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
35 static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95";
36 #endif
37 #endif /* not lint */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
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 #include <langinfo.h>
51
52 #include "shell.h"
53 #include "output.h"
54 #include "expand.h"
55 #include "nodes.h" /* for other headers */
56 #include "eval.h" /* defines cmdenviron */
57 #include "exec.h"
58 #include "syntax.h"
59 #include "options.h"
60 #include "mail.h"
61 #include "var.h"
62 #include "memalloc.h"
63 #include "error.h"
64 #include "mystring.h"
65 #include "parser.h"
66 #include "builtins.h"
67 #ifndef NO_HISTORY
68 #include "myhistedit.h"
69 #endif
70
71
72 #define VTABSIZE 39
73
74
75 struct varinit {
76 struct var *var;
77 int flags;
78 const char *text;
79 void (*func)(const char *);
80 };
81
82
83 #ifndef NO_HISTORY
84 struct var vhistsize;
85 struct var vterm;
86 #endif
87 struct var vifs;
88 struct var vmail;
89 struct var vmpath;
90 struct var vpath;
91 struct var vps1;
92 struct var vps2;
93 struct var vps4;
94 static struct var voptind;
95 struct var vdisvfork;
96
97 struct localvar *localvars;
98 int forcelocal;
99
100 static const struct varinit varinit[] = {
101 #ifndef NO_HISTORY
102 { &vhistsize, VUNSET, "HISTSIZE=",
103 sethistsize },
104 #endif
105 { &vifs, 0, "IFS= \t\n",
106 NULL },
107 { &vmail, VUNSET, "MAIL=",
108 NULL },
109 { &vmpath, VUNSET, "MAILPATH=",
110 NULL },
111 { &vpath, 0, "PATH=" _PATH_DEFPATH,
112 changepath },
113 /*
114 * vps1 depends on uid
115 */
116 { &vps2, 0, "PS2=> ",
117 NULL },
118 { &vps4, 0, "PS4=+ ",
119 NULL },
120 #ifndef NO_HISTORY
121 { &vterm, VUNSET, "TERM=",
122 setterm },
123 #endif
124 { &voptind, 0, "OPTIND=1",
125 getoptsreset },
126 { &vdisvfork, VUNSET, "SH_DISABLE_VFORK=",
127 NULL },
128 { NULL, 0, NULL,
129 NULL }
130 };
131
132 static struct var *vartab[VTABSIZE];
133
134 static const char *const locale_names[7] = {
135 "LC_COLLATE", "LC_CTYPE", "LC_MONETARY",
136 "LC_NUMERIC", "LC_TIME", "LC_MESSAGES", NULL
137 };
138 static const int locale_categories[7] = {
139 LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME, LC_MESSAGES, 0
140 };
141
142 static int varequal(const char *, const char *);
143 static struct var *find_var(const char *, struct var ***, int *);
144 static int localevar(const char *);
145 static void setvareq_const(const char *s, int flags);
146
147 extern char **environ;
148
149 /*
150 * This routine initializes the builtin variables and imports the environment.
151 * It is called when the shell is initialized.
152 */
153
154 void
initvar(void)155 initvar(void)
156 {
157 char ppid[20];
158 const struct varinit *ip;
159 struct var *vp;
160 struct var **vpp;
161 char **envp;
162
163 for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
164 if (find_var(ip->text, &vpp, &vp->name_len) != NULL)
165 continue;
166 vp->next = *vpp;
167 *vpp = vp;
168 vp->text = __DECONST(char *, ip->text);
169 vp->flags = ip->flags | VSTRFIXED | VTEXTFIXED;
170 vp->func = ip->func;
171 }
172 /*
173 * PS1 depends on uid
174 */
175 if (find_var("PS1", &vpp, &vps1.name_len) == NULL) {
176 vps1.next = *vpp;
177 *vpp = &vps1;
178 vps1.text = __DECONST(char *, geteuid() ? "PS1=$ " : "PS1=# ");
179 vps1.flags = VSTRFIXED|VTEXTFIXED;
180 }
181 fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
182 setvarsafe("PPID", ppid, 0);
183 for (envp = environ ; *envp ; envp++) {
184 if (strchr(*envp, '=')) {
185 setvareq(*envp, VEXPORT|VTEXTFIXED);
186 }
187 }
188 setvareq_const("OPTIND=1", 0);
189 }
190
191 /*
192 * Safe version of setvar, returns 1 on success 0 on failure.
193 */
194
195 int
setvarsafe(const char * name,const char * val,int flags)196 setvarsafe(const char *name, const char *val, int flags)
197 {
198 struct jmploc jmploc;
199 struct jmploc *const savehandler = handler;
200 int err = 0;
201 int inton;
202
203 inton = is_int_on();
204 if (setjmp(jmploc.loc))
205 err = 1;
206 else {
207 handler = &jmploc;
208 setvar(name, val, flags);
209 }
210 handler = savehandler;
211 SETINTON(inton);
212 return err;
213 }
214
215 /*
216 * Set the value of a variable. The flags argument is stored with the
217 * flags of the variable. If val is NULL, the variable is unset.
218 */
219
220 void
setvar(const char * name,const char * val,int flags)221 setvar(const char *name, const char *val, int flags)
222 {
223 const char *p;
224 size_t len;
225 size_t namelen;
226 size_t vallen;
227 char *nameeq;
228 int isbad;
229
230 isbad = 0;
231 p = name;
232 if (! is_name(*p))
233 isbad = 1;
234 p++;
235 for (;;) {
236 if (! is_in_name(*p)) {
237 if (*p == '\0' || *p == '=')
238 break;
239 isbad = 1;
240 }
241 p++;
242 }
243 namelen = p - name;
244 if (isbad)
245 error("%.*s: bad variable name", (int)namelen, name);
246 len = namelen + 2; /* 2 is space for '=' and '\0' */
247 if (val == NULL) {
248 flags |= VUNSET;
249 vallen = 0;
250 } else {
251 vallen = strlen(val);
252 len += vallen;
253 }
254 INTOFF;
255 nameeq = ckmalloc(len);
256 memcpy(nameeq, name, namelen);
257 nameeq[namelen] = '=';
258 if (val)
259 memcpy(nameeq + namelen + 1, val, vallen + 1);
260 else
261 nameeq[namelen + 1] = '\0';
262 setvareq(nameeq, flags);
263 INTON;
264 }
265
266 static int
localevar(const char * s)267 localevar(const char *s)
268 {
269 const char *const *ss;
270
271 if (*s != 'L')
272 return 0;
273 if (varequal(s + 1, "ANG"))
274 return 1;
275 if (strncmp(s + 1, "C_", 2) != 0)
276 return 0;
277 if (varequal(s + 3, "ALL"))
278 return 1;
279 for (ss = locale_names; *ss ; ss++)
280 if (varequal(s + 3, *ss + 3))
281 return 1;
282 return 0;
283 }
284
285
286 /*
287 * Sets/unsets an environment variable from a pointer that may actually be a
288 * pointer into environ where the string should not be manipulated.
289 */
290 static void
change_env(const char * s,int set)291 change_env(const char *s, int set)
292 {
293 char *eqp;
294 char *ss;
295
296 INTOFF;
297 ss = savestr(s);
298 if ((eqp = strchr(ss, '=')) != NULL)
299 *eqp = '\0';
300 if (set && eqp != NULL)
301 (void) setenv(ss, eqp + 1, 1);
302 else
303 (void) unsetenv(ss);
304 ckfree(ss);
305 INTON;
306
307 return;
308 }
309
310
311 /*
312 * Same as setvar except that the variable and value are passed in
313 * the first argument as name=value. Since the first argument will
314 * be actually stored in the table, it should not be a string that
315 * will go away.
316 */
317
318 void
setvareq(char * s,int flags)319 setvareq(char *s, int flags)
320 {
321 struct var *vp, **vpp;
322 int nlen;
323
324 if (aflag)
325 flags |= VEXPORT;
326 if (forcelocal && !(flags & (VNOSET | VNOLOCAL)))
327 mklocal(s);
328 vp = find_var(s, &vpp, &nlen);
329 if (vp != NULL) {
330 if (vp->flags & VREADONLY) {
331 if ((flags & (VTEXTFIXED|VSTACK)) == 0)
332 ckfree(s);
333 error("%.*s: is read only", vp->name_len, vp->text);
334 }
335 if (flags & VNOSET) {
336 if ((flags & (VTEXTFIXED|VSTACK)) == 0)
337 ckfree(s);
338 return;
339 }
340 INTOFF;
341
342 if (vp->func && (flags & VNOFUNC) == 0)
343 (*vp->func)(s + vp->name_len + 1);
344
345 if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
346 ckfree(vp->text);
347
348 vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
349 vp->flags |= flags;
350 vp->text = s;
351
352 /*
353 * We could roll this to a function, to handle it as
354 * a regular variable function callback, but why bother?
355 *
356 * Note: this assumes iflag is not set to 1 initially.
357 * As part of initvar(), this is called before arguments
358 * are looked at.
359 */
360 if ((vp == &vmpath || (vp == &vmail && ! mpathset())) &&
361 iflag == 1)
362 chkmail(1);
363 if ((vp->flags & VEXPORT) && localevar(s)) {
364 change_env(s, 1);
365 (void) setlocale(LC_ALL, "");
366 updatecharset();
367 }
368 INTON;
369 return;
370 }
371 /* not found */
372 if (flags & VNOSET) {
373 if ((flags & (VTEXTFIXED|VSTACK)) == 0)
374 ckfree(s);
375 return;
376 }
377 INTOFF;
378 vp = ckmalloc(sizeof (*vp));
379 vp->flags = flags;
380 vp->text = s;
381 vp->name_len = nlen;
382 vp->next = *vpp;
383 vp->func = NULL;
384 *vpp = vp;
385 if ((vp->flags & VEXPORT) && localevar(s)) {
386 change_env(s, 1);
387 (void) setlocale(LC_ALL, "");
388 updatecharset();
389 }
390 INTON;
391 }
392
393
394 static void
setvareq_const(const char * s,int flags)395 setvareq_const(const char *s, int flags)
396 {
397 setvareq(__DECONST(char *, s), flags | VTEXTFIXED);
398 }
399
400
401 /*
402 * Process a linked list of variable assignments.
403 */
404
405 void
listsetvar(struct arglist * list,int flags)406 listsetvar(struct arglist *list, int flags)
407 {
408 int i;
409
410 INTOFF;
411 for (i = 0; i < list->count; i++)
412 setvareq(savestr(list->args[i]), flags);
413 INTON;
414 }
415
416
417
418 /*
419 * Find the value of a variable. Returns NULL if not set.
420 */
421
422 char *
lookupvar(const char * name)423 lookupvar(const char *name)
424 {
425 struct var *v;
426
427 v = find_var(name, NULL, NULL);
428 if (v == NULL || v->flags & VUNSET)
429 return NULL;
430 return v->text + v->name_len + 1;
431 }
432
433
434
435 /*
436 * Search the environment of a builtin command. If the second argument
437 * is nonzero, return the value of a variable even if it hasn't been
438 * exported.
439 */
440
441 char *
bltinlookup(const char * name,int doall)442 bltinlookup(const char *name, int doall)
443 {
444 struct var *v;
445 char *result;
446 int i;
447
448 result = NULL;
449 if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) {
450 if (varequal(cmdenviron->args[i], name))
451 result = strchr(cmdenviron->args[i], '=') + 1;
452 }
453 if (result != NULL)
454 return result;
455
456 v = find_var(name, NULL, NULL);
457 if (v == NULL || v->flags & VUNSET ||
458 (!doall && (v->flags & VEXPORT) == 0))
459 return NULL;
460 return v->text + v->name_len + 1;
461 }
462
463
464 /*
465 * Set up locale for a builtin (LANG/LC_* assignments).
466 */
467 void
bltinsetlocale(void)468 bltinsetlocale(void)
469 {
470 int act = 0;
471 char *loc, *locdef;
472 int i;
473
474 if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) {
475 if (localevar(cmdenviron->args[i])) {
476 act = 1;
477 break;
478 }
479 }
480 if (!act)
481 return;
482 loc = bltinlookup("LC_ALL", 0);
483 INTOFF;
484 if (loc != NULL) {
485 setlocale(LC_ALL, loc);
486 INTON;
487 updatecharset();
488 return;
489 }
490 locdef = bltinlookup("LANG", 0);
491 for (i = 0; locale_names[i] != NULL; i++) {
492 loc = bltinlookup(locale_names[i], 0);
493 if (loc == NULL)
494 loc = locdef;
495 if (loc != NULL)
496 setlocale(locale_categories[i], loc);
497 }
498 INTON;
499 updatecharset();
500 }
501
502 /*
503 * Undo the effect of bltinlocaleset().
504 */
505 void
bltinunsetlocale(void)506 bltinunsetlocale(void)
507 {
508 int i;
509
510 INTOFF;
511 if (cmdenviron) for (i = 0; i < cmdenviron->count; i++) {
512 if (localevar(cmdenviron->args[i])) {
513 setlocale(LC_ALL, "");
514 updatecharset();
515 return;
516 }
517 }
518 INTON;
519 }
520
521 /*
522 * Update the localeisutf8 flag.
523 */
524 void
updatecharset(void)525 updatecharset(void)
526 {
527 char *charset;
528
529 charset = nl_langinfo(CODESET);
530 localeisutf8 = !strcmp(charset, "UTF-8");
531 }
532
533 void
initcharset(void)534 initcharset(void)
535 {
536 updatecharset();
537 initial_localeisutf8 = localeisutf8;
538 }
539
540 /*
541 * Generate a list of exported variables. This routine is used to construct
542 * the third argument to execve when executing a program.
543 */
544
545 char **
environment(void)546 environment(void)
547 {
548 int nenv;
549 struct var **vpp;
550 struct var *vp;
551 char **env, **ep;
552
553 nenv = 0;
554 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
555 for (vp = *vpp ; vp ; vp = vp->next)
556 if (vp->flags & VEXPORT)
557 nenv++;
558 }
559 ep = env = stalloc((nenv + 1) * sizeof *env);
560 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
561 for (vp = *vpp ; vp ; vp = vp->next)
562 if (vp->flags & VEXPORT)
563 *ep++ = vp->text;
564 }
565 *ep = NULL;
566 return env;
567 }
568
569
570 static int
var_compare(const void * a,const void * b)571 var_compare(const void *a, const void *b)
572 {
573 const char *const *sa, *const *sb;
574
575 sa = a;
576 sb = b;
577 /*
578 * This compares two var=value strings which creates a different
579 * order from what you would probably expect. POSIX is somewhat
580 * ambiguous on what should be sorted exactly.
581 */
582 return strcoll(*sa, *sb);
583 }
584
585
586 /*
587 * Command to list all variables which are set. This is invoked from the
588 * set command when it is called without any options or operands.
589 */
590
591 int
showvarscmd(int argc __unused,char ** argv __unused)592 showvarscmd(int argc __unused, char **argv __unused)
593 {
594 struct var **vpp;
595 struct var *vp;
596 const char *s;
597 const char **vars;
598 int i, n;
599
600 /*
601 * POSIX requires us to sort the variables.
602 */
603 n = 0;
604 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
605 for (vp = *vpp; vp; vp = vp->next) {
606 if (!(vp->flags & VUNSET))
607 n++;
608 }
609 }
610
611 INTOFF;
612 vars = ckmalloc(n * sizeof(*vars));
613 i = 0;
614 for (vpp = vartab; vpp < vartab + VTABSIZE; vpp++) {
615 for (vp = *vpp; vp; vp = vp->next) {
616 if (!(vp->flags & VUNSET))
617 vars[i++] = vp->text;
618 }
619 }
620
621 qsort(vars, n, sizeof(*vars), var_compare);
622 for (i = 0; i < n; i++) {
623 /*
624 * Skip improper variable names so the output remains usable as
625 * shell input.
626 */
627 if (!isassignment(vars[i]))
628 continue;
629 s = strchr(vars[i], '=');
630 s++;
631 outbin(vars[i], s - vars[i], out1);
632 out1qstr(s);
633 out1c('\n');
634 }
635 ckfree(vars);
636 INTON;
637
638 return 0;
639 }
640
641
642
643 /*
644 * The export and readonly commands.
645 */
646
647 int
exportcmd(int argc __unused,char ** argv)648 exportcmd(int argc __unused, char **argv)
649 {
650 struct var **vpp;
651 struct var *vp;
652 char **ap;
653 char *name;
654 char *p;
655 char *cmdname;
656 int ch, values;
657 int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
658
659 cmdname = argv[0];
660 values = 0;
661 while ((ch = nextopt("p")) != '\0') {
662 switch (ch) {
663 case 'p':
664 values = 1;
665 break;
666 }
667 }
668
669 if (values && *argptr != NULL)
670 error("-p requires no arguments");
671 if (*argptr != NULL) {
672 for (ap = argptr; (name = *ap) != NULL; ap++) {
673 if ((p = strchr(name, '=')) != NULL) {
674 p++;
675 } else {
676 vp = find_var(name, NULL, NULL);
677 if (vp != NULL) {
678 vp->flags |= flag;
679 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
680 change_env(vp->text, 1);
681 (void) setlocale(LC_ALL, "");
682 updatecharset();
683 }
684 continue;
685 }
686 }
687 setvar(name, p, flag);
688 }
689 } else {
690 for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
691 for (vp = *vpp ; vp ; vp = vp->next) {
692 if (vp->flags & flag) {
693 if (values) {
694 /*
695 * Skip improper variable names
696 * so the output remains usable
697 * as shell input.
698 */
699 if (!isassignment(vp->text))
700 continue;
701 out1str(cmdname);
702 out1c(' ');
703 }
704 if (values && !(vp->flags & VUNSET)) {
705 outbin(vp->text,
706 vp->name_len + 1, out1);
707 out1qstr(vp->text +
708 vp->name_len + 1);
709 } else
710 outbin(vp->text, vp->name_len,
711 out1);
712 out1c('\n');
713 }
714 }
715 }
716 }
717 return 0;
718 }
719
720
721 /*
722 * The "local" command.
723 */
724
725 int
localcmd(int argc __unused,char ** argv __unused)726 localcmd(int argc __unused, char **argv __unused)
727 {
728 char *name;
729
730 nextopt("");
731 if (! in_function())
732 error("Not in a function");
733 while ((name = *argptr++) != NULL) {
734 mklocal(name);
735 }
736 return 0;
737 }
738
739
740 /*
741 * Make a variable a local variable. When a variable is made local, it's
742 * value and flags are saved in a localvar structure. The saved values
743 * will be restored when the shell function returns. We handle the name
744 * "-" as a special case.
745 */
746
747 void
mklocal(char * name)748 mklocal(char *name)
749 {
750 struct localvar *lvp;
751 struct var **vpp;
752 struct var *vp;
753
754 INTOFF;
755 lvp = ckmalloc(sizeof (struct localvar));
756 if (name[0] == '-' && name[1] == '\0') {
757 lvp->text = ckmalloc(sizeof optval);
758 memcpy(lvp->text, optval, sizeof optval);
759 vp = NULL;
760 } else {
761 vp = find_var(name, &vpp, NULL);
762 if (vp == NULL) {
763 if (strchr(name, '='))
764 setvareq(savestr(name), VSTRFIXED | VNOLOCAL);
765 else
766 setvar(name, NULL, VSTRFIXED | VNOLOCAL);
767 vp = *vpp; /* the new variable */
768 lvp->text = NULL;
769 lvp->flags = VUNSET;
770 } else {
771 lvp->text = vp->text;
772 lvp->flags = vp->flags;
773 vp->flags |= VSTRFIXED|VTEXTFIXED;
774 if (name[vp->name_len] == '=')
775 setvareq(savestr(name), VNOLOCAL);
776 }
777 }
778 lvp->vp = vp;
779 lvp->next = localvars;
780 localvars = lvp;
781 INTON;
782 }
783
784
785 /*
786 * Called after a function returns.
787 */
788
789 void
poplocalvars(void)790 poplocalvars(void)
791 {
792 struct localvar *lvp;
793 struct var *vp;
794 int islocalevar;
795
796 INTOFF;
797 while ((lvp = localvars) != NULL) {
798 localvars = lvp->next;
799 vp = lvp->vp;
800 if (vp == NULL) { /* $- saved */
801 memcpy(optval, lvp->text, sizeof optval);
802 ckfree(lvp->text);
803 optschanged();
804 } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
805 (void)unsetvar(vp->text);
806 } else {
807 islocalevar = (vp->flags | lvp->flags) & VEXPORT &&
808 localevar(lvp->text);
809 if ((vp->flags & VTEXTFIXED) == 0)
810 ckfree(vp->text);
811 vp->flags = lvp->flags;
812 vp->text = lvp->text;
813 if (vp->func)
814 (*vp->func)(vp->text + vp->name_len + 1);
815 if (islocalevar) {
816 change_env(vp->text, vp->flags & VEXPORT &&
817 (vp->flags & VUNSET) == 0);
818 setlocale(LC_ALL, "");
819 updatecharset();
820 }
821 }
822 ckfree(lvp);
823 }
824 INTON;
825 }
826
827
828 int
setvarcmd(int argc,char ** argv)829 setvarcmd(int argc, char **argv)
830 {
831 if (argc <= 2)
832 return unsetcmd(argc, argv);
833 else if (argc == 3)
834 setvar(argv[1], argv[2], 0);
835 else
836 error("too many arguments");
837 return 0;
838 }
839
840
841 /*
842 * The unset builtin command.
843 */
844
845 int
unsetcmd(int argc __unused,char ** argv __unused)846 unsetcmd(int argc __unused, char **argv __unused)
847 {
848 char **ap;
849 int i;
850 int flg_func = 0;
851 int flg_var = 0;
852 int ret = 0;
853
854 while ((i = nextopt("vf")) != '\0') {
855 if (i == 'f')
856 flg_func = 1;
857 else
858 flg_var = 1;
859 }
860 if (flg_func == 0 && flg_var == 0)
861 flg_var = 1;
862
863 INTOFF;
864 for (ap = argptr; *ap ; ap++) {
865 if (flg_func)
866 ret |= unsetfunc(*ap);
867 if (flg_var)
868 ret |= unsetvar(*ap);
869 }
870 INTON;
871 return ret;
872 }
873
874
875 /*
876 * Unset the specified variable.
877 * Called with interrupts off.
878 */
879
880 int
unsetvar(const char * s)881 unsetvar(const char *s)
882 {
883 struct var **vpp;
884 struct var *vp;
885
886 vp = find_var(s, &vpp, NULL);
887 if (vp == NULL)
888 return (0);
889 if (vp->flags & VREADONLY)
890 return (1);
891 if (vp->text[vp->name_len + 1] != '\0')
892 setvar(s, "", 0);
893 if ((vp->flags & VEXPORT) && localevar(vp->text)) {
894 change_env(s, 0);
895 setlocale(LC_ALL, "");
896 updatecharset();
897 }
898 vp->flags &= ~VEXPORT;
899 vp->flags |= VUNSET;
900 if ((vp->flags & VSTRFIXED) == 0) {
901 if ((vp->flags & VTEXTFIXED) == 0)
902 ckfree(vp->text);
903 *vpp = vp->next;
904 ckfree(vp);
905 }
906 return (0);
907 }
908
909
910
911 /*
912 * Returns true if the two strings specify the same variable. The first
913 * variable name is terminated by '='; the second may be terminated by
914 * either '=' or '\0'.
915 */
916
917 static int
varequal(const char * p,const char * q)918 varequal(const char *p, const char *q)
919 {
920 while (*p == *q++) {
921 if (*p++ == '=')
922 return 1;
923 }
924 if (*p == '=' && *(q - 1) == '\0')
925 return 1;
926 return 0;
927 }
928
929 /*
930 * Search for a variable.
931 * 'name' may be terminated by '=' or a NUL.
932 * vppp is set to the pointer to vp, or the list head if vp isn't found
933 * lenp is set to the number of characters in 'name'
934 */
935
936 static struct var *
find_var(const char * name,struct var *** vppp,int * lenp)937 find_var(const char *name, struct var ***vppp, int *lenp)
938 {
939 unsigned int hashval;
940 int len;
941 struct var *vp, **vpp;
942 const char *p = name;
943
944 hashval = 0;
945 while (*p && *p != '=')
946 hashval = 2 * hashval + (unsigned char)*p++;
947 len = p - name;
948
949 if (lenp)
950 *lenp = len;
951 vpp = &vartab[hashval % VTABSIZE];
952 if (vppp)
953 *vppp = vpp;
954
955 for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
956 if (vp->name_len != len)
957 continue;
958 if (memcmp(vp->text, name, len) != 0)
959 continue;
960 if (vppp)
961 *vppp = vpp;
962 return vp;
963 }
964 return NULL;
965 }
966