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15637ed4 RG |
1 | /*- |
2 | * Copyright (c) 1991 The Regents of the University of California. | |
3 | * 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 | |
78ed81a3 | 38 | /*static char sccsid[] = "from: @(#)var.c 5.3 (Berkeley) 4/12/91";*/ |
39 | static char rcsid[] = "var.c,v 1.4 1993/08/01 18:57:58 mycroft Exp"; | |
15637ed4 RG |
40 | #endif /* not lint */ |
41 | ||
42 | /* | |
43 | * Shell variables. | |
44 | */ | |
45 | ||
46 | #include "shell.h" | |
47 | #include "output.h" | |
48 | #include "expand.h" | |
49 | #include "nodes.h" /* for other headers */ | |
50 | #include "eval.h" /* defines cmdenviron */ | |
51 | #include "exec.h" | |
52 | #include "syntax.h" | |
53 | #include "options.h" | |
54 | #include "mail.h" | |
55 | #include "var.h" | |
56 | #include "memalloc.h" | |
57 | #include "error.h" | |
58 | #include "mystring.h" | |
59 | ||
60 | ||
61 | #define VTABSIZE 39 | |
62 | ||
63 | ||
64 | struct varinit { | |
65 | struct var *var; | |
66 | int flags; | |
67 | char *text; | |
68 | }; | |
69 | ||
70 | ||
71 | #if ATTY | |
72 | struct var vatty; | |
73 | #endif | |
74 | struct var vifs; | |
75 | struct var vmail; | |
76 | struct var vmpath; | |
77 | struct var vpath; | |
78 | struct var vps1; | |
79 | struct var vps2; | |
80 | struct var vvers; | |
81 | #if ATTY | |
82 | struct var vterm; | |
83 | #endif | |
84 | ||
85 | const struct varinit varinit[] = { | |
86 | #if ATTY | |
87 | {&vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY="}, | |
88 | #endif | |
89 | {&vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n"}, | |
90 | {&vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL="}, | |
91 | {&vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH="}, | |
92 | {&vpath, VSTRFIXED|VTEXTFIXED, "PATH=:/bin:/usr/bin"}, | |
93 | /* | |
94 | * vps1 depends on uid | |
95 | */ | |
96 | {&vps2, VSTRFIXED|VTEXTFIXED, "PS2=> "}, | |
97 | #if ATTY | |
98 | {&vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM="}, | |
99 | #endif | |
100 | {NULL, 0, NULL} | |
101 | }; | |
102 | ||
103 | struct var *vartab[VTABSIZE]; | |
104 | ||
105 | STATIC void unsetvar __P((char *)); | |
106 | STATIC struct var **hashvar __P((char *)); | |
107 | STATIC int varequal __P((char *, char *)); | |
108 | ||
109 | /* | |
110 | * Initialize the varable symbol tables and import the environment | |
111 | */ | |
112 | ||
113 | #ifdef mkinit | |
114 | INCLUDE "var.h" | |
115 | INIT { | |
116 | char **envp; | |
117 | extern char **environ; | |
118 | ||
119 | initvar(); | |
120 | for (envp = environ ; *envp ; envp++) { | |
121 | if (strchr(*envp, '=')) { | |
122 | setvareq(*envp, VEXPORT|VTEXTFIXED); | |
123 | } | |
124 | } | |
125 | } | |
126 | #endif | |
127 | ||
128 | ||
129 | /* | |
130 | * This routine initializes the builtin variables. It is called when the | |
131 | * shell is initialized and again when a shell procedure is spawned. | |
132 | */ | |
133 | ||
134 | void | |
135 | initvar() { | |
136 | const struct varinit *ip; | |
137 | struct var *vp; | |
138 | struct var **vpp; | |
139 | ||
140 | for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { | |
141 | if ((vp->flags & VEXPORT) == 0) { | |
142 | vpp = hashvar(ip->text); | |
143 | vp->next = *vpp; | |
144 | *vpp = vp; | |
145 | vp->text = ip->text; | |
146 | vp->flags = ip->flags; | |
147 | } | |
148 | } | |
149 | /* | |
150 | * PS1 depends on uid | |
151 | */ | |
152 | if ((vps1.flags & VEXPORT) == 0) { | |
153 | vpp = hashvar("PS1="); | |
154 | vps1.next = *vpp; | |
155 | *vpp = &vps1; | |
156 | vps1.text = getuid() ? "PS1=$ " : "PS1=# "; | |
157 | vps1.flags = VSTRFIXED|VTEXTFIXED; | |
158 | } | |
159 | } | |
160 | ||
161 | /* | |
162 | * Set the value of a variable. The flags argument is ored with the | |
163 | * flags of the variable. If val is NULL, the variable is unset. | |
164 | */ | |
165 | ||
166 | void | |
167 | setvar(name, val, flags) | |
168 | char *name, *val; | |
169 | { | |
170 | char *p, *q; | |
171 | int len; | |
172 | int namelen; | |
173 | char *nameeq; | |
174 | int isbad; | |
175 | ||
176 | isbad = 0; | |
177 | p = name; | |
178 | if (! is_name(*p++)) | |
179 | isbad = 1; | |
180 | for (;;) { | |
181 | if (! is_in_name(*p)) { | |
182 | if (*p == '\0' || *p == '=') | |
183 | break; | |
184 | isbad = 1; | |
185 | } | |
186 | p++; | |
187 | } | |
188 | namelen = p - name; | |
189 | if (isbad) | |
190 | error("%.*s: is read only", namelen, name); | |
191 | len = namelen + 2; /* 2 is space for '=' and '\0' */ | |
192 | if (val == NULL) { | |
193 | flags |= VUNSET; | |
194 | } else { | |
195 | len += strlen(val); | |
196 | } | |
197 | p = nameeq = ckmalloc(len); | |
198 | q = name; | |
199 | while (--namelen >= 0) | |
200 | *p++ = *q++; | |
201 | *p++ = '='; | |
202 | *p = '\0'; | |
203 | if (val) | |
204 | scopy(val, p); | |
205 | setvareq(nameeq, flags); | |
206 | } | |
207 | ||
208 | ||
209 | ||
210 | /* | |
211 | * Same as setvar except that the variable and value are passed in | |
212 | * the first argument as name=value. Since the first argument will | |
213 | * be actually stored in the table, it should not be a string that | |
214 | * will go away. | |
215 | */ | |
216 | ||
217 | void | |
218 | setvareq(s, flags) | |
219 | char *s; | |
220 | { | |
221 | struct var *vp, **vpp; | |
222 | ||
223 | vpp = hashvar(s); | |
224 | for (vp = *vpp ; vp ; vp = vp->next) { | |
225 | if (varequal(s, vp->text)) { | |
226 | if (vp->flags & VREADONLY) { | |
227 | int len = strchr(s, '=') - s; | |
228 | error("%.*s: is read only", len, s); | |
229 | } | |
230 | INTOFF; | |
231 | if (vp == &vpath) | |
232 | changepath(s + 5); /* 5 = strlen("PATH=") */ | |
233 | if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) | |
234 | ckfree(vp->text); | |
235 | vp->flags &=~ (VTEXTFIXED|VSTACK|VUNSET); | |
236 | vp->flags |= flags; | |
237 | vp->text = s; | |
238 | if (vp == &vmpath || (vp == &vmail && ! mpathset())) | |
239 | chkmail(1); | |
240 | INTON; | |
241 | return; | |
242 | } | |
243 | } | |
244 | /* not found */ | |
245 | vp = ckmalloc(sizeof (*vp)); | |
246 | vp->flags = flags; | |
247 | vp->text = s; | |
248 | vp->next = *vpp; | |
249 | *vpp = vp; | |
250 | } | |
251 | ||
252 | ||
253 | ||
254 | /* | |
255 | * Process a linked list of variable assignments. | |
256 | */ | |
257 | ||
258 | void | |
259 | listsetvar(list) | |
260 | struct strlist *list; | |
261 | { | |
262 | struct strlist *lp; | |
263 | ||
264 | INTOFF; | |
265 | for (lp = list ; lp ; lp = lp->next) { | |
266 | setvareq(savestr(lp->text), 0); | |
267 | } | |
268 | INTON; | |
269 | } | |
270 | ||
271 | ||
272 | ||
273 | /* | |
274 | * Find the value of a variable. Returns NULL if not set. | |
275 | */ | |
276 | ||
277 | char * | |
278 | lookupvar(name) | |
279 | char *name; | |
280 | { | |
281 | struct var *v; | |
282 | ||
283 | for (v = *hashvar(name) ; v ; v = v->next) { | |
284 | if (varequal(v->text, name)) { | |
285 | if (v->flags & VUNSET) | |
286 | return NULL; | |
287 | return strchr(v->text, '=') + 1; | |
288 | } | |
289 | } | |
290 | return NULL; | |
291 | } | |
292 | ||
293 | ||
294 | ||
295 | /* | |
296 | * Search the environment of a builtin command. If the second argument | |
297 | * is nonzero, return the value of a variable even if it hasn't been | |
298 | * exported. | |
299 | */ | |
300 | ||
301 | char * | |
302 | bltinlookup(name, doall) | |
303 | char *name; | |
304 | { | |
305 | struct strlist *sp; | |
306 | struct var *v; | |
307 | ||
308 | for (sp = cmdenviron ; sp ; sp = sp->next) { | |
309 | if (varequal(sp->text, name)) | |
310 | return strchr(sp->text, '=') + 1; | |
311 | } | |
312 | for (v = *hashvar(name) ; v ; v = v->next) { | |
313 | if (varequal(v->text, name)) { | |
314 | if (v->flags & VUNSET | |
315 | || ! doall && (v->flags & VEXPORT) == 0) | |
316 | return NULL; | |
317 | return strchr(v->text, '=') + 1; | |
318 | } | |
319 | } | |
320 | return NULL; | |
321 | } | |
322 | ||
323 | ||
324 | ||
325 | /* | |
326 | * Generate a list of exported variables. This routine is used to construct | |
327 | * the third argument to execve when executing a program. | |
328 | */ | |
329 | ||
330 | char ** | |
331 | environment() { | |
332 | int nenv; | |
333 | struct var **vpp; | |
334 | struct var *vp; | |
335 | char **env, **ep; | |
336 | ||
337 | nenv = 0; | |
338 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
339 | for (vp = *vpp ; vp ; vp = vp->next) | |
340 | if (vp->flags & VEXPORT) | |
341 | nenv++; | |
342 | } | |
343 | ep = env = stalloc((nenv + 1) * sizeof *env); | |
344 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
345 | for (vp = *vpp ; vp ; vp = vp->next) | |
346 | if (vp->flags & VEXPORT) | |
347 | *ep++ = vp->text; | |
348 | } | |
349 | *ep = NULL; | |
350 | return env; | |
351 | } | |
352 | ||
353 | ||
354 | /* | |
355 | * Called when a shell procedure is invoked to clear out nonexported | |
356 | * variables. It is also necessary to reallocate variables of with | |
357 | * VSTACK set since these are currently allocated on the stack. | |
358 | */ | |
359 | ||
360 | #ifdef mkinit | |
361 | MKINIT void shprocvar(); | |
362 | ||
363 | SHELLPROC { | |
364 | shprocvar(); | |
365 | } | |
366 | #endif | |
367 | ||
368 | void | |
369 | shprocvar() { | |
370 | struct var **vpp; | |
371 | struct var *vp, **prev; | |
372 | ||
373 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
374 | for (prev = vpp ; (vp = *prev) != NULL ; ) { | |
375 | if ((vp->flags & VEXPORT) == 0) { | |
376 | *prev = vp->next; | |
377 | if ((vp->flags & VTEXTFIXED) == 0) | |
378 | ckfree(vp->text); | |
379 | if ((vp->flags & VSTRFIXED) == 0) | |
380 | ckfree(vp); | |
381 | } else { | |
382 | if (vp->flags & VSTACK) { | |
383 | vp->text = savestr(vp->text); | |
384 | vp->flags &=~ VSTACK; | |
385 | } | |
386 | prev = &vp->next; | |
387 | } | |
388 | } | |
389 | } | |
390 | initvar(); | |
391 | } | |
392 | ||
393 | ||
394 | ||
395 | /* | |
396 | * Command to list all variables which are set. Currently this command | |
397 | * is invoked from the set command when the set command is called without | |
398 | * any variables. | |
399 | */ | |
400 | ||
401 | int | |
402 | showvarscmd(argc, argv) char **argv; { | |
403 | struct var **vpp; | |
404 | struct var *vp; | |
405 | ||
406 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
407 | for (vp = *vpp ; vp ; vp = vp->next) { | |
408 | if ((vp->flags & VUNSET) == 0) | |
409 | out1fmt("%s\n", vp->text); | |
410 | } | |
411 | } | |
412 | return 0; | |
413 | } | |
414 | ||
415 | ||
416 | ||
417 | /* | |
418 | * The export and readonly commands. | |
419 | */ | |
420 | ||
421 | int | |
422 | exportcmd(argc, argv) char **argv; { | |
423 | struct var **vpp; | |
424 | struct var *vp; | |
425 | char *name; | |
426 | char *p; | |
427 | int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; | |
428 | ||
429 | listsetvar(cmdenviron); | |
430 | if (argc > 1) { | |
431 | while ((name = *argptr++) != NULL) { | |
432 | if ((p = strchr(name, '=')) != NULL) { | |
433 | p++; | |
434 | } else { | |
435 | vpp = hashvar(name); | |
436 | for (vp = *vpp ; vp ; vp = vp->next) { | |
437 | if (varequal(vp->text, name)) { | |
438 | vp->flags |= flag; | |
439 | goto found; | |
440 | } | |
441 | } | |
442 | } | |
443 | setvar(name, p, flag); | |
444 | found:; | |
445 | } | |
446 | } else { | |
447 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
448 | for (vp = *vpp ; vp ; vp = vp->next) { | |
449 | if (vp->flags & flag) { | |
450 | for (p = vp->text ; *p != '=' ; p++) | |
451 | out1c(*p); | |
452 | out1c('\n'); | |
453 | } | |
454 | } | |
455 | } | |
456 | } | |
457 | return 0; | |
458 | } | |
459 | ||
460 | ||
461 | /* | |
462 | * The "local" command. | |
463 | */ | |
464 | ||
465 | localcmd(argc, argv) char **argv; { | |
466 | char *name; | |
467 | ||
468 | if (! in_function()) | |
469 | error("Not in a function"); | |
470 | while ((name = *argptr++) != NULL) { | |
471 | mklocal(name); | |
472 | } | |
473 | return 0; | |
474 | } | |
475 | ||
476 | ||
477 | /* | |
478 | * Make a variable a local variable. When a variable is made local, it's | |
479 | * value and flags are saved in a localvar structure. The saved values | |
480 | * will be restored when the shell function returns. We handle the name | |
481 | * "-" as a special case. | |
482 | */ | |
483 | ||
484 | void | |
485 | mklocal(name) | |
486 | char *name; | |
487 | { | |
488 | struct localvar *lvp; | |
489 | struct var **vpp; | |
490 | struct var *vp; | |
491 | ||
492 | INTOFF; | |
493 | lvp = ckmalloc(sizeof (struct localvar)); | |
494 | if (name[0] == '-' && name[1] == '\0') { | |
495 | lvp->text = ckmalloc(sizeof optval); | |
496 | bcopy(optval, lvp->text, sizeof optval); | |
497 | vp = NULL; | |
498 | } else { | |
499 | vpp = hashvar(name); | |
500 | for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); | |
501 | if (vp == NULL) { | |
502 | if (strchr(name, '=')) | |
503 | setvareq(savestr(name), VSTRFIXED); | |
504 | else | |
505 | setvar(name, NULL, VSTRFIXED); | |
506 | vp = *vpp; /* the new variable */ | |
507 | lvp->text = NULL; | |
508 | lvp->flags = VUNSET; | |
509 | } else { | |
510 | lvp->text = vp->text; | |
511 | lvp->flags = vp->flags; | |
512 | vp->flags |= VSTRFIXED|VTEXTFIXED; | |
513 | if (strchr(name, '=')) | |
514 | setvareq(savestr(name), 0); | |
515 | } | |
516 | } | |
517 | lvp->vp = vp; | |
518 | lvp->next = localvars; | |
519 | localvars = lvp; | |
520 | INTON; | |
521 | } | |
522 | ||
523 | ||
524 | /* | |
525 | * Called after a function returns. | |
526 | */ | |
527 | ||
528 | void | |
529 | poplocalvars() { | |
530 | struct localvar *lvp; | |
531 | struct var *vp; | |
532 | ||
533 | while ((lvp = localvars) != NULL) { | |
534 | localvars = lvp->next; | |
535 | vp = lvp->vp; | |
536 | if (vp == NULL) { /* $- saved */ | |
537 | bcopy(lvp->text, optval, sizeof optval); | |
538 | ckfree(lvp->text); | |
539 | } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { | |
540 | unsetvar(vp->text); | |
541 | } else { | |
542 | if ((vp->flags & VTEXTFIXED) == 0) | |
543 | ckfree(vp->text); | |
544 | vp->flags = lvp->flags; | |
545 | vp->text = lvp->text; | |
546 | } | |
547 | ckfree(lvp); | |
548 | } | |
549 | } | |
550 | ||
551 | ||
552 | setvarcmd(argc, argv) char **argv; { | |
553 | if (argc <= 2) | |
554 | return unsetcmd(argc, argv); | |
555 | else if (argc == 3) | |
556 | setvar(argv[1], argv[2], 0); | |
557 | else | |
558 | error("List assignment not implemented"); | |
559 | return 0; | |
560 | } | |
561 | ||
562 | ||
563 | /* | |
564 | * The unset builtin command. We unset the function before we unset the | |
565 | * variable to allow a function to be unset when there is a readonly variable | |
566 | * with the same name. | |
567 | */ | |
568 | ||
569 | unsetcmd(argc, argv) char **argv; { | |
570 | char **ap; | |
571 | ||
572 | for (ap = argv + 1 ; *ap ; ap++) { | |
573 | unsetfunc(*ap); | |
574 | unsetvar(*ap); | |
575 | } | |
576 | return 0; | |
577 | } | |
578 | ||
579 | ||
580 | /* | |
581 | * Unset the specified variable. | |
582 | */ | |
583 | ||
584 | STATIC void | |
585 | unsetvar(s) | |
586 | char *s; | |
587 | { | |
588 | struct var **vpp; | |
589 | struct var *vp; | |
590 | ||
591 | vpp = hashvar(s); | |
592 | for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { | |
593 | if (varequal(vp->text, s)) { | |
594 | INTOFF; | |
595 | if (*(strchr(vp->text, '=') + 1) != '\0' | |
596 | || vp->flags & VREADONLY) { | |
597 | setvar(s, nullstr, 0); | |
598 | } | |
599 | vp->flags &=~ VEXPORT; | |
600 | vp->flags |= VUNSET; | |
601 | if ((vp->flags & VSTRFIXED) == 0) { | |
602 | if ((vp->flags & VTEXTFIXED) == 0) | |
603 | ckfree(vp->text); | |
604 | *vpp = vp->next; | |
605 | ckfree(vp); | |
606 | } | |
607 | INTON; | |
608 | return; | |
609 | } | |
610 | } | |
611 | } | |
612 | ||
613 | ||
614 | ||
615 | /* | |
616 | * Find the appropriate entry in the hash table from the name. | |
617 | */ | |
618 | ||
619 | STATIC struct var ** | |
620 | hashvar(p) | |
621 | register char *p; | |
622 | { | |
623 | unsigned int hashval; | |
624 | ||
625 | hashval = *p << 4; | |
626 | while (*p && *p != '=') | |
627 | hashval += *p++; | |
628 | return &vartab[hashval % VTABSIZE]; | |
629 | } | |
630 | ||
631 | ||
632 | ||
633 | /* | |
634 | * Returns true if the two strings specify the same varable. The first | |
635 | * variable name is terminated by '='; the second may be terminated by | |
636 | * either '=' or '\0'. | |
637 | */ | |
638 | ||
639 | STATIC int | |
640 | varequal(p, q) | |
641 | register char *p, *q; | |
642 | { | |
643 | while (*p == *q++) { | |
644 | if (*p++ == '=') | |
645 | return 1; | |
646 | } | |
647 | if (*p == '=' && *(q - 1) == '\0') | |
648 | return 1; | |
649 | return 0; | |
650 | } |