exec.c revision 36150 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38#if 0
39static char sccsid[] = "@(#)exec.c	8.4 (Berkeley) 6/8/95";
40#endif
41static const char rcsid[] =
42	"$Id$";
43#endif /* not lint */
44
45#include <sys/types.h>
46#include <sys/stat.h>
47#include <unistd.h>
48#include <fcntl.h>
49#include <errno.h>
50#include <stdlib.h>
51
52/*
53 * When commands are first encountered, they are entered in a hash table.
54 * This ensures that a full path search will not have to be done for them
55 * on each invocation.
56 *
57 * We should investigate converting to a linear search, even though that
58 * would make the command name "hash" a misnomer.
59 */
60
61#include "shell.h"
62#include "main.h"
63#include "nodes.h"
64#include "parser.h"
65#include "redir.h"
66#include "eval.h"
67#include "exec.h"
68#include "builtins.h"
69#include "var.h"
70#include "options.h"
71#include "input.h"
72#include "output.h"
73#include "syntax.h"
74#include "memalloc.h"
75#include "error.h"
76#include "init.h"
77#include "mystring.h"
78#include "show.h"
79#include "jobs.h"
80#include "alias.h"
81
82
83#define CMDTABLESIZE 31		/* should be prime */
84#define ARB 1			/* actual size determined at run time */
85
86
87
88struct tblentry {
89	struct tblentry *next;	/* next entry in hash chain */
90	union param param;	/* definition of builtin function */
91	short cmdtype;		/* index identifying command */
92	char rehash;		/* if set, cd done since entry created */
93	char cmdname[ARB];	/* name of command */
94};
95
96
97STATIC struct tblentry *cmdtable[CMDTABLESIZE];
98STATIC int builtinloc = -1;		/* index in path of %builtin, or -1 */
99int exerrno = 0;			/* Last exec error */
100
101
102STATIC void tryexec __P((char *, char **, char **));
103#ifndef BSD
104STATIC void execinterp __P((char **, char **));
105#endif
106STATIC void printentry __P((struct tblentry *, int));
107STATIC void clearcmdentry __P((int));
108STATIC struct tblentry *cmdlookup __P((char *, int));
109STATIC void delete_cmd_entry __P((void));
110
111
112
113/*
114 * Exec a program.  Never returns.  If you change this routine, you may
115 * have to change the find_command routine as well.
116 */
117
118void
119shellexec(argv, envp, path, index)
120	char **argv, **envp;
121	char *path;
122	int index;
123{
124	char *cmdname;
125	int e;
126
127	if (strchr(argv[0], '/') != NULL) {
128		tryexec(argv[0], argv, envp);
129		e = errno;
130	} else {
131		e = ENOENT;
132		while ((cmdname = padvance(&path, argv[0])) != NULL) {
133			if (--index < 0 && pathopt == NULL) {
134				tryexec(cmdname, argv, envp);
135				if (errno != ENOENT && errno != ENOTDIR)
136					e = errno;
137			}
138			stunalloc(cmdname);
139		}
140	}
141
142	/* Map to POSIX errors */
143	switch (e) {
144	case EACCES:
145		exerrno = 126;
146		break;
147	case ENOENT:
148		exerrno = 127;
149		break;
150	default:
151		exerrno = 2;
152		break;
153	}
154	exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC));
155}
156
157
158STATIC void
159tryexec(cmd, argv, envp)
160	char *cmd;
161	char **argv;
162	char **envp;
163	{
164	int e;
165#ifndef BSD
166	char *p;
167#endif
168
169#ifdef SYSV
170	do {
171		execve(cmd, argv, envp);
172	} while (errno == EINTR);
173#else
174	execve(cmd, argv, envp);
175#endif
176	e = errno;
177	if (e == ENOEXEC) {
178		initshellproc();
179		setinputfile(cmd, 0);
180		commandname = arg0 = savestr(argv[0]);
181#ifndef BSD
182		pgetc(); pungetc();		/* fill up input buffer */
183		p = parsenextc;
184		if (parsenleft > 2 && p[0] == '#' && p[1] == '!') {
185			argv[0] = cmd;
186			execinterp(argv, envp);
187		}
188#endif
189		setparam(argv + 1);
190		exraise(EXSHELLPROC);
191		/*NOTREACHED*/
192	}
193	errno = e;
194}
195
196
197#ifndef BSD
198/*
199 * Execute an interpreter introduced by "#!", for systems where this
200 * feature has not been built into the kernel.  If the interpreter is
201 * the shell, return (effectively ignoring the "#!").  If the execution
202 * of the interpreter fails, exit.
203 *
204 * This code peeks inside the input buffer in order to avoid actually
205 * reading any input.  It would benefit from a rewrite.
206 */
207
208#define NEWARGS 5
209
210STATIC void
211execinterp(argv, envp)
212	char **argv, **envp;
213	{
214	int n;
215	char *inp;
216	char *outp;
217	char c;
218	char *p;
219	char **ap;
220	char *newargs[NEWARGS];
221	int i;
222	char **ap2;
223	char **new;
224
225	n = parsenleft - 2;
226	inp = parsenextc + 2;
227	ap = newargs;
228	for (;;) {
229		while (--n >= 0 && (*inp == ' ' || *inp == '\t'))
230			inp++;
231		if (n < 0)
232			goto bad;
233		if ((c = *inp++) == '\n')
234			break;
235		if (ap == &newargs[NEWARGS])
236bad:		  error("Bad #! line");
237		STARTSTACKSTR(outp);
238		do {
239			STPUTC(c, outp);
240		} while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n');
241		STPUTC('\0', outp);
242		n++, inp--;
243		*ap++ = grabstackstr(outp);
244	}
245	if (ap == newargs + 1) {	/* if no args, maybe no exec is needed */
246		p = newargs[0];
247		for (;;) {
248			if (equal(p, "sh") || equal(p, "ash")) {
249				return;
250			}
251			while (*p != '/') {
252				if (*p == '\0')
253					goto break2;
254				p++;
255			}
256			p++;
257		}
258break2:;
259	}
260	i = (char *)ap - (char *)newargs;		/* size in bytes */
261	if (i == 0)
262		error("Bad #! line");
263	for (ap2 = argv ; *ap2++ != NULL ; );
264	new = ckmalloc(i + ((char *)ap2 - (char *)argv));
265	ap = newargs, ap2 = new;
266	while ((i -= sizeof (char **)) >= 0)
267		*ap2++ = *ap++;
268	ap = argv;
269	while (*ap2++ = *ap++);
270	shellexec(new, envp, pathval(), 0);
271}
272#endif
273
274
275
276/*
277 * Do a path search.  The variable path (passed by reference) should be
278 * set to the start of the path before the first call; padvance will update
279 * this value as it proceeds.  Successive calls to padvance will return
280 * the possible path expansions in sequence.  If an option (indicated by
281 * a percent sign) appears in the path entry then the global variable
282 * pathopt will be set to point to it; otherwise pathopt will be set to
283 * NULL.
284 */
285
286char *pathopt;
287
288char *
289padvance(path, name)
290	char **path;
291	char *name;
292	{
293	char *p, *q;
294	char *start;
295	int len;
296
297	if (*path == NULL)
298		return NULL;
299	start = *path;
300	for (p = start ; *p && *p != ':' && *p != '%' ; p++);
301	len = p - start + strlen(name) + 2;	/* "2" is for '/' and '\0' */
302	while (stackblocksize() < len)
303		growstackblock();
304	q = stackblock();
305	if (p != start) {
306		memcpy(q, start, p - start);
307		q += p - start;
308		*q++ = '/';
309	}
310	strcpy(q, name);
311	pathopt = NULL;
312	if (*p == '%') {
313		pathopt = ++p;
314		while (*p && *p != ':')  p++;
315	}
316	if (*p == ':')
317		*path = p + 1;
318	else
319		*path = NULL;
320	return stalloc(len);
321}
322
323
324
325/*** Command hashing code ***/
326
327
328int
329hashcmd(argc, argv)
330	int argc __unused;
331	char **argv __unused;
332{
333	struct tblentry **pp;
334	struct tblentry *cmdp;
335	int c;
336	int verbose;
337	struct cmdentry entry;
338	char *name;
339
340	verbose = 0;
341	while ((c = nextopt("rv")) != '\0') {
342		if (c == 'r') {
343			clearcmdentry(0);
344		} else if (c == 'v') {
345			verbose++;
346		}
347	}
348	if (*argptr == NULL) {
349		for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
350			for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
351				printentry(cmdp, verbose);
352			}
353		}
354		return 0;
355	}
356	while ((name = *argptr) != NULL) {
357		if ((cmdp = cmdlookup(name, 0)) != NULL
358		 && (cmdp->cmdtype == CMDNORMAL
359		     || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
360			delete_cmd_entry();
361		find_command(name, &entry, 1, pathval());
362		if (verbose) {
363			if (entry.cmdtype != CMDUNKNOWN) {	/* if no error msg */
364				cmdp = cmdlookup(name, 0);
365				printentry(cmdp, verbose);
366			}
367			flushall();
368		}
369		argptr++;
370	}
371	return 0;
372}
373
374
375STATIC void
376printentry(cmdp, verbose)
377	struct tblentry *cmdp;
378	int verbose;
379	{
380	int index;
381	char *path;
382	char *name;
383
384	if (cmdp->cmdtype == CMDNORMAL) {
385		index = cmdp->param.index;
386		path = pathval();
387		do {
388			name = padvance(&path, cmdp->cmdname);
389			stunalloc(name);
390		} while (--index >= 0);
391		out1str(name);
392	} else if (cmdp->cmdtype == CMDBUILTIN) {
393		out1fmt("builtin %s", cmdp->cmdname);
394	} else if (cmdp->cmdtype == CMDFUNCTION) {
395		out1fmt("function %s", cmdp->cmdname);
396		if (verbose) {
397			INTOFF;
398			name = commandtext(cmdp->param.func);
399			out1c(' ');
400			out1str(name);
401			ckfree(name);
402			INTON;
403		}
404#ifdef DEBUG
405	} else {
406		error("internal error: cmdtype %d", cmdp->cmdtype);
407#endif
408	}
409	if (cmdp->rehash)
410		out1c('*');
411	out1c('\n');
412}
413
414
415
416/*
417 * Resolve a command name.  If you change this routine, you may have to
418 * change the shellexec routine as well.
419 */
420
421void
422find_command(name, entry, printerr, path)
423	char *name;
424	struct cmdentry *entry;
425	int printerr;
426	char *path;
427{
428	struct tblentry *cmdp;
429	int index;
430	int prev;
431	char *fullname;
432	struct stat statb;
433	int e;
434	int i;
435
436	/* If name contains a slash, don't use the hash table */
437	if (strchr(name, '/') != NULL) {
438		entry->cmdtype = CMDNORMAL;
439		entry->u.index = 0;
440		return;
441	}
442
443	/* If name is in the table, and not invalidated by cd, we're done */
444	if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0)
445		goto success;
446
447	/* If %builtin not in path, check for builtin next */
448	if (builtinloc < 0 && (i = find_builtin(name)) >= 0) {
449		INTOFF;
450		cmdp = cmdlookup(name, 1);
451		cmdp->cmdtype = CMDBUILTIN;
452		cmdp->param.index = i;
453		INTON;
454		goto success;
455	}
456
457	/* We have to search path. */
458	prev = -1;		/* where to start */
459	if (cmdp) {		/* doing a rehash */
460		if (cmdp->cmdtype == CMDBUILTIN)
461			prev = builtinloc;
462		else
463			prev = cmdp->param.index;
464	}
465
466	e = ENOENT;
467	index = -1;
468loop:
469	while ((fullname = padvance(&path, name)) != NULL) {
470		stunalloc(fullname);
471		index++;
472		if (pathopt) {
473			if (prefix("builtin", pathopt)) {
474				if ((i = find_builtin(name)) < 0)
475					goto loop;
476				INTOFF;
477				cmdp = cmdlookup(name, 1);
478				cmdp->cmdtype = CMDBUILTIN;
479				cmdp->param.index = i;
480				INTON;
481				goto success;
482			} else if (prefix("func", pathopt)) {
483				/* handled below */
484			} else {
485				goto loop;	/* ignore unimplemented options */
486			}
487		}
488		/* if rehash, don't redo absolute path names */
489		if (fullname[0] == '/' && index <= prev) {
490			if (index < prev)
491				goto loop;
492			TRACE(("searchexec \"%s\": no change\n", name));
493			goto success;
494		}
495		while (stat(fullname, &statb) < 0) {
496#ifdef SYSV
497			if (errno == EINTR)
498				continue;
499#endif
500			if (errno != ENOENT && errno != ENOTDIR)
501				e = errno;
502			goto loop;
503		}
504		e = EACCES;	/* if we fail, this will be the error */
505		if (!S_ISREG(statb.st_mode))
506			goto loop;
507		if (pathopt) {		/* this is a %func directory */
508			stalloc(strlen(fullname) + 1);
509			readcmdfile(fullname);
510			if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION)
511				error("%s not defined in %s", name, fullname);
512			stunalloc(fullname);
513			goto success;
514		}
515#ifdef notdef
516		if (statb.st_uid == geteuid()) {
517			if ((statb.st_mode & 0100) == 0)
518				goto loop;
519		} else if (statb.st_gid == getegid()) {
520			if ((statb.st_mode & 010) == 0)
521				goto loop;
522		} else {
523			if ((statb.st_mode & 01) == 0)
524				goto loop;
525		}
526#endif
527		TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
528		INTOFF;
529		cmdp = cmdlookup(name, 1);
530		cmdp->cmdtype = CMDNORMAL;
531		cmdp->param.index = index;
532		INTON;
533		goto success;
534	}
535
536	/* We failed.  If there was an entry for this command, delete it */
537	if (cmdp)
538		delete_cmd_entry();
539	if (printerr)
540		outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
541	entry->cmdtype = CMDUNKNOWN;
542	return;
543
544success:
545	cmdp->rehash = 0;
546	entry->cmdtype = cmdp->cmdtype;
547	entry->u = cmdp->param;
548}
549
550
551
552/*
553 * Search the table of builtin commands.
554 */
555
556int
557find_builtin(name)
558	char *name;
559{
560	const struct builtincmd *bp;
561
562	for (bp = builtincmd ; bp->name ; bp++) {
563		if (*bp->name == *name && equal(bp->name, name))
564			return bp->code;
565	}
566	return -1;
567}
568
569
570
571/*
572 * Called when a cd is done.  Marks all commands so the next time they
573 * are executed they will be rehashed.
574 */
575
576void
577hashcd() {
578	struct tblentry **pp;
579	struct tblentry *cmdp;
580
581	for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
582		for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
583			if (cmdp->cmdtype == CMDNORMAL
584			 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
585				cmdp->rehash = 1;
586		}
587	}
588}
589
590
591
592/*
593 * Called before PATH is changed.  The argument is the new value of PATH;
594 * pathval() still returns the old value at this point.  Called with
595 * interrupts off.
596 */
597
598void
599changepath(newval)
600	const char *newval;
601{
602	const char *old, *new;
603	int index;
604	int firstchange;
605	int bltin;
606
607	old = pathval();
608	new = newval;
609	firstchange = 9999;	/* assume no change */
610	index = 0;
611	bltin = -1;
612	for (;;) {
613		if (*old != *new) {
614			firstchange = index;
615			if ((*old == '\0' && *new == ':')
616			 || (*old == ':' && *new == '\0'))
617				firstchange++;
618			old = new;	/* ignore subsequent differences */
619		}
620		if (*new == '\0')
621			break;
622		if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
623			bltin = index;
624		if (*new == ':') {
625			index++;
626		}
627		new++, old++;
628	}
629	if (builtinloc < 0 && bltin >= 0)
630		builtinloc = bltin;		/* zap builtins */
631	if (builtinloc >= 0 && bltin < 0)
632		firstchange = 0;
633	clearcmdentry(firstchange);
634	builtinloc = bltin;
635}
636
637
638/*
639 * Clear out command entries.  The argument specifies the first entry in
640 * PATH which has changed.
641 */
642
643STATIC void
644clearcmdentry(firstchange)
645	int firstchange;
646{
647	struct tblentry **tblp;
648	struct tblentry **pp;
649	struct tblentry *cmdp;
650
651	INTOFF;
652	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
653		pp = tblp;
654		while ((cmdp = *pp) != NULL) {
655			if ((cmdp->cmdtype == CMDNORMAL &&
656			     cmdp->param.index >= firstchange)
657			 || (cmdp->cmdtype == CMDBUILTIN &&
658			     builtinloc >= firstchange)) {
659				*pp = cmdp->next;
660				ckfree(cmdp);
661			} else {
662				pp = &cmdp->next;
663			}
664		}
665	}
666	INTON;
667}
668
669
670/*
671 * Delete all functions.
672 */
673
674#ifdef mkinit
675MKINIT void deletefuncs();
676
677SHELLPROC {
678	deletefuncs();
679}
680#endif
681
682void
683deletefuncs() {
684	struct tblentry **tblp;
685	struct tblentry **pp;
686	struct tblentry *cmdp;
687
688	INTOFF;
689	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
690		pp = tblp;
691		while ((cmdp = *pp) != NULL) {
692			if (cmdp->cmdtype == CMDFUNCTION) {
693				*pp = cmdp->next;
694				freefunc(cmdp->param.func);
695				ckfree(cmdp);
696			} else {
697				pp = &cmdp->next;
698			}
699		}
700	}
701	INTON;
702}
703
704
705
706/*
707 * Locate a command in the command hash table.  If "add" is nonzero,
708 * add the command to the table if it is not already present.  The
709 * variable "lastcmdentry" is set to point to the address of the link
710 * pointing to the entry, so that delete_cmd_entry can delete the
711 * entry.
712 */
713
714struct tblentry **lastcmdentry;
715
716
717STATIC struct tblentry *
718cmdlookup(name, add)
719	char *name;
720	int add;
721{
722	int hashval;
723	char *p;
724	struct tblentry *cmdp;
725	struct tblentry **pp;
726
727	p = name;
728	hashval = *p << 4;
729	while (*p)
730		hashval += *p++;
731	hashval &= 0x7FFF;
732	pp = &cmdtable[hashval % CMDTABLESIZE];
733	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
734		if (equal(cmdp->cmdname, name))
735			break;
736		pp = &cmdp->next;
737	}
738	if (add && cmdp == NULL) {
739		INTOFF;
740		cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
741					+ strlen(name) + 1);
742		cmdp->next = NULL;
743		cmdp->cmdtype = CMDUNKNOWN;
744		cmdp->rehash = 0;
745		strcpy(cmdp->cmdname, name);
746		INTON;
747	}
748	lastcmdentry = pp;
749	return cmdp;
750}
751
752/*
753 * Delete the command entry returned on the last lookup.
754 */
755
756STATIC void
757delete_cmd_entry() {
758	struct tblentry *cmdp;
759
760	INTOFF;
761	cmdp = *lastcmdentry;
762	*lastcmdentry = cmdp->next;
763	ckfree(cmdp);
764	INTON;
765}
766
767
768
769#ifdef notdef
770void
771getcmdentry(name, entry)
772	char *name;
773	struct cmdentry *entry;
774	{
775	struct tblentry *cmdp = cmdlookup(name, 0);
776
777	if (cmdp) {
778		entry->u = cmdp->param;
779		entry->cmdtype = cmdp->cmdtype;
780	} else {
781		entry->cmdtype = CMDUNKNOWN;
782		entry->u.index = 0;
783	}
784}
785#endif
786
787
788/*
789 * Add a new command entry, replacing any existing command entry for
790 * the same name.
791 */
792
793void
794addcmdentry(name, entry)
795	char *name;
796	struct cmdentry *entry;
797	{
798	struct tblentry *cmdp;
799
800	INTOFF;
801	cmdp = cmdlookup(name, 1);
802	if (cmdp->cmdtype == CMDFUNCTION) {
803		freefunc(cmdp->param.func);
804	}
805	cmdp->cmdtype = entry->cmdtype;
806	cmdp->param = entry->u;
807	INTON;
808}
809
810
811/*
812 * Define a shell function.
813 */
814
815void
816defun(name, func)
817	char *name;
818	union node *func;
819	{
820	struct cmdentry entry;
821
822	INTOFF;
823	entry.cmdtype = CMDFUNCTION;
824	entry.u.func = copyfunc(func);
825	addcmdentry(name, &entry);
826	INTON;
827}
828
829
830/*
831 * Delete a function if it exists.
832 */
833
834int
835unsetfunc(name)
836	char *name;
837	{
838	struct tblentry *cmdp;
839
840	if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) {
841		freefunc(cmdp->param.func);
842		delete_cmd_entry();
843		return (0);
844	}
845	return (1);
846}
847
848/*
849 * Locate and print what a word is...
850 */
851
852int
853typecmd(argc, argv)
854	int argc;
855	char **argv;
856{
857	struct cmdentry entry;
858	struct tblentry *cmdp;
859	char **pp;
860	struct alias *ap;
861	int i;
862	int error = 0;
863	extern char *const parsekwd[];
864
865	for (i = 1; i < argc; i++) {
866		out1str(argv[i]);
867		/* First look at the keywords */
868		for (pp = (char **)parsekwd; *pp; pp++)
869			if (**pp == *argv[i] && equal(*pp, argv[i]))
870				break;
871
872		if (*pp) {
873			out1str(" is a shell keyword\n");
874			continue;
875		}
876
877		/* Then look at the aliases */
878		if ((ap = lookupalias(argv[i], 1)) != NULL) {
879			out1fmt(" is an alias for %s\n", ap->val);
880			continue;
881		}
882
883		/* Then check if it is a tracked alias */
884		if ((cmdp = cmdlookup(argv[i], 0)) != NULL) {
885			entry.cmdtype = cmdp->cmdtype;
886			entry.u = cmdp->param;
887		}
888		else {
889			/* Finally use brute force */
890			find_command(argv[i], &entry, 0, pathval());
891		}
892
893		switch (entry.cmdtype) {
894		case CMDNORMAL: {
895			int j = entry.u.index;
896			char *path = pathval(), *name;
897			do {
898				name = padvance(&path, argv[i]);
899				stunalloc(name);
900			} while (--j >= 0);
901			out1fmt(" is%s %s\n",
902			    cmdp ? " a tracked alias for" : "", name);
903			break;
904		}
905		case CMDFUNCTION:
906			out1str(" is a shell function\n");
907			break;
908
909		case CMDBUILTIN:
910			out1str(" is a shell builtin\n");
911			break;
912
913		default:
914			out1str(" not found\n");
915			error |= 127;
916			break;
917		}
918	}
919	return error;
920}
921