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 | * | |
8 | * %sccs.include.redist.c% | |
9 | */ | |
10 | ||
11 | #ifndef lint | |
d1b73048 | 12 | static char sccsid[] = "@(#)var.c 8.1 (Berkeley) %G%"; |
8f1981e0 KB |
13 | #endif /* not lint */ |
14 | ||
15 | /* | |
16 | * Shell variables. | |
17 | */ | |
18 | ||
8f1981e0 KB |
19 | #include "shell.h" |
20 | #include "output.h" | |
21 | #include "expand.h" | |
22 | #include "nodes.h" /* for other headers */ | |
23 | #include "eval.h" /* defines cmdenviron */ | |
24 | #include "exec.h" | |
25 | #include "syntax.h" | |
26 | #include "options.h" | |
27 | #include "mail.h" | |
28 | #include "var.h" | |
29 | #include "memalloc.h" | |
30 | #include "error.h" | |
31 | #include "mystring.h" | |
32 | ||
33 | ||
34 | #define VTABSIZE 39 | |
35 | ||
36 | ||
37 | struct varinit { | |
38 | struct var *var; | |
39 | int flags; | |
40 | char *text; | |
41 | }; | |
42 | ||
43 | ||
44 | #if ATTY | |
45 | struct var vatty; | |
46 | #endif | |
1da339d9 | 47 | struct var vhistsize; |
8f1981e0 KB |
48 | struct var vifs; |
49 | struct var vmail; | |
50 | struct var vmpath; | |
51 | struct var vpath; | |
52 | struct var vps1; | |
53 | struct var vps2; | |
54 | struct var vvers; | |
55 | #if ATTY | |
56 | struct var vterm; | |
57 | #endif | |
58 | ||
59 | const struct varinit varinit[] = { | |
60 | #if ATTY | |
61 | {&vatty, VSTRFIXED|VTEXTFIXED|VUNSET, "ATTY="}, | |
62 | #endif | |
1da339d9 | 63 | {&vhistsize, VSTRFIXED|VTEXTFIXED|VUNSET, "HISTSIZE="}, |
8f1981e0 KB |
64 | {&vifs, VSTRFIXED|VTEXTFIXED, "IFS= \t\n"}, |
65 | {&vmail, VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL="}, | |
66 | {&vmpath, VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH="}, | |
67 | {&vpath, VSTRFIXED|VTEXTFIXED, "PATH=:/bin:/usr/bin"}, | |
913003f6 MT |
68 | /* |
69 | * vps1 depends on uid | |
70 | */ | |
8f1981e0 | 71 | {&vps2, VSTRFIXED|VTEXTFIXED, "PS2=> "}, |
8f1981e0 KB |
72 | #if ATTY |
73 | {&vterm, VSTRFIXED|VTEXTFIXED|VUNSET, "TERM="}, | |
74 | #endif | |
75 | {NULL, 0, NULL} | |
76 | }; | |
77 | ||
78 | struct var *vartab[VTABSIZE]; | |
79 | ||
e6fa84d4 | 80 | STATIC int unsetvar __P((char *)); |
913003f6 MT |
81 | STATIC struct var **hashvar __P((char *)); |
82 | STATIC int varequal __P((char *, char *)); | |
8f1981e0 KB |
83 | |
84 | /* | |
85 | * Initialize the varable symbol tables and import the environment | |
86 | */ | |
87 | ||
88 | #ifdef mkinit | |
89 | INCLUDE "var.h" | |
90 | INIT { | |
91 | char **envp; | |
92 | extern char **environ; | |
93 | ||
94 | initvar(); | |
95 | for (envp = environ ; *envp ; envp++) { | |
96 | if (strchr(*envp, '=')) { | |
97 | setvareq(*envp, VEXPORT|VTEXTFIXED); | |
98 | } | |
99 | } | |
100 | } | |
101 | #endif | |
102 | ||
103 | ||
104 | /* | |
105 | * This routine initializes the builtin variables. It is called when the | |
106 | * shell is initialized and again when a shell procedure is spawned. | |
107 | */ | |
108 | ||
109 | void | |
110 | initvar() { | |
111 | const struct varinit *ip; | |
112 | struct var *vp; | |
113 | struct var **vpp; | |
114 | ||
115 | for (ip = varinit ; (vp = ip->var) != NULL ; ip++) { | |
116 | if ((vp->flags & VEXPORT) == 0) { | |
117 | vpp = hashvar(ip->text); | |
118 | vp->next = *vpp; | |
119 | *vpp = vp; | |
120 | vp->text = ip->text; | |
121 | vp->flags = ip->flags; | |
122 | } | |
123 | } | |
913003f6 MT |
124 | /* |
125 | * PS1 depends on uid | |
126 | */ | |
127 | if ((vps1.flags & VEXPORT) == 0) { | |
128 | vpp = hashvar("PS1="); | |
129 | vps1.next = *vpp; | |
130 | *vpp = &vps1; | |
d08083e8 | 131 | vps1.text = geteuid() ? "PS1=$ " : "PS1=# "; |
913003f6 MT |
132 | vps1.flags = VSTRFIXED|VTEXTFIXED; |
133 | } | |
ddba57cd | 134 | } |
8f1981e0 KB |
135 | |
136 | /* | |
137 | * Set the value of a variable. The flags argument is ored with the | |
138 | * flags of the variable. If val is NULL, the variable is unset. | |
139 | */ | |
140 | ||
141 | void | |
142 | setvar(name, val, flags) | |
143 | char *name, *val; | |
144 | { | |
145 | char *p, *q; | |
146 | int len; | |
147 | int namelen; | |
148 | char *nameeq; | |
149 | int isbad; | |
150 | ||
151 | isbad = 0; | |
152 | p = name; | |
153 | if (! is_name(*p++)) | |
154 | isbad = 1; | |
155 | for (;;) { | |
156 | if (! is_in_name(*p)) { | |
157 | if (*p == '\0' || *p == '=') | |
158 | break; | |
159 | isbad = 1; | |
160 | } | |
161 | p++; | |
162 | } | |
163 | namelen = p - name; | |
164 | if (isbad) | |
c671e886 | 165 | error("%.*s: bad variable name", namelen, name); |
8f1981e0 KB |
166 | len = namelen + 2; /* 2 is space for '=' and '\0' */ |
167 | if (val == NULL) { | |
168 | flags |= VUNSET; | |
169 | } else { | |
170 | len += strlen(val); | |
171 | } | |
172 | p = nameeq = ckmalloc(len); | |
173 | q = name; | |
174 | while (--namelen >= 0) | |
175 | *p++ = *q++; | |
176 | *p++ = '='; | |
177 | *p = '\0'; | |
178 | if (val) | |
179 | scopy(val, p); | |
180 | setvareq(nameeq, flags); | |
181 | } | |
182 | ||
183 | ||
184 | ||
185 | /* | |
186 | * Same as setvar except that the variable and value are passed in | |
187 | * the first argument as name=value. Since the first argument will | |
188 | * be actually stored in the table, it should not be a string that | |
189 | * will go away. | |
190 | */ | |
191 | ||
192 | void | |
193 | setvareq(s, flags) | |
194 | char *s; | |
195 | { | |
196 | struct var *vp, **vpp; | |
197 | ||
198 | vpp = hashvar(s); | |
199 | for (vp = *vpp ; vp ; vp = vp->next) { | |
200 | if (varequal(s, vp->text)) { | |
201 | if (vp->flags & VREADONLY) { | |
202 | int len = strchr(s, '=') - s; | |
203 | error("%.*s: is read only", len, s); | |
204 | } | |
205 | INTOFF; | |
206 | if (vp == &vpath) | |
207 | changepath(s + 5); /* 5 = strlen("PATH=") */ | |
208 | if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) | |
209 | ckfree(vp->text); | |
210 | vp->flags &=~ (VTEXTFIXED|VSTACK|VUNSET); | |
211 | vp->flags |= flags; | |
212 | vp->text = s; | |
213 | if (vp == &vmpath || (vp == &vmail && ! mpathset())) | |
214 | chkmail(1); | |
1da339d9 MT |
215 | if (vp == &vhistsize) |
216 | sethistsize(); | |
8f1981e0 KB |
217 | INTON; |
218 | return; | |
219 | } | |
220 | } | |
221 | /* not found */ | |
222 | vp = ckmalloc(sizeof (*vp)); | |
223 | vp->flags = flags; | |
224 | vp->text = s; | |
225 | vp->next = *vpp; | |
226 | *vpp = vp; | |
227 | } | |
228 | ||
229 | ||
230 | ||
231 | /* | |
232 | * Process a linked list of variable assignments. | |
233 | */ | |
234 | ||
235 | void | |
236 | listsetvar(list) | |
237 | struct strlist *list; | |
238 | { | |
239 | struct strlist *lp; | |
240 | ||
241 | INTOFF; | |
242 | for (lp = list ; lp ; lp = lp->next) { | |
243 | setvareq(savestr(lp->text), 0); | |
244 | } | |
245 | INTON; | |
246 | } | |
247 | ||
248 | ||
249 | ||
250 | /* | |
251 | * Find the value of a variable. Returns NULL if not set. | |
252 | */ | |
253 | ||
254 | char * | |
255 | lookupvar(name) | |
256 | char *name; | |
257 | { | |
258 | struct var *v; | |
259 | ||
260 | for (v = *hashvar(name) ; v ; v = v->next) { | |
261 | if (varequal(v->text, name)) { | |
262 | if (v->flags & VUNSET) | |
263 | return NULL; | |
264 | return strchr(v->text, '=') + 1; | |
265 | } | |
266 | } | |
267 | return NULL; | |
268 | } | |
269 | ||
270 | ||
271 | ||
272 | /* | |
273 | * Search the environment of a builtin command. If the second argument | |
274 | * is nonzero, return the value of a variable even if it hasn't been | |
275 | * exported. | |
276 | */ | |
277 | ||
278 | char * | |
279 | bltinlookup(name, doall) | |
280 | char *name; | |
281 | { | |
282 | struct strlist *sp; | |
283 | struct var *v; | |
284 | ||
285 | for (sp = cmdenviron ; sp ; sp = sp->next) { | |
286 | if (varequal(sp->text, name)) | |
287 | return strchr(sp->text, '=') + 1; | |
288 | } | |
289 | for (v = *hashvar(name) ; v ; v = v->next) { | |
290 | if (varequal(v->text, name)) { | |
291 | if (v->flags & VUNSET | |
292 | || ! doall && (v->flags & VEXPORT) == 0) | |
293 | return NULL; | |
294 | return strchr(v->text, '=') + 1; | |
295 | } | |
296 | } | |
297 | return NULL; | |
298 | } | |
299 | ||
300 | ||
301 | ||
302 | /* | |
303 | * Generate a list of exported variables. This routine is used to construct | |
304 | * the third argument to execve when executing a program. | |
305 | */ | |
306 | ||
307 | char ** | |
308 | environment() { | |
309 | int nenv; | |
310 | struct var **vpp; | |
311 | struct var *vp; | |
312 | char **env, **ep; | |
313 | ||
314 | nenv = 0; | |
315 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
316 | for (vp = *vpp ; vp ; vp = vp->next) | |
317 | if (vp->flags & VEXPORT) | |
318 | nenv++; | |
319 | } | |
320 | ep = env = stalloc((nenv + 1) * sizeof *env); | |
321 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
322 | for (vp = *vpp ; vp ; vp = vp->next) | |
323 | if (vp->flags & VEXPORT) | |
324 | *ep++ = vp->text; | |
325 | } | |
326 | *ep = NULL; | |
327 | return env; | |
328 | } | |
329 | ||
330 | ||
331 | /* | |
332 | * Called when a shell procedure is invoked to clear out nonexported | |
333 | * variables. It is also necessary to reallocate variables of with | |
334 | * VSTACK set since these are currently allocated on the stack. | |
335 | */ | |
336 | ||
337 | #ifdef mkinit | |
338 | MKINIT void shprocvar(); | |
339 | ||
340 | SHELLPROC { | |
341 | shprocvar(); | |
342 | } | |
343 | #endif | |
344 | ||
345 | void | |
346 | shprocvar() { | |
347 | struct var **vpp; | |
348 | struct var *vp, **prev; | |
349 | ||
350 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
351 | for (prev = vpp ; (vp = *prev) != NULL ; ) { | |
352 | if ((vp->flags & VEXPORT) == 0) { | |
353 | *prev = vp->next; | |
354 | if ((vp->flags & VTEXTFIXED) == 0) | |
355 | ckfree(vp->text); | |
356 | if ((vp->flags & VSTRFIXED) == 0) | |
357 | ckfree(vp); | |
358 | } else { | |
359 | if (vp->flags & VSTACK) { | |
360 | vp->text = savestr(vp->text); | |
361 | vp->flags &=~ VSTACK; | |
362 | } | |
363 | prev = &vp->next; | |
364 | } | |
365 | } | |
366 | } | |
367 | initvar(); | |
368 | } | |
369 | ||
370 | ||
371 | ||
372 | /* | |
373 | * Command to list all variables which are set. Currently this command | |
374 | * is invoked from the set command when the set command is called without | |
375 | * any variables. | |
376 | */ | |
377 | ||
378 | int | |
379 | showvarscmd(argc, argv) char **argv; { | |
380 | struct var **vpp; | |
381 | struct var *vp; | |
382 | ||
383 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
384 | for (vp = *vpp ; vp ; vp = vp->next) { | |
385 | if ((vp->flags & VUNSET) == 0) | |
386 | out1fmt("%s\n", vp->text); | |
387 | } | |
388 | } | |
389 | return 0; | |
390 | } | |
391 | ||
392 | ||
393 | ||
394 | /* | |
395 | * The export and readonly commands. | |
396 | */ | |
397 | ||
398 | int | |
399 | exportcmd(argc, argv) char **argv; { | |
400 | struct var **vpp; | |
401 | struct var *vp; | |
402 | char *name; | |
403 | char *p; | |
404 | int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT; | |
405 | ||
406 | listsetvar(cmdenviron); | |
407 | if (argc > 1) { | |
408 | while ((name = *argptr++) != NULL) { | |
409 | if ((p = strchr(name, '=')) != NULL) { | |
410 | p++; | |
411 | } else { | |
412 | vpp = hashvar(name); | |
413 | for (vp = *vpp ; vp ; vp = vp->next) { | |
414 | if (varequal(vp->text, name)) { | |
415 | vp->flags |= flag; | |
416 | goto found; | |
417 | } | |
418 | } | |
419 | } | |
420 | setvar(name, p, flag); | |
421 | found:; | |
422 | } | |
423 | } else { | |
424 | for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) { | |
425 | for (vp = *vpp ; vp ; vp = vp->next) { | |
426 | if (vp->flags & flag) { | |
427 | for (p = vp->text ; *p != '=' ; p++) | |
428 | out1c(*p); | |
429 | out1c('\n'); | |
430 | } | |
431 | } | |
432 | } | |
433 | } | |
434 | return 0; | |
435 | } | |
436 | ||
437 | ||
438 | /* | |
439 | * The "local" command. | |
440 | */ | |
441 | ||
442 | localcmd(argc, argv) char **argv; { | |
443 | char *name; | |
444 | ||
445 | if (! in_function()) | |
446 | error("Not in a function"); | |
447 | while ((name = *argptr++) != NULL) { | |
448 | mklocal(name); | |
449 | } | |
450 | return 0; | |
451 | } | |
452 | ||
453 | ||
454 | /* | |
455 | * Make a variable a local variable. When a variable is made local, it's | |
456 | * value and flags are saved in a localvar structure. The saved values | |
457 | * will be restored when the shell function returns. We handle the name | |
458 | * "-" as a special case. | |
459 | */ | |
460 | ||
461 | void | |
462 | mklocal(name) | |
463 | char *name; | |
464 | { | |
465 | struct localvar *lvp; | |
466 | struct var **vpp; | |
467 | struct var *vp; | |
468 | ||
469 | INTOFF; | |
470 | lvp = ckmalloc(sizeof (struct localvar)); | |
471 | if (name[0] == '-' && name[1] == '\0') { | |
1da339d9 MT |
472 | lvp->text = ckmalloc(sizeof optlist); |
473 | bcopy(optlist, lvp->text, sizeof optlist); | |
8f1981e0 KB |
474 | vp = NULL; |
475 | } else { | |
476 | vpp = hashvar(name); | |
477 | for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next); | |
478 | if (vp == NULL) { | |
479 | if (strchr(name, '=')) | |
480 | setvareq(savestr(name), VSTRFIXED); | |
481 | else | |
482 | setvar(name, NULL, VSTRFIXED); | |
483 | vp = *vpp; /* the new variable */ | |
484 | lvp->text = NULL; | |
485 | lvp->flags = VUNSET; | |
486 | } else { | |
487 | lvp->text = vp->text; | |
488 | lvp->flags = vp->flags; | |
489 | vp->flags |= VSTRFIXED|VTEXTFIXED; | |
490 | if (strchr(name, '=')) | |
491 | setvareq(savestr(name), 0); | |
492 | } | |
493 | } | |
494 | lvp->vp = vp; | |
495 | lvp->next = localvars; | |
496 | localvars = lvp; | |
497 | INTON; | |
498 | } | |
499 | ||
500 | ||
501 | /* | |
502 | * Called after a function returns. | |
503 | */ | |
504 | ||
505 | void | |
506 | poplocalvars() { | |
507 | struct localvar *lvp; | |
508 | struct var *vp; | |
509 | ||
510 | while ((lvp = localvars) != NULL) { | |
511 | localvars = lvp->next; | |
512 | vp = lvp->vp; | |
513 | if (vp == NULL) { /* $- saved */ | |
1da339d9 | 514 | bcopy(lvp->text, optlist, sizeof optlist); |
8f1981e0 KB |
515 | ckfree(lvp->text); |
516 | } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { | |
e6fa84d4 | 517 | (void)unsetvar(vp->text); |
8f1981e0 KB |
518 | } else { |
519 | if ((vp->flags & VTEXTFIXED) == 0) | |
520 | ckfree(vp->text); | |
521 | vp->flags = lvp->flags; | |
522 | vp->text = lvp->text; | |
523 | } | |
524 | ckfree(lvp); | |
525 | } | |
526 | } | |
527 | ||
528 | ||
529 | setvarcmd(argc, argv) char **argv; { | |
530 | if (argc <= 2) | |
531 | return unsetcmd(argc, argv); | |
532 | else if (argc == 3) | |
533 | setvar(argv[1], argv[2], 0); | |
534 | else | |
535 | error("List assignment not implemented"); | |
536 | return 0; | |
537 | } | |
538 | ||
539 | ||
540 | /* | |
541 | * The unset builtin command. We unset the function before we unset the | |
542 | * variable to allow a function to be unset when there is a readonly variable | |
543 | * with the same name. | |
544 | */ | |
545 | ||
546 | unsetcmd(argc, argv) char **argv; { | |
547 | char **ap; | |
e6fa84d4 MT |
548 | int i; |
549 | int flg_func = 0; | |
550 | int flg_var = 0; | |
551 | int ret = 0; | |
552 | ||
553 | while ((i = nextopt("vf")) != '\0') { | |
554 | if (i == 'f') | |
555 | flg_func = 1; | |
556 | else | |
557 | flg_var = 1; | |
8f1981e0 | 558 | } |
e6fa84d4 MT |
559 | if (flg_func == 0 && flg_var == 0) |
560 | flg_var = 1; | |
561 | ||
562 | for (ap = argptr; *ap ; ap++) { | |
563 | if (flg_func) | |
564 | ret |= unsetfunc(*ap); | |
565 | if (flg_var) | |
566 | ret |= unsetvar(*ap); | |
567 | } | |
568 | return ret; | |
8f1981e0 KB |
569 | } |
570 | ||
571 | ||
572 | /* | |
573 | * Unset the specified variable. | |
574 | */ | |
575 | ||
e6fa84d4 | 576 | STATIC int |
8f1981e0 KB |
577 | unsetvar(s) |
578 | char *s; | |
579 | { | |
580 | struct var **vpp; | |
581 | struct var *vp; | |
582 | ||
583 | vpp = hashvar(s); | |
584 | for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) { | |
585 | if (varequal(vp->text, s)) { | |
e6fa84d4 MT |
586 | if (vp->flags & VREADONLY) |
587 | return (1); | |
8f1981e0 | 588 | INTOFF; |
e6fa84d4 | 589 | if (*(strchr(vp->text, '=') + 1) != '\0') |
8f1981e0 | 590 | setvar(s, nullstr, 0); |
8f1981e0 KB |
591 | vp->flags &=~ VEXPORT; |
592 | vp->flags |= VUNSET; | |
593 | if ((vp->flags & VSTRFIXED) == 0) { | |
594 | if ((vp->flags & VTEXTFIXED) == 0) | |
595 | ckfree(vp->text); | |
596 | *vpp = vp->next; | |
597 | ckfree(vp); | |
598 | } | |
599 | INTON; | |
e6fa84d4 | 600 | return (0); |
8f1981e0 KB |
601 | } |
602 | } | |
e6fa84d4 MT |
603 | |
604 | return (1); | |
8f1981e0 KB |
605 | } |
606 | ||
607 | ||
608 | ||
609 | /* | |
610 | * Find the appropriate entry in the hash table from the name. | |
611 | */ | |
612 | ||
613 | STATIC struct var ** | |
614 | hashvar(p) | |
615 | register char *p; | |
616 | { | |
617 | unsigned int hashval; | |
618 | ||
619 | hashval = *p << 4; | |
620 | while (*p && *p != '=') | |
621 | hashval += *p++; | |
622 | return &vartab[hashval % VTABSIZE]; | |
623 | } | |
624 | ||
625 | ||
626 | ||
627 | /* | |
628 | * Returns true if the two strings specify the same varable. The first | |
629 | * variable name is terminated by '='; the second may be terminated by | |
630 | * either '=' or '\0'. | |
631 | */ | |
632 | ||
633 | STATIC int | |
634 | varequal(p, q) | |
635 | register char *p, *q; | |
636 | { | |
637 | while (*p == *q++) { | |
638 | if (*p++ == '=') | |
639 | return 1; | |
640 | } | |
641 | if (*p == '=' && *(q - 1) == '\0') | |
642 | return 1; | |
643 | return 0; | |
644 | } |