Commit | Line | Data |
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8f1981e0 | 1 | /*- |
d1b73048 KB |
2 | * Copyright (c) 1991, 1993 |
3 | * The Regents of the University of California. All rights reserved. | |
8f1981e0 KB |
4 | * |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Kenneth Almquist. | |
7 | * | |
ad787160 C |
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. | |
8f1981e0 KB |
35 | */ |
36 | ||
37 | #ifndef lint | |
fd88f5c5 | 38 | static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95"; |
8f1981e0 KB |
39 | #endif /* not lint */ |
40 | ||
13b3e634 CZ |
41 | #include <unistd.h> |
42 | #include <stdlib.h> | |
43 | ||
8f1981e0 KB |
44 | /* |
45 | * Shell variables. | |
46 | */ | |
47 | ||
8f1981e0 KB |
48 | #include "shell.h" |
49 | #include "output.h" | |
50 | #include "expand.h" | |
51 | #include "nodes.h" /* for other headers */ | |
52 | #include "eval.h" /* defines cmdenviron */ | |
53 | #include "exec.h" | |
54 | #include "syntax.h" | |
55 | #include "options.h" | |
56 | #include "mail.h" | |
57 | #include "var.h" | |
58 | #include "memalloc.h" | |
59 | #include "error.h" | |
60 | #include "mystring.h" | |
13b3e634 CZ |
61 | #ifndef NO_HISTORY |
62 | #include "myhistedit.h" | |
63 | #endif | |
8f1981e0 KB |
64 | |
65 | ||
66 | #define VTABSIZE 39 | |
67 | ||
68 | ||
69 | struct varinit { | |
70 | struct var *var; | |
71 | int flags; | |
72 | char *text; | |
73 | }; | |
74 | ||
75 | ||
76 | #if ATTY | |
77 | struct var vatty; | |
78 | #endif | |
13b3e634 | 79 | #ifndef NO_HISTORY |
1da339d9 | 80 | struct var vhistsize; |
13b3e634 | 81 | #endif |
8f1981e0 KB |
82 | struct var vifs; |
83 | struct var vmail; | |
84 | struct var vmpath; | |
85 | struct var vpath; | |
86 | struct var vps1; | |
87 | struct var vps2; | |
88 | struct var vvers; | |
89 | #if ATTY | |
90 | struct var vterm; | |
91 | #endif | |
92 | ||
93 | const struct varinit varinit[] = { | |
94 | #if ATTY | |
95 | {&vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY="}, | |
96 | #endif | |
13b3e634 | 97 | #ifndef NO_HISTORY |
1da339d9 | 98 | {&vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE="}, |
13b3e634 | 99 | #endif |
8f1981e0 KB |
100 | {&vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n"}, |
101 | {&vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL="}, | |
102 | {&vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH="}, | |
13b3e634 | 103 | {&vpath, VSTRFIXED|VTEXTFIXED, "PATH=/bin:/usr/bin"}, |
913003f6 MT |
104 | /* |
105 | * vps1 depends on uid | |
106 | */ | |
8f1981e0 | 107 | {&vps2, VSTRFIXED|VTEXTFIXED, "PS2=> "}, |
8f1981e0 KB |
108 | #if ATTY |
109 | {&vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM="}, | |
110 | #endif | |
111 | {NULL, 0, NULL} | |
112 | }; | |
113 | ||
114 | struct var *vartab[VTABSIZE]; | |
115 | ||
e6fa84d4 | 116 | STATIC int unsetvar __P((char *)); |
913003f6 MT |
117 | STATIC struct var **hashvar __P((char *)); |
118 | STATIC int varequal __P((char *, char *)); | |
8f1981e0 KB |
119 | |
120 | /* | |
121 | * Initialize the varable symbol tables and import the environment | |
122 | */ | |
123 | ||
124 | #ifdef mkinit | |
125 | INCLUDE "var.h" | |
126 | INIT { | |
127 | char **envp; | |
128 | extern char **environ; | |
129 | ||
130 | initvar(); | |
131 | for (envp = environ ; *envp ; envp++) { | |
132 | if (strchr(*envp, '=')) { | |
133 | setvareq(*envp, VEXPORT|VTEXTFIXED); | |
134 | } | |
135 | } | |
136 | } | |
137 | #endif | |
138 | ||
139 | ||
140 | /* | |
141 | * This routine initializes the builtin variables. It is called when the | |
142 | * shell is initialized and again when a shell procedure is spawned. | |
143 | */ | |
144 | ||
145 | void | |
146 | initvar() { | |
147 | const struct varinit *ip; | |
148 | struct var *vp; | |
149 | struct var **vpp; | |
150 | ||
151 | for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { | |
152 | if ((vp->flags & VEXPORT) == 0) { | |
153 | vpp = hashvar(ip->text); | |
154 | vp->next = *vpp; | |
155 | *vpp = vp; | |
156 | vp->text = ip->text; | |
157 | vp->flags = ip->flags; | |
158 | } | |
159 | } | |
913003f6 MT |
160 | /* |
161 | * PS1 depends on uid | |
162 | */ | |
163 | if ((vps1.flags & VEXPORT) == 0) { | |
164 | vpp = hashvar("PS1="); | |
165 | vps1.next = *vpp; | |
166 | *vpp = &vps1; | |
d08083e8 | 167 | vps1.text = geteuid() ? "PS1=$ " : "PS1=# "; |
913003f6 MT |
168 | vps1.flags = VSTRFIXED|VTEXTFIXED; |
169 | } | |
ddba57cd | 170 | } |
8f1981e0 KB |
171 | |
172 | /* | |
173 | * Set the value of a variable. The flags argument is ored with the | |
174 | * flags of the variable. If val is NULL, the variable is unset. | |
175 | */ | |
176 | ||
177 | void | |
178 | setvar(name, val, flags) | |
179 | char *name, *val; | |
13b3e634 CZ |
180 | int flags; |
181 | { | |
8f1981e0 KB |
182 | char *p, *q; |
183 | int len; | |
184 | int namelen; | |
185 | char *nameeq; | |
186 | int isbad; | |
187 | ||
188 | isbad = 0; | |
189 | p = name; | |
190 | if (! is_name(*p++)) | |
191 | isbad = 1; | |
192 | for (;;) { | |
193 | if (! is_in_name(*p)) { | |
194 | if (*p == '\0' || *p == '=') | |
195 | break; | |
196 | isbad = 1; | |
197 | } | |
198 | p++; | |
199 | } | |
200 | namelen = p - name; | |
201 | if (isbad) | |
c671e886 | 202 | error("%.*s: bad variable name", namelen, name); |
8f1981e0 KB |
203 | len = namelen + 2; /* 2 is space for '=' and '\0' */ |
204 | if (val == NULL) { | |
205 | flags |= VUNSET; | |
206 | } else { | |
207 | len += strlen(val); | |
208 | } | |
209 | p = nameeq = ckmalloc(len); | |
210 | q = name; | |
211 | while (--namelen >= 0) | |
212 | *p++ = *q++; | |
213 | *p++ = '='; | |
214 | *p = '\0'; | |
215 | if (val) | |
216 | scopy(val, p); | |
217 | setvareq(nameeq, flags); | |
218 | } | |
219 | ||
220 | ||
221 | ||
222 | /* | |
223 | * Same as setvar except that the variable and value are passed in | |
224 | * the first argument as name=value. Since the first argument will | |
225 | * be actually stored in the table, it should not be a string that | |
226 | * will go away. | |
227 | */ | |
228 | ||
229 | void | |
230 | setvareq(s, flags) | |
231 | char *s; | |
13b3e634 CZ |
232 | int flags; |
233 | { | |
8f1981e0 KB |
234 | struct var *vp, **vpp; |
235 | ||
236 | vpp = hashvar(s); | |
237 | for (vp = *vpp ; vp ; vp = vp->next) { | |
238 | if (varequal(s, vp->text)) { | |
239 | if (vp->flags & VREADONLY) { | |
240 | int len = strchr(s, '=') - s; | |
241 | error("%.*s: is read only", len, s); | |
242 | } | |
243 | INTOFF; | |
244 | if (vp == &vpath) | |
245 | changepath(s + 5); /* 5 = strlen("PATH=") */ | |
246 | if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) | |
247 | ckfree(vp->text); | |
248 | vp->flags &=~ (VTEXTFIXED|VSTACK|VUNSET); | |
249 | vp->flags |= flags; | |
250 | vp->text = s; | |
251 | if (vp == &vmpath || (vp == &vmail && ! mpathset())) | |
252 | chkmail(1); | |
13b3e634 | 253 | #ifndef NO_HISTORY |
1da339d9 MT |
254 | if (vp == &vhistsize) |
255 | sethistsize(); | |
13b3e634 | 256 | #endif |
8f1981e0 KB |
257 | INTON; |
258 | return; | |
259 | } | |
260 | } | |
261 | /* not found */ | |
262 | vp = ckmalloc(sizeof (*vp)); | |
263 | vp->flags = flags; | |
264 | vp->text = s; | |
265 | vp->next = *vpp; | |
266 | *vpp = vp; | |
267 | } | |
268 | ||
269 | ||
270 | ||
271 | /* | |
272 | * Process a linked list of variable assignments. | |
273 | */ | |
274 | ||
275 | void | |
276 | listsetvar(list) | |
277 | struct strlist *list; | |
278 | { | |
279 | struct strlist *lp; | |
280 | ||
281 | INTOFF; | |
282 | for (lp = list ; lp ; lp = lp->next) { | |
283 | setvareq(savestr(lp->text), 0); | |
284 | } | |
285 | INTON; | |
286 | } | |
287 | ||
288 | ||
289 | ||
290 | /* | |
291 | * Find the value of a variable. Returns NULL if not set. | |
292 | */ | |
293 | ||
294 | char * | |
295 | lookupvar(name) | |
296 | char *name; | |
297 | { | |
298 | struct var *v; | |
299 | ||
300 | for (v = *hashvar(name) ; v ; v = v->next) { | |
301 | if (varequal(v->text, name)) { | |
302 | if (v->flags & VUNSET) | |
303 | return NULL; | |
304 | return strchr(v->text, '=') + 1; | |
305 | } | |
306 | } | |
307 | return NULL; | |
308 | } | |
309 | ||
310 | ||
311 | ||
312 | /* | |
313 | * Search the environment of a builtin command. If the second argument | |
314 | * is nonzero, return the value of a variable even if it hasn't been | |
315 | * exported. | |
316 | */ | |
317 | ||
318 | char * | |
319 | bltinlookup(name, doall) | |
320 | char *name; | |
13b3e634 CZ |
321 | int doall; |
322 | { | |
8f1981e0 KB |
323 | struct strlist *sp; |
324 | struct var *v; | |
325 | ||
326 | for (sp = cmdenviron ; sp ; sp = sp->next) { | |
327 | if (varequal(sp->text, name)) | |
328 | return strchr(sp->text, '=') + 1; | |
329 | } | |
330 | for (v = *hashvar(name) ; v ; v = v->next) { | |
331 | if (varequal(v->text, name)) { | |
13b3e634 CZ |
332 | if ((v->flags & VUNSET) |
333 | || (!doall && (v->flags & VEXPORT) == 0)) | |
8f1981e0 KB |
334 | return NULL; |
335 | return strchr(v->text, '=') + 1; | |
336 | } | |
337 | } | |
338 | return NULL; | |
339 | } | |
340 | ||
341 | ||
342 | ||
343 | /* | |
344 | * Generate a list of exported variables. This routine is used to construct | |
345 | * the third argument to execve when executing a program. | |
346 | */ | |
347 | ||
348 | char ** | |
349 | environment() { | |
350 | int nenv; | |
351 | struct var **vpp; | |
352 | struct var *vp; | |
353 | char **env, **ep; | |
354 | ||
355 | nenv = 0; | |
356 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
357 | for (vp = *vpp ; vp ; vp = vp->next) | |
358 | if (vp->flags & VEXPORT) | |
359 | nenv++; | |
360 | } | |
361 | ep = env = stalloc((nenv + 1) * sizeof *env); | |
362 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
363 | for (vp = *vpp ; vp ; vp = vp->next) | |
364 | if (vp->flags & VEXPORT) | |
365 | *ep++ = vp->text; | |
366 | } | |
367 | *ep = NULL; | |
368 | return env; | |
369 | } | |
370 | ||
371 | ||
372 | /* | |
373 | * Called when a shell procedure is invoked to clear out nonexported | |
374 | * variables. It is also necessary to reallocate variables of with | |
375 | * VSTACK set since these are currently allocated on the stack. | |
376 | */ | |
377 | ||
378 | #ifdef mkinit | |
379 | MKINIT void shprocvar(); | |
380 | ||
381 | SHELLPROC { | |
382 | shprocvar(); | |
383 | } | |
384 | #endif | |
385 | ||
386 | void | |
387 | shprocvar() { | |
388 | struct var **vpp; | |
389 | struct var *vp, **prev; | |
390 | ||
391 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
392 | for (prev = vpp ; (vp = *prev) != NULL ; ) { | |
393 | if ((vp->flags & VEXPORT) == 0) { | |
394 | *prev = vp->next; | |
395 | if ((vp->flags & VTEXTFIXED) == 0) | |
396 | ckfree(vp->text); | |
397 | if ((vp->flags & VSTRFIXED) == 0) | |
398 | ckfree(vp); | |
399 | } else { | |
400 | if (vp->flags & VSTACK) { | |
401 | vp->text = savestr(vp->text); | |
402 | vp->flags &=~ VSTACK; | |
403 | } | |
404 | prev = &vp->next; | |
405 | } | |
406 | } | |
407 | } | |
408 | initvar(); | |
409 | } | |
410 | ||
411 | ||
412 | ||
413 | /* | |
414 | * Command to list all variables which are set. Currently this command | |
415 | * is invoked from the set command when the set command is called without | |
416 | * any variables. | |
417 | */ | |
418 | ||
419 | int | |
13b3e634 CZ |
420 | showvarscmd(argc, argv) |
421 | int argc; | |
422 | char **argv; | |
423 | { | |
8f1981e0 KB |
424 | struct var **vpp; |
425 | struct var *vp; | |
426 | ||
427 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
428 | for (vp = *vpp ; vp ; vp = vp->next) { | |
429 | if ((vp->flags & VUNSET) == 0) | |
430 | out1fmt("%s\n", vp->text); | |
431 | } | |
432 | } | |
433 | return 0; | |
434 | } | |
435 | ||
436 | ||
437 | ||
438 | /* | |
439 | * The export and readonly commands. | |
440 | */ | |
441 | ||
442 | int | |
13b3e634 CZ |
443 | exportcmd(argc, argv) |
444 | int argc; | |
445 | char **argv; | |
446 | { | |
8f1981e0 KB |
447 | struct var **vpp; |
448 | struct var *vp; | |
449 | char *name; | |
450 | char *p; | |
451 | int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; | |
452 | ||
453 | listsetvar(cmdenviron); | |
454 | if (argc > 1) { | |
455 | while ((name = *argptr++) != NULL) { | |
456 | if ((p = strchr(name, '=')) != NULL) { | |
457 | p++; | |
458 | } else { | |
459 | vpp = hashvar(name); | |
460 | for (vp = *vpp ; vp ; vp = vp->next) { | |
461 | if (varequal(vp->text, name)) { | |
462 | vp->flags |= flag; | |
463 | goto found; | |
464 | } | |
465 | } | |
466 | } | |
467 | setvar(name, p, flag); | |
468 | found:; | |
469 | } | |
470 | } else { | |
471 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
472 | for (vp = *vpp ; vp ; vp = vp->next) { | |
473 | if (vp->flags & flag) { | |
474 | for (p = vp->text ; *p != '=' ; p++) | |
475 | out1c(*p); | |
476 | out1c('\n'); | |
477 | } | |
478 | } | |
479 | } | |
480 | } | |
481 | return 0; | |
482 | } | |
483 | ||
484 | ||
485 | /* | |
486 | * The "local" command. | |
487 | */ | |
488 | ||
13b3e634 CZ |
489 | int |
490 | localcmd(argc, argv) | |
491 | int argc; | |
492 | char **argv; | |
493 | { | |
8f1981e0 KB |
494 | char *name; |
495 | ||
496 | if (! in_function()) | |
497 | error("Not in a function"); | |
498 | while ((name = *argptr++) != NULL) { | |
499 | mklocal(name); | |
500 | } | |
501 | return 0; | |
502 | } | |
503 | ||
504 | ||
505 | /* | |
506 | * Make a variable a local variable. When a variable is made local, it's | |
507 | * value and flags are saved in a localvar structure. The saved values | |
508 | * will be restored when the shell function returns. We handle the name | |
509 | * "-" as a special case. | |
510 | */ | |
511 | ||
512 | void | |
513 | mklocal(name) | |
514 | char *name; | |
515 | { | |
516 | struct localvar *lvp; | |
517 | struct var **vpp; | |
518 | struct var *vp; | |
519 | ||
520 | INTOFF; | |
521 | lvp = ckmalloc(sizeof (struct localvar)); | |
522 | if (name[0] == '-' && name[1] == '\0') { | |
1da339d9 | 523 | lvp->text = ckmalloc(sizeof optlist); |
13b3e634 | 524 | memcpy(lvp->text, optlist, sizeof optlist); |
8f1981e0 KB |
525 | vp = NULL; |
526 | } else { | |
527 | vpp = hashvar(name); | |
528 | for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); | |
529 | if (vp == NULL) { | |
530 | if (strchr(name, '=')) | |
531 | setvareq(savestr(name), VSTRFIXED); | |
532 | else | |
533 | setvar(name, NULL, VSTRFIXED); | |
534 | vp = *vpp; /* the new variable */ | |
535 | lvp->text = NULL; | |
536 | lvp->flags = VUNSET; | |
537 | } else { | |
538 | lvp->text = vp->text; | |
539 | lvp->flags = vp->flags; | |
540 | vp->flags |= VSTRFIXED|VTEXTFIXED; | |
541 | if (strchr(name, '=')) | |
542 | setvareq(savestr(name), 0); | |
543 | } | |
544 | } | |
545 | lvp->vp = vp; | |
546 | lvp->next = localvars; | |
547 | localvars = lvp; | |
548 | INTON; | |
549 | } | |
550 | ||
551 | ||
552 | /* | |
553 | * Called after a function returns. | |
554 | */ | |
555 | ||
556 | void | |
557 | poplocalvars() { | |
558 | struct localvar *lvp; | |
559 | struct var *vp; | |
560 | ||
561 | while ((lvp = localvars) != NULL) { | |
562 | localvars = lvp->next; | |
563 | vp = lvp->vp; | |
564 | if (vp == NULL) { /* $- saved */ | |
13b3e634 | 565 | memcpy(optlist, lvp->text, sizeof optlist); |
8f1981e0 KB |
566 | ckfree(lvp->text); |
567 | } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { | |
e6fa84d4 | 568 | (void)unsetvar(vp->text); |
8f1981e0 KB |
569 | } else { |
570 | if ((vp->flags & VTEXTFIXED) == 0) | |
571 | ckfree(vp->text); | |
572 | vp->flags = lvp->flags; | |
573 | vp->text = lvp->text; | |
574 | } | |
575 | ckfree(lvp); | |
576 | } | |
577 | } | |
578 | ||
579 | ||
13b3e634 CZ |
580 | int |
581 | setvarcmd(argc, argv) | |
582 | int argc; | |
583 | char **argv; | |
584 | { | |
8f1981e0 KB |
585 | if (argc <= 2) |
586 | return unsetcmd(argc, argv); | |
587 | else if (argc == 3) | |
588 | setvar(argv[1], argv[2], 0); | |
589 | else | |
590 | error("List assignment not implemented"); | |
591 | return 0; | |
592 | } | |
593 | ||
594 | ||
595 | /* | |
596 | * The unset builtin command. We unset the function before we unset the | |
597 | * variable to allow a function to be unset when there is a readonly variable | |
598 | * with the same name. | |
599 | */ | |
600 | ||
13b3e634 CZ |
601 | int |
602 | unsetcmd(argc, argv) | |
603 | int argc; | |
604 | char **argv; | |
605 | { | |
8f1981e0 | 606 | char **ap; |
e6fa84d4 MT |
607 | int i; |
608 | int flg_func = 0; | |
609 | int flg_var = 0; | |
610 | int ret = 0; | |
611 | ||
612 | while ((i = nextopt("vf")) != '\0') { | |
613 | if (i == 'f') | |
614 | flg_func = 1; | |
615 | else | |
616 | flg_var = 1; | |
8f1981e0 | 617 | } |
e6fa84d4 MT |
618 | if (flg_func == 0 && flg_var == 0) |
619 | flg_var = 1; | |
620 | ||
621 | for (ap = argptr; *ap ; ap++) { | |
622 | if (flg_func) | |
623 | ret |= unsetfunc(*ap); | |
624 | if (flg_var) | |
625 | ret |= unsetvar(*ap); | |
626 | } | |
627 | return ret; | |
8f1981e0 KB |
628 | } |
629 | ||
630 | ||
631 | /* | |
632 | * Unset the specified variable. | |
633 | */ | |
634 | ||
e6fa84d4 | 635 | STATIC int |
8f1981e0 KB |
636 | unsetvar(s) |
637 | char *s; | |
638 | { | |
639 | struct var **vpp; | |
640 | struct var *vp; | |
641 | ||
642 | vpp = hashvar(s); | |
643 | for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { | |
644 | if (varequal(vp->text, s)) { | |
e6fa84d4 MT |
645 | if (vp->flags & VREADONLY) |
646 | return (1); | |
8f1981e0 | 647 | INTOFF; |
e6fa84d4 | 648 | if (*(strchr(vp->text, '=') + 1) != '\0') |
8f1981e0 | 649 | setvar(s, nullstr, 0); |
8f1981e0 KB |
650 | vp->flags &=~ VEXPORT; |
651 | vp->flags |= VUNSET; | |
652 | if ((vp->flags & VSTRFIXED) == 0) { | |
653 | if ((vp->flags & VTEXTFIXED) == 0) | |
654 | ckfree(vp->text); | |
655 | *vpp = vp->next; | |
656 | ckfree(vp); | |
657 | } | |
658 | INTON; | |
e6fa84d4 | 659 | return (0); |
8f1981e0 KB |
660 | } |
661 | } | |
e6fa84d4 MT |
662 | |
663 | return (1); | |
8f1981e0 KB |
664 | } |
665 | ||
666 | ||
667 | ||
668 | /* | |
669 | * Find the appropriate entry in the hash table from the name. | |
670 | */ | |
671 | ||
672 | STATIC struct var ** | |
673 | hashvar(p) | |
674 | register char *p; | |
675 | { | |
676 | unsigned int hashval; | |
677 | ||
678 | hashval = *p << 4; | |
679 | while (*p && *p != '=') | |
680 | hashval += *p++; | |
681 | return &vartab[hashval % VTABSIZE]; | |
682 | } | |
683 | ||
684 | ||
685 | ||
686 | /* | |
687 | * Returns true if the two strings specify the same varable. The first | |
688 | * variable name is terminated by '='; the second may be terminated by | |
689 | * either '=' or '\0'. | |
690 | */ | |
691 | ||
692 | STATIC int | |
693 | varequal(p, q) | |
694 | register char *p, *q; | |
695 | { | |
696 | while (*p == *q++) { | |
697 | if (*p++ == '=') | |
698 | return 1; | |
699 | } | |
700 | if (*p == '=' && *(q - 1) == '\0') | |
701 | return 1; | |
702 | return 0; | |
703 | } |