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[dragonfly.git] / bin / sh / var.c
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MD
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 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38#if 0
39static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95";
40#endif
41#endif /* not lint */
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: src/bin/sh/var.c,v 1.15.2.2 2002/08/27 01:36:28 tjr Exp $");
44
45#include <unistd.h>
46#include <stdlib.h>
47
48/*
49 * Shell variables.
50 */
51
52#include <locale.h>
53
54#include "shell.h"
55#include "output.h"
56#include "expand.h"
57#include "nodes.h" /* for other headers */
58#include "eval.h" /* defines cmdenviron */
59#include "exec.h"
60#include "syntax.h"
61#include "options.h"
62#include "mail.h"
63#include "var.h"
64#include "memalloc.h"
65#include "error.h"
66#include "mystring.h"
67#include "parser.h"
68#ifndef NO_HISTORY
69#include "myhistedit.h"
70#endif
71
72
73#define VTABSIZE 39
74
75
76struct varinit {
77 struct var *var;
78 int flags;
79 char *text;
80 void (*func)(const char *);
81};
82
83
84#if ATTY
85struct var vatty;
86#endif
87#ifndef NO_HISTORY
88struct var vhistsize;
89#endif
90struct var vifs;
91struct var vmail;
92struct var vmpath;
93struct var vpath;
94struct var vppid;
95struct var vps1;
96struct var vps2;
97struct var vvers;
98#if ATTY
99struct var vterm;
100#endif
101struct var voptind;
102
103const struct varinit varinit[] = {
104#if ATTY
105 { &vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY=",
106 NULL },
107#endif
108#ifndef NO_HISTORY
109 { &vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE=",
110 sethistsize },
111#endif
112 { &vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n",
113 NULL },
114 { &vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL=",
115 NULL },
116 { &vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH=",
117 NULL },
118 { &vpath, VSTRFIXED|VTEXTFIXED, "PATH=/bin:/usr/bin",
119 changepath },
120 { &vppid, VSTRFIXED|VTEXTFIXED|VUNSET, "PPID=",
121 NULL },
122 /*
123 * vps1 depends on uid
124 */
125 { &vps2, VSTRFIXED|VTEXTFIXED, "PS2=> ",
126 NULL },
127#if ATTY
128 { &vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM=",
129 NULL },
130#endif
131 { &voptind, VSTRFIXED|VTEXTFIXED, "OPTIND=1",
132 getoptsreset },
133 { NULL, 0, NULL,
134 NULL }
135};
136
137struct var *vartab[VTABSIZE];
138
139STATIC struct var **hashvar(char *);
140STATIC int varequal(char *, char *);
141STATIC int localevar(char *);
142
143/*
144 * Initialize the varable symbol tables and import the environment
145 */
146
147#ifdef mkinit
148INCLUDE "var.h"
149INIT {
150 char **envp;
151 extern char **environ;
152
153 initvar();
154 for (envp = environ ; *envp ; envp++) {
155 if (strchr(*envp, '=')) {
156 setvareq(*envp, VEXPORT|VTEXTFIXED);
157 }
158 }
159}
160#endif
161
162
163/*
164 * This routine initializes the builtin variables. It is called when the
165 * shell is initialized and again when a shell procedure is spawned.
166 */
167
168void
169initvar(void)
170{
171 char ppid[20];
172 const struct varinit *ip;
173 struct var *vp;
174 struct var **vpp;
175
176 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
177 if ((vp->flags & VEXPORT) == 0) {
178 vpp = hashvar(ip->text);
179 vp->next = *vpp;
180 *vpp = vp;
181 vp->text = ip->text;
182 vp->flags = ip->flags;
183 vp->func = ip->func;
184 }
185 }
186 /*
187 * PS1 depends on uid
188 */
189 if ((vps1.flags & VEXPORT) == 0) {
190 vpp = hashvar("PS1=");
191 vps1.next = *vpp;
192 *vpp = &vps1;
193 vps1.text = geteuid() ? "PS1=$ " : "PS1=# ";
194 vps1.flags = VSTRFIXED|VTEXTFIXED;
195 }
196 if ((vppid.flags & VEXPORT) == 0) {
197 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
198 setvarsafe("PPID", ppid, 0);
199 }
200}
201
202/*
203 * Safe version of setvar, returns 1 on success 0 on failure.
204 */
205
206int
207setvarsafe(char *name, char *val, int flags)
208{
209 struct jmploc jmploc;
210 struct jmploc *volatile savehandler = handler;
211 int err = 0;
212#if __GNUC__
213 /* Avoid longjmp clobbering */
214 (void) &err;
215#endif
216
217 if (setjmp(jmploc.loc))
218 err = 1;
219 else {
220 handler = &jmploc;
221 setvar(name, val, flags);
222 }
223 handler = savehandler;
224 return err;
225}
226
227/*
228 * Set the value of a variable. The flags argument is tored with the
229 * flags of the variable. If val is NULL, the variable is unset.
230 */
231
232void
233setvar(char *name, char *val, int flags)
234{
235 char *p, *q;
236 int len;
237 int namelen;
238 char *nameeq;
239 int isbad;
240
241 isbad = 0;
242 p = name;
243 if (! is_name(*p))
244 isbad = 1;
245 p++;
246 for (;;) {
247 if (! is_in_name(*p)) {
248 if (*p == '\0' || *p == '=')
249 break;
250 isbad = 1;
251 }
252 p++;
253 }
254 namelen = p - name;
255 if (isbad)
256 error("%.*s: bad variable name", namelen, name);
257 len = namelen + 2; /* 2 is space for '=' and '\0' */
258 if (val == NULL) {
259 flags |= VUNSET;
260 } else {
261 len += strlen(val);
262 }
263 p = nameeq = ckmalloc(len);
264 q = name;
265 while (--namelen >= 0)
266 *p++ = *q++;
267 *p++ = '=';
268 *p = '\0';
269 if (val)
270 scopy(val, p);
271 setvareq(nameeq, flags);
272}
273
274STATIC int
275localevar(char *s)
276{
277 static char *lnames[7] = {
278 "ALL", "COLLATE", "CTYPE", "MONETARY",
279 "NUMERIC", "TIME", NULL
280 };
281 char **ss;
282
283 if (*s != 'L')
284 return 0;
285 if (varequal(s + 1, "ANG"))
286 return 1;
287 if (strncmp(s + 1, "C_", 2) != 0)
288 return 0;
289 for (ss = lnames; *ss ; ss++)
290 if (varequal(s + 3, *ss))
291 return 1;
292 return 0;
293}
294
295/*
296 * Same as setvar except that the variable and value are passed in
297 * the first argument as name=value. Since the first argument will
298 * be actually stored in the table, it should not be a string that
299 * will go away.
300 */
301
302void
303setvareq(char *s, int flags)
304{
305 struct var *vp, **vpp;
306 int len;
307
308 if (aflag)
309 flags |= VEXPORT;
310 vpp = hashvar(s);
311 for (vp = *vpp ; vp ; vp = vp->next) {
312 if (varequal(s, vp->text)) {
313 if (vp->flags & VREADONLY) {
314 len = strchr(s, '=') - s;
315 error("%.*s: is read only", len, s);
316 }
317 INTOFF;
318
319 if (vp->func && (flags & VNOFUNC) == 0)
320 (*vp->func)(strchr(s, '=') + 1);
321
322 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
323 ckfree(vp->text);
324
325 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
326 vp->flags |= flags;
327 vp->text = s;
328
329 /*
330 * We could roll this to a function, to handle it as
331 * a regular variable function callback, but why bother?
332 */
333 if (vp == &vmpath || (vp == &vmail && ! mpathset()))
334 chkmail(1);
335 if ((vp->flags & VEXPORT) && localevar(s)) {
336 putenv(s);
337 (void) setlocale(LC_ALL, "");
338 }
339 INTON;
340 return;
341 }
342 }
343 /* not found */
344 vp = ckmalloc(sizeof (*vp));
345 vp->flags = flags;
346 vp->text = s;
347 vp->next = *vpp;
348 vp->func = NULL;
349 INTOFF;
350 *vpp = vp;
351 if ((vp->flags & VEXPORT) && localevar(s)) {
352 putenv(s);
353 (void) setlocale(LC_ALL, "");
354 }
355 INTON;
356}
357
358
359
360/*
361 * Process a linked list of variable assignments.
362 */
363
364void
365listsetvar(struct strlist *list)
366{
367 struct strlist *lp;
368
369 INTOFF;
370 for (lp = list ; lp ; lp = lp->next) {
371 setvareq(savestr(lp->text), 0);
372 }
373 INTON;
374}
375
376
377
378/*
379 * Find the value of a variable. Returns NULL if not set.
380 */
381
382char *
383lookupvar(char *name)
384{
385 struct var *v;
386
387 for (v = *hashvar(name) ; v ; v = v->next) {
388 if (varequal(v->text, name)) {
389 if (v->flags & VUNSET)
390 return NULL;
391 return strchr(v->text, '=') + 1;
392 }
393 }
394 return NULL;
395}
396
397
398
399/*
400 * Search the environment of a builtin command. If the second argument
401 * is nonzero, return the value of a variable even if it hasn't been
402 * exported.
403 */
404
405char *
406bltinlookup(char *name, int doall)
407{
408 struct strlist *sp;
409 struct var *v;
410
411 for (sp = cmdenviron ; sp ; sp = sp->next) {
412 if (varequal(sp->text, name))
413 return strchr(sp->text, '=') + 1;
414 }
415 for (v = *hashvar(name) ; v ; v = v->next) {
416 if (varequal(v->text, name)) {
417 if ((v->flags & VUNSET)
418 || (!doall && (v->flags & VEXPORT) == 0))
419 return NULL;
420 return strchr(v->text, '=') + 1;
421 }
422 }
423 return NULL;
424}
425
426
427
428/*
429 * Generate a list of exported variables. This routine is used to construct
430 * the third argument to execve when executing a program.
431 */
432
433char **
434environment(void)
435{
436 int nenv;
437 struct var **vpp;
438 struct var *vp;
439 char **env, **ep;
440
441 nenv = 0;
442 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
443 for (vp = *vpp ; vp ; vp = vp->next)
444 if (vp->flags & VEXPORT)
445 nenv++;
446 }
447 ep = env = stalloc((nenv + 1) * sizeof *env);
448 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
449 for (vp = *vpp ; vp ; vp = vp->next)
450 if (vp->flags & VEXPORT)
451 *ep++ = vp->text;
452 }
453 *ep = NULL;
454 return env;
455}
456
457
458/*
459 * Called when a shell procedure is invoked to clear out nonexported
460 * variables. It is also necessary to reallocate variables of with
461 * VSTACK set since these are currently allocated on the stack.
462 */
463
464#ifdef mkinit
465MKINIT void shprocvar();
466
467SHELLPROC {
468 shprocvar();
469}
470#endif
471
472void
473shprocvar(void)
474{
475 struct var **vpp;
476 struct var *vp, **prev;
477
478 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
479 for (prev = vpp ; (vp = *prev) != NULL ; ) {
480 if ((vp->flags & VEXPORT) == 0) {
481 *prev = vp->next;
482 if ((vp->flags & VTEXTFIXED) == 0)
483 ckfree(vp->text);
484 if ((vp->flags & VSTRFIXED) == 0)
485 ckfree(vp);
486 } else {
487 if (vp->flags & VSTACK) {
488 vp->text = savestr(vp->text);
489 vp->flags &=~ VSTACK;
490 }
491 prev = &vp->next;
492 }
493 }
494 }
495 initvar();
496}
497
498
499
500/*
501 * Command to list all variables which are set. Currently this command
502 * is invoked from the set command when the set command is called without
503 * any variables.
504 */
505
506int
507showvarscmd(int argc __unused, char **argv __unused)
508{
509 struct var **vpp;
510 struct var *vp;
511 const char *s;
512
513 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
514 for (vp = *vpp ; vp ; vp = vp->next) {
515 if (vp->flags & VUNSET)
516 continue;
517 for (s = vp->text; *s != '='; s++)
518 out1c(*s);
519 out1c('=');
520 out1qstr(s + 1);
521 out1c('\n');
522 }
523 }
524 return 0;
525}
526
527
528
529/*
530 * The export and readonly commands.
531 */
532
533int
534exportcmd(int argc, char **argv)
535{
536 struct var **vpp;
537 struct var *vp;
538 char *name;
539 char *p;
540 char *cmdname;
541 int ch, values;
542 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
543
544 cmdname = argv[0];
545 optreset = optind = 1;
546 opterr = 0;
547 values = 0;
548 while ((ch = getopt(argc, argv, "p")) != -1) {
549 switch (ch) {
550 case 'p':
551 values = 1;
552 break;
553 case '?':
554 default:
555 error("unknown option: -%c", optopt);
556 }
557 }
558 argc -= optind;
559 argv += optind;
560
561 listsetvar(cmdenviron);
562 if (argc != 0) {
563 while ((name = *argptr++) != NULL) {
564 if ((p = strchr(name, '=')) != NULL) {
565 p++;
566 } else {
567 vpp = hashvar(name);
568 for (vp = *vpp ; vp ; vp = vp->next) {
569 if (varequal(vp->text, name)) {
570
571 vp->flags |= flag;
572 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
573 putenv(vp->text);
574 (void) setlocale(LC_ALL, "");
575 }
576 goto found;
577 }
578 }
579 }
580 setvar(name, p, flag);
581found:;
582 }
583 } else {
584 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
585 for (vp = *vpp ; vp ; vp = vp->next) {
586 if (vp->flags & flag) {
587 if (values) {
588 out1str(cmdname);
589 out1c(' ');
590 }
591 for (p = vp->text ; *p != '=' ; p++)
592 out1c(*p);
593 if (values && !(vp->flags & VUNSET)) {
594 out1c('=');
595 out1qstr(p + 1);
596 }
597 out1c('\n');
598 }
599 }
600 }
601 }
602 return 0;
603}
604
605
606/*
607 * The "local" command.
608 */
609
610int
611localcmd(int argc __unused, char **argv __unused)
612{
613 char *name;
614
615 if (! in_function())
616 error("Not in a function");
617 while ((name = *argptr++) != NULL) {
618 mklocal(name);
619 }
620 return 0;
621}
622
623
624/*
625 * Make a variable a local variable. When a variable is made local, it's
626 * value and flags are saved in a localvar structure. The saved values
627 * will be restored when the shell function returns. We handle the name
628 * "-" as a special case.
629 */
630
631void
632mklocal(char *name)
633{
634 struct localvar *lvp;
635 struct var **vpp;
636 struct var *vp;
637
638 INTOFF;
639 lvp = ckmalloc(sizeof (struct localvar));
640 if (name[0] == '-' && name[1] == '\0') {
641 lvp->text = ckmalloc(sizeof optlist);
642 memcpy(lvp->text, optlist, sizeof optlist);
643 vp = NULL;
644 } else {
645 vpp = hashvar(name);
646 for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
647 if (vp == NULL) {
648 if (strchr(name, '='))
649 setvareq(savestr(name), VSTRFIXED);
650 else
651 setvar(name, NULL, VSTRFIXED);
652 vp = *vpp; /* the new variable */
653 lvp->text = NULL;
654 lvp->flags = VUNSET;
655 } else {
656 lvp->text = vp->text;
657 lvp->flags = vp->flags;
658 vp->flags |= VSTRFIXED|VTEXTFIXED;
659 if (strchr(name, '='))
660 setvareq(savestr(name), 0);
661 }
662 }
663 lvp->vp = vp;
664 lvp->next = localvars;
665 localvars = lvp;
666 INTON;
667}
668
669
670/*
671 * Called after a function returns.
672 */
673
674void
675poplocalvars(void)
676{
677 struct localvar *lvp;
678 struct var *vp;
679
680 while ((lvp = localvars) != NULL) {
681 localvars = lvp->next;
682 vp = lvp->vp;
683 if (vp == NULL) { /* $- saved */
684 memcpy(optlist, lvp->text, sizeof optlist);
685 ckfree(lvp->text);
686 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
687 (void)unsetvar(vp->text);
688 } else {
689 if ((vp->flags & VTEXTFIXED) == 0)
690 ckfree(vp->text);
691 vp->flags = lvp->flags;
692 vp->text = lvp->text;
693 }
694 ckfree(lvp);
695 }
696}
697
698
699int
700setvarcmd(int argc, char **argv)
701{
702 if (argc <= 2)
703 return unsetcmd(argc, argv);
704 else if (argc == 3)
705 setvar(argv[1], argv[2], 0);
706 else
707 error("List assignment not implemented");
708 return 0;
709}
710
711
712/*
713 * The unset builtin command. We unset the function before we unset the
714 * variable to allow a function to be unset when there is a readonly variable
715 * with the same name.
716 */
717
718int
719unsetcmd(int argc __unused, char **argv __unused)
720{
721 char **ap;
722 int i;
723 int flg_func = 0;
724 int flg_var = 0;
725 int ret = 0;
726
727 while ((i = nextopt("vf")) != '\0') {
728 if (i == 'f')
729 flg_func = 1;
730 else
731 flg_var = 1;
732 }
733 if (flg_func == 0 && flg_var == 0)
734 flg_var = 1;
735
736 for (ap = argptr; *ap ; ap++) {
737 if (flg_func)
738 ret |= unsetfunc(*ap);
739 if (flg_var)
740 ret |= unsetvar(*ap);
741 }
742 return ret;
743}
744
745
746/*
747 * Unset the specified variable.
748 */
749
750int
751unsetvar(char *s)
752{
753 struct var **vpp;
754 struct var *vp;
755
756 vpp = hashvar(s);
757 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
758 if (varequal(vp->text, s)) {
759 if (vp->flags & VREADONLY)
760 return (1);
761 INTOFF;
762 if (*(strchr(vp->text, '=') + 1) != '\0')
763 setvar(s, nullstr, 0);
764 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
765 unsetenv(s);
766 setlocale(LC_ALL, "");
767 }
768 vp->flags &= ~VEXPORT;
769 vp->flags |= VUNSET;
770 if ((vp->flags & VSTRFIXED) == 0) {
771 if ((vp->flags & VTEXTFIXED) == 0)
772 ckfree(vp->text);
773 *vpp = vp->next;
774 ckfree(vp);
775 }
776 INTON;
777 return (0);
778 }
779 }
780
781 return (1);
782}
783
784
785
786/*
787 * Find the appropriate entry in the hash table from the name.
788 */
789
790STATIC struct var **
791hashvar(char *p)
792{
793 unsigned int hashval;
794
795 hashval = ((unsigned char) *p) << 4;
796 while (*p && *p != '=')
797 hashval += (unsigned char) *p++;
798 return &vartab[hashval % VTABSIZE];
799}
800
801
802
803/*
804 * Returns true if the two strings specify the same varable. The first
805 * variable name is terminated by '='; the second may be terminated by
806 * either '=' or '\0'.
807 */
808
809STATIC int
810varequal(char *p, char *q)
811{
812 while (*p == *q++) {
813 if (*p++ == '=')
814 return 1;
815 }
816 if (*p == '=' && *(q - 1) == '\0')
817 return 1;
818 return 0;
819}