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/contrib/tcsh/sh.exec.c

https://bitbucket.org/freebsd/freebsd-head/
C | 1196 lines | 950 code | 80 blank | 166 comment | 172 complexity | 346f5a20ecad41329829684c5bc97ae3 MD5 | raw file
   1/* $Header: /p/tcsh/cvsroot/tcsh/sh.exec.c,v 3.79 2011/02/25 23:58:34 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
  35RCSID("$tcsh: sh.exec.c,v 3.79 2011/02/25 23:58:34 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 */
  65static char *exerr;		/* Execution error message */
  66static 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
  88static unsigned long *xhash = NULL;
  89static unsigned int hashlength = 0, uhashlength = 0;
  90static unsigned int hashwidth = 0, uhashwidth = 0;
  91static 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
 129static 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
 138static int hits, misses;
 139#endif /* VFORK */
 140
 141/* Dummy search path for just absolute search when no path */
 142static Char *justabs[] = {STRNULL, 0};
 143
 144static	void	pexerr		(void) __attribute__((__noreturn__));
 145static	void	texec		(Char *, Char **);
 146int	hashname	(Char *);
 147static	int 	iscommand	(Char *);
 148
 149void
 150doexec(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;
 268retry:
 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 */
 312cont:
 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
 333static void
 334pexerr(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 */
 357static void
 358texec(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
 527struct 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
 538static void
 539execash_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*/
 564void
 565execash(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
 620void
 621xechoit(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*/
 636void
 637dohash(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*/
 767void
 768dounhash(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*/
 780void
 781hashstat(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 */
 803int
 804hashname(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
 813static int
 814iscommand(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;
 831retry:
 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	}
 857cont:
 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 */
 887int
 888executable(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
 913struct tellmewhat_s0_cleanup
 914{
 915    Char **dest, *val;
 916};
 917
 918static void
 919tellmewhat_s0_cleanup(void *xstate)
 920{
 921    struct tellmewhat_s0_cleanup *state;
 922
 923    state = xstate;
 924    *state->dest = state->val;
 925}
 926
 927int
 928tellmewhat(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*/
1068void
1069dowhere(Char **v, struct command *c)
1070{
1071    int found = 1;
1072    USE(c);
1073    for (v++; *v; v++)
1074	found &= find_cmd(*v, 1);
1075    /* Make status nonzero if any command is not found. */
1076    if (!found)
1077	setcopy(STRstatus, STR1, VAR_READWRITE);
1078}
1079
1080int
1081find_cmd(Char *cmd, int prt)
1082{
1083    struct varent *var;
1084    const struct biltins *bptr;
1085    Char **pv;
1086    Char *sv;
1087    int hashval, rehashed, i, ex, rval = 0;
1088
1089    if (prt && any(short2str(cmd), '/')) {
1090	xprintf("%s", CGETS(13, 7, "where: / in command makes no sense\n"));
1091	return rval;
1092    }
1093
1094    /* first, look for an alias */
1095
1096    if (prt && adrof1(cmd, &aliases)) {
1097	if ((var = adrof1(cmd, &aliases)) != NULL) {
1098	    xprintf(CGETS(13, 8, "%S is aliased to "), cmd);
1099	    if (var->vec != NULL)
1100		blkpr(var->vec);
1101	    xputchar('\n');
1102	    rval = 1;
1103	}
1104    }
1105
1106    /* next, look for a shell builtin */
1107
1108    for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
1109	if (eq(cmd, str2short(bptr->bname))) {
1110	    rval = 1;
1111	    if (prt)
1112		xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1113	    else
1114		return rval;
1115	}
1116    }
1117#ifdef WINNT_NATIVE
1118    for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
1119	if (eq(cmd, str2short(bptr->bname))) {
1120	    rval = 1;
1121	    if (prt)
1122		xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1123	    else
1124		return rval;
1125	}
1126    }
1127#endif /* WINNT_NATIVE*/
1128
1129    /* last, look through the path for the command */
1130
1131    if ((var = adrof(STRpath)) == NULL)
1132	return rval;
1133
1134    hashval = havhash ? hashname(cmd) : 0;
1135
1136    sv = Strspl(STRslash, cmd);
1137    cleanup_push(sv, xfree);
1138
1139    rehashed = 0;
1140retry:
1141    for (pv = var->vec, i = 0; pv && *pv; pv++, i++) {
1142	if (havhash && !eq(*pv, STRdot)) {
1143#ifdef FASTHASH
1144	    if (!bit(hashval, i))
1145		continue;
1146#else /* OLDHASH */
1147	    int hashval1 = hash(hashval, i);
1148	    if (!bit(xhash, hashval1))
1149		continue;
1150#endif /* FASTHASH */
1151	}
1152	ex = executable(*pv, sv, 0);
1153#ifdef FASTHASH
1154	if (!ex && (hashdebug & 2)) {
1155	    xprintf("%s", CGETS(13, 10, "hash miss: "));
1156	    ex = 1;	/* Force printing */
1157	}
1158#endif /* FASTHASH */
1159	if (ex) {
1160	    rval = 1;
1161	    if (prt) {
1162		xprintf("%S/", *pv);
1163		xprintf("%S\n", cmd);
1164	    }
1165	    else
1166		return rval;
1167	}
1168    }
1169    if (adrof(STRautorehash) && !rehashed && havhash) {
1170	dohash(NULL, NULL);
1171	rehashed = 1;
1172	goto retry;
1173    }
1174    cleanup_until(sv);
1175    return rval;
1176}
1177#ifdef WINNT_NATIVE
1178int hashval_extern(cp)
1179	Char *cp;
1180{
1181	return havhash?hashname(cp):0;
1182}
1183int bit_extern(val,i)
1184	int val;
1185	int i;
1186{
1187	return bit(val,i);
1188}
1189void bis_extern(val,i)
1190	int val;
1191	int i;
1192{
1193	bis(val,i);
1194}
1195#endif /* WINNT_NATIVE */
1196