source: trunk/ash/exec.c@ 3232

Last change on this file since 3232 was 3229, checked in by bird, 18 years ago

PC_SLASHES
File size: 27.0 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#ifdef PC_SLASHES
335 char *s;
336#endif
337 const char *start;
338 int len;
339
340 if (*path == NULL)
341 return NULL;
342 start = *path;
343#ifdef PC_PATH_SEP
344 for (p = start ; *p && *p != ';' && *p != '%' ; p++);
345#else
346 for (p = start ; *p && *p != ':' && *p != '%' ; p++);
347#endif
348 len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */
349#ifdef PC_EXE_EXTS
350 len += 4; /* "4" is for .exe/.com/.cmd/.bat/.btm */
351#endif
352 while (stackblocksize() < len)
353 growstackblock();
354#ifdef PC_SLASHES
355 s =
356#endif
357 q = stackblock();
358 if (p != start) {
359 memcpy(q, start, p - start);
360 q += p - start;
361 *q++ = '/';
362 }
363 strcpy(q, name);
364#ifdef PC_SLASHES
365 while ((s = strchr(s, '\\')) != NULL)
366 *s++ = '/';
367#endif
368 pathopt = NULL;
369 if (*p == '%') {
370 pathopt = ++p;
371#ifdef PC_PATH_SEP
372 while (*p && *p != ';') p++;
373#else
374 while (*p && *p != ':') p++;
375#endif
376 }
377#ifdef PC_PATH_SEP
378 if (*p == ';')
379#else
380 if (*p == ':')
381#endif
382 *path = p + 1;
383 else
384 *path = NULL;
385 return stalloc(len);
386}
387
388
389#ifdef PC_EXE_EXTS
390STATIC int stat_pc_exec_exts(char *fullname, struct stat *st, int has_ext)
391{
392 /* skip the SYSV crap */
393 if (stat(fullname, st) >= 0)
394 return 0;
395 if (!has_ext && errno == ENOENT)
396 {
397 char *psz = strchr(fullname, '\0');
398 memcpy(psz, ".exe", 5);
399 if (stat(fullname, st) >= 0)
400 return 0;
401 if (errno != ENOENT && errno != ENOTDIR)
402 return -1;
403
404 memcpy(psz, ".cmd", 5);
405 if (stat(fullname, st) >= 0)
406 return 0;
407 if (errno != ENOENT && errno != ENOTDIR)
408 return -1;
409
410 memcpy(psz, ".bat", 5);
411 if (stat(fullname, st) >= 0)
412 return 0;
413 if (errno != ENOENT && errno != ENOTDIR)
414 return -1;
415
416 memcpy(psz, ".com", 5);
417 if (stat(fullname, st) >= 0)
418 return 0;
419 if (errno != ENOENT && errno != ENOTDIR)
420 return -1;
421
422 memcpy(psz, ".btm", 5);
423 if (stat(fullname, st) >= 0)
424 return 0;
425 *psz = '\0';
426 }
427 return -1;
428}
429#endif /* PC_EXE_EXTS */
430
431
432
433/*** Command hashing code ***/
434
435
436int
437hashcmd(int argc, char **argv)
438{
439 struct tblentry **pp;
440 struct tblentry *cmdp;
441 int c;
442 int verbose;
443 struct cmdentry entry;
444 char *name;
445
446 verbose = 0;
447 while ((c = nextopt("rv")) != '\0') {
448 if (c == 'r') {
449 clearcmdentry(0);
450 } else if (c == 'v') {
451 verbose++;
452 }
453 }
454 if (*argptr == NULL) {
455 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
456 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
457 if (verbose || cmdp->cmdtype == CMDNORMAL)
458 printentry(cmdp, verbose);
459 }
460 }
461 return 0;
462 }
463 while ((name = *argptr) != NULL) {
464 if ((cmdp = cmdlookup(name, 0)) != NULL
465 && (cmdp->cmdtype == CMDNORMAL
466 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
467 delete_cmd_entry();
468 find_command(name, &entry, DO_ERR, pathval());
469 if (verbose) {
470 if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
471 cmdp = cmdlookup(name, 0);
472 printentry(cmdp, verbose);
473 }
474 output_flushall();
475 }
476 argptr++;
477 }
478 return 0;
479}
480
481
482STATIC void
483printentry(struct tblentry *cmdp, int verbose)
484{
485 int idx;
486 const char *path;
487 char *name;
488
489 switch (cmdp->cmdtype) {
490 case CMDNORMAL:
491 idx = cmdp->param.index;
492 path = pathval();
493 do {
494 name = padvance(&path, cmdp->cmdname);
495 stunalloc(name);
496 } while (--idx >= 0);
497 out1str(name);
498 break;
499 case CMDSPLBLTIN:
500 out1fmt("special builtin %s", cmdp->cmdname);
501 break;
502 case CMDBUILTIN:
503 out1fmt("builtin %s", cmdp->cmdname);
504 break;
505 case CMDFUNCTION:
506 out1fmt("function %s", cmdp->cmdname);
507 if (verbose) {
508 struct procstat ps;
509 INTOFF;
510 commandtext(&ps, cmdp->param.func);
511 INTON;
512 out1str("() { ");
513 out1str(ps.cmd);
514 out1str("; }");
515 }
516 break;
517 default:
518 error("internal error: %s cmdtype %d", cmdp->cmdname, cmdp->cmdtype);
519 }
520 if (cmdp->rehash)
521 out1c('*');
522 out1c('\n');
523}
524
525
526
527/*
528 * Resolve a command name. If you change this routine, you may have to
529 * change the shellexec routine as well.
530 */
531
532void
533find_command(char *name, struct cmdentry *entry, int act, const char *path)
534{
535 struct tblentry *cmdp, loc_cmd;
536 int idx;
537 int prev;
538 char *fullname;
539 struct stat statb;
540 int e;
541 int (*bltin)(int,char **);
542
543#ifdef PC_EXE_EXTS
544 int has_ext = strlen(name) - 4;
545 has_ext = has_ext > 0
546 && name[has_ext] == '.'
547 /* use strstr and upper/lower permuated extensions to avoid multiple strcasecmp calls. */
548 && strstr("exe;" "Exe;" "EXe;" "EXE;" "ExE;" "eXe;" "eXE;" "exE;"
549 "cmd;" "Cmd;" "CMd;" "CMD;" "CmD;" "cMd;" "cMD;" "cmD;"
550 "com;" "Com;" "COm;" "COM;" "CoM;" "cOm;" "cOM;" "coM;"
551 "bat;" "Bat;" "BAt;" "BAT;" "BaT;" "bAt;" "bAT;" "baT;"
552 "btm;" "Btm;" "BTm;" "BTM;" "BtM;" "bTm;" "bTM;" "btM;",
553 name + has_ext + 1)
554 != NULL;
555#endif
556
557 /* If name contains a slash, don't use PATH or hash table */
558 if (strchr(name, '/') != NULL) {
559 if (act & DO_ABS) {
560 while (stat(name, &statb) < 0) {
561#ifdef SYSV
562 if (errno == EINTR)
563 continue;
564#endif
565 if (errno != ENOENT && errno != ENOTDIR)
566 e = errno;
567 entry->cmdtype = CMDUNKNOWN;
568 entry->u.index = -1;
569 return;
570 }
571 entry->cmdtype = CMDNORMAL;
572 entry->u.index = -1;
573 return;
574 }
575 entry->cmdtype = CMDNORMAL;
576 entry->u.index = 0;
577 return;
578 }
579
580 if (path != pathval())
581 act |= DO_ALTPATH;
582
583 if (act & DO_ALTPATH && strstr(path, "%builtin") != NULL)
584 act |= DO_ALTBLTIN;
585
586 /* If name is in the table, check answer will be ok */
587 if ((cmdp = cmdlookup(name, 0)) != NULL) {
588 do {
589 switch (cmdp->cmdtype) {
590 case CMDNORMAL:
591 if (act & DO_ALTPATH) {
592 cmdp = NULL;
593 continue;
594 }
595 break;
596 case CMDFUNCTION:
597 if (act & DO_NOFUNC) {
598 cmdp = NULL;
599 continue;
600 }
601 break;
602 case CMDBUILTIN:
603 if ((act & DO_ALTBLTIN) || builtinloc >= 0) {
604 cmdp = NULL;
605 continue;
606 }
607 break;
608 }
609 /* if not invalidated by cd, we're done */
610 if (cmdp->rehash == 0)
611 goto success;
612 } while (0);
613 }
614
615 /* If %builtin not in path, check for builtin next */
616 if ((act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc < 0) &&
617 (bltin = find_builtin(name)) != 0)
618 goto builtin_success;
619
620 /* We have to search path. */
621 prev = -1; /* where to start */
622 if (cmdp) { /* doing a rehash */
623 if (cmdp->cmdtype == CMDBUILTIN)
624 prev = builtinloc;
625 else
626 prev = cmdp->param.index;
627 }
628
629 e = ENOENT;
630 idx = -1;
631loop:
632 while ((fullname = padvance(&path, name)) != NULL) {
633 stunalloc(fullname);
634 idx++;
635 if (pathopt) {
636 if (prefix("builtin", pathopt)) {
637 if ((bltin = find_builtin(name)) == 0)
638 goto loop;
639 goto builtin_success;
640 } else if (prefix("func", pathopt)) {
641 /* handled below */
642 } else {
643 /* ignore unimplemented options */
644 goto loop;
645 }
646 }
647 /* if rehash, don't redo absolute path names */
648 if (fullname[0] == '/' && idx <= prev) {
649 if (idx < prev)
650 goto loop;
651 TRACE(("searchexec \"%s\": no change\n", name));
652 goto success;
653 }
654#ifdef PC_EXE_EXTS
655 while (stat_pc_exec_exts(fullname, &statb, has_ext) < 0) {
656#else
657 while (stat(fullname, &statb) < 0) {
658#endif
659#ifdef SYSV
660 if (errno == EINTR)
661 continue;
662#endif
663 if (errno != ENOENT && errno != ENOTDIR)
664 e = errno;
665
666 goto loop;
667 }
668 e = EACCES; /* if we fail, this will be the error */
669 if (!S_ISREG(statb.st_mode))
670 goto loop;
671 if (pathopt) { /* this is a %func directory */
672 if (act & DO_NOFUNC)
673 goto loop;
674 stalloc(strlen(fullname) + 1);
675 readcmdfile(fullname);
676 if ((cmdp = cmdlookup(name, 0)) == NULL ||
677 cmdp->cmdtype != CMDFUNCTION)
678 error("%s not defined in %s", name, fullname);
679 stunalloc(fullname);
680 goto success;
681 }
682#ifdef notdef
683 /* XXX this code stops root executing stuff, and is buggy
684 if you need a group from the group list. */
685 if (statb.st_uid == geteuid()) {
686 if ((statb.st_mode & 0100) == 0)
687 goto loop;
688 } else if (statb.st_gid == getegid()) {
689 if ((statb.st_mode & 010) == 0)
690 goto loop;
691 } else {
692 if ((statb.st_mode & 01) == 0)
693 goto loop;
694 }
695#endif
696 TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
697 INTOFF;
698 if (act & DO_ALTPATH) {
699 stalloc(strlen(fullname) + 1);
700 cmdp = &loc_cmd;
701 } else
702 cmdp = cmdlookup(name, 1);
703 cmdp->cmdtype = CMDNORMAL;
704 cmdp->param.index = idx;
705 INTON;
706 goto success;
707 }
708
709 /* We failed. If there was an entry for this command, delete it */
710 if (cmdp)
711 delete_cmd_entry();
712 if (act & DO_ERR)
713 outfmt(out2, "%s: %s\n", name, errmsg(e, E_EXEC));
714 entry->cmdtype = CMDUNKNOWN;
715 return;
716
717builtin_success:
718 INTOFF;
719 if (act & DO_ALTPATH)
720 cmdp = &loc_cmd;
721 else
722 cmdp = cmdlookup(name, 1);
723 if (cmdp->cmdtype == CMDFUNCTION)
724 /* DO_NOFUNC must have been set */
725 cmdp = &loc_cmd;
726 cmdp->cmdtype = CMDBUILTIN;
727 cmdp->param.bltin = bltin;
728 INTON;
729success:
730 cmdp->rehash = 0;
731 entry->cmdtype = cmdp->cmdtype;
732 entry->u = cmdp->param;
733}
734
735
736
737/*
738 * Search the table of builtin commands.
739 */
740
741int
742(*find_builtin(name))(int, char **)
743 char *name;
744{
745 const struct builtincmd *bp;
746
747 for (bp = builtincmd ; bp->name ; bp++) {
748 if (*bp->name == *name && equal(bp->name, name))
749 return bp->builtin;
750 }
751 return 0;
752}
753
754int
755(*find_splbltin(name))(int, char **)
756 char *name;
757{
758 const struct builtincmd *bp;
759
760 for (bp = splbltincmd ; bp->name ; bp++) {
761 if (*bp->name == *name && equal(bp->name, name))
762 return bp->builtin;
763 }
764 return 0;
765}
766
767/*
768 * At shell startup put special builtins into hash table.
769 * ensures they are executed first (see posix).
770 * We stop functions being added with the same name
771 * (as they are impossible to call)
772 */
773
774void
775hash_special_builtins(void)
776{
777 const struct builtincmd *bp;
778 struct tblentry *cmdp;
779
780 for (bp = splbltincmd ; bp->name ; bp++) {
781 cmdp = cmdlookup(bp->name, 1);
782 cmdp->cmdtype = CMDSPLBLTIN;
783 cmdp->param.bltin = bp->builtin;
784 }
785}
786
787
788
789/*
790 * Called when a cd is done. Marks all commands so the next time they
791 * are executed they will be rehashed.
792 */
793
794void
795hashcd(void)
796{
797 struct tblentry **pp;
798 struct tblentry *cmdp;
799
800 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
801 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
802 if (cmdp->cmdtype == CMDNORMAL
803 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
804 cmdp->rehash = 1;
805 }
806 }
807}
808
809
810
811/*
812 * Fix command hash table when PATH changed.
813 * Called before PATH is changed. The argument is the new value of PATH;
814 * pathval() still returns the old value at this point.
815 * Called with interrupts off.
816 */
817
818void
819changepath(const char *newval)
820{
821 const char *old, *new;
822 int idx;
823 int firstchange;
824 int bltin;
825
826 old = pathval();
827 new = newval;
828 firstchange = 9999; /* assume no change */
829 idx = 0;
830 bltin = -1;
831 for (;;) {
832 if (*old != *new) {
833 firstchange = idx;
834#ifdef PC_PATH_SEP
835 if ((*old == '\0' && *new == ';')
836 || (*old == ';' && *new == '\0'))
837#else
838 if ((*old == '\0' && *new == ':')
839 || (*old == ':' && *new == '\0'))
840#endif
841 firstchange++;
842 old = new; /* ignore subsequent differences */
843 }
844 if (*new == '\0')
845 break;
846 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
847 bltin = idx;
848#ifdef PC_PATH_SEP
849 if (*new == ';') {
850#else
851 if (*new == ':') {
852#endif
853 idx++;
854 }
855 new++, old++;
856 }
857 if (builtinloc < 0 && bltin >= 0)
858 builtinloc = bltin; /* zap builtins */
859 if (builtinloc >= 0 && bltin < 0)
860 firstchange = 0;
861 clearcmdentry(firstchange);
862 builtinloc = bltin;
863}
864
865
866/*
867 * Clear out command entries. The argument specifies the first entry in
868 * PATH which has changed.
869 */
870
871STATIC void
872clearcmdentry(int firstchange)
873{
874 struct tblentry **tblp;
875 struct tblentry **pp;
876 struct tblentry *cmdp;
877
878 INTOFF;
879 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
880 pp = tblp;
881 while ((cmdp = *pp) != NULL) {
882 if ((cmdp->cmdtype == CMDNORMAL &&
883 cmdp->param.index >= firstchange)
884 || (cmdp->cmdtype == CMDBUILTIN &&
885 builtinloc >= firstchange)) {
886 *pp = cmdp->next;
887 ckfree(cmdp);
888 } else {
889 pp = &cmdp->next;
890 }
891 }
892 }
893 INTON;
894}
895
896
897/*
898 * Delete all functions.
899 */
900
901#ifdef mkinit
902MKINIT void deletefuncs(void);
903MKINIT void hash_special_builtins(void);
904
905INIT {
906 hash_special_builtins();
907}
908
909SHELLPROC {
910 deletefuncs();
911}
912#endif
913
914void
915deletefuncs(void)
916{
917 struct tblentry **tblp;
918 struct tblentry **pp;
919 struct tblentry *cmdp;
920
921 INTOFF;
922 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
923 pp = tblp;
924 while ((cmdp = *pp) != NULL) {
925 if (cmdp->cmdtype == CMDFUNCTION) {
926 *pp = cmdp->next;
927 freefunc(cmdp->param.func);
928 ckfree(cmdp);
929 } else {
930 pp = &cmdp->next;
931 }
932 }
933 }
934 INTON;
935}
936
937
938
939/*
940 * Locate a command in the command hash table. If "add" is nonzero,
941 * add the command to the table if it is not already present. The
942 * variable "lastcmdentry" is set to point to the address of the link
943 * pointing to the entry, so that delete_cmd_entry can delete the
944 * entry.
945 */
946
947struct tblentry **lastcmdentry;
948
949
950STATIC struct tblentry *
951cmdlookup(const char *name, int add)
952{
953 int hashval;
954 const char *p;
955 struct tblentry *cmdp;
956 struct tblentry **pp;
957
958 p = name;
959 hashval = *p << 4;
960 while (*p)
961 hashval += *p++;
962 hashval &= 0x7FFF;
963 pp = &cmdtable[hashval % CMDTABLESIZE];
964 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
965 if (equal(cmdp->cmdname, name))
966 break;
967 pp = &cmdp->next;
968 }
969 if (add && cmdp == NULL) {
970 INTOFF;
971 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
972 + strlen(name) + 1);
973 cmdp->next = NULL;
974 cmdp->cmdtype = CMDUNKNOWN;
975 cmdp->rehash = 0;
976 strcpy(cmdp->cmdname, name);
977 INTON;
978 }
979 lastcmdentry = pp;
980 return cmdp;
981}
982
983/*
984 * Delete the command entry returned on the last lookup.
985 */
986
987STATIC void
988delete_cmd_entry(void)
989{
990 struct tblentry *cmdp;
991
992 INTOFF;
993 cmdp = *lastcmdentry;
994 *lastcmdentry = cmdp->next;
995 ckfree(cmdp);
996 INTON;
997}
998
999
1000
1001#ifdef notdef
1002void
1003getcmdentry(char *name, struct cmdentry *entry)
1004{
1005 struct tblentry *cmdp = cmdlookup(name, 0);
1006
1007 if (cmdp) {
1008 entry->u = cmdp->param;
1009 entry->cmdtype = cmdp->cmdtype;
1010 } else {
1011 entry->cmdtype = CMDUNKNOWN;
1012 entry->u.index = 0;
1013 }
1014}
1015#endif
1016
1017
1018/*
1019 * Add a new command entry, replacing any existing command entry for
1020 * the same name - except special builtins.
1021 */
1022
1023STATIC void
1024addcmdentry(char *name, struct cmdentry *entry)
1025{
1026 struct tblentry *cmdp;
1027
1028 INTOFF;
1029 cmdp = cmdlookup(name, 1);
1030 if (cmdp->cmdtype != CMDSPLBLTIN) {
1031 if (cmdp->cmdtype == CMDFUNCTION) {
1032 freefunc(cmdp->param.func);
1033 }
1034 cmdp->cmdtype = entry->cmdtype;
1035 cmdp->param = entry->u;
1036 }
1037 INTON;
1038}
1039
1040
1041/*
1042 * Define a shell function.
1043 */
1044
1045void
1046defun(char *name, union node *func)
1047{
1048 struct cmdentry entry;
1049
1050 INTOFF;
1051 entry.cmdtype = CMDFUNCTION;
1052 entry.u.func = copyfunc(func);
1053 addcmdentry(name, &entry);
1054 INTON;
1055}
1056
1057
1058/*
1059 * Delete a function if it exists.
1060 */
1061
1062int
1063unsetfunc(char *name)
1064{
1065 struct tblentry *cmdp;
1066
1067 if ((cmdp = cmdlookup(name, 0)) != NULL &&
1068 cmdp->cmdtype == CMDFUNCTION) {
1069 freefunc(cmdp->param.func);
1070 delete_cmd_entry();
1071 return (0);
1072 }
1073 return (1);
1074}
1075
1076/*
1077 * Locate and print what a word is...
1078 * also used for 'command -[v|V]'
1079 */
1080
1081int
1082typecmd(int argc, char **argv)
1083{
1084 struct cmdentry entry;
1085 struct tblentry *cmdp;
1086 char * const *pp;
1087 struct alias *ap;
1088 int err = 0;
1089 char *arg;
1090 int c;
1091 int V_flag = 0;
1092 int v_flag = 0;
1093 int p_flag = 0;
1094
1095 while ((c = nextopt("vVp")) != 0) {
1096 switch (c) {
1097 case 'v': v_flag = 1; break;
1098 case 'V': V_flag = 1; break;
1099 case 'p': p_flag = 1; break;
1100 }
1101 }
1102
1103 if (p_flag && (v_flag || V_flag))
1104 error("cannot specify -p with -v or -V");
1105
1106 while ((arg = *argptr++)) {
1107 if (!v_flag)
1108 out1str(arg);
1109 /* First look at the keywords */
1110 for (pp = parsekwd; *pp; pp++)
1111 if (**pp == *arg && equal(*pp, arg))
1112 break;
1113
1114 if (*pp) {
1115 if (v_flag)
1116 err = 1;
1117 else
1118 out1str(" is a shell keyword\n");
1119 continue;
1120 }
1121
1122 /* Then look at the aliases */
1123 if ((ap = lookupalias(arg, 1)) != NULL) {
1124 if (!v_flag)
1125 out1fmt(" is an alias for \n");
1126 out1fmt("%s\n", ap->val);
1127 continue;
1128 }
1129
1130 /* Then check if it is a tracked alias */
1131 if ((cmdp = cmdlookup(arg, 0)) != NULL) {
1132 entry.cmdtype = cmdp->cmdtype;
1133 entry.u = cmdp->param;
1134 } else {
1135 /* Finally use brute force */
1136 find_command(arg, &entry, DO_ABS, pathval());
1137 }
1138
1139 switch (entry.cmdtype) {
1140 case CMDNORMAL: {
1141 if (strchr(arg, '/') == NULL) {
1142 const char *path = pathval();
1143 char *name;
1144 int j = entry.u.index;
1145 do {
1146 name = padvance(&path, arg);
1147 stunalloc(name);
1148 } while (--j >= 0);
1149 if (!v_flag)
1150 out1fmt(" is%s ",
1151 cmdp ? " a tracked alias for" : "");
1152 out1fmt("%s\n", name);
1153 } else {
1154 if (access(arg, X_OK) == 0) {
1155 if (!v_flag)
1156 out1fmt(" is ");
1157 out1fmt("%s\n", arg);
1158 } else {
1159 if (!v_flag)
1160 out1fmt(": %s\n",
1161 strerror(errno));
1162 else
1163 err = 126;
1164 }
1165 }
1166 break;
1167 }
1168 case CMDFUNCTION:
1169 if (!v_flag)
1170 out1str(" is a shell function\n");
1171 else
1172 out1fmt("%s\n", arg);
1173 break;
1174
1175 case CMDBUILTIN:
1176 if (!v_flag)
1177 out1str(" is a shell builtin\n");
1178 else
1179 out1fmt("%s\n", arg);
1180 break;
1181
1182 case CMDSPLBLTIN:
1183 if (!v_flag)
1184 out1str(" is a special shell builtin\n");
1185 else
1186 out1fmt("%s\n", arg);
1187 break;
1188
1189 default:
1190 if (!v_flag)
1191 out1str(": not found\n");
1192 err = 127;
1193 break;
1194 }
1195 }
1196 return err;
1197}
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