit(hashval, i))
1125                 continue;
1126 #else /* OLDHASH */
1127             int hashval1 = hash(hashval, i);
1128             if (!bit(xhash, hashval1))
1129                 continue;
1130 #endif /* FASTHASH */
1131         }
1132         ex = executable(*pv, sv, 0);
1133 #ifdef FASTHASH
1134         if (!ex && (hashdebug & 2)) {
1135             xprintf(CGETS(13, 10, "hash miss: "));
1136             ex = 1;     /* Force printing */
1137         }
1138 #endif /* FASTHASH */
1139         if (ex) {
1140             rval = 1;
1141             if (prt) {
1142                 xprintf("%S/", *pv);
1143                 xprintf("%S\n", cmd);
1144             }
1145             else
1146                 return rval;
1147         }
1148     }
1149     cleanup_until(sv);
1150     return rval;
1151 }
1152 #ifdef WINNT_NATIVE
1153 int hashval_extern(cp)
1154         Char *cp;
1155 {
1156         return havhash?hashname(cp):0;
1157 }
1158 int bit_extern(val,i)
1159         int val;
1160         int i;
1161 {
1162         return bit(val,i);
1163 }
1164 void bis_extern(val,i)
1165         int val;
1166         int i;
1167 {
1168         bis(val,i);
1169 }
1170 #endif /* WINNT_NATIVE */
1171