2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
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9 * modification, are permitted provided that the following conditions
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20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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35 static char sccsid[] = "@(#)exec.c 8.4 (Berkeley) 6/8/95";
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include <sys/types.h>
49 * When commands are first encountered, they are entered in a hash table.
50 * This ensures that a full path search will not have to be done for them
53 * We should investigate converting to a linear search, even though that
54 * would make the command name "hash" a misnomer.
79 #define CMDTABLESIZE 31 /* should be prime */
80 #define ARB 1 /* actual size determined at run time */
85 struct tblentry *next; /* next entry in hash chain */
86 union param param; /* definition of builtin function */
87 int special; /* flag for special builtin commands */
88 short cmdtype; /* index identifying command */
89 char rehash; /* if set, cd done since entry created */
90 char cmdname[ARB]; /* name of command */
94 static struct tblentry *cmdtable[CMDTABLESIZE];
95 static int builtinloc = -1; /* index in path of %builtin, or -1 */
96 int exerrno = 0; /* Last exec error */
99 static void tryexec(char *, char **, char **);
100 static void printentry(struct tblentry *, int);
101 static struct tblentry *cmdlookup(const char *, int);
102 static void delete_cmd_entry(void);
107 * Exec a program. Never returns. If you change this routine, you may
108 * have to change the find_command routine as well.
112 shellexec(char **argv, char **envp, const char *path, int idx)
117 if (strchr(argv[0], '/') != NULL) {
118 tryexec(argv[0], argv, envp);
122 while ((cmdname = padvance(&path, argv[0])) != NULL) {
123 if (--idx < 0 && pathopt == NULL) {
124 tryexec(cmdname, argv, envp);
125 if (errno != ENOENT && errno != ENOTDIR)
132 /* Map to POSIX errors */
144 if (e == ENOENT || e == ENOTDIR)
145 exerror(EXEXEC, "%s: not found", argv[0]);
146 exerror(EXEXEC, "%s: %s", argv[0], strerror(e));
151 tryexec(char *cmd, char **argv, char **envp)
155 execve(cmd, argv, envp);
159 setinputfile(cmd, 0);
160 commandname = arg0 = savestr(argv[0]);
162 exraise(EXSHELLPROC);
169 * Do a path search. The variable path (passed by reference) should be
170 * set to the start of the path before the first call; padvance will update
171 * this value as it proceeds. Successive calls to padvance will return
172 * the possible path expansions in sequence. If an option (indicated by
173 * a percent sign) appears in the path entry then the global variable
174 * pathopt will be set to point to it; otherwise pathopt will be set to
181 padvance(const char **path, const char *name)
183 const char *p, *start;
190 for (p = start; *p && *p != ':' && *p != '%'; p++)
192 len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */
193 while (stackblocksize() < len)
197 memcpy(q, start, p - start);
205 while (*p && *p != ':') p++;
216 /*** Command hashing code ***/
220 hashcmd(int argc __unused, char **argv __unused)
222 struct tblentry **pp;
223 struct tblentry *cmdp;
226 struct cmdentry entry;
230 while ((c = nextopt("rv")) != '\0') {
233 } else if (c == 'v') {
237 if (*argptr == NULL) {
238 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
239 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
240 if (cmdp->cmdtype == CMDNORMAL)
241 printentry(cmdp, verbose);
246 while ((name = *argptr) != NULL) {
247 if ((cmdp = cmdlookup(name, 0)) != NULL
248 && (cmdp->cmdtype == CMDNORMAL
249 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
251 find_command(name, &entry, 1, pathval());
253 if (entry.cmdtype != CMDUNKNOWN) { /* if no error msg */
254 cmdp = cmdlookup(name, 0);
256 printentry(cmdp, verbose);
258 outfmt(&errout, "%s: not found\n", name);
269 printentry(struct tblentry *cmdp, int verbose)
275 if (cmdp->cmdtype == CMDNORMAL) {
276 idx = cmdp->param.index;
279 name = padvance(&path, cmdp->cmdname);
281 } while (--idx >= 0);
283 } else if (cmdp->cmdtype == CMDBUILTIN) {
284 out1fmt("builtin %s", cmdp->cmdname);
285 } else if (cmdp->cmdtype == CMDFUNCTION) {
286 out1fmt("function %s", cmdp->cmdname);
289 name = commandtext(getfuncnode(cmdp->param.func));
297 error("internal error: cmdtype %d", cmdp->cmdtype);
308 * Resolve a command name. If you change this routine, you may have to
309 * change the shellexec routine as well.
313 find_command(const char *name, struct cmdentry *entry, int printerr,
316 struct tblentry *cmdp;
325 /* If name contains a slash, don't use the hash table */
326 if (strchr(name, '/') != NULL) {
327 entry->cmdtype = CMDNORMAL;
332 /* If name is in the table, and not invalidated by cd, we're done */
333 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->rehash == 0)
336 /* If %builtin not in path, check for builtin next */
337 if (builtinloc < 0 && (i = find_builtin(name, &spec)) >= 0) {
339 cmdp = cmdlookup(name, 1);
340 cmdp->cmdtype = CMDBUILTIN;
341 cmdp->param.index = i;
342 cmdp->special = spec;
347 /* We have to search path. */
348 prev = -1; /* where to start */
349 if (cmdp) { /* doing a rehash */
350 if (cmdp->cmdtype == CMDBUILTIN)
353 prev = cmdp->param.index;
359 while ((fullname = padvance(&path, name)) != NULL) {
363 if (prefix("builtin", pathopt)) {
364 if ((i = find_builtin(name, &spec)) < 0)
367 cmdp = cmdlookup(name, 1);
368 cmdp->cmdtype = CMDBUILTIN;
369 cmdp->param.index = i;
370 cmdp->special = spec;
373 } else if (prefix("func", pathopt)) {
376 goto loop; /* ignore unimplemented options */
379 /* if rehash, don't redo absolute path names */
380 if (fullname[0] == '/' && idx <= prev) {
383 TRACE(("searchexec \"%s\": no change\n", name));
386 if (stat(fullname, &statb) < 0) {
387 if (errno != ENOENT && errno != ENOTDIR)
391 e = EACCES; /* if we fail, this will be the error */
392 if (!S_ISREG(statb.st_mode))
394 if (pathopt) { /* this is a %func directory */
395 stalloc(strlen(fullname) + 1);
396 readcmdfile(fullname);
397 if ((cmdp = cmdlookup(name, 0)) == NULL || cmdp->cmdtype != CMDFUNCTION)
398 error("%s not defined in %s", name, fullname);
403 if (statb.st_uid == geteuid()) {
404 if ((statb.st_mode & 0100) == 0)
406 } else if (statb.st_gid == getegid()) {
407 if ((statb.st_mode & 010) == 0)
410 if ((statb.st_mode & 01) == 0)
414 TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
416 cmdp = cmdlookup(name, 1);
417 cmdp->cmdtype = CMDNORMAL;
418 cmdp->param.index = idx;
423 /* We failed. If there was an entry for this command, delete it */
427 if (e == ENOENT || e == ENOTDIR)
428 outfmt(out2, "%s: not found\n", name);
430 outfmt(out2, "%s: %s\n", name, strerror(e));
432 entry->cmdtype = CMDUNKNOWN;
437 entry->cmdtype = cmdp->cmdtype;
438 entry->u = cmdp->param;
439 entry->special = cmdp->special;
445 * Search the table of builtin commands.
449 find_builtin(const char *name, int *special)
451 const struct builtincmd *bp;
453 for (bp = builtincmd ; bp->name ; bp++) {
454 if (*bp->name == *name && equal(bp->name, name)) {
455 *special = bp->special;
465 * Called when a cd is done. Marks all commands so the next time they
466 * are executed they will be rehashed.
472 struct tblentry **pp;
473 struct tblentry *cmdp;
475 for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
476 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
477 if (cmdp->cmdtype == CMDNORMAL
478 || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0))
487 * Called before PATH is changed. The argument is the new value of PATH;
488 * pathval() still returns the old value at this point. Called with
493 changepath(const char *newval)
495 const char *old, *new;
502 firstchange = 9999; /* assume no change */
508 if ((*old == '\0' && *new == ':')
509 || (*old == ':' && *new == '\0'))
511 old = new; /* ignore subsequent differences */
515 if (*new == '%' && bltin < 0 && prefix("builtin", new + 1))
522 if (builtinloc < 0 && bltin >= 0)
523 builtinloc = bltin; /* zap builtins */
524 if (builtinloc >= 0 && bltin < 0)
526 clearcmdentry(firstchange);
532 * Clear out command entries. The argument specifies the first entry in
533 * PATH which has changed.
537 clearcmdentry(int firstchange)
539 struct tblentry **tblp;
540 struct tblentry **pp;
541 struct tblentry *cmdp;
544 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
546 while ((cmdp = *pp) != NULL) {
547 if ((cmdp->cmdtype == CMDNORMAL &&
548 cmdp->param.index >= firstchange)
549 || (cmdp->cmdtype == CMDBUILTIN &&
550 builtinloc >= firstchange)) {
563 * Delete all functions.
567 MKINIT void deletefuncs(void);
577 struct tblentry **tblp;
578 struct tblentry **pp;
579 struct tblentry *cmdp;
582 for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
584 while ((cmdp = *pp) != NULL) {
585 if (cmdp->cmdtype == CMDFUNCTION) {
587 unreffunc(cmdp->param.func);
600 * Locate a command in the command hash table. If "add" is nonzero,
601 * add the command to the table if it is not already present. The
602 * variable "lastcmdentry" is set to point to the address of the link
603 * pointing to the entry, so that delete_cmd_entry can delete the
607 static struct tblentry **lastcmdentry;
610 static struct tblentry *
611 cmdlookup(const char *name, int add)
615 struct tblentry *cmdp;
616 struct tblentry **pp;
623 pp = &cmdtable[hashval % CMDTABLESIZE];
624 for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
625 if (equal(cmdp->cmdname, name))
629 if (add && cmdp == NULL) {
631 cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
634 cmdp->cmdtype = CMDUNKNOWN;
636 strcpy(cmdp->cmdname, name);
644 * Delete the command entry returned on the last lookup.
648 delete_cmd_entry(void)
650 struct tblentry *cmdp;
653 cmdp = *lastcmdentry;
654 *lastcmdentry = cmdp->next;
662 * Add a new command entry, replacing any existing command entry for
667 addcmdentry(const char *name, struct cmdentry *entry)
669 struct tblentry *cmdp;
672 cmdp = cmdlookup(name, 1);
673 if (cmdp->cmdtype == CMDFUNCTION) {
674 unreffunc(cmdp->param.func);
676 cmdp->cmdtype = entry->cmdtype;
677 cmdp->param = entry->u;
683 * Define a shell function.
687 defun(const char *name, union node *func)
689 struct cmdentry entry;
692 entry.cmdtype = CMDFUNCTION;
693 entry.u.func = copyfunc(func);
694 addcmdentry(name, &entry);
700 * Delete a function if it exists.
704 unsetfunc(const char *name)
706 struct tblentry *cmdp;
708 if ((cmdp = cmdlookup(name, 0)) != NULL && cmdp->cmdtype == CMDFUNCTION) {
709 unreffunc(cmdp->param.func);
717 * Shared code for the following builtin commands:
718 * type, command -v, command -V
722 typecmd_impl(int argc, char **argv, int cmd)
724 struct cmdentry entry;
725 struct tblentry *cmdp;
726 const char *const *pp;
731 for (i = 1; i < argc; i++) {
732 /* First look at the keywords */
733 for (pp = parsekwd; *pp; pp++)
734 if (**pp == *argv[i] && equal(*pp, argv[i]))
738 if (cmd == TYPECMD_SMALLV)
739 out1fmt("%s\n", argv[i]);
741 out1fmt("%s is a shell keyword\n", argv[i]);
745 /* Then look at the aliases */
746 if ((ap = lookupalias(argv[i], 1)) != NULL) {
747 if (cmd == TYPECMD_SMALLV)
748 out1fmt("alias %s='%s'\n", argv[i], ap->val);
750 out1fmt("%s is an alias for %s\n", argv[i],
755 /* Then check if it is a tracked alias */
756 if ((cmdp = cmdlookup(argv[i], 0)) != NULL) {
757 entry.cmdtype = cmdp->cmdtype;
758 entry.u = cmdp->param;
759 entry.special = cmdp->special;
762 /* Finally use brute force */
763 find_command(argv[i], &entry, 0, pathval());
766 switch (entry.cmdtype) {
768 if (strchr(argv[i], '/') == NULL) {
769 const char *path = pathval();
771 int j = entry.u.index;
773 name = padvance(&path, argv[i]);
776 if (cmd == TYPECMD_SMALLV)
777 out1fmt("%s\n", name);
779 out1fmt("%s is%s %s\n", argv[i],
780 (cmdp && cmd == TYPECMD_TYPE) ?
781 " a tracked alias for" : "",
784 if (eaccess(argv[i], X_OK) == 0) {
785 if (cmd == TYPECMD_SMALLV)
786 out1fmt("%s\n", argv[i]);
788 out1fmt("%s is %s\n", argv[i],
791 if (cmd != TYPECMD_SMALLV)
792 outfmt(out2, "%s: %s\n",
793 argv[i], strerror(errno));
800 if (cmd == TYPECMD_SMALLV)
801 out1fmt("%s\n", argv[i]);
803 out1fmt("%s is a shell function\n", argv[i]);
807 if (cmd == TYPECMD_SMALLV)
808 out1fmt("%s\n", argv[i]);
809 else if (entry.special)
810 out1fmt("%s is a special shell builtin\n",
813 out1fmt("%s is a shell builtin\n", argv[i]);
817 if (cmd != TYPECMD_SMALLV)
818 outfmt(out2, "%s: not found\n", argv[i]);
827 * Locate and print what a word is...
831 typecmd(int argc, char **argv)
833 return typecmd_impl(argc, argv, TYPECMD_TYPE);