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Last change on this file since 3604 was 3279, checked in by bird, 18 years ago
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1	/* $NetBSD: exec.c,v 1.37 2003/08/07 09:05:31 agc Exp $ */
2
3	/*-
4	* Copyright (c) 1991, 1993
5	* The Regents of the University of California. All rights reserved.
6	*
7	* This code is derived from software contributed to Berkeley by
8	* Kenneth Almquist.
9	*
10	* Redistribution and use in source and binary forms, with or without
11	* modification, are permitted provided that the following conditions
12	* are met:
13	* 1. Redistributions of source code must retain the above copyright
14	* notice, this list of conditions and the following disclaimer.
15	* 2. Redistributions in binary form must reproduce the above copyright
16	* notice, this list of conditions and the following disclaimer in the
17	* documentation and/or other materials provided with the distribution.
18	* 3. Neither the name of the University nor the names of its contributors
19	* may be used to endorse or promote products derived from this software
20	* without specific prior written permission.
21	*
22	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32	* SUCH DAMAGE.
33	*/
34
35	#include <sys/cdefs.h>
36	#ifndef lint
37	#if 0
38	static char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95";
39	#else
40	__RCSID("$NetBSD: exec.c,v 1.37 2003/08/07 09:05:31 agc Exp $");
41	#endif
42	#endif /* not lint */
43
44	#include <sys/types.h>
45	#include <sys/stat.h>
46	#include <sys/wait.h>
47	#include <unistd.h>
48	#include <fcntl.h>
49	#include <errno.h>
50	#include <stdio.h>
51	#include <stdlib.h>
52
53	/*
54	* When commands are first encountered, they are entered in a hash table.
55	* This ensures that a full path search will not have to be done for them
56	* on each invocation.
57	*
58	* We should investigate converting to a linear search, even though that
59	* would make the command name "hash" a misnomer.
60	*/
61
62	#include "shell.h"
63	#include "main.h"
64	#include "nodes.h"
65	#include "parser.h"
66	#include "redir.h"
67	#include "eval.h"
68	#include "exec.h"
69	#include "builtins.h"
70	#include "var.h"
71	#include "options.h"
72	#include "input.h"
73	#include "output.h"
74	#include "syntax.h"
75	#include "memalloc.h"
76	#include "error.h"
77	#include "init.h"
78	#include "mystring.h"
79	#include "show.h"
80	#include "jobs.h"
81	#include "alias.h"
82	#ifdef __INNOTEK_LIBC__
83	#include <InnoTekLIBC/backend.h>
84	#endif
85
86
87	#define CMDTABLESIZE 31 /* should be prime */
88	#define ARB 1 /* actual size determined at run time */
89
90
91
92	struct tblentry {
93	struct tblentry next; / next entry in hash chain */
94	union param param; /* definition of builtin function */
95	short cmdtype; /* index identifying command */
96	char rehash; /* if set, cd done since entry created */
97	char cmdname[ARB]; /* name of command */
98	};
99
100
101	STATIC struct tblentry *cmdtable[CMDTABLESIZE];
102	STATIC int builtinloc = -1; /* index in path of %builtin, or -1 */
103	int exerrno = 0; /* Last exec error */
104
105
106	STATIC void tryexec(char , char , char *, int, int);
107	STATIC void execinterp(char , char );
108	STATIC void printentry(struct tblentry *, int);
109	STATIC void clearcmdentry(int);
110	STATIC struct tblentry cmdlookup(const char , int);
111	STATIC void delete_cmd_entry(void);
112	#ifdef PC_EXE_EXTS
113	STATIC int stat_pc_exec_exts(char fullname, struct stat st, int has_ext);
114	#endif
115
116
117	extern char *const parsekwd[];
118
119	/*
120	* Exec a program. Never returns. If you change this routine, you may
121	* have to change the find_command routine as well.
122	*/
123
124	void
125	shellexec(char argv, char envp, const char *path, int idx, int vforked)
126	{
127	char *cmdname;
128	int e;
129	#ifdef PC_EXE_EXTS
130	int has_ext = strlen(argv[0]) - 4;
131	has_ext = has_ext > 0
132	&& argv[0][has_ext] == '.'
133	/* use strstr and upper/lower permuated extensions to avoid multiple strcasecmp calls. */
134	&& strstr("exe;" "Exe;" "EXe;" "EXE;" "ExE;" "eXe;" "eXE;" "exE;"
135	"cmd;" "Cmd;" "CMd;" "CMD;" "CmD;" "cMd;" "cMD;" "cmD;"
136	"com;" "Com;" "COm;" "COM;" "CoM;" "cOm;" "cOM;" "coM;"
137	"bat;" "Bat;" "BAt;" "BAT;" "BaT;" "bAt;" "bAT;" "baT;"
138	"btm;" "Btm;" "BTm;" "BTM;" "BtM;" "bTm;" "bTM;" "btM;",
139	argv[0] + has_ext + 1)
140	!= NULL;
141	#else
142	const int has_ext = 1;
143	#endif
144	TRACE(("shellexec: argv[0]=%s idx=%d\n", argv[0], idx));
145	if (strchr(argv[0], '/') != NULL) {
146	cmdname = stalloc(strlen(argv[0]) + 5);
147	strcpy(cmdname, argv[0]);
148	tryexec(cmdname, argv, envp, vforked, has_ext);
149	TRACE(("shellexec: cmdname=%s\n", cmdname));
150	stunalloc(cmdname);
151	e = errno;
152	} else {
153	e = ENOENT;
154	while ((cmdname = padvance(&path, argv[0])) != NULL) {
155	if (--idx < 0 && pathopt == NULL) {
156	tryexec(cmdname, argv, envp, vforked, has_ext);
157	if (errno != ENOENT && errno != ENOTDIR)
158	e = errno;
159	}
160	stunalloc(cmdname);
161	}
162	}
163
164	/* Map to POSIX errors */
165	switch (e) {
166	case EACCES:
167	exerrno = 126;
168	break;
169	case ENOENT:
170	exerrno = 127;
171	break;
172	default:
173	exerrno = 2;
174	break;
175	}
176	TRACE(("shellexec failed for '%s', errno %d, vforked %d, suppressint %d\n",
177	argv[0], e, vforked, suppressint ));
178	exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC));
179	/* NOTREACHED */
180	}
181
182
183	STATIC void
184	tryexec(char cmd, char argv, char *envp, int vforked, int has_ext)
185	{
186	int e;
187	#ifdef EXEC_HASH_BANG_SCRIPT
188	char *p;
189	#endif
190	#ifdef PC_EXE_EXTS
191	/* exploit the effect of stat_pc_exec_exts which adds the
192	* correct extentions to the file.
193	*/
194	struct stat st;
195	if (!has_ext)
196	stat_pc_exec_exts(cmd, &st, 0);
197	#endif
198	#if defined __INNOTEK_LIBC__ && defined EXEC_HASH_BANG_SCRIPT
199	__libc_Back_gfProcessHandleHashBangScripts = 0;
200	#endif
201
202	#ifdef SYSV
203	do {
204	execve(cmd, argv, envp);
205	} while (errno == EINTR);
206	#else
207	execve(cmd, argv, envp);
208	#endif
209	e = errno;
210	if (e == ENOEXEC) {
211	if (vforked) {
212	/* We are currently vfork(2)ed, so raise an
213	* exception, and evalcommand will try again
214	* with a normal fork(2).
215	*/
216	exraise(EXSHELLPROC);
217	}
218	initshellproc();
219	setinputfile(cmd, 0);
220	commandname = arg0 = savestr(argv[0]);
221	#ifdef EXEC_HASH_BANG_SCRIPT
222	pgetc(); pungetc(); /* fill up input buffer */
223	p = parsenextc;
224	if (parsenleft > 2 && p[0] == '#' && p[1] == '!') {
225	argv[0] = cmd;
226	execinterp(argv, envp);
227	}
228	#endif
229	setparam(argv + 1);
230	exraise(EXSHELLPROC);
231	}
232	#ifdef __OS2__
233	/* A lot of scripts references some core /bin/ programs, like for
234	instance the bash testcases. So, to make life easier, we map
235	a small set of these to @unixroot and or the PATH to simplify
236	porting. */
237	else if (!strncmp(cmd, "/bin/", sizeof("/bin/") - 1)) {
238	char *name = cmd+ sizeof("/bin/") - 1;
239	int search_path = 1;
240	if (!strcmp(name, "sh")
241	\|\| !strcmp(name, "sh.exe")
242	\|\| !strcmp(name, "bash")
243	\|\| !strcmp(name, "bash.exe")
244	\|\| !strcmp(name, "ash")
245	\|\| !strcmp(name, "ash.exe")
246	\|\| !strcmp(name, "ls")
247	\|\| !strcmp(name, "ls.exe")
248	\|\| !strcmp(name, "cat")
249	\|\| !strcmp(name, "cat.exe")
250	\|\| !strcmp(name, "mkdir")
251	\|\| !strcmp(name, "mkdir.exe")
252	\|\| !strcmp(name, "expr")
253	\|\| !strcmp(name, "expr.exe")
254	\|\| !strcmp(name, "pwd")
255	\|\| !strcmp(name, "pwd.exe")
256	\|\| !strcmp(name, "tr")
257	\|\| !strcmp(name, "tr.exe")
258	\|\| !strcmp(name, "test")
259	\|\| !strcmp(name, "test.exe")
260	\|\| !strcmp(name, "echo")
261	\|\| !strcmp(name, "echo.exe")
262	\|\| (search_path = 0)
263	\|\| !strcmp(name, "sort")
264	\|\| !strcmp(name, "sort.exe")
265	\|\| !strcmp(name, "cp")
266	\|\| !strcmp(name, "cp.exe")
267	\|\| !strcmp(name, "rm")
268	\|\| !strcmp(name, "rm.exe")
269	\|\| !strcmp(name, "unlink")
270	\|\| !strcmp(name, "unlink.exe")
271	\|\| !strcmp(name, "mv")
272	\|\| !strcmp(name, "mv.exe")
273	\|\| !strcmp(name, "rmdir")
274	\|\| !strcmp(name, "rmdir.exe")
275	) {
276	char tmp[48];
277	strcat(strcpy(tmp, "/@unixroot"), cmd);
278	execve(tmp, argv, envp);
279	if (search_path) {
280	strcpy(tmp, name);
281	if (!strchr(name, '.'))
282	strcat(tmp, ".exe");
283	execvpe(tmp, argv, envp);
284	}
285	}
286	}
287	#endif
288	errno = e;
289	}
290
291
292	#ifdef EXEC_HASH_BANG_SCRIPT
293	/*
294	* Execute an interpreter introduced by "#!", for systems where this
295	* feature has not been built into the kernel. If the interpreter is
296	* the shell, return (effectively ignoring the "#!"). If the execution
297	* of the interpreter fails, exit.
298	*
299	* This code peeks inside the input buffer in order to avoid actually
300	* reading any input. It would benefit from a rewrite.
301	*/
302
303	#define NEWARGS 5
304
305	STATIC void
306	execinterp(char argv, char envp)
307	{
308	int n;
309	char *inp;
310	char *outp;
311	char c;
312	char *p;
313	char **ap;
314	char *newargs[NEWARGS];
315	int i;
316	char **ap2;
317	char **new;
318
319	n = parsenleft - 2;
320	inp = parsenextc + 2;
321	ap = newargs;
322	for (;;) {
323	while (--n >= 0 && (inp == ' ' \|\| inp == '\t'))
324	inp++;
325	if (n < 0)
326	goto bad;
327	if ((c = *inp++) == '\n')
328	break;
329	if (ap == &newargs[NEWARGS])
330	bad: error("Bad #! line");
331	STARTSTACKSTR(outp);
332	do {
333	STPUTC(c, outp);
334	} while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n');
335	STPUTC('\0', outp);
336	n++, inp--;
337	*ap++ = grabstackstr(outp);
338	}
339	if (ap == newargs + 1) { /* if no args, maybe no exec is needed */
340	p = newargs[0];
341	for (;;) {
342	if (equal(p, "sh") \|\| equal(p, "ash")) {
343	TRACE(("hash bang self\n"));
344	return;
345	}
346	while (*p != '/') {
347	if (*p == '\0')
348	goto break2;
349	p++;
350	}
351	p++;
352	}
353	break2:;
354	}
355	i = (char )ap - (char )newargs; /* size in bytes */
356	if (i == 0)
357	error("Bad #! line");
358	for (ap2 = argv ; *ap2++ != NULL ; );
359	new = ckmalloc(i + ((char )ap2 - (char )argv));
360	ap = newargs, ap2 = new;
361	while ((i -= sizeof (char **)) >= 0)
362	ap2++ = ap++;
363	ap = argv;
364	while (ap2++ = ap++);
365	TRACE(("hash bang '%s'\n", new[0]));
366	shellexec(new, envp, pathval(), 0, 0);
367	/* NOTREACHED */
368	}
369	#endif
370
371
372
373	/*
374	* Do a path search. The variable path (passed by reference) should be
375	* set to the start of the path before the first call; padvance will update
376	* this value as it proceeds. Successive calls to padvance will return
377	* the possible path expansions in sequence. If an option (indicated by
378	* a percent sign) appears in the path entry then the global variable
379	* pathopt will be set to point to it; otherwise pathopt will be set to
380	* NULL.
381	*/
382
383	const char *pathopt;
384
385	char *
386	padvance(const char *path, const char name)
387	{
388	const char *p;
389	char *q;
390	#ifdef PC_SLASHES
391	char *s;
392	#endif
393	const char *start;
394	int len;
395
396	if (*path == NULL)
397	return NULL;
398	start = *path;
399	#ifdef PC_PATH_SEP
400	for (p = start ; p && p != ';' && *p != '%' ; p++);
401	#else
402	for (p = start ; p && p != ':' && *p != '%' ; p++);
403	#endif
404	len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */
405	#ifdef PC_EXE_EXTS
406	len += 4; /* "4" is for .exe/.com/.cmd/.bat/.btm */
407	#endif
408	while (stackblocksize() < len)
409	growstackblock();
410	#ifdef PC_SLASHES
411	s =
412	#endif
413	q = stackblock();
414	if (p != start) {
415	memcpy(q, start, p - start);
416	q += p - start;
417	*q++ = '/';
418	}
419	strcpy(q, name);
420	#ifdef PC_SLASHES
421	while ((s = strchr(s, '\\')) != NULL)
422	*s++ = '/';
423	#endif
424	pathopt = NULL;
425	if (*p == '%') {
426	pathopt = ++p;
427	#ifdef PC_PATH_SEP
428	while (p && p != ';') p++;
429	#else
430	while (p && p != ':') p++;
431	#endif
432	}
433	#ifdef PC_PATH_SEP
434	if (*p == ';')
435	#else
436	if (*p == ':')
437	#endif
438	*path = p + 1;
439	else
440	*path = NULL;
441	return stalloc(len);
442	}
443
444
445	#ifdef PC_EXE_EXTS
446	STATIC int stat_pc_exec_exts(char fullname, struct stat st, int has_ext)
447	{
448	/* skip the SYSV crap */
449	if (stat(fullname, st) >= 0)
450	return 0;
451	if (!has_ext && errno == ENOENT)
452	{
453	char *psz = strchr(fullname, '\0');
454	memcpy(psz, ".exe", 5);
455	if (stat(fullname, st) >= 0)
456	return 0;
457	if (errno != ENOENT && errno != ENOTDIR)
458	return -1;
459
460	memcpy(psz, ".cmd", 5);
461	if (stat(fullname, st) >= 0)
462	return 0;
463	if (errno != ENOENT && errno != ENOTDIR)
464	return -1;
465
466	memcpy(psz, ".bat", 5);
467	if (stat(fullname, st) >= 0)
468	return 0;
469	if (errno != ENOENT && errno != ENOTDIR)
470	return -1;
471
472	memcpy(psz, ".com", 5);
473	if (stat(fullname, st) >= 0)
474	return 0;
475	if (errno != ENOENT && errno != ENOTDIR)
476	return -1;
477
478	memcpy(psz, ".btm", 5);
479	if (stat(fullname, st) >= 0)
480	return 0;
481	*psz = '\0';
482	}
483	return -1;
484	}
485	#endif /* PC_EXE_EXTS */
486
487
488
489	/* Command hashing code */
490
491
492	int
493	hashcmd(int argc, char **argv)
494	{
495	struct tblentry **pp;
496	struct tblentry *cmdp;
497	int c;
498	int verbose;
499	struct cmdentry entry;
500	char *name;
501
502	verbose = 0;
503	while ((c = nextopt("rv")) != '\0') {
504	if (c == 'r') {
505	clearcmdentry(0);
506	} else if (c == 'v') {
507	verbose++;
508	}
509	}
510	if (*argptr == NULL) {
511	for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
512	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
513	if (verbose \|\| cmdp->cmdtype == CMDNORMAL)
514	printentry(cmdp, verbose);
515	}
516	}
517	return 0;
518	}
519	while ((name = *argptr) != NULL) {
520	if ((cmdp = cmdlookup(name, 0)) != NULL
521	&& (cmdp->cmdtype == CMDNORMAL
522	\|\| (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
523	delete_cmd_entry();
524	find_command(name, &entry, DO_ERR, pathval());
525	if (verbose) {
526	if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
527	cmdp = cmdlookup(name, 0);
528	printentry(cmdp, verbose);
529	}
530	output_flushall();
531	}
532	argptr++;
533	}
534	return 0;
535	}
536
537
538	STATIC void
539	printentry(struct tblentry *cmdp, int verbose)
540	{
541	int idx;
542	const char *path;
543	char *name;
544
545	switch (cmdp->cmdtype) {
546	case CMDNORMAL:
547	idx = cmdp->param.index;
548	path = pathval();
549	do {
550	name = padvance(&path, cmdp->cmdname);
551	stunalloc(name);
552	} while (--idx >= 0);
553	out1str(name);
554	break;
555	case CMDSPLBLTIN:
556	out1fmt("special builtin %s", cmdp->cmdname);
557	break;
558	case CMDBUILTIN:
559	out1fmt("builtin %s", cmdp->cmdname);
560	break;
561	case CMDFUNCTION:
562	out1fmt("function %s", cmdp->cmdname);
563	if (verbose) {
564	struct procstat ps;
565	INTOFF;
566	commandtext(&ps, cmdp->param.func);
567	INTON;
568	out1str("() { ");
569	out1str(ps.cmd);
570	out1str("; }");
571	}
572	break;
573	default:
574	error("internal error: %s cmdtype %d", cmdp->cmdname, cmdp->cmdtype);
575	}
576	if (cmdp->rehash)
577	out1c('*');
578	out1c('\n');
579	}
580
581
582
583	/*
584	* Resolve a command name. If you change this routine, you may have to
585	* change the shellexec routine as well.
586	*/
587
588	void
589	find_command(char name, struct cmdentry entry, int act, const char *path)
590	{
591	struct tblentry *cmdp, loc_cmd;
592	int idx;
593	int prev;
594	char *fullname;
595	struct stat statb;
596	int e;
597	int (bltin)(int,char *);
598
599	#ifdef PC_EXE_EXTS
600	int has_ext = strlen(name) - 4;
601	has_ext = has_ext > 0
602	&& name[has_ext] == '.'
603	/* use strstr and upper/lower permuated extensions to avoid multiple strcasecmp calls. */
604	&& strstr("exe;" "Exe;" "EXe;" "EXE;" "ExE;" "eXe;" "eXE;" "exE;"
605	"cmd;" "Cmd;" "CMd;" "CMD;" "CmD;" "cMd;" "cMD;" "cmD;"
606	"com;" "Com;" "COm;" "COM;" "CoM;" "cOm;" "cOM;" "coM;"
607	"bat;" "Bat;" "BAt;" "BAT;" "BaT;" "bAt;" "bAT;" "baT;"
608	"btm;" "Btm;" "BTm;" "BTM;" "BtM;" "bTm;" "bTM;" "btM;",
609	name + has_ext + 1)
610	!= NULL;
611	#endif
612
613	/* If name contains a slash, don't use PATH or hash table */
614	if (strchr(name, '/') != NULL) {
615	if (act & DO_ABS) {
616	while (stat(name, &statb) < 0) {
617	#ifdef SYSV
618	if (errno == EINTR)
619	continue;
620	#endif
621	if (errno != ENOENT && errno != ENOTDIR)
622	e = errno;
623	entry->cmdtype = CMDUNKNOWN;
624	entry->u.index = -1;
625	return;
626	}
627	entry->cmdtype = CMDNORMAL;
628	entry->u.index = -1;
629	return;
630	}
631	entry->cmdtype = CMDNORMAL;
632	entry->u.index = 0;
633	return;
634	}
635
636	if (path != pathval())
637	act \|= DO_ALTPATH;
638
639	if (act & DO_ALTPATH && strstr(path, "%builtin") != NULL)
640	act \|= DO_ALTBLTIN;
641
642	/* If name is in the table, check answer will be ok */
643	if ((cmdp = cmdlookup(name, 0)) != NULL) {
644	do {
645	switch (cmdp->cmdtype) {
646	case CMDNORMAL:
647	if (act & DO_ALTPATH) {
648	cmdp = NULL;
649	continue;
650	}
651	break;
652	case CMDFUNCTION:
653	if (act & DO_NOFUNC) {
654	cmdp = NULL;
655	continue;
656	}
657	break;
658	case CMDBUILTIN:
659	if ((act & DO_ALTBLTIN) \|\| builtinloc >= 0) {
660	cmdp = NULL;
661	continue;
662	}
663	break;
664	}
665	/* if not invalidated by cd, we're done */
666	if (cmdp->rehash == 0)
667	goto success;
668	} while (0);
669	}
670
671	/* If %builtin not in path, check for builtin next */
672	if ((act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc < 0) &&
673	(bltin = find_builtin(name)) != 0)
674	goto builtin_success;
675
676	/* We have to search path. */
677	prev = -1; /* where to start */
678	if (cmdp) { /* doing a rehash */
679	if (cmdp->cmdtype == CMDBUILTIN)
680	prev = builtinloc;
681	else
682	prev = cmdp->param.index;
683	}
684
685	e = ENOENT;
686	idx = -1;
687	loop:
688	while ((fullname = padvance(&path, name)) != NULL) {
689	stunalloc(fullname);
690	idx++;
691	if (pathopt) {
692	if (prefix("builtin", pathopt)) {
693	if ((bltin = find_builtin(name)) == 0)
694	goto loop;
695	goto builtin_success;
696	} else if (prefix("func", pathopt)) {
697	/* handled below */
698	} else {
699	/* ignore unimplemented options */
700	goto loop;
701	}
702	}
703	/* if rehash, don't redo absolute path names */
704	if (fullname[0] == '/' && idx <= prev) {
705	if (idx < prev)
706	goto loop;
707	TRACE(("searchexec \"%s\": no change\n", name));
708	goto success;
709	}
710	#ifdef PC_EXE_EXTS
711	while (stat_pc_exec_exts(fullname, &statb, has_ext) < 0) {
712	#else
713	while (stat(fullname, &statb) < 0) {
714	#endif
715	#ifdef SYSV
716	if (errno == EINTR)
717	continue;
718	#endif
719	if (errno != ENOENT && errno != ENOTDIR)
720	e = errno;
721
722	goto loop;
723	}
724	e = EACCES; /* if we fail, this will be the error */
725	if (!S_ISREG(statb.st_mode))
726	goto loop;
727	if (pathopt) { /* this is a %func directory */
728	if (act & DO_NOFUNC)
729	goto loop;
730	stalloc(strlen(fullname) + 1);
731	readcmdfile(fullname);
732	if ((cmdp = cmdlookup(name, 0)) == NULL \|\|
733	cmdp->cmdtype != CMDFUNCTION)
734	error("%s not defined in %s", name, fullname);
735	stunalloc(fullname);
736	goto success;
737	}
738	#ifdef notdef
739	/* XXX this code stops root executing stuff, and is buggy
740	if you need a group from the group list. */
741	if (statb.st_uid == geteuid()) {
742	if ((statb.st_mode & 0100) == 0)
743	goto loop;
744	} else if (statb.st_gid == getegid()) {
745	if ((statb.st_mode & 010) == 0)
746	goto loop;
747	} else {
748	if ((statb.st_mode & 01) == 0)
749	goto loop;
750	}
751	#endif
752	TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
753	INTOFF;
754	if (act & DO_ALTPATH) {
755	stalloc(strlen(fullname) + 1);
756	cmdp = &loc_cmd;
757	} else
758	cmdp = cmdlookup(name, 1);
759	cmdp->cmdtype = CMDNORMAL;
760	cmdp->param.index = idx;
761	INTON;
762	goto success;
763	}
764
765	/* We failed. If there was an entry for this command, delete it */
766	if (cmdp)
767	delete_cmd_entry();
768	if (act & DO_ERR)
769	outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
770	entry->cmdtype = CMDUNKNOWN;
771	return;
772
773	builtin_success:
774	INTOFF;
775	if (act & DO_ALTPATH)
776	cmdp = &loc_cmd;
777	else
778	cmdp = cmdlookup(name, 1);
779	if (cmdp->cmdtype == CMDFUNCTION)
780	/* DO_NOFUNC must have been set */
781	cmdp = &loc_cmd;
782	cmdp->cmdtype = CMDBUILTIN;
783	cmdp->param.bltin = bltin;
784	INTON;
785	success:
786	cmdp->rehash = 0;
787	entry->cmdtype = cmdp->cmdtype;
788	entry->u = cmdp->param;
789	}
790
791
792
793	/*
794	* Search the table of builtin commands.
795	*/
796
797	int
798	(find_builtin(name))(int, char *)
799	char *name;
800	{
801	const struct builtincmd *bp;
802
803	for (bp = builtincmd ; bp->name ; bp++) {
804	if (bp->name == name && equal(bp->name, name))
805	return bp->builtin;
806	}
807	return 0;
808	}
809
810	int
811	(find_splbltin(name))(int, char *)
812	char *name;
813	{
814	const struct builtincmd *bp;
815
816	for (bp = splbltincmd ; bp->name ; bp++) {
817	if (bp->name == name && equal(bp->name, name))
818	return bp->builtin;
819	}
820	return 0;
821	}
822
823	/*
824	* At shell startup put special builtins into hash table.
825	* ensures they are executed first (see posix).
826	* We stop functions being added with the same name
827	* (as they are impossible to call)
828	*/
829
830	void
831	hash_special_builtins(void)
832	{
833	const struct builtincmd *bp;
834	struct tblentry *cmdp;
835
836	for (bp = splbltincmd ; bp->name ; bp++) {
837	cmdp = cmdlookup(bp->name, 1);
838	cmdp->cmdtype = CMDSPLBLTIN;
839	cmdp->param.bltin = bp->builtin;
840	}
841	}
842
843
844
845	/*
846	* Called when a cd is done. Marks all commands so the next time they
847	* are executed they will be rehashed.
848	*/
849
850	void
851	hashcd(void)
852	{
853	struct tblentry **pp;
854	struct tblentry *cmdp;
855
856	for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
857	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
858	if (cmdp->cmdtype == CMDNORMAL
859	\|\| (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
860	cmdp->rehash = 1;
861	}
862	}
863	}
864
865
866
867	/*
868	* Fix command hash table when PATH changed.
869	* Called before PATH is changed. The argument is the new value of PATH;
870	* pathval() still returns the old value at this point.
871	* Called with interrupts off.
872	*/
873
874	void
875	changepath(const char *newval)
876	{
877	const char old, new;
878	int idx;
879	int firstchange;
880	int bltin;
881
882	old = pathval();
883	new = newval;
884	firstchange = 9999; /* assume no change */
885	idx = 0;
886	bltin = -1;
887	for (;;) {
888	if (old != new) {
889	firstchange = idx;
890	#ifdef PC_PATH_SEP
891	if ((old == '\0' && new == ';')
892	\|\| (old == ';' && new == '\0'))
893	#else
894	if ((old == '\0' && new == ':')
895	\|\| (old == ':' && new == '\0'))
896	#endif
897	firstchange++;
898	old = new; /* ignore subsequent differences */
899	}
900	if (*new == '\0')
901	break;
902	if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
903	bltin = idx;
904	#ifdef PC_PATH_SEP
905	if (*new == ';') {
906	#else
907	if (*new == ':') {
908	#endif
909	idx++;
910	}
911	new++, old++;
912	}
913	if (builtinloc < 0 && bltin >= 0)
914	builtinloc = bltin; /* zap builtins */
915	if (builtinloc >= 0 && bltin < 0)
916	firstchange = 0;
917	clearcmdentry(firstchange);
918	builtinloc = bltin;
919	}
920
921
922	/*
923	* Clear out command entries. The argument specifies the first entry in
924	* PATH which has changed.
925	*/
926
927	STATIC void
928	clearcmdentry(int firstchange)
929	{
930	struct tblentry **tblp;
931	struct tblentry **pp;
932	struct tblentry *cmdp;
933
934	INTOFF;
935	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
936	pp = tblp;
937	while ((cmdp = *pp) != NULL) {
938	if ((cmdp->cmdtype == CMDNORMAL &&
939	cmdp->param.index >= firstchange)
940	\|\| (cmdp->cmdtype == CMDBUILTIN &&
941	builtinloc >= firstchange)) {
942	*pp = cmdp->next;
943	ckfree(cmdp);
944	} else {
945	pp = &cmdp->next;
946	}
947	}
948	}
949	INTON;
950	}
951
952
953	/*
954	* Delete all functions.
955	*/
956
957	#ifdef mkinit
958	MKINIT void deletefuncs(void);
959	MKINIT void hash_special_builtins(void);
960
961	INIT {
962	hash_special_builtins();
963	}
964
965	SHELLPROC {
966	deletefuncs();
967	}
968	#endif
969
970	void
971	deletefuncs(void)
972	{
973	struct tblentry **tblp;
974	struct tblentry **pp;
975	struct tblentry *cmdp;
976
977	INTOFF;
978	for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
979	pp = tblp;
980	while ((cmdp = *pp) != NULL) {
981	if (cmdp->cmdtype == CMDFUNCTION) {
982	*pp = cmdp->next;
983	freefunc(cmdp->param.func);
984	ckfree(cmdp);
985	} else {
986	pp = &cmdp->next;
987	}
988	}
989	}
990	INTON;
991	}
992
993
994
995	/*
996	* Locate a command in the command hash table. If "add" is nonzero,
997	* add the command to the table if it is not already present. The
998	* variable "lastcmdentry" is set to point to the address of the link
999	* pointing to the entry, so that delete_cmd_entry can delete the
1000	* entry.
1001	*/
1002
1003	struct tblentry **lastcmdentry;
1004
1005
1006	STATIC struct tblentry *
1007	cmdlookup(const char *name, int add)
1008	{
1009	int hashval;
1010	const char *p;
1011	struct tblentry *cmdp;
1012	struct tblentry **pp;
1013
1014	p = name;
1015	hashval = *p << 4;
1016	while (*p)
1017	hashval += *p++;
1018	hashval &= 0x7FFF;
1019	pp = &cmdtable[hashval % CMDTABLESIZE];
1020	for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
1021	if (equal(cmdp->cmdname, name))
1022	break;
1023	pp = &cmdp->next;
1024	}
1025	if (add && cmdp == NULL) {
1026	INTOFF;
1027	cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
1028	+ strlen(name) + 1);
1029	cmdp->next = NULL;
1030	cmdp->cmdtype = CMDUNKNOWN;
1031	cmdp->rehash = 0;
1032	strcpy(cmdp->cmdname, name);
1033	INTON;
1034	}
1035	lastcmdentry = pp;
1036	return cmdp;
1037	}
1038
1039	/*
1040	* Delete the command entry returned on the last lookup.
1041	*/
1042
1043	STATIC void
1044	delete_cmd_entry(void)
1045	{
1046	struct tblentry *cmdp;
1047
1048	INTOFF;
1049	cmdp = *lastcmdentry;
1050	*lastcmdentry = cmdp->next;
1051	ckfree(cmdp);
1052	INTON;
1053	}
1054
1055
1056
1057	#ifdef notdef
1058	void
1059	getcmdentry(char name, struct cmdentry entry)
1060	{
1061	struct tblentry *cmdp = cmdlookup(name, 0);
1062
1063	if (cmdp) {
1064	entry->u = cmdp->param;
1065	entry->cmdtype = cmdp->cmdtype;
1066	} else {
1067	entry->cmdtype = CMDUNKNOWN;
1068	entry->u.index = 0;
1069	}
1070	}
1071	#endif
1072
1073
1074	/*
1075	* Add a new command entry, replacing any existing command entry for
1076	* the same name - except special builtins.
1077	*/
1078
1079	STATIC void
1080	addcmdentry(char name, struct cmdentry entry)
1081	{
1082	struct tblentry *cmdp;
1083
1084	INTOFF;
1085	cmdp = cmdlookup(name, 1);
1086	if (cmdp->cmdtype != CMDSPLBLTIN) {
1087	if (cmdp->cmdtype == CMDFUNCTION) {
1088	freefunc(cmdp->param.func);
1089	}
1090	cmdp->cmdtype = entry->cmdtype;
1091	cmdp->param = entry->u;
1092	}
1093	INTON;
1094	}
1095
1096
1097	/*
1098	* Define a shell function.
1099	*/
1100
1101	void
1102	defun(char name, union node func)
1103	{
1104	struct cmdentry entry;
1105
1106	INTOFF;
1107	entry.cmdtype = CMDFUNCTION;
1108	entry.u.func = copyfunc(func);
1109	addcmdentry(name, &entry);
1110	INTON;
1111	}
1112
1113
1114	/*
1115	* Delete a function if it exists.
1116	*/
1117
1118	int
1119	unsetfunc(char *name)
1120	{
1121	struct tblentry *cmdp;
1122
1123	if ((cmdp = cmdlookup(name, 0)) != NULL &&
1124	cmdp->cmdtype == CMDFUNCTION) {
1125	freefunc(cmdp->param.func);
1126	delete_cmd_entry();
1127	return (0);
1128	}
1129	return (1);
1130	}
1131
1132	/*
1133	* Locate and print what a word is...
1134	* also used for 'command -[v\|V]'
1135	*/
1136
1137	int
1138	typecmd(int argc, char **argv)
1139	{
1140	struct cmdentry entry;
1141	struct tblentry *cmdp;
1142	char * const *pp;
1143	struct alias *ap;
1144	int err = 0;
1145	char *arg;
1146	int c;
1147	int V_flag = 0;
1148	int v_flag = 0;
1149	int p_flag = 0;
1150
1151	while ((c = nextopt("vVp")) != 0) {
1152	switch (c) {
1153	case 'v': v_flag = 1; break;
1154	case 'V': V_flag = 1; break;
1155	case 'p': p_flag = 1; break;
1156	}
1157	}
1158
1159	if (p_flag && (v_flag \|\| V_flag))
1160	error("cannot specify -p with -v or -V");
1161
1162	while ((arg = *argptr++)) {
1163	if (!v_flag)
1164	out1str(arg);
1165	/* First look at the keywords */
1166	for (pp = parsekwd; *pp; pp++)
1167	if (*pp == arg && equal(*pp, arg))
1168	break;
1169
1170	if (*pp) {
1171	if (v_flag)
1172	err = 1;
1173	else
1174	out1str(" is a shell keyword\n");
1175	continue;
1176	}
1177
1178	/* Then look at the aliases */
1179	if ((ap = lookupalias(arg, 1)) != NULL) {
1180	if (!v_flag)
1181	out1fmt(" is an alias for \n");
1182	out1fmt("%s\n", ap->val);
1183	continue;
1184	}
1185
1186	/* Then check if it is a tracked alias */
1187	if ((cmdp = cmdlookup(arg, 0)) != NULL) {
1188	entry.cmdtype = cmdp->cmdtype;
1189	entry.u = cmdp->param;
1190	} else {
1191	/* Finally use brute force */
1192	find_command(arg, &entry, DO_ABS, pathval());
1193	}
1194
1195	switch (entry.cmdtype) {
1196	case CMDNORMAL: {
1197	if (strchr(arg, '/') == NULL) {
1198	const char *path = pathval();
1199	char *name;
1200	int j = entry.u.index;
1201	do {
1202	name = padvance(&path, arg);
1203	stunalloc(name);
1204	} while (--j >= 0);
1205	if (!v_flag)
1206	out1fmt(" is%s ",
1207	cmdp ? " a tracked alias for" : "");
1208	out1fmt("%s\n", name);
1209	} else {
1210	if (access(arg, X_OK) == 0) {
1211	if (!v_flag)
1212	out1fmt(" is ");
1213	out1fmt("%s\n", arg);
1214	} else {
1215	if (!v_flag)
1216	out1fmt(": %s\n",
1217	strerror(errno));
1218	else
1219	err = 126;
1220	}
1221	}
1222	break;
1223	}
1224	case CMDFUNCTION:
1225	if (!v_flag)
1226	out1str(" is a shell function\n");
1227	else
1228	out1fmt("%s\n", arg);
1229	break;
1230
1231	case CMDBUILTIN:
1232	if (!v_flag)
1233	out1str(" is a shell builtin\n");
1234	else
1235	out1fmt("%s\n", arg);
1236	break;
1237
1238	case CMDSPLBLTIN:
1239	if (!v_flag)
1240	out1str(" is a special shell builtin\n");
1241	else
1242	out1fmt("%s\n", arg);
1243	break;
1244
1245	default:
1246	if (!v_flag)
1247	out1str(": not found\n");
1248	err = 127;
1249	break;
1250	}
1251	}
1252	return err;
1253	}

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