source: trunk/src/ash/exec.c@ 626

Last change on this file since 626 was 626, checked in by bird, 19 years ago

Current libc code (based on NetBSD sh 2005-07-03).
  • Property svn:eol-style set to native
File size: 25.7 KB
Line 
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
38static 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
92struct 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
101STATIC struct tblentry *cmdtable[CMDTABLESIZE];
102STATIC int builtinloc = -1; /* index in path of %builtin, or -1 */
103int exerrno = 0; /* Last exec error */
104
105
106STATIC void tryexec(char *, char **, char **, int, int);
107STATIC void execinterp(char **, char **);
108STATIC void printentry(struct tblentry *, int);
109STATIC void clearcmdentry(int);
110STATIC struct tblentry *cmdlookup(const char *, int);
111STATIC void delete_cmd_entry(void);
112#ifdef PC_EXE_EXTS
113STATIC int stat_pc_exec_exts(char *fullname, struct stat *st, int has_ext);
114#endif
115
116
117extern 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
124void
125shellexec(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
183STATIC void
184tryexec(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 errno = e;
233}
234
235
236#ifdef EXEC_HASH_BANG_SCRIPT
237/*
238 * Execute an interpreter introduced by "#!", for systems where this
239 * feature has not been built into the kernel. If the interpreter is
240 * the shell, return (effectively ignoring the "#!"). If the execution
241 * of the interpreter fails, exit.
242 *
243 * This code peeks inside the input buffer in order to avoid actually
244 * reading any input. It would benefit from a rewrite.
245 */
246
247#define NEWARGS 5
248
249STATIC void
250execinterp(char **argv, char **envp)
251{
252 int n;
253 char *inp;
254 char *outp;
255 char c;
256 char *p;
257 char **ap;
258 char *newargs[NEWARGS];
259 int i;
260 char **ap2;
261 char **new;
262
263 n = parsenleft - 2;
264 inp = parsenextc + 2;
265 ap = newargs;
266 for (;;) {
267 while (--n >= 0 && (*inp == ' ' || *inp == '\t'))
268 inp++;
269 if (n < 0)
270 goto bad;
271 if ((c = *inp++) == '\n')
272 break;
273 if (ap == &newargs[NEWARGS])
274bad: error("Bad #! line");
275 STARTSTACKSTR(outp);
276 do {
277 STPUTC(c, outp);
278 } while (--n >= 0 && (c = *inp++) != ' ' && c != '\t' && c != '\n');
279 STPUTC('\0', outp);
280 n++, inp--;
281 *ap++ = grabstackstr(outp);
282 }
283 if (ap == newargs + 1) { /* if no args, maybe no exec is needed */
284 p = newargs[0];
285 for (;;) {
286 if (equal(p, "sh") || equal(p, "ash")) {
287 TRACE(("hash bang self\n"));
288 return;
289 }
290 while (*p != '/') {
291 if (*p == '\0')
292 goto break2;
293 p++;
294 }
295 p++;
296 }
297break2:;
298 }
299 i = (char *)ap - (char *)newargs; /* size in bytes */
300 if (i == 0)
301 error("Bad #! line");
302 for (ap2 = argv ; *ap2++ != NULL ; );
303 new = ckmalloc(i + ((char *)ap2 - (char *)argv));
304 ap = newargs, ap2 = new;
305 while ((i -= sizeof (char **)) >= 0)
306 *ap2++ = *ap++;
307 ap = argv;
308 while (*ap2++ = *ap++);
309 TRACE(("hash bang '%s'\n", new[0]));
310 shellexec(new, envp, pathval(), 0, 0);
311 /* NOTREACHED */
312}
313#endif
314
315
316
317/*
318 * Do a path search. The variable path (passed by reference) should be
319 * set to the start of the path before the first call; padvance will update
320 * this value as it proceeds. Successive calls to padvance will return
321 * the possible path expansions in sequence. If an option (indicated by
322 * a percent sign) appears in the path entry then the global variable
323 * pathopt will be set to point to it; otherwise pathopt will be set to
324 * NULL.
325 */
326
327const char *pathopt;
328
329char *
330padvance(const char **path, const char *name)
331{
332 const char *p;
333 char *q;
334 const char *start;
335 int len;
336
337 if (*path == NULL)
338 return NULL;
339 start = *path;
340#ifdef PC_PATH_SEP
341 for (p = start ; *p && *p != ';' && *p != '%' ; p++);
342#else
343 for (p = start ; *p && *p != ':' && *p != '%' ; p++);
344#endif
345 len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */
346#ifdef PC_EXE_EXTS
347 len += 4; /* "4" is for .exe/.com/.cmd/.bat/.btm */
348#endif
349 while (stackblocksize() < len)
350 growstackblock();
351 q = stackblock();
352 if (p != start) {
353 memcpy(q, start, p - start);
354 q += p - start;
355 *q++ = '/';
356 }
357 strcpy(q, name);
358 pathopt = NULL;
359 if (*p == '%') {
360 pathopt = ++p;
361#ifdef PC_PATH_SEP
362 while (*p && *p != ';') p++;
363#else
364 while (*p && *p != ':') p++;
365#endif
366 }
367#ifdef PC_PATH_SEP
368 if (*p == ';')
369#else
370 if (*p == ':')
371#endif
372 *path = p + 1;
373 else
374 *path = NULL;
375 return stalloc(len);
376}
377
378
379#ifdef PC_EXE_EXTS
380STATIC int stat_pc_exec_exts(char *fullname, struct stat *st, int has_ext)
381{
382 /* skip the SYSV crap */
383 if (stat(fullname, st) >= 0)
384 return 0;
385 if (!has_ext && errno == ENOENT)
386 {
387 char *psz = strchr(fullname, '\0');
388 memcpy(psz, ".exe", 5);
389 if (stat(fullname, st) >= 0)
390 return 0;
391 if (errno != ENOENT && errno != ENOTDIR)
392 return -1;
393
394 memcpy(psz, ".cmd", 5);
395 if (stat(fullname, st) >= 0)
396 return 0;
397 if (errno != ENOENT && errno != ENOTDIR)
398 return -1;
399
400 memcpy(psz, ".bat", 5);
401 if (stat(fullname, st) >= 0)
402 return 0;
403 if (errno != ENOENT && errno != ENOTDIR)
404 return -1;
405
406 memcpy(psz, ".com", 5);
407 if (stat(fullname, st) >= 0)
408 return 0;
409 if (errno != ENOENT && errno != ENOTDIR)
410 return -1;
411
412 memcpy(psz, ".btm", 5);
413 if (stat(fullname, st) >= 0)
414 return 0;
415 *psz = '\0';
416 }
417 return -1;
418}
419#endif /* PC_EXE_EXTS */
420
421
422
423/*** Command hashing code ***/
424
425
426int
427hashcmd(int argc, char **argv)
428{
429 struct tblentry **pp;
430 struct tblentry *cmdp;
431 int c;
432 int verbose;
433 struct cmdentry entry;
434 char *name;
435
436 verbose = 0;
437 while ((c = nextopt("rv")) != '\0') {
438 if (c == 'r') {
439 clearcmdentry(0);
440 } else if (c == 'v') {
441 verbose++;
442 }
443 }
444 if (*argptr == NULL) {
445 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
446 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
447 if (verbose || cmdp->cmdtype == CMDNORMAL)
448 printentry(cmdp, verbose);
449 }
450 }
451 return 0;
452 }
453 while ((name = *argptr) != NULL) {
454 if ((cmdp = cmdlookup(name, 0)) != NULL
455 && (cmdp->cmdtype == CMDNORMAL
456 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
457 delete_cmd_entry();
458 find_command(name, &entry, DO_ERR, pathval());
459 if (verbose) {
460 if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
461 cmdp = cmdlookup(name, 0);
462 printentry(cmdp, verbose);
463 }
464 output_flushall();
465 }
466 argptr++;
467 }
468 return 0;
469}
470
471
472STATIC void
473printentry(struct tblentry *cmdp, int verbose)
474{
475 int idx;
476 const char *path;
477 char *name;
478
479 switch (cmdp->cmdtype) {
480 case CMDNORMAL:
481 idx = cmdp->param.index;
482 path = pathval();
483 do {
484 name = padvance(&path, cmdp->cmdname);
485 stunalloc(name);
486 } while (--idx >= 0);
487 out1str(name);
488 break;
489 case CMDSPLBLTIN:
490 out1fmt("special builtin %s", cmdp->cmdname);
491 break;
492 case CMDBUILTIN:
493 out1fmt("builtin %s", cmdp->cmdname);
494 break;
495 case CMDFUNCTION:
496 out1fmt("function %s", cmdp->cmdname);
497 if (verbose) {
498 struct procstat ps;
499 INTOFF;
500 commandtext(&ps, cmdp->param.func);
501 INTON;
502 out1str("() { ");
503 out1str(ps.cmd);
504 out1str("; }");
505 }
506 break;
507 default:
508 error("internal error: %s cmdtype %d", cmdp->cmdname, cmdp->cmdtype);
509 }
510 if (cmdp->rehash)
511 out1c('*');
512 out1c('\n');
513}
514
515
516
517/*
518 * Resolve a command name. If you change this routine, you may have to
519 * change the shellexec routine as well.
520 */
521
522void
523find_command(char *name, struct cmdentry *entry, int act, const char *path)
524{
525 struct tblentry *cmdp, loc_cmd;
526 int idx;
527 int prev;
528 char *fullname;
529 struct stat statb;
530 int e;
531 int (*bltin)(int,char **);
532
533#ifdef PC_EXE_EXTS
534 int has_ext = strlen(name) - 4;
535 has_ext = has_ext > 0
536 && name[has_ext] == '.'
537 /* use strstr and upper/lower permuated extensions to avoid multiple strcasecmp calls. */
538 && strstr("exe;" "Exe;" "EXe;" "EXE;" "ExE;" "eXe;" "eXE;" "exE;"
539 "cmd;" "Cmd;" "CMd;" "CMD;" "CmD;" "cMd;" "cMD;" "cmD;"
540 "com;" "Com;" "COm;" "COM;" "CoM;" "cOm;" "cOM;" "coM;"
541 "bat;" "Bat;" "BAt;" "BAT;" "BaT;" "bAt;" "bAT;" "baT;"
542 "btm;" "Btm;" "BTm;" "BTM;" "BtM;" "bTm;" "bTM;" "btM;",
543 name + has_ext + 1)
544 != NULL;
545#endif
546
547 /* If name contains a slash, don't use PATH or hash table */
548 if (strchr(name, '/') != NULL) {
549 if (act & DO_ABS) {
550 while (stat(name, &statb) < 0) {
551#ifdef SYSV
552 if (errno == EINTR)
553 continue;
554#endif
555 if (errno != ENOENT && errno != ENOTDIR)
556 e = errno;
557 entry->cmdtype = CMDUNKNOWN;
558 entry->u.index = -1;
559 return;
560 }
561 entry->cmdtype = CMDNORMAL;
562 entry->u.index = -1;
563 return;
564 }
565 entry->cmdtype = CMDNORMAL;
566 entry->u.index = 0;
567 return;
568 }
569
570 if (path != pathval())
571 act |= DO_ALTPATH;
572
573 if (act & DO_ALTPATH && strstr(path, "%builtin") != NULL)
574 act |= DO_ALTBLTIN;
575
576 /* If name is in the table, check answer will be ok */
577 if ((cmdp = cmdlookup(name, 0)) != NULL) {
578 do {
579 switch (cmdp->cmdtype) {
580 case CMDNORMAL:
581 if (act & DO_ALTPATH) {
582 cmdp = NULL;
583 continue;
584 }
585 break;
586 case CMDFUNCTION:
587 if (act & DO_NOFUNC) {
588 cmdp = NULL;
589 continue;
590 }
591 break;
592 case CMDBUILTIN:
593 if ((act & DO_ALTBLTIN) || builtinloc >= 0) {
594 cmdp = NULL;
595 continue;
596 }
597 break;
598 }
599 /* if not invalidated by cd, we're done */
600 if (cmdp->rehash == 0)
601 goto success;
602 } while (0);
603 }
604
605 /* If %builtin not in path, check for builtin next */
606 if ((act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc < 0) &&
607 (bltin = find_builtin(name)) != 0)
608 goto builtin_success;
609
610 /* We have to search path. */
611 prev = -1; /* where to start */
612 if (cmdp) { /* doing a rehash */
613 if (cmdp->cmdtype == CMDBUILTIN)
614 prev = builtinloc;
615 else
616 prev = cmdp->param.index;
617 }
618
619 e = ENOENT;
620 idx = -1;
621loop:
622 while ((fullname = padvance(&path, name)) != NULL) {
623 stunalloc(fullname);
624 idx++;
625 if (pathopt) {
626 if (prefix("builtin", pathopt)) {
627 if ((bltin = find_builtin(name)) == 0)
628 goto loop;
629 goto builtin_success;
630 } else if (prefix("func", pathopt)) {
631 /* handled below */
632 } else {
633 /* ignore unimplemented options */
634 goto loop;
635 }
636 }
637 /* if rehash, don't redo absolute path names */
638 if (fullname[0] == '/' && idx <= prev) {
639 if (idx < prev)
640 goto loop;
641 TRACE(("searchexec \"%s\": no change\n", name));
642 goto success;
643 }
644#ifdef PC_EXE_EXTS
645 while (stat_pc_exec_exts(fullname, &statb, has_ext) < 0) {
646#else
647 while (stat(fullname, &statb) < 0) {
648#endif
649#ifdef SYSV
650 if (errno == EINTR)
651 continue;
652#endif
653 if (errno != ENOENT && errno != ENOTDIR)
654 e = errno;
655
656 goto loop;
657 }
658 e = EACCES; /* if we fail, this will be the error */
659 if (!S_ISREG(statb.st_mode))
660 goto loop;
661 if (pathopt) { /* this is a %func directory */
662 if (act & DO_NOFUNC)
663 goto loop;
664 stalloc(strlen(fullname) + 1);
665 readcmdfile(fullname);
666 if ((cmdp = cmdlookup(name, 0)) == NULL ||
667 cmdp->cmdtype != CMDFUNCTION)
668 error("%s not defined in %s", name, fullname);
669 stunalloc(fullname);
670 goto success;
671 }
672#ifdef notdef
673 /* XXX this code stops root executing stuff, and is buggy
674 if you need a group from the group list. */
675 if (statb.st_uid == geteuid()) {
676 if ((statb.st_mode & 0100) == 0)
677 goto loop;
678 } else if (statb.st_gid == getegid()) {
679 if ((statb.st_mode & 010) == 0)
680 goto loop;
681 } else {
682 if ((statb.st_mode & 01) == 0)
683 goto loop;
684 }
685#endif
686 TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
687 INTOFF;
688 if (act & DO_ALTPATH) {
689 stalloc(strlen(fullname) + 1);
690 cmdp = &loc_cmd;
691 } else
692 cmdp = cmdlookup(name, 1);
693 cmdp->cmdtype = CMDNORMAL;
694 cmdp->param.index = idx;
695 INTON;
696 goto success;
697 }
698
699 /* We failed. If there was an entry for this command, delete it */
700 if (cmdp)
701 delete_cmd_entry();
702 if (act & DO_ERR)
703 outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
704 entry->cmdtype = CMDUNKNOWN;
705 return;
706
707builtin_success:
708 INTOFF;
709 if (act & DO_ALTPATH)
710 cmdp = &loc_cmd;
711 else
712 cmdp = cmdlookup(name, 1);
713 if (cmdp->cmdtype == CMDFUNCTION)
714 /* DO_NOFUNC must have been set */
715 cmdp = &loc_cmd;
716 cmdp->cmdtype = CMDBUILTIN;
717 cmdp->param.bltin = bltin;
718 INTON;
719success:
720 cmdp->rehash = 0;
721 entry->cmdtype = cmdp->cmdtype;
722 entry->u = cmdp->param;
723}
724
725
726
727/*
728 * Search the table of builtin commands.
729 */
730
731int
732(*find_builtin(name))(int, char **)
733 char *name;
734{
735 const struct builtincmd *bp;
736
737 for (bp = builtincmd ; bp->name ; bp++) {
738 if (*bp->name == *name && equal(bp->name, name))
739 return bp->builtin;
740 }
741 return 0;
742}
743
744int
745(*find_splbltin(name))(int, char **)
746 char *name;
747{
748 const struct builtincmd *bp;
749
750 for (bp = splbltincmd ; bp->name ; bp++) {
751 if (*bp->name == *name && equal(bp->name, name))
752 return bp->builtin;
753 }
754 return 0;
755}
756
757/*
758 * At shell startup put special builtins into hash table.
759 * ensures they are executed first (see posix).
760 * We stop functions being added with the same name
761 * (as they are impossible to call)
762 */
763
764void
765hash_special_builtins(void)
766{
767 const struct builtincmd *bp;
768 struct tblentry *cmdp;
769
770 for (bp = splbltincmd ; bp->name ; bp++) {
771 cmdp = cmdlookup(bp->name, 1);
772 cmdp->cmdtype = CMDSPLBLTIN;
773 cmdp->param.bltin = bp->builtin;
774 }
775}
776
777
778
779/*
780 * Called when a cd is done. Marks all commands so the next time they
781 * are executed they will be rehashed.
782 */
783
784void
785hashcd(void)
786{
787 struct tblentry **pp;
788 struct tblentry *cmdp;
789
790 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
791 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
792 if (cmdp->cmdtype == CMDNORMAL
793 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
794 cmdp->rehash = 1;
795 }
796 }
797}
798
799
800
801/*
802 * Fix command hash table when PATH changed.
803 * Called before PATH is changed. The argument is the new value of PATH;
804 * pathval() still returns the old value at this point.
805 * Called with interrupts off.
806 */
807
808void
809changepath(const char *newval)
810{
811 const char *old, *new;
812 int idx;
813 int firstchange;
814 int bltin;
815
816 old = pathval();
817 new = newval;
818 firstchange = 9999; /* assume no change */
819 idx = 0;
820 bltin = -1;
821 for (;;) {
822 if (*old != *new) {
823 firstchange = idx;
824#ifdef PC_PATH_SEP
825 if ((*old == '\0' && *new == ';')
826 || (*old == ';' && *new == '\0'))
827#else
828 if ((*old == '\0' && *new == ':')
829 || (*old == ':' && *new == '\0'))
830#endif
831 firstchange++;
832 old = new; /* ignore subsequent differences */
833 }
834 if (*new == '\0')
835 break;
836 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
837 bltin = idx;
838#ifdef PC_PATH_SEP
839 if (*new == ';') {
840#else
841 if (*new == ':') {
842#endif
843 idx++;
844 }
845 new++, old++;
846 }
847 if (builtinloc < 0 && bltin >= 0)
848 builtinloc = bltin; /* zap builtins */
849 if (builtinloc >= 0 && bltin < 0)
850 firstchange = 0;
851 clearcmdentry(firstchange);
852 builtinloc = bltin;
853}
854
855
856/*
857 * Clear out command entries. The argument specifies the first entry in
858 * PATH which has changed.
859 */
860
861STATIC void
862clearcmdentry(int firstchange)
863{
864 struct tblentry **tblp;
865 struct tblentry **pp;
866 struct tblentry *cmdp;
867
868 INTOFF;
869 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
870 pp = tblp;
871 while ((cmdp = *pp) != NULL) {
872 if ((cmdp->cmdtype == CMDNORMAL &&
873 cmdp->param.index >= firstchange)
874 || (cmdp->cmdtype == CMDBUILTIN &&
875 builtinloc >= firstchange)) {
876 *pp = cmdp->next;
877 ckfree(cmdp);
878 } else {
879 pp = &cmdp->next;
880 }
881 }
882 }
883 INTON;
884}
885
886
887/*
888 * Delete all functions.
889 */
890
891#ifdef mkinit
892MKINIT void deletefuncs(void);
893MKINIT void hash_special_builtins(void);
894
895INIT {
896 hash_special_builtins();
897}
898
899SHELLPROC {
900 deletefuncs();
901}
902#endif
903
904void
905deletefuncs(void)
906{
907 struct tblentry **tblp;
908 struct tblentry **pp;
909 struct tblentry *cmdp;
910
911 INTOFF;
912 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
913 pp = tblp;
914 while ((cmdp = *pp) != NULL) {
915 if (cmdp->cmdtype == CMDFUNCTION) {
916 *pp = cmdp->next;
917 freefunc(cmdp->param.func);
918 ckfree(cmdp);
919 } else {
920 pp = &cmdp->next;
921 }
922 }
923 }
924 INTON;
925}
926
927
928
929/*
930 * Locate a command in the command hash table. If "add" is nonzero,
931 * add the command to the table if it is not already present. The
932 * variable "lastcmdentry" is set to point to the address of the link
933 * pointing to the entry, so that delete_cmd_entry can delete the
934 * entry.
935 */
936
937struct tblentry **lastcmdentry;
938
939
940STATIC struct tblentry *
941cmdlookup(const char *name, int add)
942{
943 int hashval;
944 const char *p;
945 struct tblentry *cmdp;
946 struct tblentry **pp;
947
948 p = name;
949 hashval = *p << 4;
950 while (*p)
951 hashval += *p++;
952 hashval &= 0x7FFF;
953 pp = &cmdtable[hashval % CMDTABLESIZE];
954 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
955 if (equal(cmdp->cmdname, name))
956 break;
957 pp = &cmdp->next;
958 }
959 if (add && cmdp == NULL) {
960 INTOFF;
961 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
962 + strlen(name) + 1);
963 cmdp->next = NULL;
964 cmdp->cmdtype = CMDUNKNOWN;
965 cmdp->rehash = 0;
966 strcpy(cmdp->cmdname, name);
967 INTON;
968 }
969 lastcmdentry = pp;
970 return cmdp;
971}
972
973/*
974 * Delete the command entry returned on the last lookup.
975 */
976
977STATIC void
978delete_cmd_entry(void)
979{
980 struct tblentry *cmdp;
981
982 INTOFF;
983 cmdp = *lastcmdentry;
984 *lastcmdentry = cmdp->next;
985 ckfree(cmdp);
986 INTON;
987}
988
989
990
991#ifdef notdef
992void
993getcmdentry(char *name, struct cmdentry *entry)
994{
995 struct tblentry *cmdp = cmdlookup(name, 0);
996
997 if (cmdp) {
998 entry->u = cmdp->param;
999 entry->cmdtype = cmdp->cmdtype;
1000 } else {
1001 entry->cmdtype = CMDUNKNOWN;
1002 entry->u.index = 0;
1003 }
1004}
1005#endif
1006
1007
1008/*
1009 * Add a new command entry, replacing any existing command entry for
1010 * the same name - except special builtins.
1011 */
1012
1013STATIC void
1014addcmdentry(char *name, struct cmdentry *entry)
1015{
1016 struct tblentry *cmdp;
1017
1018 INTOFF;
1019 cmdp = cmdlookup(name, 1);
1020 if (cmdp->cmdtype != CMDSPLBLTIN) {
1021 if (cmdp->cmdtype == CMDFUNCTION) {
1022 freefunc(cmdp->param.func);
1023 }
1024 cmdp->cmdtype = entry->cmdtype;
1025 cmdp->param = entry->u;
1026 }
1027 INTON;
1028}
1029
1030
1031/*
1032 * Define a shell function.
1033 */
1034
1035void
1036defun(char *name, union node *func)
1037{
1038 struct cmdentry entry;
1039
1040 INTOFF;
1041 entry.cmdtype = CMDFUNCTION;
1042 entry.u.func = copyfunc(func);
1043 addcmdentry(name, &entry);
1044 INTON;
1045}
1046
1047
1048/*
1049 * Delete a function if it exists.
1050 */
1051
1052int
1053unsetfunc(char *name)
1054{
1055 struct tblentry *cmdp;
1056
1057 if ((cmdp = cmdlookup(name, 0)) != NULL &&
1058 cmdp->cmdtype == CMDFUNCTION) {
1059 freefunc(cmdp->param.func);
1060 delete_cmd_entry();
1061 return (0);
1062 }
1063 return (1);
1064}
1065
1066/*
1067 * Locate and print what a word is...
1068 * also used for 'command -[v|V]'
1069 */
1070
1071int
1072typecmd(int argc, char **argv)
1073{
1074 struct cmdentry entry;
1075 struct tblentry *cmdp;
1076 char * const *pp;
1077 struct alias *ap;
1078 int err = 0;
1079 char *arg;
1080 int c;
1081 int V_flag = 0;
1082 int v_flag = 0;
1083 int p_flag = 0;
1084
1085 while ((c = nextopt("vVp")) != 0) {
1086 switch (c) {
1087 case 'v': v_flag = 1; break;
1088 case 'V': V_flag = 1; break;
1089 case 'p': p_flag = 1; break;
1090 }
1091 }
1092
1093 if (p_flag && (v_flag || V_flag))
1094 error("cannot specify -p with -v or -V");
1095
1096 while ((arg = *argptr++)) {
1097 if (!v_flag)
1098 out1str(arg);
1099 /* First look at the keywords */
1100 for (pp = parsekwd; *pp; pp++)
1101 if (**pp == *arg && equal(*pp, arg))
1102 break;
1103
1104 if (*pp) {
1105 if (v_flag)
1106 err = 1;
1107 else
1108 out1str(" is a shell keyword\n");
1109 continue;
1110 }
1111
1112 /* Then look at the aliases */
1113 if ((ap = lookupalias(arg, 1)) != NULL) {
1114 if (!v_flag)
1115 out1fmt(" is an alias for \n");
1116 out1fmt("%s\n", ap->val);
1117 continue;
1118 }
1119
1120 /* Then check if it is a tracked alias */
1121 if ((cmdp = cmdlookup(arg, 0)) != NULL) {
1122 entry.cmdtype = cmdp->cmdtype;
1123 entry.u = cmdp->param;
1124 } else {
1125 /* Finally use brute force */
1126 find_command(arg, &entry, DO_ABS, pathval());
1127 }
1128
1129 switch (entry.cmdtype) {
1130 case CMDNORMAL: {
1131 if (strchr(arg, '/') == NULL) {
1132 const char *path = pathval();
1133 char *name;
1134 int j = entry.u.index;
1135 do {
1136 name = padvance(&path, arg);
1137 stunalloc(name);
1138 } while (--j >= 0);
1139 if (!v_flag)
1140 out1fmt(" is%s ",
1141 cmdp ? " a tracked alias for" : "");
1142 out1fmt("%s\n", name);
1143 } else {
1144 if (access(arg, X_OK) == 0) {
1145 if (!v_flag)
1146 out1fmt(" is ");
1147 out1fmt("%s\n", arg);
1148 } else {
1149 if (!v_flag)
1150 out1fmt(": %s\n",
1151 strerror(errno));
1152 else
1153 err = 126;
1154 }
1155 }
1156 break;
1157 }
1158 case CMDFUNCTION:
1159 if (!v_flag)
1160 out1str(" is a shell function\n");
1161 else
1162 out1fmt("%s\n", arg);
1163 break;
1164
1165 case CMDBUILTIN:
1166 if (!v_flag)
1167 out1str(" is a shell builtin\n");
1168 else
1169 out1fmt("%s\n", arg);
1170 break;
1171
1172 case CMDSPLBLTIN:
1173 if (!v_flag)
1174 out1str(" is a special shell builtin\n");
1175 else
1176 out1fmt("%s\n", arg);
1177 break;
1178
1179 default:
1180 if (!v_flag)
1181 out1str(": not found\n");
1182 err = 127;
1183 break;
1184 }
1185 }
1186 return err;
1187}
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