1/*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
|
39__FBSDID("$FreeBSD: head/bin/sh/var.c 169133 2007-04-30 15:01:33Z ache $");
|
| 39__FBSDID("$FreeBSD: head/bin/sh/var.c 169177 2007-05-01 16:02:44Z ache $"); |
40
41#include <unistd.h>
42#include <stdlib.h>
43#include <paths.h>
44
45/*
46 * Shell variables.
47 */
48
49#include <locale.h>
50
51#include "shell.h"
52#include "output.h"
53#include "expand.h"
54#include "nodes.h" /* for other headers */
55#include "eval.h" /* defines cmdenviron */
56#include "exec.h"
57#include "syntax.h"
58#include "options.h"
59#include "mail.h"
60#include "var.h"
61#include "memalloc.h"
62#include "error.h"
63#include "mystring.h"
64#include "parser.h"
65#ifndef NO_HISTORY
66#include "myhistedit.h"
67#endif
68
69
70#define VTABSIZE 39
71
72
73struct varinit {
74 struct var *var;
75 int flags;
76 char *text;
77 void (*func)(const char *);
78};
79
80
81#ifndef NO_HISTORY
82struct var vhistsize;
83#endif
84struct var vifs;
85struct var vmail;
86struct var vmpath;
87struct var vpath;
88struct var vppid;
89struct var vps1;
90struct var vps2;
91struct var vps4;
92struct var vvers;
93STATIC struct var voptind;
94
95STATIC const struct varinit varinit[] = {
96#ifndef NO_HISTORY
97 { &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=",
98 sethistsize },
99#endif
100 { &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n",
101 NULL },
102 { &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=",
103 NULL },
104 { &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=",
105 NULL },
106 { &vpath, VSTRFIXED|VTEXTFIXED, "PATH=" _PATH_DEFPATH,
107 changepath },
108 { &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=",
109 NULL },
110 /*
111 * vps1 depends on uid
112 */
113 { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ",
114 NULL },
115 { &vps4, VSTRFIXED|VTEXTFIXED, "PS4=+ ",
116 NULL },
117 { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1",
118 getoptsreset },
119 { NULL, 0, NULL,
120 NULL }
121};
122
123STATIC struct var *vartab[VTABSIZE];
124
125STATIC struct var **hashvar(char *);
126STATIC int varequal(char *, char *);
127STATIC int localevar(char *);
128
129/*
130 * Initialize the variable symbol tables and import the environment.
131 */
132
133#ifdef mkinit
134INCLUDE "var.h"
135INIT {
136 char **envp;
137 extern char **environ;
138
139 initvar();
140 for (envp = environ ; *envp ; envp++) {
141 if (strchr(*envp, '=')) {
142 setvareq(*envp, VEXPORT|VTEXTFIXED);
143 }
144 }
145}
146#endif
147
148
149/*
150 * This routine initializes the builtin variables. It is called when the
151 * shell is initialized and again when a shell procedure is spawned.
152 */
153
154void
155initvar(void)
156{
157 char ppid[20];
158 const struct varinit *ip;
159 struct var *vp;
160 struct var **vpp;
161
162 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
163 if ((vp->flags & VEXPORT) == 0) {
164 vpp = hashvar(ip->text);
165 vp->next = *vpp;
166 *vpp = vp;
167 vp->text = ip->text;
168 vp->flags = ip->flags;
169 vp->func = ip->func;
170 }
171 }
172 /*
173 * PS1 depends on uid
174 */
175 if ((vps1.flags & VEXPORT) == 0) {
176 vpp = hashvar("PS1=");
177 vps1.next = *vpp;
178 *vpp = &vps1;
179 vps1.text = geteuid() ? "PS1=$ " : "PS1=# ";
180 vps1.flags = VSTRFIXED|VTEXTFIXED;
181 }
182 if ((vppid.flags & VEXPORT) == 0) {
183 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
184 setvarsafe("PPID", ppid, 0);
185 }
186}
187
188/*
189 * Safe version of setvar, returns 1 on success 0 on failure.
190 */
191
192int
193setvarsafe(char *name, char *val, int flags)
194{
195 struct jmploc jmploc;
196 struct jmploc *volatile savehandler = handler;
197 int err = 0;
198#if __GNUC__
199 /* Avoid longjmp clobbering */
200 (void) &err;
201#endif
202
203 if (setjmp(jmploc.loc))
204 err = 1;
205 else {
206 handler = &jmploc;
207 setvar(name, val, flags);
208 }
209 handler = savehandler;
210 return err;
211}
212
213/*
214 * Set the value of a variable. The flags argument is stored with the
215 * flags of the variable. If val is NULL, the variable is unset.
216 */
217
218void
219setvar(char *name, char *val, int flags)
220{
221 char *p, *q;
222 int len;
223 int namelen;
224 char *nameeq;
225 int isbad;
226
227 isbad = 0;
228 p = name;
229 if (! is_name(*p))
230 isbad = 1;
231 p++;
232 for (;;) {
233 if (! is_in_name(*p)) {
234 if (*p == '\0' || *p == '=')
235 break;
236 isbad = 1;
237 }
238 p++;
239 }
240 namelen = p - name;
241 if (isbad)
242 error("%.*s: bad variable name", namelen, name);
243 len = namelen + 2; /* 2 is space for '=' and '\0' */
244 if (val == NULL) {
245 flags |= VUNSET;
246 } else {
247 len += strlen(val);
248 }
249 p = nameeq = ckmalloc(len);
250 q = name;
251 while (--namelen >= 0)
252 *p++ = *q++;
253 *p++ = '=';
254 *p = '\0';
255 if (val)
256 scopy(val, p);
257 setvareq(nameeq, flags);
258}
259
260STATIC int
261localevar(char *s)
262{
263 static char *lnames[7] = {
264 "ALL", "COLLATE", "CTYPE", "MONETARY",
265 "NUMERIC", "TIME", NULL
266 };
267 char **ss;
268
269 if (*s != 'L')
270 return 0;
271 if (varequal(s + 1, "ANG"))
272 return 1;
273 if (strncmp(s + 1, "C_", 2) != 0)
274 return 0;
275 for (ss = lnames; *ss ; ss++)
276 if (varequal(s + 3, *ss))
277 return 1;
278 return 0;
279}
280
281/*
282 * Same as setvar except that the variable and value are passed in
283 * the first argument as name=value. Since the first argument will
284 * be actually stored in the table, it should not be a string that
285 * will go away.
286 */
287
288void
289setvareq(char *s, int flags)
290{
291 struct var *vp, **vpp;
292 int len;
293
294 if (aflag)
295 flags |= VEXPORT;
296 vpp = hashvar(s);
297 for (vp = *vpp ; vp ; vp = vp->next) {
298 if (varequal(s, vp->text)) {
299 if (vp->flags & VREADONLY) {
300 len = strchr(s, '=') - s;
301 error("%.*s: is read only", len, s);
302 }
303 INTOFF;
304
305 if (vp->func && (flags & VNOFUNC) == 0)
306 (*vp->func)(strchr(s, '=') + 1);
307
308 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
309 ckfree(vp->text);
310
311 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
312 vp->flags |= flags;
313 vp->text = s;
314
315 /*
316 * We could roll this to a function, to handle it as
317 * a regular variable function callback, but why bother?
318 */
319 if (vp == &vmpath || (vp == &vmail && ! mpathset()))
320 chkmail(1);
321 if ((vp->flags & VEXPORT) && localevar(s)) {
|
322 (void) putenv(savestr(s));
|
| 322 putenv(s); |
323 (void) setlocale(LC_ALL, "");
324 }
325 INTON;
326 return;
327 }
328 }
329 /* not found */
330 vp = ckmalloc(sizeof (*vp));
331 vp->flags = flags;
332 vp->text = s;
333 vp->next = *vpp;
334 vp->func = NULL;
335 INTOFF;
336 *vpp = vp;
337 if ((vp->flags & VEXPORT) && localevar(s)) {
|
338 (void) putenv(savestr(s));
|
| 338 putenv(s); |
339 (void) setlocale(LC_ALL, "");
340 }
341 INTON;
342}
343
344
345
346/*
347 * Process a linked list of variable assignments.
348 */
349
350void
351listsetvar(struct strlist *list)
352{
353 struct strlist *lp;
354
355 INTOFF;
356 for (lp = list ; lp ; lp = lp->next) {
357 setvareq(savestr(lp->text), 0);
358 }
359 INTON;
360}
361
362
363
364/*
365 * Find the value of a variable. Returns NULL if not set.
366 */
367
368char *
369lookupvar(char *name)
370{
371 struct var *v;
372
373 for (v = *hashvar(name) ; v ; v = v->next) {
374 if (varequal(v->text, name)) {
375 if (v->flags & VUNSET)
376 return NULL;
377 return strchr(v->text, '=') + 1;
378 }
379 }
380 return NULL;
381}
382
383
384
385/*
386 * Search the environment of a builtin command. If the second argument
387 * is nonzero, return the value of a variable even if it hasn't been
388 * exported.
389 */
390
391char *
392bltinlookup(char *name, int doall)
393{
394 struct strlist *sp;
395 struct var *v;
396
397 for (sp = cmdenviron ; sp ; sp = sp->next) {
398 if (varequal(sp->text, name))
399 return strchr(sp->text, '=') + 1;
400 }
401 for (v = *hashvar(name) ; v ; v = v->next) {
402 if (varequal(v->text, name)) {
403 if ((v->flags & VUNSET)
404 || (!doall && (v->flags & VEXPORT) == 0))
405 return NULL;
406 return strchr(v->text, '=') + 1;
407 }
408 }
409 return NULL;
410}
411
412
413
414/*
415 * Generate a list of exported variables. This routine is used to construct
416 * the third argument to execve when executing a program.
417 */
418
419char **
420environment(void)
421{
422 int nenv;
423 struct var **vpp;
424 struct var *vp;
425 char **env, **ep;
426
427 nenv = 0;
428 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
429 for (vp = *vpp ; vp ; vp = vp->next)
430 if (vp->flags & VEXPORT)
431 nenv++;
432 }
433 ep = env = stalloc((nenv + 1) * sizeof *env);
434 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
435 for (vp = *vpp ; vp ; vp = vp->next)
436 if (vp->flags & VEXPORT)
437 *ep++ = vp->text;
438 }
439 *ep = NULL;
440 return env;
441}
442
443
444/*
445 * Called when a shell procedure is invoked to clear out nonexported
446 * variables. It is also necessary to reallocate variables of with
447 * VSTACK set since these are currently allocated on the stack.
448 */
449
450#ifdef mkinit
451MKINIT void shprocvar(void);
452
453SHELLPROC {
454 shprocvar();
455}
456#endif
457
458void
459shprocvar(void)
460{
461 struct var **vpp;
462 struct var *vp, **prev;
463
464 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
465 for (prev = vpp ; (vp = *prev) != NULL ; ) {
466 if ((vp->flags & VEXPORT) == 0) {
467 *prev = vp->next;
468 if ((vp->flags & VTEXTFIXED) == 0)
469 ckfree(vp->text);
470 if ((vp->flags & VSTRFIXED) == 0)
471 ckfree(vp);
472 } else {
473 if (vp->flags & VSTACK) {
474 vp->text = savestr(vp->text);
475 vp->flags &=~ VSTACK;
476 }
477 prev = &vp->next;
478 }
479 }
480 }
481 initvar();
482}
483
484
485static int
486var_compare(const void *a, const void *b)
487{
488 const char *const *sa, *const *sb;
489
490 sa = a;
491 sb = b;
492 /*
493 * This compares two var=value strings which creates a different
494 * order from what you would probably expect. POSIX is somewhat
495 * ambiguous on what should be sorted exactly.
496 */
497 return strcoll(*sa, *sb);
498}
499
500
501/*
502 * Command to list all variables which are set. Currently this command
503 * is invoked from the set command when the set command is called without
504 * any variables.
505 */
506
507int
508showvarscmd(int argc __unused, char **argv __unused)
509{
510 struct var **vpp;
511 struct var *vp;
512 const char *s;
513 const char **vars;
514 int i, n;
515
516 /*
517 * POSIX requires us to sort the variables.
518 */
519 n = 0;
520 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
521 for (vp = *vpp; vp; vp = vp->next) {
522 if (!(vp->flags & VUNSET))
523 n++;
524 }
525 }
526
527 INTON;
528 vars = ckmalloc(n * sizeof(*vars));
529 i = 0;
530 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
531 for (vp = *vpp; vp; vp = vp->next) {
532 if (!(vp->flags & VUNSET))
533 vars[i++] = vp->text;
534 }
535 }
536
537 qsort(vars, n, sizeof(*vars), var_compare);
538 for (i = 0; i < n; i++) {
539 for (s = vars[i]; *s != '='; s++)
540 out1c(*s);
541 out1c('=');
542 out1qstr(s + 1);
543 out1c('\n');
544 }
545 ckfree(vars);
546 INTOFF;
547
548 return 0;
549}
550
551
552
553/*
554 * The export and readonly commands.
555 */
556
557int
558exportcmd(int argc, char **argv)
559{
560 struct var **vpp;
561 struct var *vp;
562 char *name;
563 char *p;
564 char *cmdname;
565 int ch, values;
566 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
567
568 cmdname = argv[0];
569 optreset = optind = 1;
570 opterr = 0;
571 values = 0;
572 while ((ch = getopt(argc, argv, "p")) != -1) {
573 switch (ch) {
574 case 'p':
575 values = 1;
576 break;
577 case '?':
578 default:
579 error("unknown option: -%c", optopt);
580 }
581 }
582 argc -= optind;
583 argv += optind;
584
585 if (values && argc != 0)
586 error("-p requires no arguments");
587 listsetvar(cmdenviron);
588 if (argc != 0) {
589 while ((name = *argv++) != NULL) {
590 if ((p = strchr(name, '=')) != NULL) {
591 p++;
592 } else {
593 vpp = hashvar(name);
594 for (vp = *vpp ; vp ; vp = vp->next) {
595 if (varequal(vp->text, name)) {
596
597 vp->flags |= flag;
598 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
|
599 (void) putenv(savestr(vp->text));
|
| 599 putenv(vp->text); |
600 (void) setlocale(LC_ALL, "");
601 }
602 goto found;
603 }
604 }
605 }
606 setvar(name, p, flag);
607found:;
608 }
609 } else {
610 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
611 for (vp = *vpp ; vp ; vp = vp->next) {
612 if (vp->flags & flag) {
613 if (values) {
614 out1str(cmdname);
615 out1c(' ');
616 }
617 for (p = vp->text ; *p != '=' ; p++)
618 out1c(*p);
619 if (values && !(vp->flags & VUNSET)) {
620 out1c('=');
621 out1qstr(p + 1);
622 }
623 out1c('\n');
624 }
625 }
626 }
627 }
628 return 0;
629}
630
631
632/*
633 * The "local" command.
634 */
635
636int
637localcmd(int argc __unused, char **argv __unused)
638{
639 char *name;
640
641 if (! in_function())
642 error("Not in a function");
643 while ((name = *argptr++) != NULL) {
644 mklocal(name);
645 }
646 return 0;
647}
648
649
650/*
651 * Make a variable a local variable. When a variable is made local, it's
652 * value and flags are saved in a localvar structure. The saved values
653 * will be restored when the shell function returns. We handle the name
654 * "-" as a special case.
655 */
656
657void
658mklocal(char *name)
659{
660 struct localvar *lvp;
661 struct var **vpp;
662 struct var *vp;
663
664 INTOFF;
665 lvp = ckmalloc(sizeof (struct localvar));
666 if (name[0] == '-' && name[1] == '\0') {
667 lvp->text = ckmalloc(sizeof optlist);
668 memcpy(lvp->text, optlist, sizeof optlist);
669 vp = NULL;
670 } else {
671 vpp = hashvar(name);
672 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
673 if (vp == NULL) {
674 if (strchr(name, '='))
675 setvareq(savestr(name), VSTRFIXED);
676 else
677 setvar(name, NULL, VSTRFIXED);
678 vp = *vpp; /* the new variable */
679 lvp->text = NULL;
680 lvp->flags = VUNSET;
681 } else {
682 lvp->text = vp->text;
683 lvp->flags = vp->flags;
684 vp->flags |= VSTRFIXED|VTEXTFIXED;
685 if (strchr(name, '='))
686 setvareq(savestr(name), 0);
687 }
688 }
689 lvp->vp = vp;
690 lvp->next = localvars;
691 localvars = lvp;
692 INTON;
693}
694
695
696/*
697 * Called after a function returns.
698 */
699
700void
701poplocalvars(void)
702{
703 struct localvar *lvp;
704 struct var *vp;
705
706 while ((lvp = localvars) != NULL) {
707 localvars = lvp->next;
708 vp = lvp->vp;
709 if (vp == NULL) { /* $- saved */
710 memcpy(optlist, lvp->text, sizeof optlist);
711 ckfree(lvp->text);
712 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
713 (void)unsetvar(vp->text);
714 } else {
715 if ((vp->flags & VTEXTFIXED) == 0)
716 ckfree(vp->text);
717 vp->flags = lvp->flags;
718 vp->text = lvp->text;
719 }
720 ckfree(lvp);
721 }
722}
723
724
725int
726setvarcmd(int argc, char **argv)
727{
728 if (argc <= 2)
729 return unsetcmd(argc, argv);
730 else if (argc == 3)
731 setvar(argv[1], argv[2], 0);
732 else
733 error("List assignment not implemented");
734 return 0;
735}
736
737
738/*
739 * The unset builtin command. We unset the function before we unset the
740 * variable to allow a function to be unset when there is a readonly variable
741 * with the same name.
742 */
743
744int
745unsetcmd(int argc __unused, char **argv __unused)
746{
747 char **ap;
748 int i;
749 int flg_func = 0;
750 int flg_var = 0;
751 int ret = 0;
752
753 while ((i = nextopt("vf")) != '\0') {
754 if (i == 'f')
755 flg_func = 1;
756 else
757 flg_var = 1;
758 }
759 if (flg_func == 0 && flg_var == 0)
760 flg_var = 1;
761
762 for (ap = argptr; *ap ; ap++) {
763 if (flg_func)
764 ret |= unsetfunc(*ap);
765 if (flg_var)
766 ret |= unsetvar(*ap);
767 }
768 return ret;
769}
770
771
772/*
773 * Unset the specified variable.
774 */
775
776int
777unsetvar(char *s)
778{
|
779 char *eqp, *ss;
|
779 struct var **vpp;
780 struct var *vp;
781
782 vpp = hashvar(s);
783 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
784 if (varequal(vp->text, s)) {
785 if (vp->flags & VREADONLY)
786 return (1);
787 INTOFF;
788 if (*(strchr(vp->text, '=') + 1) != '\0')
789 setvar(s, nullstr, 0);
790 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
|
792 ss = savestr(s);
793 if ((eqp = strchr(ss, '=')) != NULL)
794 *eqp = '\0';
795 (void) unsetenv(ss);
796 ckfree(ss);
|
| 791 unsetenv(s); |
792 setlocale(LC_ALL, "");
793 }
794 vp->flags &= ~VEXPORT;
795 vp->flags |= VUNSET;
796 if ((vp->flags & VSTRFIXED) == 0) {
797 if ((vp->flags & VTEXTFIXED) == 0)
798 ckfree(vp->text);
799 *vpp = vp->next;
800 ckfree(vp);
801 }
802 INTON;
803 return (0);
804 }
805 }
806
807 return (0);
808}
809
810
811
812/*
813 * Find the appropriate entry in the hash table from the name.
814 */
815
816STATIC struct var **
817hashvar(char *p)
818{
819 unsigned int hashval;
820
821 hashval = ((unsigned char) *p) << 4;
822 while (*p && *p != '=')
823 hashval += (unsigned char) *p++;
824 return &vartab[hashval % VTABSIZE];
825}
826
827
828
829/*
830 * Returns true if the two strings specify the same varable. The first
831 * variable name is terminated by '='; the second may be terminated by
832 * either '=' or '\0'.
833 */
834
835STATIC int
836varequal(char *p, char *q)
837{
838 while (*p == *q++) {
839 if (*p++ == '=')
840 return 1;
841 }
842 if (*p == '=' && *(q - 1) == '\0')
843 return 1;
844 return 0;
845}
|