1 /* $NetBSD: var.c,v 1.26 2024/09/08 17:28:36 rillig Exp $ */
2
3 #include <sys/cdefs.h>
4
5 #ifndef lint
6 __RCSID("$NetBSD: var.c,v 1.26 2024/09/08 17:28:36 rillig Exp $");
7 #endif
8
9 #include <sys/stat.h>
10 #include <sys/time.h>
11 #include <time.h>
12 #include <ctype.h>
13 #include <stdbool.h>
14
15 #include "sh.h"
16 #include "ksh_limval.h"
17
18 /*
19 * Variables
20 *
21 * WARNING: unreadable code, needs a rewrite
22 *
23 * if (flag&INTEGER), val.i contains integer value, and type contains base.
24 * otherwise, (val.s + type) contains string value.
25 * if (flag&EXPORT), val.s contains "name=value" for E-Z exporting.
26 */
27 static struct tbl vtemp;
28 static struct table specials;
29 static char *formatstr ARGS((struct tbl *vp, const char *s));
30 static void export ARGS((struct tbl *vp, const char *val));
31 static int special ARGS((const char *name));
32 static void unspecial ARGS((const char *name));
33 static void getspec ARGS((struct tbl *vp));
34 static void setspec ARGS((struct tbl *vp));
35 static void unsetspec ARGS((struct tbl *vp));
36 static struct tbl *arraysearch ARGS((struct tbl *, int));
37
38 /*
39 * create a new block for function calls and simple commands
40 * assume caller has allocated and set up e->loc
41 */
42 void
newblock()43 newblock()
44 {
45 struct block *l;
46 static char *const empty[] = {null};
47
48 l = (struct block *) alloc(sizeof(struct block), ATEMP);
49 l->flags = 0;
50 ainit(&l->area); /* todo: could use e->area (l->area => l->areap) */
51 if (!e->loc) {
52 l->argc = 0;
53 l->argv = (char **) __UNCONST(empty);
54 } else {
55 l->argc = e->loc->argc;
56 l->argv = e->loc->argv;
57 }
58 l->exit = l->error = NULL;
59 tinit(&l->vars, &l->area, 0);
60 tinit(&l->funs, &l->area, 0);
61 l->next = e->loc;
62 e->loc = l;
63 }
64
65 /*
66 * pop a block handling special variables
67 */
68 void
popblock()69 popblock()
70 {
71 struct block *l = e->loc;
72 struct tbl *vp, **vpp = l->vars.tbls, *vq;
73 int i;
74
75 e->loc = l->next; /* pop block */
76 for (i = l->vars.size; --i >= 0; ) {
77 if ((vp = *vpp++) != NULL && (vp->flag&SPECIAL)) {
78 if ((vq = global(vp->name))->flag & ISSET)
79 setspec(vq);
80 else
81 unsetspec(vq);
82 }
83 }
84 if (l->flags & BF_DOGETOPTS)
85 user_opt = l->getopts_state;
86 afreeall(&l->area);
87 afree(l, ATEMP);
88 }
89
90 /* called by main() to initialize variable data structures */
91 void
initvar()92 initvar()
93 {
94 static const struct {
95 const char *name;
96 int v;
97 } names[] = {
98 { "COLUMNS", V_COLUMNS },
99 { "IFS", V_IFS },
100 { "OPTIND", V_OPTIND },
101 { "PATH", V_PATH },
102 { "POSIXLY_CORRECT", V_POSIXLY_CORRECT },
103 { "TMPDIR", V_TMPDIR },
104 #ifdef HISTORY
105 { "HISTFILE", V_HISTFILE },
106 { "HISTSIZE", V_HISTSIZE },
107 #endif /* HISTORY */
108 #ifdef EDIT
109 { "EDITOR", V_EDITOR },
110 { "VISUAL", V_VISUAL },
111 #endif /* EDIT */
112 #ifdef KSH
113 { "MAIL", V_MAIL },
114 { "MAILCHECK", V_MAILCHECK },
115 { "MAILPATH", V_MAILPATH },
116 { "RANDOM", V_RANDOM },
117 { "SECONDS", V_SECONDS },
118 { "TMOUT", V_TMOUT },
119 #endif /* KSH */
120 { "LINENO", V_LINENO },
121 { (char *) 0, 0 }
122 };
123 int i;
124 struct tbl *tp;
125
126 tinit(&specials, APERM, 32); /* must be 2^n (currently 17 specials) */
127 for (i = 0; names[i].name; i++) {
128 tp = tenter(&specials, names[i].name, hash(names[i].name));
129 tp->flag = DEFINED|ISSET;
130 tp->type = names[i].v;
131 }
132 }
133
134 /* Used to calculate an array index for global()/local(). Sets *arrayp to
135 * non-zero if this is an array, sets *valp to the array index, returns
136 * the basename of the array.
137 */
138 const char *array_index_calc(const char *n, bool *arrayp, int *valp);
139
140 const char *
array_index_calc(n,arrayp,valp)141 array_index_calc(n, arrayp, valp)
142 const char *n;
143 bool *arrayp;
144 int *valp;
145 {
146 const char *p;
147 int len;
148
149 *arrayp = false;
150 p = skip_varname(n, false);
151 if (p != n && *p == '[' && (len = array_ref_len(p))) {
152 char *sub, *tmp;
153 long rval;
154
155 /* Calculate the value of the subscript */
156 *arrayp = true;
157 tmp = str_nsave(p+1, len-2, ATEMP);
158 sub = substitute(tmp, 0);
159 afree(tmp, ATEMP);
160 n = str_nsave(n, p - n, ATEMP);
161 evaluate(sub, &rval, KSH_UNWIND_ERROR);
162 if (rval < 0 || rval > ARRAYMAX)
163 errorf("%s: subscript out of range", n);
164 *valp = rval;
165 afree(sub, ATEMP);
166 }
167 return n;
168 }
169
170 /*
171 * Search for variable, if not found create globally.
172 */
173 struct tbl *
global(n)174 global(n)
175 const char *n;
176 {
177 struct block *l = e->loc;
178 struct tbl *vp;
179 int c;
180 unsigned h;
181 bool array;
182 int val;
183
184 /* Check to see if this is an array */
185 n = array_index_calc(n, &array, &val);
186 h = hash(n);
187 c = n[0];
188 if (!letter(c)) {
189 if (array)
190 errorf("bad substitution");
191 vp = &vtemp;
192 vp->flag = DEFINED;
193 vp->type = 0;
194 vp->areap = ATEMP;
195 *vp->name = c;
196 if (digit(c)) {
197 for (c = 0; digit(*n); n++)
198 c = c*10 + *n-'0';
199 if (c <= l->argc)
200 /* setstr can't fail here */
201 setstr(vp, l->argv[c], KSH_RETURN_ERROR);
202 vp->flag |= RDONLY;
203 return vp;
204 }
205 vp->flag |= RDONLY;
206 if (n[1] != '\0')
207 return vp;
208 vp->flag |= ISSET|INTEGER;
209 switch (c) {
210 case '$':
211 vp->val.i = kshpid;
212 break;
213 case '!':
214 /* If no job, expand to nothing */
215 if ((vp->val.i = j_async()) == 0)
216 vp->flag &= ~(ISSET|INTEGER);
217 break;
218 case '?':
219 vp->val.i = exstat;
220 break;
221 case '#':
222 vp->val.i = l->argc;
223 break;
224 case '-':
225 vp->flag &= ~INTEGER;
226 vp->val.s = getoptions();
227 break;
228 default:
229 vp->flag &= ~(ISSET|INTEGER);
230 }
231 return vp;
232 }
233 for (l = e->loc; ; l = l->next) {
234 vp = mytsearch(&l->vars, n, h);
235 if (vp != NULL) {
236 if (array)
237 return arraysearch(vp, val);
238 else
239 return vp;
240 }
241 if (l->next == NULL)
242 break;
243 }
244 vp = tenter(&l->vars, n, h);
245 if (array)
246 vp = arraysearch(vp, val);
247 vp->flag |= DEFINED;
248 if (special(n))
249 vp->flag |= SPECIAL;
250 return vp;
251 }
252
253 /*
254 * Search for local variable, if not found create locally.
255 */
256 struct tbl *
local(const char * n,bool copy)257 local(const char *n, bool copy)
258 {
259 struct block *l = e->loc;
260 struct tbl *vp;
261 unsigned h;
262 bool array;
263 int val;
264
265 /* Check to see if this is an array */
266 n = array_index_calc(n, &array, &val);
267 h = hash(n);
268 if (!letter(*n)) {
269 vp = &vtemp;
270 vp->flag = DEFINED|RDONLY;
271 vp->type = 0;
272 vp->areap = ATEMP;
273 return vp;
274 }
275 vp = tenter(&l->vars, n, h);
276 if (copy && !(vp->flag & DEFINED)) {
277 struct block *ll = l;
278 struct tbl *vq = (struct tbl *) 0;
279
280 while ((ll = ll->next) && !(vq = mytsearch(&ll->vars, n, h)))
281 ;
282 if (vq) {
283 vp->flag |= vq->flag & (EXPORT|INTEGER|RDONLY
284 |LJUST|RJUST|ZEROFIL
285 |LCASEV|UCASEV_AL|INT_U|INT_L);
286 if (vq->flag & INTEGER)
287 vp->type = vq->type;
288 vp->u2.field = vq->u2.field;
289 }
290 }
291 if (array)
292 vp = arraysearch(vp, val);
293 vp->flag |= DEFINED;
294 if (special(n))
295 vp->flag |= SPECIAL;
296 return vp;
297 }
298
299 /* get variable string value */
300 char *
str_val(vp)301 str_val(vp)
302 struct tbl *vp;
303 {
304 char *s;
305
306 if ((vp->flag&SPECIAL))
307 getspec(vp);
308 if (!(vp->flag&ISSET))
309 s = null; /* special to dollar() */
310 else if (!(vp->flag&INTEGER)) /* string source */
311 s = vp->val.s + vp->type;
312 else { /* integer source */
313 /* worst case number length is when base=2, so use BITS(long) */
314 /* minus base # number null */
315 static char strbuf[1 + 2 + 1 + BITS(long) + 1];
316 const char *digits = (vp->flag & UCASEV_AL) ?
317 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
318 : "0123456789abcdefghijklmnopqrstuvwxyz";
319 unsigned long n;
320 int base;
321
322 s = strbuf + sizeof(strbuf);
323 if (vp->flag & INT_U)
324 n = (unsigned long) vp->val.i;
325 else
326 n = (vp->val.i < 0) ? -vp->val.i : vp->val.i;
327 base = (vp->type == 0) ? 10 : vp->type;
328
329 *--s = '\0';
330 do {
331 *--s = digits[n % base];
332 n /= base;
333 } while (n != 0);
334 if (base != 10) {
335 *--s = '#';
336 *--s = digits[base % 10];
337 if (base >= 10)
338 *--s = digits[base / 10];
339 }
340 if (!(vp->flag & INT_U) && vp->val.i < 0)
341 *--s = '-';
342 if (vp->flag & (RJUST|LJUST)) { /* case already dealt with */
343 s = formatstr(vp, s);
344 (void)strlcpy(strbuf, s, sizeof(strbuf));
345 afree(s, ATEMP);
346 s = strbuf;
347 }
348 }
349 return s;
350 }
351
352 /* get variable integer value, with error checking */
353 long
intval(vp)354 intval(vp)
355 struct tbl *vp;
356 {
357 long num;
358 int base;
359
360 base = getint(vp, &num);
361 if (base == -1)
362 /* XXX check calls - is error here ok by POSIX? */
363 errorf("%s: bad number", str_val(vp));
364 return num;
365 }
366
367 /* set variable to string value */
368 int
setstr(vq,s,error_ok)369 setstr(vq, s, error_ok)
370 struct tbl *vq;
371 const char *s;
372 int error_ok;
373 {
374 char *fs = NULL;
375 int no_ro_check = error_ok & 0x4;
376 error_ok &= ~0x4;
377 if ((vq->flag & RDONLY) && !no_ro_check) {
378 warningf(true, "%s: is read only", vq->name);
379 if (!error_ok)
380 errorf("%s", null);
381 return 0;
382 }
383 if (!(vq->flag&INTEGER)) { /* string dest */
384 if ((vq->flag&ALLOC)) {
385 /* debugging */
386 if (s >= vq->val.s
387 && s <= vq->val.s + strlen(vq->val.s))
388 internal_errorf(true,
389 "setstr: %s=%s: assigning to self",
390 vq->name, s);
391 afree((void*)vq->val.s, vq->areap);
392 }
393 vq->flag &= ~(ISSET|ALLOC);
394 vq->type = 0;
395 if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
396 s = fs = formatstr(vq, s);
397 if ((vq->flag&EXPORT))
398 export(vq, s);
399 else {
400 vq->val.s = str_save(s, vq->areap);
401 vq->flag |= ALLOC;
402 }
403 } else /* integer dest */
404 if (!v_evaluate(vq, s, error_ok))
405 return 0;
406 vq->flag |= ISSET;
407 if ((vq->flag&SPECIAL))
408 setspec(vq);
409 if (fs)
410 afree(fs, ATEMP);
411 return 1;
412 }
413
414 /* set variable to integer */
415 void
setint(vq,n)416 setint(vq, n)
417 struct tbl *vq;
418 long n;
419 {
420 if (!(vq->flag&INTEGER)) {
421 struct tbl *vp = &vtemp;
422 vp->flag = (ISSET|INTEGER);
423 vp->type = 0;
424 vp->areap = ATEMP;
425 vp->val.i = n;
426 /* setstr can't fail here */
427 setstr(vq, str_val(vp), KSH_RETURN_ERROR);
428 } else
429 vq->val.i = n;
430 vq->flag |= ISSET;
431 if ((vq->flag&SPECIAL))
432 setspec(vq);
433 }
434
435 int
getint(vp,nump)436 getint(vp, nump)
437 struct tbl *vp;
438 long *nump;
439 {
440 char *s;
441 int c;
442 int base, neg;
443 int have_base = 0;
444 long num;
445
446 if (vp->flag&SPECIAL)
447 getspec(vp);
448 /* XXX is it possible for ISSET to be set and val.s to be 0? */
449 if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
450 return -1;
451 if (vp->flag&INTEGER) {
452 *nump = vp->val.i;
453 return vp->type;
454 }
455 s = vp->val.s + vp->type;
456 if (s == NULL) /* redundant given initial test */
457 s = null;
458 base = 10;
459 num = 0;
460 neg = 0;
461 if (*s == '-') {
462 neg = 1;
463 s++;
464 }
465 if (s[0] == '0' && s[1] == 'x') {
466 base = 16;
467 have_base = 1;
468 s += 2;
469 }
470 for (c = (unsigned char)*s++; c ; c = (unsigned char)*s++) {
471 if (c == '#') {
472 base = (int) num;
473 if (have_base || base < 2 || base > 36)
474 return -1;
475 num = 0;
476 have_base = 1;
477 } else if (letnum(c)) {
478 if (isdigit(c))
479 c -= '0';
480 else if (islower(c))
481 c -= 'a' - 10; /* todo: assumes ascii */
482 else if (isupper(c))
483 c -= 'A' - 10; /* todo: assumes ascii */
484 else
485 c = -1; /* _: force error */
486 if (c < 0 || c >= base)
487 return -1;
488 num = num * base + c;
489 } else
490 return -1;
491 }
492 if (neg)
493 num = -num;
494 *nump = num;
495 return base;
496 }
497
498 /* convert variable vq to integer variable, setting its value from vp
499 * (vq and vp may be the same)
500 */
501 struct tbl *
setint_v(vq,vp)502 setint_v(vq, vp)
503 struct tbl *vq, *vp;
504 {
505 int base;
506 long num;
507
508 if ((base = getint(vp, &num)) == -1)
509 return NULL;
510 if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
511 vq->flag &= ~ALLOC;
512 afree(vq->val.s, vq->areap);
513 }
514 vq->val.i = num;
515 if (vq->type == 0) /* default base */
516 vq->type = base;
517 vq->flag |= ISSET|INTEGER;
518 if (vq->flag&SPECIAL)
519 setspec(vq);
520 return vq;
521 }
522
523 static char *
formatstr(vp,s)524 formatstr(vp, s)
525 struct tbl *vp;
526 const char *s;
527 {
528 int olen, nlen;
529 char *p, *q;
530
531 olen = strlen(s);
532
533 if (vp->flag & (RJUST|LJUST)) {
534 if (!vp->u2.field) /* default field width */
535 vp->u2.field = olen;
536 nlen = vp->u2.field;
537 } else
538 nlen = olen;
539
540 p = (char *) alloc(nlen + 1, ATEMP);
541 if (vp->flag & (RJUST|LJUST)) {
542 int slen;
543
544 if (vp->flag & RJUST) {
545 const char *r = s + olen;
546 /* strip trailing spaces (at&t ksh uses q[-1] == ' ') */
547 while (r > s && isspace((unsigned char)r[-1]))
548 --r;
549 slen = r - s;
550 if (slen > vp->u2.field) {
551 s += slen - vp->u2.field;
552 slen = vp->u2.field;
553 }
554 shf_snprintf(p, nlen + 1,
555 ((vp->flag & ZEROFIL) && digit(*s)) ?
556 "%0*s%.*s" : "%*s%.*s",
557 vp->u2.field - slen, null, slen, s);
558 } else {
559 /* strip leading spaces/zeros */
560 while (isspace((unsigned char)*s))
561 s++;
562 if (vp->flag & ZEROFIL)
563 while (*s == '0')
564 s++;
565 shf_snprintf(p, nlen + 1, "%-*.*s",
566 vp->u2.field, vp->u2.field, s);
567 }
568 } else
569 memcpy(p, s, olen + 1);
570
571 if (vp->flag & UCASEV_AL) {
572 for (q = p; *q; q++)
573 if (islower((unsigned char)*q))
574 *q = toupper((unsigned char)*q);
575 } else if (vp->flag & LCASEV) {
576 for (q = p; *q; q++)
577 if (isupper((unsigned char)*q))
578 *q = tolower((unsigned char)*q);
579 }
580
581 return p;
582 }
583
584 /*
585 * make vp->val.s be "name=value" for quick exporting.
586 */
587 static void
export(vp,val)588 export(vp, val)
589 struct tbl *vp;
590 const char *val;
591 {
592 char *xp;
593 char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
594 int namelen = strlen(vp->name);
595 int vallen = strlen(val) + 1;
596
597 vp->flag |= ALLOC;
598 xp = (char*)alloc(namelen + 1 + vallen, vp->areap);
599 memcpy(vp->val.s = xp, vp->name, namelen);
600 xp += namelen;
601 *xp++ = '=';
602 vp->type = xp - vp->val.s; /* offset to value */
603 memcpy(xp, val, vallen);
604 if (op != NULL)
605 afree((void*)op, vp->areap);
606 }
607
608 /*
609 * lookup variable (according to (set&LOCAL)),
610 * set its attributes (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL,
611 * LCASEV, UCASEV_AL), and optionally set its value if an assignment.
612 */
613 struct tbl *
typeset(var,set,clr,field,base)614 typeset(var, set, clr, field, base)
615 const char *var;
616 Tflag clr, set;
617 int field, base;
618 {
619 struct tbl *vp;
620 struct tbl *vpbase, *t;
621 char *tvar;
622 const char *val;
623
624 /* check for valid variable name, search for value */
625 val = skip_varname(var, false);
626 if (val == var)
627 return NULL;
628 if (*val == '[') {
629 int len;
630
631 len = array_ref_len(val);
632 if (len == 0)
633 return NULL;
634 /* IMPORT is only used when the shell starts up and is
635 * setting up its environment. Allow only simple array
636 * references at this time since parameter/command substitution
637 * is performed on the [expression], which would be a major
638 * security hole.
639 */
640 if (set & IMPORT) {
641 int i;
642 for (i = 1; i < len - 1; i++)
643 if (!digit(val[i]))
644 return NULL;
645 }
646 val += len;
647 }
648 if (*val == '=')
649 tvar = str_nsave(var, val++ - var, ATEMP);
650 else {
651 /* Importing from original environment: must have an = */
652 if (set & IMPORT)
653 return NULL;
654 tvar = (char *) __UNCONST(var);
655 val = NULL;
656 }
657
658 /* Prevent typeset from creating a local PATH/ENV/SHELL */
659 if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0
660 || strcmp(tvar, "ENV") == 0
661 || strcmp(tvar, "SHELL") == 0))
662 errorf("%s: restricted", tvar);
663
664 vp = (set&LOCAL) ? local(tvar, (set & LOCAL_COPY) ? true : false)
665 : global(tvar);
666 set &= ~(LOCAL|LOCAL_COPY);
667
668 vpbase = (vp->flag & ARRAY) ? global(arrayname(var)) : vp;
669
670 /* only allow export flag to be set. at&t ksh allows any attribute to
671 * be changed, which means it can be truncated or modified
672 * (-L/-R/-Z/-i).
673 */
674 if ((vpbase->flag&RDONLY)
675 && (val || clr || (set & ~EXPORT)))
676 /* XXX check calls - is error here ok by POSIX? */
677 errorf("%s: is read only", tvar);
678 if (val)
679 afree(tvar, ATEMP);
680
681 /* most calls are with set/clr == 0 */
682 if (set | clr) {
683 int ok = 1;
684 /* XXX if x[0] isn't set, there will be problems: need to have
685 * one copy of attributes for arrays...
686 */
687 for (t = vpbase; t; t = t->u.array) {
688 int fake_assign;
689 char UNINITIALIZED(*s);
690 char UNINITIALIZED(*free_me);
691
692 fake_assign = (t->flag & ISSET) && (!val || t != vp)
693 && ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL))
694 || ((t->flag & INTEGER) && (clr & INTEGER))
695 || (!(t->flag & INTEGER) && (set & INTEGER)));
696 if (fake_assign) {
697 if (t->flag & INTEGER) {
698 s = str_val(t);
699 free_me = (char *) 0;
700 } else {
701 s = t->val.s + t->type;
702 free_me = (t->flag & ALLOC) ? t->val.s
703 : (char *) 0;
704 }
705 t->flag &= ~ALLOC;
706 }
707 if (!(t->flag & INTEGER) && (set & INTEGER)) {
708 t->type = 0;
709 t->flag &= ~ALLOC;
710 }
711 t->flag = (t->flag | set) & ~clr;
712 /* Don't change base if assignment is to be done,
713 * in case assignment fails.
714 */
715 if ((set & INTEGER) && base > 0 && (!val || t != vp))
716 t->type = base;
717 if (set & (LJUST|RJUST|ZEROFIL))
718 t->u2.field = field;
719 if (fake_assign) {
720 if (!setstr(t, s, KSH_RETURN_ERROR)) {
721 /* Somewhat arbitrary action here:
722 * zap contents of variable, but keep
723 * the flag settings.
724 */
725 ok = 0;
726 if (t->flag & INTEGER)
727 t->flag &= ~ISSET;
728 else {
729 if (t->flag & ALLOC)
730 afree((void*) t->val.s,
731 t->areap);
732 t->flag &= ~(ISSET|ALLOC);
733 t->type = 0;
734 }
735 }
736 if (free_me)
737 afree((void *) free_me, t->areap);
738 }
739 }
740 if (!ok)
741 errorf("%s", null);
742 }
743
744 if (val != NULL) {
745 if (vp->flag&INTEGER) {
746 /* do not zero base before assignment */
747 setstr(vp, val, KSH_UNWIND_ERROR | 0x4);
748 /* Done after assignment to override default */
749 if (base > 0)
750 vp->type = base;
751 } else
752 /* setstr can't fail (readonly check already done) */
753 setstr(vp, val, KSH_RETURN_ERROR | 0x4);
754 }
755
756 /* only x[0] is ever exported, so use vpbase */
757 if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER)
758 && vpbase->type == 0)
759 export(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
760
761 return vp;
762 }
763
764 /* Unset a variable. array_ref is set if there was an array reference in
765 * the name lookup (eg, x[2]).
766 */
767 void
unset(vp,array_ref)768 unset(vp, array_ref)
769 struct tbl *vp;
770 int array_ref;
771 {
772 if (vp->flag & ALLOC)
773 afree((void*)vp->val.s, vp->areap);
774 if ((vp->flag & ARRAY) && !array_ref) {
775 struct tbl *a, *tmp;
776
777 /* Free up entire array */
778 for (a = vp->u.array; a; ) {
779 tmp = a;
780 a = a->u.array;
781 if (tmp->flag & ALLOC)
782 afree((void *) tmp->val.s, tmp->areap);
783 afree(tmp, tmp->areap);
784 }
785 vp->u.array = (struct tbl *) 0;
786 }
787 /* If foo[0] is being unset, the remainder of the array is kept... */
788 vp->flag &= SPECIAL | (array_ref ? ARRAY|DEFINED : 0);
789 if (vp->flag & SPECIAL)
790 unsetspec(vp); /* responsible for `unspecial'ing var */
791 }
792
793 /* return a pointer to the first char past a legal variable name (returns the
794 * argument if there is no legal name, returns * a pointer to the terminating
795 * null if whole string is legal).
796 */
797 char *
skip_varname(s,aok)798 skip_varname(s, aok)
799 const char *s;
800 int aok;
801 {
802 int alen;
803
804 if (s && letter(*s)) {
805 while (*++s && letnum(*s))
806 ;
807 if (aok && *s == '[' && (alen = array_ref_len(s)))
808 s += alen;
809 }
810 return (char *) __UNCONST(s);
811 }
812
813 /* Return a pointer to the first character past any legal variable name. */
814 char *
skip_wdvarname(s,aok)815 skip_wdvarname(s, aok)
816 const char *s;
817 int aok; /* skip array de-reference? */
818 {
819 if (s[0] == CHAR && letter(s[1])) {
820 do
821 s += 2;
822 while (s[0] == CHAR && letnum(s[1]));
823 if (aok && s[0] == CHAR && s[1] == '[') {
824 /* skip possible array de-reference */
825 const char *p = s;
826 char c;
827 int depth = 0;
828
829 while (1) {
830 if (p[0] != CHAR)
831 break;
832 c = p[1];
833 p += 2;
834 if (c == '[')
835 depth++;
836 else if (c == ']' && --depth == 0) {
837 s = p;
838 break;
839 }
840 }
841 }
842 }
843 return (char *) __UNCONST(s);
844 }
845
846 /* Check if coded string s is a variable name */
847 int
is_wdvarname(s,aok)848 is_wdvarname(s, aok)
849 const char *s;
850 int aok;
851 {
852 char *p = skip_wdvarname(s, aok);
853
854 return p != s && p[0] == EOS;
855 }
856
857 /* Check if coded string s is a variable assignment */
858 int
is_wdvarassign(s)859 is_wdvarassign(s)
860 const char *s;
861 {
862 char *p = skip_wdvarname(s, true);
863
864 return p != s && p[0] == CHAR && p[1] == '=';
865 }
866
867 /*
868 * Make the exported environment from the exported names in the dictionary.
869 */
870 char **
makenv()871 makenv()
872 {
873 struct block *l = e->loc;
874 XPtrV env;
875 struct tbl *vp, **vpp;
876 int i;
877
878 XPinit(env, 64);
879 for (l = e->loc; l != NULL; l = l->next)
880 for (vpp = l->vars.tbls, i = l->vars.size; --i >= 0; )
881 if ((vp = *vpp++) != NULL
882 && (vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
883 struct block *l2;
884 struct tbl *vp2;
885 unsigned h = hash(vp->name);
886
887 /* unexport any redefined instances */
888 for (l2 = l->next; l2 != NULL; l2 = l2->next) {
889 vp2 = mytsearch(&l2->vars, vp->name, h);
890 if (vp2 != NULL)
891 vp2->flag &= ~EXPORT;
892 }
893 if ((vp->flag&INTEGER)) {
894 /* integer to string */
895 char *val;
896 val = str_val(vp);
897 vp->flag &= ~(INTEGER|RDONLY);
898 /* setstr can't fail here */
899 setstr(vp, val, KSH_RETURN_ERROR);
900 }
901 XPput(env, vp->val.s);
902 }
903 XPput(env, NULL);
904 return (char **) XPclose(env);
905 }
906
907 /*
908 * Called after a fork in parent to bump the random number generator.
909 * Done to ensure children will not get the same random number sequence
910 * if the parent doesn't use $RANDOM.
911 */
912 void
change_random()913 change_random()
914 {
915 rand();
916 }
917
918 /*
919 * handle special variables with side effects - PATH, SECONDS.
920 */
921
922 /* Test if name is a special parameter */
923 static int
special(name)924 special(name)
925 const char * name;
926 {
927 struct tbl *tp;
928
929 tp = mytsearch(&specials, name, hash(name));
930 return tp && (tp->flag & ISSET) ? tp->type : V_NONE;
931 }
932
933 /* Make a variable non-special */
934 static void
unspecial(name)935 unspecial(name)
936 const char * name;
937 {
938 struct tbl *tp;
939
940 tp = mytsearch(&specials, name, hash(name));
941 if (tp)
942 mytdelete(tp);
943 }
944
945 #ifdef KSH
946 static time_t seconds; /* time SECONDS last set */
947 #endif /* KSH */
948 static int user_lineno; /* what user set $LINENO to */
949
950 static void
getspec(vp)951 getspec(vp)
952 struct tbl *vp;
953 {
954 switch (special(vp->name)) {
955 #ifdef KSH
956 case V_SECONDS:
957 vp->flag &= ~SPECIAL;
958 /* On start up the value of SECONDS is used before seconds
959 * has been set - don't do anything in this case
960 * (see initcoms[] in main.c).
961 */
962 if (vp->flag & ISSET)
963 setint(vp, (long) (time((time_t *)0) - seconds));
964 vp->flag |= SPECIAL;
965 break;
966 case V_RANDOM:
967 vp->flag &= ~SPECIAL;
968 setint(vp, (long) (rand() & 0x7fff));
969 vp->flag |= SPECIAL;
970 break;
971 #endif /* KSH */
972 #ifdef HISTORY
973 case V_HISTSIZE:
974 vp->flag &= ~SPECIAL;
975 setint(vp, (long) histsize);
976 vp->flag |= SPECIAL;
977 break;
978 #endif /* HISTORY */
979 case V_OPTIND:
980 vp->flag &= ~SPECIAL;
981 setint(vp, (long) user_opt.uoptind);
982 vp->flag |= SPECIAL;
983 break;
984 case V_LINENO:
985 vp->flag &= ~SPECIAL;
986 setint(vp, (long) current_lineno + user_lineno);
987 vp->flag |= SPECIAL;
988 break;
989 }
990 }
991
992 static void
setspec(vp)993 setspec(vp)
994 struct tbl *vp;
995 {
996 char *s;
997
998 switch (special(vp->name)) {
999 case V_PATH:
1000 if (path)
1001 afree(path, APERM);
1002 path = str_save(str_val(vp), APERM);
1003 flushcom(1); /* clear tracked aliases */
1004 break;
1005 case V_IFS:
1006 setctypes(s = str_val(vp), C_IFS);
1007 ifs0 = *s;
1008 break;
1009 case V_OPTIND:
1010 vp->flag &= ~SPECIAL;
1011 getopts_reset((int) intval(vp));
1012 vp->flag |= SPECIAL;
1013 break;
1014 case V_POSIXLY_CORRECT:
1015 change_flag(FPOSIX, OF_SPECIAL, 1);
1016 break;
1017 case V_TMPDIR:
1018 if (tmpdir) {
1019 afree(tmpdir, APERM);
1020 tmpdir = (char *) 0;
1021 }
1022 /* Use tmpdir iff it is an absolute path, is writable and
1023 * searchable and is a directory...
1024 */
1025 {
1026 struct stat statb;
1027 s = str_val(vp);
1028 if (ISABSPATH(s) && eaccess(s, W_OK|X_OK) == 0
1029 && stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
1030 tmpdir = str_save(s, APERM);
1031 }
1032 break;
1033 #ifdef HISTORY
1034 case V_HISTSIZE:
1035 vp->flag &= ~SPECIAL;
1036 sethistsize((int) intval(vp));
1037 vp->flag |= SPECIAL;
1038 break;
1039 case V_HISTFILE:
1040 sethistfile(str_val(vp));
1041 break;
1042 #endif /* HISTORY */
1043 #ifdef EDIT
1044 case V_VISUAL:
1045 set_editmode(str_val(vp));
1046 break;
1047 case V_EDITOR:
1048 if (!(global("VISUAL")->flag & ISSET))
1049 set_editmode(str_val(vp));
1050 break;
1051 case V_COLUMNS:
1052 if ((x_cols = intval(vp)) <= MIN_COLS)
1053 x_cols = MIN_COLS;
1054 break;
1055 #endif /* EDIT */
1056 #ifdef KSH
1057 case V_MAIL:
1058 mbset(str_val(vp));
1059 break;
1060 case V_MAILPATH:
1061 mpset(str_val(vp));
1062 break;
1063 case V_MAILCHECK:
1064 vp->flag &= ~SPECIAL;
1065 mcset(intval(vp));
1066 vp->flag |= SPECIAL;
1067 break;
1068 case V_RANDOM:
1069 vp->flag &= ~SPECIAL;
1070 srand((unsigned int)intval(vp));
1071 vp->flag |= SPECIAL;
1072 break;
1073 case V_SECONDS:
1074 vp->flag &= ~SPECIAL;
1075 seconds = time((time_t*) 0) - intval(vp);
1076 vp->flag |= SPECIAL;
1077 break;
1078 case V_TMOUT:
1079 /* at&t ksh seems to do this (only listen if integer) */
1080 if (vp->flag & INTEGER)
1081 ksh_tmout = vp->val.i >= 0 ? vp->val.i : 0;
1082 break;
1083 #endif /* KSH */
1084 case V_LINENO:
1085 vp->flag &= ~SPECIAL;
1086 /* The -1 is because line numbering starts at 1. */
1087 user_lineno = (unsigned int) intval(vp) - current_lineno - 1;
1088 vp->flag |= SPECIAL;
1089 break;
1090 }
1091 }
1092
1093 static void
unsetspec(vp)1094 unsetspec(vp)
1095 struct tbl *vp;
1096 {
1097 switch (special(vp->name)) {
1098 case V_PATH:
1099 if (path)
1100 afree(path, APERM);
1101 path = str_save(def_path, APERM);
1102 flushcom(1); /* clear tracked aliases */
1103 break;
1104 case V_IFS:
1105 setctypes(" \t\n", C_IFS);
1106 ifs0 = ' ';
1107 break;
1108 case V_TMPDIR:
1109 /* should not become unspecial */
1110 if (tmpdir) {
1111 afree(tmpdir, APERM);
1112 tmpdir = (char *) 0;
1113 }
1114 break;
1115 #ifdef KSH
1116 case V_MAIL:
1117 mbset((char *) 0);
1118 break;
1119 case V_MAILPATH:
1120 mpset((char *) 0);
1121 break;
1122 #endif /* KSH */
1123
1124 case V_LINENO:
1125 #ifdef KSH
1126 case V_MAILCHECK: /* at&t ksh leaves previous value in place */
1127 case V_RANDOM:
1128 case V_SECONDS:
1129 case V_TMOUT: /* at&t ksh leaves previous value in place */
1130 #endif /* KSH */
1131 unspecial(vp->name);
1132 break;
1133
1134 /* at&t ksh man page says OPTIND, OPTARG and _ lose special meaning,
1135 * but OPTARG does not (still set by getopts) and _ is also still
1136 * set in various places.
1137 * Don't know what at&t does for:
1138 * MAIL, MAILPATH, HISTSIZE, HISTFILE,
1139 * Unsetting these in at&t ksh does not lose the `specialness':
1140 * no effect: IFS, COLUMNS, PATH, TMPDIR,
1141 * VISUAL, EDITOR,
1142 * pdkshisms: no effect:
1143 * POSIXLY_CORRECT (use set +o posix instead)
1144 */
1145 }
1146 }
1147
1148 /*
1149 * Search for (and possibly create) a table entry starting with
1150 * vp, indexed by val.
1151 */
1152 static struct tbl *
arraysearch(vp,val)1153 arraysearch(vp, val)
1154 struct tbl *vp;
1155 int val;
1156 {
1157 struct tbl *prev, *curr, *new;
1158 size_t namelen = strlen(vp->name) + 1;
1159
1160 vp->flag |= ARRAY|DEFINED;
1161
1162 /* The table entry is always [0] */
1163 if (val == 0) {
1164 vp->index = 0;
1165 return vp;
1166 }
1167 prev = vp;
1168 curr = vp->u.array;
1169 while (curr && curr->index < val) {
1170 prev = curr;
1171 curr = curr->u.array;
1172 }
1173 if (curr && curr->index == val) {
1174 if (curr->flag&ISSET)
1175 return curr;
1176 else
1177 new = curr;
1178 } else
1179 new = (struct tbl *)alloc(sizeof(struct tbl) + namelen,
1180 vp->areap);
1181 strlcpy(new->name, vp->name, namelen);
1182 new->flag = vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL);
1183 new->type = vp->type;
1184 new->areap = vp->areap;
1185 new->u2.field = vp->u2.field;
1186 new->index = val;
1187 if (curr != new) { /* not reusing old array entry */
1188 prev->u.array = new;
1189 new->u.array = curr;
1190 }
1191 return new;
1192 }
1193
1194 /* Return the length of an array reference (eg, [1+2]) - cp is assumed
1195 * to point to the open bracket. Returns 0 if there is no matching closing
1196 * bracket.
1197 */
1198 int
array_ref_len(cp)1199 array_ref_len(cp)
1200 const char *cp;
1201 {
1202 const char *s = cp;
1203 int c;
1204 int depth = 0;
1205
1206 while ((c = *s++) && (c != ']' || --depth))
1207 if (c == '[')
1208 depth++;
1209 if (!c)
1210 return 0;
1211 return s - cp;
1212 }
1213
1214 /*
1215 * Make a copy of the base of an array name
1216 */
1217 char *
arrayname(str)1218 arrayname(str)
1219 const char *str;
1220 {
1221 const char *p;
1222
1223 if ((p = strchr(str, '[')) == 0)
1224 /* Shouldn't happen, but why worry? */
1225 return (char *) __UNCONST(str);
1226
1227 return str_nsave(str, p - str, ATEMP);
1228 }
1229
1230 /* Set (or overwrite, if !reset) the array variable var to the values in vals.
1231 */
1232 void
set_array(var,reset,vals)1233 set_array(var, reset, vals)
1234 const char *var;
1235 int reset;
1236 char **vals;
1237 {
1238 struct tbl *vp, *vq;
1239 int i;
1240
1241 /* to get local array, use "typeset foo; set -A foo" */
1242 vp = global(var);
1243
1244 /* Note: at&t ksh allows set -A but not set +A of a read-only var */
1245 if ((vp->flag&RDONLY))
1246 errorf("%s: is read only", var);
1247 /* This code is quite non-optimal */
1248 if (reset > 0)
1249 /* trash existing values and attributes */
1250 unset(vp, 0);
1251 /* todo: would be nice for assignment to completely succeed or
1252 * completely fail. Only really affects integer arrays:
1253 * evaluation of some of vals[] may fail...
1254 */
1255 for (i = 0; vals[i]; i++) {
1256 vq = arraysearch(vp, i);
1257 /* would be nice to deal with errors here... (see above) */
1258 setstr(vq, vals[i], KSH_RETURN_ERROR);
1259 }
1260 }
1261