xref: /freebsd/contrib/tcsh/sh.exec.c (revision 6780ab54325a71e7e70112b11657973edde8655e)
1 /* $Header: /src/pub/tcsh/sh.exec.c,v 3.56 2002/06/25 19:02:11 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("$Id: sh.exec.c,v 3.56 2002/06/25 19:02:11 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 			 (1L << (i & (widthof(t) - 1))))
97 # define tbis(f, i, t)	(((t *) xhash)[(f)] |= \
98 			 (1L << (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		__P((void));
145 static	void	texec		__P((Char *, Char **));
146 int	hashname	__P((Char *));
147 static	int 	iscommand	__P((Char *));
148 
149 void
150 doexec(t, do_glob)
151     register struct command *t;
152     bool do_glob;
153 {
154     Char *dp, **pv, **av, *sav;
155     struct varent *v;
156     bool slash;
157     int hashval, i;
158     Char   *blk[2];
159 
160     /*
161      * Glob the command name. We will search $path even if this does something,
162      * as in sh but not in csh.  One special case: if there is no PATH, then we
163      * execute only commands which start with '/'.
164      */
165     blk[0] = t->t_dcom[0];
166     blk[1] = 0;
167     gflag = 0;
168     if (do_glob)
169 	tglob(blk);
170     if (gflag) {
171 	pv = globall(blk);
172 	if (pv == 0) {
173 	    setname(short2str(blk[0]));
174 	    stderror(ERR_NAME | ERR_NOMATCH);
175 	}
176 	gargv = 0;
177     }
178     else
179 	pv = saveblk(blk);
180 
181     trim(pv);
182 
183     exerr = 0;
184     expath = Strsave(pv[0]);
185 #ifdef VFORK
186     Vexpath = expath;
187 #endif /* VFORK */
188 
189     v = adrof(STRpath);
190     if (v == 0 && expath[0] != '/' && expath[0] != '.') {
191 	blkfree(pv);
192 	pexerr();
193     }
194     slash = any(short2str(expath), '/');
195 
196     /*
197      * Glob the argument list, if necessary. Otherwise trim off the quote bits.
198      */
199     gflag = 0;
200     av = &t->t_dcom[1];
201     if (do_glob)
202 	tglob(av);
203     if (gflag) {
204 	av = globall(av);
205 	if (av == 0) {
206 	    blkfree(pv);
207 	    setname(short2str(expath));
208 	    stderror(ERR_NAME | ERR_NOMATCH);
209 	}
210 	gargv = 0;
211     }
212     else
213 	av = saveblk(av);
214 
215     blkfree(t->t_dcom);
216     t->t_dcom = blkspl(pv, av);
217     xfree((ptr_t) pv);
218     xfree((ptr_t) av);
219     av = t->t_dcom;
220     trim(av);
221 
222     if (*av == NULL || **av == '\0')
223 	pexerr();
224 
225     xechoit(av);		/* Echo command if -x */
226 #ifdef CLOSE_ON_EXEC
227     /*
228      * Since all internal file descriptors are set to close on exec, we don't
229      * need to close them explicitly here.  Just reorient ourselves for error
230      * messages.
231      */
232     SHIN = 0;
233     SHOUT = 1;
234     SHDIAG = 2;
235     OLDSTD = 0;
236     isoutatty = isatty(SHOUT);
237     isdiagatty = isatty(SHDIAG);
238 #else
239     closech();			/* Close random fd's */
240 #endif
241     /*
242      * We must do this AFTER any possible forking (like `foo` in glob) so that
243      * this shell can still do subprocesses.
244      */
245 #ifdef BSDSIGS
246     (void) sigsetmask((sigmask_t) 0);
247 #else /* BSDSIGS */
248     (void) sigrelse(SIGINT);
249     (void) sigrelse(SIGCHLD);
250 #endif /* BSDSIGS */
251 
252     /*
253      * If no path, no words in path, or a / in the filename then restrict the
254      * command search.
255      */
256     if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
257 	pv = justabs;
258     else
259 	pv = v->vec;
260     sav = Strspl(STRslash, *av);/* / command name for postpending */
261 #ifdef VFORK
262     Vsav = sav;
263 #endif /* VFORK */
264     hashval = havhash ? hashname(*av) : 0;
265 
266     i = 0;
267 #ifdef VFORK
268     hits++;
269 #endif /* VFORK */
270     do {
271 	/*
272 	 * Try to save time by looking at the hash table for where this command
273 	 * could be.  If we are doing delayed hashing, then we put the names in
274 	 * one at a time, as the user enters them.  This is kinda like Korn
275 	 * Shell's "tracked aliases".
276 	 */
277 	if (!slash && ABSOLUTEP(pv[0]) && havhash) {
278 #ifdef FASTHASH
279 	    if (!bit(hashval, i))
280 		goto cont;
281 #else /* OLDHASH */
282 	    int hashval1 = hash(hashval, i);
283 	    if (!bit(xhash, hashval1))
284 		goto cont;
285 #endif /* FASTHASH */
286 	}
287 	if (pv[0][0] == 0 || eq(pv[0], STRdot))	/* don't make ./xxx */
288 	{
289 
290 #ifdef COHERENT
291 	    if (t->t_dflg & F_AMPERSAND) {
292 # ifdef JOBDEBUG
293     	        xprintf("set SIGINT to SIG_IGN\n");
294     	        xprintf("set SIGQUIT to SIG_DFL\n");
295 # endif /* JOBDEBUG */
296     	        (void) signal(SIGINT,SIG_IGN); /* may not be necessary */
297 	        (void) signal(SIGQUIT,SIG_DFL);
298 	    }
299 
300 	    if (gointr && eq(gointr, STRminus)) {
301 # ifdef JOBDEBUG
302     	        xprintf("set SIGINT to SIG_IGN\n");
303     	        xprintf("set SIGQUIT to SIG_IGN\n");
304 # endif /* JOBDEBUG */
305     	        (void) signal(SIGINT,SIG_IGN); /* may not be necessary */
306 	        (void) signal(SIGQUIT,SIG_IGN);
307 	    }
308 #endif /* COHERENT */
309 
310 	    texec(*av, av);
311 }
312 	else {
313 	    dp = Strspl(*pv, sav);
314 #ifdef VFORK
315 	    Vdp = dp;
316 #endif /* VFORK */
317 
318 #ifdef COHERENT
319 	    if ((t->t_dflg & F_AMPERSAND)) {
320 # ifdef JOBDEBUG
321     	        xprintf("set SIGINT to SIG_IGN\n");
322 # endif /* JOBDEBUG */
323 		/*
324 		 * this is necessary on Coherent or all background
325 		 * jobs are killed by CTRL-C
326 		 * (there must be a better fix for this)
327 		 */
328     	        (void) signal(SIGINT,SIG_IGN);
329 	    }
330 	    if (gointr && eq(gointr,STRminus)) {
331 # ifdef JOBDEBUG
332     	        xprintf("set SIGINT to SIG_IGN\n");
333     	        xprintf("set SIGQUIT to SIG_IGN\n");
334 # endif /* JOBDEBUG */
335     	        (void) signal(SIGINT,SIG_IGN); /* may not be necessary */
336 	        (void) signal(SIGQUIT,SIG_IGN);
337 	    }
338 #endif /* COHERENT */
339 
340 	    texec(dp, av);
341 #ifdef VFORK
342 	    Vdp = 0;
343 #endif /* VFORK */
344 	    xfree((ptr_t) dp);
345 	}
346 #ifdef VFORK
347 	misses++;
348 #endif /* VFORK */
349 cont:
350 	pv++;
351 	i++;
352     } while (*pv);
353 #ifdef VFORK
354     hits--;
355     Vsav = 0;
356 #endif /* VFORK */
357     xfree((ptr_t) sav);
358     pexerr();
359 }
360 
361 static void
362 pexerr()
363 {
364     /* Couldn't find the damn thing */
365     if (expath) {
366 	setname(short2str(expath));
367 #ifdef VFORK
368 	Vexpath = 0;
369 #endif /* VFORK */
370 	xfree((ptr_t) expath);
371 	expath = 0;
372     }
373     else
374 	setname("");
375     if (exerr)
376 	stderror(ERR_NAME | ERR_STRING, exerr);
377     stderror(ERR_NAME | ERR_COMMAND);
378 }
379 
380 /*
381  * Execute command f, arg list t.
382  * Record error message if not found.
383  * Also do shell scripts here.
384  */
385 static void
386 texec(sf, st)
387     Char   *sf;
388     register Char **st;
389 {
390     register char **t;
391     register char *f;
392     register struct varent *v;
393     Char  **vp;
394     Char   *lastsh[2];
395     char    pref[2];
396     int     fd;
397     Char   *st0, **ost;
398 
399     /* The order for the conversions is significant */
400     t = short2blk(st);
401     f = short2str(sf);
402 #ifdef VFORK
403     Vt = t;
404 #endif /* VFORK */
405     errno = 0;			/* don't use a previous error */
406 #ifdef apollo
407     /*
408      * If we try to execute an nfs mounted directory on the apollo, we
409      * hang forever. So until apollo fixes that..
410      */
411     {
412 	struct stat stb;
413 	if (stat(f, &stb) == 0 && S_ISDIR(stb.st_mode))
414 	    errno = EISDIR;
415     }
416     if (errno == 0)
417 #endif /* apollo */
418     {
419 #ifdef ISC_POSIX_EXEC_BUG
420 	__setostype(0);		/* "0" is "__OS_SYSV" in <sys/user.h> */
421 #endif /* ISC_POSIX_EXEC_BUG */
422 	(void) execv(f, t);
423 #ifdef ISC_POSIX_EXEC_BUG
424 	__setostype(1);		/* "1" is "__OS_POSIX" in <sys/user.h> */
425 #endif /* ISC_POSIX_EXEC_BUG */
426     }
427 #ifdef VFORK
428     Vt = 0;
429 #endif /* VFORK */
430     blkfree((Char **) t);
431     switch (errno) {
432 
433     case ENOEXEC:
434 #ifdef WINNT_NATIVE
435 		nt_feed_to_cmd(f,t);
436 #endif /* WINNT_NATIVE */
437 	/*
438 	 * From: casper@fwi.uva.nl (Casper H.S. Dik) If we could not execute
439 	 * it, don't feed it to the shell if it looks like a binary!
440 	 */
441 	if ((fd = open(f, O_RDONLY)) != -1) {
442 	    int nread;
443 	    if ((nread = read(fd, (char *) pref, 2)) == 2) {
444 		if (!Isprint(pref[0]) && (pref[0] != '\n' && pref[0] != '\t')) {
445 		    (void) close(fd);
446 		    /*
447 		     * We *know* what ENOEXEC means.
448 		     */
449 		    stderror(ERR_ARCH, f, strerror(errno));
450 		}
451 	    }
452 	    else if (nread < 0 && errno != EINTR) {
453 #ifdef convex
454 		/* need to print error incase the file is migrated */
455 		stderror(ERR_SYSTEM, f, strerror(errno));
456 #endif
457 	    }
458 #ifdef _PATH_BSHELL
459 	    else {
460 		pref[0] = '#';
461 		pref[1] = '\0';
462 	    }
463 #endif
464 	}
465 #ifdef HASHBANG
466 	if (fd == -1 ||
467 	    pref[0] != '#' || pref[1] != '!' || hashbang(fd, &vp) == -1) {
468 #endif /* HASHBANG */
469 	/*
470 	 * If there is an alias for shell, then put the words of the alias in
471 	 * front of the argument list replacing the command name. Note no
472 	 * interpretation of the words at this point.
473 	 */
474 	    v = adrof1(STRshell, &aliases);
475 	    if (v == NULL || v->vec == NULL) {
476 		vp = lastsh;
477 		vp[0] = adrof(STRshell) ? varval(STRshell) : STR_SHELLPATH;
478 		vp[1] = NULL;
479 #ifdef _PATH_BSHELL
480 		if (fd != -1
481 # ifndef ISC	/* Compatible with ISC's /bin/csh */
482 		    && pref[0] != '#'
483 # endif /* ISC */
484 		    )
485 		    vp[0] = STR_BSHELL;
486 #endif
487 		vp = saveblk(vp);
488 	    }
489 	    else
490 		vp = saveblk(v->vec);
491 #ifdef HASHBANG
492 	}
493 #endif /* HASHBANG */
494 	if (fd != -1)
495 	    (void) close(fd);
496 
497 	st0 = st[0];
498 	st[0] = sf;
499 	ost = st;
500 	st = blkspl(vp, st);	/* Splice up the new arglst */
501 	ost[0] = st0;
502 	sf = *st;
503 	/* The order for the conversions is significant */
504 	t = short2blk(st);
505 	f = short2str(sf);
506 	xfree((ptr_t) st);
507 	blkfree((Char **) vp);
508 #ifdef VFORK
509 	Vt = t;
510 #endif /* VFORK */
511 #ifdef ISC_POSIX_EXEC_BUG
512 	__setostype(0);		/* "0" is "__OS_SYSV" in <sys/user.h> */
513 #endif /* ISC_POSIX_EXEC_BUG */
514 	(void) execv(f, t);
515 #ifdef ISC_POSIX_EXEC_BUG
516 	__setostype(1);		/* "1" is "__OS_POSIX" in <sys/user.h> */
517 #endif /* ISC_POSIX_EXEC_BUG */
518 #ifdef VFORK
519 	Vt = 0;
520 #endif /* VFORK */
521 	blkfree((Char **) t);
522 	/* The sky is falling, the sky is falling! */
523 	stderror(ERR_SYSTEM, f, strerror(errno));
524 	break;
525 
526     case ENOMEM:
527 	stderror(ERR_SYSTEM, f, strerror(errno));
528 	break;
529 
530 #ifdef _IBMR2
531     case 0:			/* execv fails and returns 0! */
532 #endif /* _IBMR2 */
533     case ENOENT:
534 	break;
535 
536     default:
537 	if (exerr == 0) {
538 	    exerr = strerror(errno);
539 	    if (expath)
540 		xfree((ptr_t) expath);
541 	    expath = Strsave(sf);
542 #ifdef VFORK
543 	    Vexpath = expath;
544 #endif /* VFORK */
545 	}
546 	break;
547     }
548 }
549 
550 /*ARGSUSED*/
551 void
552 execash(t, kp)
553     Char  **t;
554     register struct command *kp;
555 {
556     int     saveIN, saveOUT, saveDIAG, saveSTD;
557     int     oSHIN;
558     int     oSHOUT;
559     int     oSHDIAG;
560     int     oOLDSTD;
561     jmp_buf_t osetexit;
562     int	    my_reenter;
563     int     odidfds;
564 #ifndef CLOSE_ON_EXEC
565     int	    odidcch;
566 #endif /* CLOSE_ON_EXEC */
567     signalfun_t osigint, osigquit, osigterm;
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     osigint  = signal(SIGINT, parintr);
580     osigquit = signal(SIGQUIT, parintr);
581     osigterm = signal(SIGTERM, parterm);
582 
583     odidfds = didfds;
584 #ifndef CLOSE_ON_EXEC
585     odidcch = didcch;
586 #endif /* CLOSE_ON_EXEC */
587     oSHIN = SHIN;
588     oSHOUT = SHOUT;
589     oSHDIAG = SHDIAG;
590     oOLDSTD = OLDSTD;
591 
592     saveIN = dcopy(SHIN, -1);
593     saveOUT = dcopy(SHOUT, -1);
594     saveDIAG = dcopy(SHDIAG, -1);
595     saveSTD = dcopy(OLDSTD, -1);
596 
597     lshift(kp->t_dcom, 1);
598 
599     getexit(osetexit);
600 
601     /* PWP: setjmp/longjmp bugfix for optimizing compilers */
602 #ifdef cray
603     my_reenter = 1;             /* assume non-zero return val */
604     if (setexit() == 0) {
605         my_reenter = 0;         /* Oh well, we were wrong */
606 #else /* !cray */
607     if ((my_reenter = setexit()) == 0) {
608 #endif /* cray */
609 	SHIN = dcopy(0, -1);
610 	SHOUT = dcopy(1, -1);
611 	SHDIAG = dcopy(2, -1);
612 #ifndef CLOSE_ON_EXEC
613 	didcch = 0;
614 #endif /* CLOSE_ON_EXEC */
615 	didfds = 0;
616 	/*
617 	 * Decrement the shell level
618 	 */
619 	shlvl(-1);
620 #ifdef WINNT_NATIVE
621 	__nt_really_exec=1;
622 #endif /* WINNT_NATIVE */
623 	doexec(kp, 1);
624     }
625 
626     (void) sigset(SIGINT, osigint);
627     (void) sigset(SIGQUIT, osigquit);
628     (void) sigset(SIGTERM, osigterm);
629 
630     doneinp = 0;
631 #ifndef CLOSE_ON_EXEC
632     didcch = odidcch;
633 #endif /* CLOSE_ON_EXEC */
634     didfds = odidfds;
635     (void) close(SHIN);
636     (void) close(SHOUT);
637     (void) close(SHDIAG);
638     (void) close(OLDSTD);
639     SHIN = dmove(saveIN, oSHIN);
640     SHOUT = dmove(saveOUT, oSHOUT);
641     SHDIAG = dmove(saveDIAG, oSHDIAG);
642     OLDSTD = dmove(saveSTD, oOLDSTD);
643 
644     resexit(osetexit);
645     if (my_reenter)
646 	stderror(ERR_SILENT);
647 }
648 
649 void
650 xechoit(t)
651     Char  **t;
652 {
653     if (adrof(STRecho)) {
654 	int odidfds = didfds;
655 	flush();
656 	haderr = 1;
657 	didfds = 0;
658 	blkpr(t), xputchar('\n');
659 	flush();
660 	didfds = odidfds;
661 	haderr = 0;
662     }
663 }
664 
665 /*ARGSUSED*/
666 void
667 dohash(vv, c)
668     Char **vv;
669     struct command *c;
670 {
671 #ifdef COMMENT
672     struct stat stb;
673 #endif
674     DIR    *dirp;
675     register struct dirent *dp;
676     int     i = 0;
677     struct varent *v = adrof(STRpath);
678     Char  **pv;
679     int hashval;
680 #ifdef WINNT_NATIVE
681     int is_windir; /* check if it is the windows directory */
682     USE(hashval);
683 #endif /* WINNT_NATIVE */
684 
685     USE(c);
686 #ifdef FASTHASH
687     if (vv && vv[1]) {
688         uhashlength = atoi(short2str(vv[1]));
689         if (vv[2]) {
690 	    uhashwidth = atoi(short2str(vv[2]));
691 	    if ((uhashwidth != sizeof(unsigned char)) &&
692 	        (uhashwidth != sizeof(unsigned short)) &&
693 	        (uhashwidth != sizeof(unsigned long)))
694 	        uhashwidth = 0;
695 	    if (vv[3])
696 		hashdebug = atoi(short2str(vv[3]));
697         }
698     }
699 
700     if (uhashwidth)
701 	hashwidth = uhashwidth;
702     else {
703 	hashwidth = 0;
704 	if (v == NULL)
705 	    return;
706 	for (pv = v->vec; pv && *pv; pv++, hashwidth++)
707 	    continue;
708 	if (hashwidth <= widthof(unsigned char))
709 	    hashwidth = sizeof(unsigned char);
710 	else if (hashwidth <= widthof(unsigned short))
711 	    hashwidth = sizeof(unsigned short);
712 	else if (hashwidth <= widthof(unsigned int))
713 	    hashwidth = sizeof(unsigned int);
714 	else
715 	    hashwidth = sizeof(unsigned long);
716     }
717 
718     if (uhashlength)
719 	hashlength = uhashlength;
720     else
721         hashlength = hashwidth * (8*64);/* "average" files per dir in path */
722 
723     if (xhash)
724         xfree((ptr_t) xhash);
725     xhash = (unsigned long *) xcalloc((size_t) (hashlength * hashwidth),
726 				      (size_t) 1);
727 #endif /* FASTHASH */
728 
729     (void) getusername(NULL);	/* flush the tilde cashe */
730     tw_cmd_free();
731     havhash = 1;
732     if (v == NULL)
733 	return;
734     for (pv = v->vec; pv && *pv; pv++, i++) {
735 	if (!ABSOLUTEP(pv[0]))
736 	    continue;
737 	dirp = opendir(short2str(*pv));
738 	if (dirp == NULL)
739 	    continue;
740 #ifdef COMMENT			/* this isn't needed.  opendir won't open
741 				 * non-dirs */
742 	if (fstat(dirp->dd_fd, &stb) < 0 || !S_ISDIR(stb.st_mode)) {
743 	    (void) closedir(dirp);
744 	    continue;
745 	}
746 #endif
747 #ifdef WINNT_NATIVE
748 	is_windir = nt_check_if_windir(short2str(*pv));
749 #endif /* WINNT_NATIVE */
750 	while ((dp = readdir(dirp)) != NULL) {
751 	    if (dp->d_ino == 0)
752 		continue;
753 	    if (dp->d_name[0] == '.' &&
754 		(dp->d_name[1] == '\0' ||
755 		 (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
756 		continue;
757 #ifdef WINNT_NATIVE
758 	    nt_check_name_and_hash(is_windir, dp->d_name, i);
759 #else /* !WINNT_NATIVE*/
760 #if defined(_UWIN) || defined(__CYGWIN__)
761 	    /* Turn foo.{exe,com,bat} into foo since UWIN's readdir returns
762 	     * the file with the .exe, .com, .bat extension
763 	     */
764 	    {
765 		size_t	ext = strlen(dp->d_name) - 4;
766 		if ((ext > 0) && (strcmp(&dp->d_name[ext], ".exe") == 0 ||
767 				  strcmp(&dp->d_name[ext], ".bat") == 0 ||
768 				  strcmp(&dp->d_name[ext], ".com") == 0))
769 		    dp->d_name[ext] = '\0';
770 	    }
771 #endif /* _UWIN || __CYGWIN__ */
772 # ifdef FASTHASH
773 	    hashval = hashname(str2short(dp->d_name));
774 	    bis(hashval, i);
775 	    if (hashdebug & 1)
776 	        xprintf(CGETS(13, 1, "hash=%-4d dir=%-2d prog=%s\n"),
777 		        hashname(str2short(dp->d_name)), i, dp->d_name);
778 # else /* OLD HASH */
779 	    hashval = hash(hashname(str2short(dp->d_name)), i);
780 	    bis(xhash, hashval);
781 # endif /* FASTHASH */
782 	    /* tw_add_comm_name (dp->d_name); */
783 #endif /* WINNT_NATIVE */
784 	}
785 	(void) closedir(dirp);
786     }
787 }
788 
789 /*ARGSUSED*/
790 void
791 dounhash(v, c)
792     Char **v;
793     struct command *c;
794 {
795     USE(c);
796     USE(v);
797     havhash = 0;
798 #ifdef FASTHASH
799     if (xhash) {
800        xfree((ptr_t) xhash);
801        xhash = NULL;
802     }
803 #endif /* FASTHASH */
804 }
805 
806 /*ARGSUSED*/
807 void
808 hashstat(v, c)
809     Char **v;
810     struct command *c;
811 {
812     USE(c);
813     USE(v);
814 #ifdef FASTHASH
815    if (havhash && hashlength && hashwidth)
816       xprintf(CGETS(13, 2, "%d hash buckets of %d bits each\n"),
817 	      hashlength, hashwidth*8);
818    if (hashdebug)
819       xprintf(CGETS(13, 3, "debug mask = 0x%08x\n"), hashdebug);
820 #endif /* FASTHASH */
821 #ifdef VFORK
822    if (hits + misses)
823       xprintf(CGETS(13, 4, "%d hits, %d misses, %d%%\n"),
824 	      hits, misses, 100 * hits / (hits + misses));
825 #endif
826 }
827 
828 
829 /*
830  * Hash a command name.
831  */
832 int
833 hashname(cp)
834     register Char *cp;
835 {
836     register unsigned long h;
837 
838     for (h = 0; *cp; cp++)
839 	h = hash(h, *cp);
840     return ((int) h);
841 }
842 
843 static int
844 iscommand(name)
845     Char   *name;
846 {
847     register Char **pv;
848     register Char *sav;
849     register struct varent *v;
850     register bool slash = any(short2str(name), '/');
851     register int hashval, i;
852 
853     v = adrof(STRpath);
854     if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
855 	pv = justabs;
856     else
857 	pv = v->vec;
858     sav = Strspl(STRslash, name);	/* / command name for postpending */
859     hashval = havhash ? hashname(name) : 0;
860     i = 0;
861     do {
862 	if (!slash && ABSOLUTEP(pv[0]) && havhash) {
863 #ifdef FASTHASH
864 	    if (!bit(hashval, i))
865 		goto cont;
866 #else /* OLDHASH */
867 	    int hashval1 = hash(hashval, i);
868 	    if (!bit(xhash, hashval1))
869 		goto cont;
870 #endif /* FASTHASH */
871 	}
872 	if (pv[0][0] == 0 || eq(pv[0], STRdot)) {	/* don't make ./xxx */
873 	    if (executable(NULL, name, 0)) {
874 		xfree((ptr_t) sav);
875 		return i + 1;
876 	    }
877 	}
878 	else {
879 	    if (executable(*pv, sav, 0)) {
880 		xfree((ptr_t) sav);
881 		return i + 1;
882 	    }
883 	}
884 cont:
885 	pv++;
886 	i++;
887     } while (*pv);
888     xfree((ptr_t) sav);
889     return 0;
890 }
891 
892 /* Also by:
893  *  Andreas Luik <luik@isaak.isa.de>
894  *  I S A  GmbH - Informationssysteme fuer computerintegrierte Automatisierung
895  *  Azenberstr. 35
896  *  D-7000 Stuttgart 1
897  *  West-Germany
898  * is the executable() routine below and changes to iscommand().
899  * Thanks again!!
900  */
901 
902 #ifndef WINNT_NATIVE
903 /*
904  * executable() examines the pathname obtained by concatenating dir and name
905  * (dir may be NULL), and returns 1 either if it is executable by us, or
906  * if dir_ok is set and the pathname refers to a directory.
907  * This is a bit kludgy, but in the name of optimization...
908  */
909 int
910 executable(dir, name, dir_ok)
911     Char   *dir, *name;
912     bool    dir_ok;
913 {
914     struct stat stbuf;
915     Char    path[MAXPATHLEN + 1];
916     char   *strname;
917     (void) memset(path, 0, sizeof(path));
918 
919     if (dir && *dir) {
920 	copyn(path, dir, MAXPATHLEN);
921 	catn(path, name, MAXPATHLEN);
922 	strname = short2str(path);
923     }
924     else
925 	strname = short2str(name);
926 
927     return (stat(strname, &stbuf) != -1 &&
928 	    ((dir_ok && S_ISDIR(stbuf.st_mode)) ||
929 	     (S_ISREG(stbuf.st_mode) &&
930     /* save time by not calling access() in the hopeless case */
931 	      (stbuf.st_mode & (S_IXOTH | S_IXGRP | S_IXUSR)) &&
932 	      access(strname, X_OK) == 0
933 	)));
934 }
935 #endif /*!WINNT_NATIVE*/
936 
937 int
938 tellmewhat(lexp, str)
939     struct wordent *lexp;
940     Char *str;
941 {
942     register int i;
943     register struct biltins *bptr;
944     register struct wordent *sp = lexp->next;
945     bool    aliased = 0, found;
946     Char   *s0, *s1, *s2, *cmd;
947     Char    qc;
948 
949     if (adrof1(sp->word, &aliases)) {
950 	alias(lexp);
951 	sp = lexp->next;
952 	aliased = 1;
953     }
954 
955     s0 = sp->word;		/* to get the memory freeing right... */
956 
957     /* handle quoted alias hack */
958     if ((*(sp->word) & (QUOTE | TRIM)) == QUOTE)
959 	(sp->word)++;
960 
961     /* do quoting, if it hasn't been done */
962     s1 = s2 = sp->word;
963     while (*s2)
964 	switch (*s2) {
965 	case '\'':
966 	case '"':
967 	    qc = *s2++;
968 	    while (*s2 && *s2 != qc)
969 		*s1++ = *s2++ | QUOTE;
970 	    if (*s2)
971 		s2++;
972 	    break;
973 	case '\\':
974 	    if (*++s2)
975 		*s1++ = *s2++ | QUOTE;
976 	    break;
977 	default:
978 	    *s1++ = *s2++;
979 	}
980     *s1 = '\0';
981 
982     for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
983 	if (eq(sp->word, str2short(bptr->bname))) {
984 	    if (str == NULL) {
985 		if (aliased)
986 		    prlex(lexp);
987 		xprintf(CGETS(13, 5, "%S: shell built-in command.\n"),
988 			      sp->word);
989 		flush();
990 	    }
991 	    else
992 		(void) Strcpy(str, sp->word);
993 	    sp->word = s0;	/* we save and then restore this */
994 	    return TRUE;
995 	}
996     }
997 #ifdef WINNT_NATIVE
998     for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
999 	if (eq(sp->word, str2short(bptr->bname))) {
1000 	    if (str == NULL) {
1001 		if (aliased)
1002 		    prlex(lexp);
1003 		xprintf(CGETS(13, 5, "%S: shell built-in command.\n"),
1004 			      sp->word);
1005 		flush();
1006 	    }
1007 	    else
1008 		(void) Strcpy(str, sp->word);
1009 	    sp->word = s0;	/* we save and then restore this */
1010 	    return TRUE;
1011 	}
1012     }
1013 #endif /* WINNT_NATIVE*/
1014 
1015     sp->word = cmd = globone(sp->word, G_IGNORE);
1016 
1017     if ((i = iscommand(sp->word)) != 0) {
1018 	register Char **pv;
1019 	register struct varent *v;
1020 	bool    slash = any(short2str(sp->word), '/');
1021 
1022 	v = adrof(STRpath);
1023 	if (v == NULL || v->vec == NULL || v->vec[0] == NULL || slash)
1024 	    pv = justabs;
1025 	else
1026 	    pv = v->vec;
1027 
1028 	while (--i)
1029 	    pv++;
1030 	if (pv[0][0] == 0 || eq(pv[0], STRdot)) {
1031 	    if (!slash) {
1032 		sp->word = Strspl(STRdotsl, sp->word);
1033 		prlex(lexp);
1034 		xfree((ptr_t) sp->word);
1035 	    }
1036 	    else
1037 		prlex(lexp);
1038 	}
1039 	else {
1040 	    s1 = Strspl(*pv, STRslash);
1041 	    sp->word = Strspl(s1, sp->word);
1042 	    xfree((ptr_t) s1);
1043 	    if (str == NULL)
1044 		prlex(lexp);
1045 	    else
1046 		(void) Strcpy(str, sp->word);
1047 	    xfree((ptr_t) sp->word);
1048 	}
1049 	found = 1;
1050     }
1051     else {
1052 	if (str == NULL) {
1053 	    if (aliased)
1054 		prlex(lexp);
1055 	    xprintf(CGETS(13, 6, "%S: Command not found.\n"), sp->word);
1056 	    flush();
1057 	}
1058 	else
1059 	    (void) Strcpy(str, sp->word);
1060 	found = 0;
1061     }
1062     sp->word = s0;		/* we save and then restore this */
1063     xfree((ptr_t) cmd);
1064     return found;
1065 }
1066 
1067 /*
1068  * Builtin to look at and list all places a command may be defined:
1069  * aliases, shell builtins, and the path.
1070  *
1071  * Marc Horowitz <marc@mit.edu>
1072  * MIT Student Information Processing Board
1073  */
1074 
1075 /*ARGSUSED*/
1076 void
1077 dowhere(v, c)
1078     register Char **v;
1079     struct command *c;
1080 {
1081     int found = 1;
1082     USE(c);
1083     for (v++; *v; v++)
1084 	found &= find_cmd(*v, 1);
1085     /* Make status nonzero if any command is not found. */
1086     if (!found)
1087       set(STRstatus, Strsave(STR1), VAR_READWRITE);
1088 }
1089 
1090 int
1091 find_cmd(cmd, prt)
1092     Char *cmd;
1093     int prt;
1094 {
1095     struct varent *var;
1096     struct biltins *bptr;
1097     Char **pv;
1098     Char *sv;
1099     int hashval, i, ex, rval = 0;
1100 
1101     if (prt && any(short2str(cmd), '/')) {
1102 	xprintf(CGETS(13, 7, "where: / in command makes no sense\n"));
1103 	return rval;
1104     }
1105 
1106     /* first, look for an alias */
1107 
1108     if (prt && adrof1(cmd, &aliases)) {
1109 	if ((var = adrof1(cmd, &aliases)) != NULL) {
1110 	    xprintf(CGETS(13, 8, "%S is aliased to "), cmd);
1111 	    if (var->vec != NULL)
1112 		blkpr(var->vec);
1113 	    xputchar('\n');
1114 	    rval = 1;
1115 	}
1116     }
1117 
1118     /* next, look for a shell builtin */
1119 
1120     for (bptr = bfunc; bptr < &bfunc[nbfunc]; bptr++) {
1121 	if (eq(cmd, str2short(bptr->bname))) {
1122 	    rval = 1;
1123 	    if (prt)
1124 		xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1125 	    else
1126 		return rval;
1127 	}
1128     }
1129 #ifdef WINNT_NATIVE
1130     for (bptr = nt_bfunc; bptr < &nt_bfunc[nt_nbfunc]; bptr++) {
1131 	if (eq(cmd, str2short(bptr->bname))) {
1132 	    rval = 1;
1133 	    if (prt)
1134 		xprintf(CGETS(13, 9, "%S is a shell built-in\n"), cmd);
1135 	    else
1136 		return rval;
1137 	}
1138     }
1139 #endif /* WINNT_NATIVE*/
1140 
1141     /* last, look through the path for the command */
1142 
1143     if ((var = adrof(STRpath)) == NULL)
1144 	return rval;
1145 
1146     hashval = havhash ? hashname(cmd) : 0;
1147 
1148     sv = Strspl(STRslash, cmd);
1149 
1150     for (pv = var->vec, i = 0; pv && *pv; pv++, i++) {
1151 	if (havhash && !eq(*pv, STRdot)) {
1152 #ifdef FASTHASH
1153 	    if (!bit(hashval, i))
1154 		continue;
1155 #else /* OLDHASH */
1156 	    int hashval1 = hash(hashval, i);
1157 	    if (!bit(xhash, hashval1))
1158 		continue;
1159 #endif /* FASTHASH */
1160 	}
1161 	ex = executable(*pv, sv, 0);
1162 #ifdef FASTHASH
1163 	if (!ex && (hashdebug & 2)) {
1164 	    xprintf(CGETS(13, 10, "hash miss: "));
1165 	    ex = 1;	/* Force printing */
1166 	}
1167 #endif /* FASTHASH */
1168 	if (ex) {
1169 	    rval = 1;
1170 	    if (prt) {
1171 		xprintf("%S/", *pv);
1172 		xprintf("%S\n", cmd);
1173 	    }
1174 	    else
1175 		return rval;
1176 	}
1177     }
1178     xfree((ptr_t) sv);
1179     return rval;
1180 }
1181 #ifdef WINNT_NATIVE
1182 int hashval_extern(cp)
1183 	Char *cp;
1184 {
1185 	return havhash?hashname(cp):0;
1186 }
1187 int bit_extern(val,i)
1188 	int val;
1189 	int i;
1190 {
1191 	return bit(val,i);
1192 }
1193 void bis_extern(val,i)
1194 	int val;
1195 	int i;
1196 {
1197 	bis(val,i);
1198 }
1199 #endif /* WINNT_NATIVE */
1200 
1201