var.c
1/* $OpenBSD: var.c,v 1.72 2021/03/05 15:22:03 zhuk Exp $ */
2
3#include <sys/stat.h>
4#include <sys/time.h>
5
6#include <ctype.h>
7#include <errno.h>
8#include <inttypes.h>
9#include <limits.h>
10#include <stdlib.h>
11#include <string.h>
12#include <time.h>
13#include <unistd.h>
14#ifndef SMALL
15# include <term.h>
16# include <curses.h>
17#endif
18
19#include "sh.h"
20
21/*
22 * Variables
23 *
24 * WARNING: unreadable code, needs a rewrite
25 *
26 * if (flag&INTEGER), val.i contains integer value, and type contains base.
27 * otherwise, (val.s + type) contains string value.
28 * if (flag&EXPORT), val.s contains "name=value" for E-Z exporting.
29 */
30static struct tbl vtemp;
31static struct table specials;
32static char *formatstr(struct tbl *, const char *);
33static void export(struct tbl *, const char *);
34static int special(const char *);
35static void unspecial(const char *);
36static void getspec(struct tbl *);
37static void setspec(struct tbl *);
38static void unsetspec(struct tbl *);
39static struct tbl *arraysearch(struct tbl *, int);
40
41/*
42 * create a new block for function calls and simple commands
43 * assume caller has allocated and set up genv->loc
44 */
45void
46newblock(void)
47{
48 struct block *l;
49 static char *const empty[] = {null};
50
51 l = alloc(sizeof(struct block), ATEMP);
52 l->flags = 0;
53 ainit(&l->area); /* todo: could use genv->area (l->area => l->areap) */
54 if (!genv->loc) {
55 l->argc = 0;
56 l->argv = (char **) empty;
57 } else {
58 l->argc = genv->loc->argc;
59 l->argv = genv->loc->argv;
60 }
61 l->exit = l->error = NULL;
62 ktinit(&l->vars, &l->area, 0);
63 ktinit(&l->funs, &l->area, 0);
64 l->next = genv->loc;
65 genv->loc = l;
66}
67
68/*
69 * pop a block handling special variables
70 */
71void
72popblock(void)
73{
74 struct block *l = genv->loc;
75 struct tbl *vp, **vpp = l->vars.tbls, *vq;
76 int i;
77
78 genv->loc = l->next; /* pop block */
79 for (i = l->vars.size; --i >= 0; )
80 if ((vp = *vpp++) != NULL && (vp->flag&SPECIAL)) {
81 if ((vq = global(vp->name))->flag & ISSET)
82 setspec(vq);
83 else
84 unsetspec(vq);
85 }
86 if (l->flags & BF_DOGETOPTS)
87 user_opt = l->getopts_state;
88 afreeall(&l->area);
89 afree(l, ATEMP);
90}
91
92/* called by main() to initialize variable data structures */
93void
94initvar(void)
95{
96 static const struct {
97 const char *name;
98 int v;
99 } names[] = {
100 { "COLUMNS", V_COLUMNS },
101 { "IFS", V_IFS },
102 { "OPTIND", V_OPTIND },
103 { "PATH", V_PATH },
104 { "POSIXLY_CORRECT", V_POSIXLY_CORRECT },
105 { "TMPDIR", V_TMPDIR },
106 { "HISTCONTROL", V_HISTCONTROL },
107 { "HISTFILE", V_HISTFILE },
108 { "HISTSIZE", V_HISTSIZE },
109 { "EDITOR", V_EDITOR },
110 { "VISUAL", V_VISUAL },
111 { "MAIL", V_MAIL },
112 { "MAILCHECK", V_MAILCHECK },
113 { "MAILPATH", V_MAILPATH },
114 { "RANDOM", V_RANDOM },
115 { "SECONDS", V_SECONDS },
116 { "TMOUT", V_TMOUT },
117 { "LINENO", V_LINENO },
118 { "TERM", V_TERM },
119 { NULL, 0 }
120 };
121 int i;
122 struct tbl *tp;
123
124 ktinit(&specials, APERM, 32); /* must be 2^n (currently 19 specials) */
125 for (i = 0; names[i].name; i++) {
126 tp = ktenter(&specials, names[i].name, hash(names[i].name));
127 tp->flag = DEFINED|ISSET;
128 tp->type = names[i].v;
129 }
130}
131
132/* Used to calculate an array index for global()/local(). Sets *arrayp to
133 * non-zero if this is an array, sets *valp to the array index, returns
134 * the basename of the array.
135 */
136static const char *
137array_index_calc(const char *n, bool *arrayp, int *valp)
138{
139 const char *p;
140 int len;
141
142 *arrayp = false;
143 p = skip_varname(n, false);
144 if (p != n && *p == '[' && (len = array_ref_len(p))) {
145 char *sub, *tmp;
146 int64_t rval;
147
148 /* Calculate the value of the subscript */
149 *arrayp = true;
150 tmp = str_nsave(p+1, len-2, ATEMP);
151 sub = substitute(tmp, 0);
152 afree(tmp, ATEMP);
153 n = str_nsave(n, p - n, ATEMP);
154 evaluate(sub, &rval, KSH_UNWIND_ERROR, true);
155 if (rval < 0 || rval > INT_MAX)
156 errorf("%s: subscript %" PRIi64 " out of range",
157 n, rval);
158 *valp = rval;
159 afree(sub, ATEMP);
160 }
161 return n;
162}
163
164/*
165 * Search for variable, if not found create globally.
166 */
167struct tbl *
168global(const char *n)
169{
170 struct block *l = genv->loc;
171 struct tbl *vp;
172 long num;
173 int c;
174 unsigned int h;
175 bool array;
176 int val;
177
178 /* Check to see if this is an array */
179 n = array_index_calc(n, &array, &val);
180 h = hash(n);
181 c = (unsigned char)n[0];
182 if (!letter(c)) {
183 if (array)
184 errorf("bad substitution");
185 vp = &vtemp;
186 vp->flag = DEFINED;
187 vp->type = 0;
188 vp->areap = ATEMP;
189 *vp->name = c;
190 if (digit(c)) {
191 errno = 0;
192 num = strtol(n, NULL, 10);
193 if (errno == 0 && num <= l->argc)
194 /* setstr can't fail here */
195 setstr(vp, l->argv[num], KSH_RETURN_ERROR);
196 vp->flag |= RDONLY;
197 return vp;
198 }
199 vp->flag |= RDONLY;
200 if (n[1] != '\0')
201 return vp;
202 vp->flag |= ISSET|INTEGER;
203 switch (c) {
204 case '$':
205 vp->val.i = kshpid;
206 break;
207 case '!':
208 /* If no job, expand to nothing */
209 if ((vp->val.i = j_async()) == 0)
210 vp->flag &= ~(ISSET|INTEGER);
211 break;
212 case '?':
213 vp->val.i = exstat;
214 break;
215 case '#':
216 vp->val.i = l->argc;
217 break;
218 case '-':
219 vp->flag &= ~INTEGER;
220 vp->val.s = getoptions();
221 break;
222 default:
223 vp->flag &= ~(ISSET|INTEGER);
224 }
225 return vp;
226 }
227 for (l = genv->loc; ; l = l->next) {
228 vp = ktsearch(&l->vars, n, h);
229 if (vp != NULL) {
230 if (array)
231 return arraysearch(vp, val);
232 else
233 return vp;
234 }
235 if (l->next == NULL)
236 break;
237 }
238 vp = ktenter(&l->vars, n, h);
239 if (array)
240 vp = arraysearch(vp, val);
241 vp->flag |= DEFINED;
242 if (special(n))
243 vp->flag |= SPECIAL;
244 return vp;
245}
246
247/*
248 * Search for local variable, if not found create locally.
249 */
250struct tbl *
251local(const char *n, bool copy)
252{
253 struct block *l = genv->loc;
254 struct tbl *vp;
255 unsigned int h;
256 bool array;
257 int val;
258
259 /* Check to see if this is an array */
260 n = array_index_calc(n, &array, &val);
261 h = hash(n);
262 if (!letter(*n)) {
263 vp = &vtemp;
264 vp->flag = DEFINED|RDONLY;
265 vp->type = 0;
266 vp->areap = ATEMP;
267 return vp;
268 }
269 vp = ktenter(&l->vars, n, h);
270 if (copy && !(vp->flag & DEFINED)) {
271 struct block *ll = l;
272 struct tbl *vq = NULL;
273
274 while ((ll = ll->next) && !(vq = ktsearch(&ll->vars, n, h)))
275 ;
276 if (vq) {
277 vp->flag |= vq->flag &
278 (EXPORT | INTEGER | RDONLY | LJUST | RJUST |
279 ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
280 if (vq->flag & INTEGER)
281 vp->type = vq->type;
282 vp->u2.field = vq->u2.field;
283 }
284 }
285 if (array)
286 vp = arraysearch(vp, val);
287 vp->flag |= DEFINED;
288 if (special(n))
289 vp->flag |= SPECIAL;
290 return vp;
291}
292
293/* get variable string value */
294char *
295str_val(struct tbl *vp)
296{
297 char *s;
298
299 if ((vp->flag&SPECIAL))
300 getspec(vp);
301 if (!(vp->flag&ISSET))
302 s = null; /* special to dollar() */
303 else if (!(vp->flag&INTEGER)) /* string source */
304 s = vp->val.s + vp->type;
305 else { /* integer source */
306 /* worst case number length is when base=2, so use
307 * minus base # number BITS(int64_t) NUL */
308 char strbuf[1 + 2 + 1 + BITS(int64_t) + 1];
309 const char *digits = (vp->flag & UCASEV_AL) ?
310 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" :
311 "0123456789abcdefghijklmnopqrstuvwxyz";
312 uint64_t n;
313 unsigned int base;
314
315 s = strbuf + sizeof(strbuf);
316 if (vp->flag & INT_U)
317 n = (uint64_t) vp->val.i;
318 else
319 n = (vp->val.i < 0) ? -vp->val.i : vp->val.i;
320 base = (vp->type == 0) ? 10 : vp->type;
321 if (base < 2 || base > strlen(digits))
322 base = 10;
323
324 *--s = '\0';
325 do {
326 *--s = digits[n % base];
327 n /= base;
328 } while (n != 0);
329 if (base != 10) {
330 *--s = '#';
331 *--s = digits[base % 10];
332 if (base >= 10)
333 *--s = digits[base / 10];
334 }
335 if (!(vp->flag & INT_U) && vp->val.i < 0)
336 *--s = '-';
337 if (vp->flag & (RJUST|LJUST)) /* case already dealt with */
338 s = formatstr(vp, s);
339 else
340 s = str_save(s, ATEMP);
341 }
342 return s;
343}
344
345/* get variable integer value, with error checking */
346int64_t
347intval(struct tbl *vp)
348{
349 int64_t num;
350 int base;
351
352 base = getint(vp, &num, false);
353 if (base == -1)
354 /* XXX check calls - is error here ok by POSIX? */
355 errorf("%s: bad number", str_val(vp));
356 return num;
357}
358
359/* set variable to string value */
360int
361setstr(struct tbl *vq, const char *s, int error_ok)
362{
363 const char *fs = NULL;
364 int no_ro_check = error_ok & KSH_IGNORE_RDONLY;
365 error_ok &= ~KSH_IGNORE_RDONLY;
366 if ((vq->flag & RDONLY) && !no_ro_check) {
367 warningf(true, "%s: is read only", vq->name);
368 if (!error_ok)
369 errorf(NULL);
370 return 0;
371 }
372 if (!(vq->flag&INTEGER)) { /* string dest */
373 if ((vq->flag&ALLOC)) {
374 /* debugging */
375 if (s >= vq->val.s &&
376 s <= vq->val.s + strlen(vq->val.s))
377 internal_errorf("%s: %s=%s: assigning to self",
378 __func__, vq->name, s);
379 afree(vq->val.s, vq->areap);
380 }
381 vq->flag &= ~(ISSET|ALLOC);
382 vq->type = 0;
383 if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
384 fs = s = formatstr(vq, s);
385 if ((vq->flag&EXPORT))
386 export(vq, s);
387 else {
388 vq->val.s = str_save(s, vq->areap);
389 vq->flag |= ALLOC;
390 }
391 } else { /* integer dest */
392 if (!v_evaluate(vq, s, error_ok, true))
393 return 0;
394 }
395 vq->flag |= ISSET;
396 if ((vq->flag&SPECIAL))
397 setspec(vq);
398 afree((void *)fs, ATEMP);
399 return 1;
400}
401
402/* set variable to integer */
403void
404setint(struct tbl *vq, int64_t n)
405{
406 if (!(vq->flag&INTEGER)) {
407 struct tbl *vp = &vtemp;
408 vp->flag = (ISSET|INTEGER);
409 vp->type = 0;
410 vp->areap = ATEMP;
411 vp->val.i = n;
412 /* setstr can't fail here */
413 setstr(vq, str_val(vp), KSH_RETURN_ERROR);
414 } else
415 vq->val.i = n;
416 vq->flag |= ISSET;
417 if ((vq->flag&SPECIAL))
418 setspec(vq);
419}
420
421int
422getint(struct tbl *vp, int64_t *nump, bool arith)
423{
424 char *s;
425 int c;
426 int base, neg;
427 int have_base = 0;
428 int64_t num;
429
430 if (vp->flag&SPECIAL)
431 getspec(vp);
432 /* XXX is it possible for ISSET to be set and val.s to be 0? */
433 if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
434 return -1;
435 if (vp->flag&INTEGER) {
436 *nump = vp->val.i;
437 return vp->type;
438 }
439 s = vp->val.s + vp->type;
440 if (s == NULL) /* redundant given initial test */
441 s = null;
442 base = 10;
443 num = 0;
444 neg = 0;
445 if (arith && *s == '0' && *(s+1)) {
446 s++;
447 if (*s == 'x' || *s == 'X') {
448 s++;
449 base = 16;
450 } else if (vp->flag & ZEROFIL) {
451 while (*s == '0')
452 s++;
453 } else
454 base = 8;
455 have_base++;
456 }
457 for (c = (unsigned char)*s++; c ; c = (unsigned char)*s++) {
458 if (c == '-') {
459 neg++;
460 } else if (c == '#') {
461 base = (int) num;
462 if (have_base || base < 2 || base > 36)
463 return -1;
464 num = 0;
465 have_base = 1;
466 } else if (letnum(c)) {
467 if (isdigit(c))
468 c -= '0';
469 else if (islower(c))
470 c -= 'a' - 10; /* todo: assumes ascii */
471 else if (isupper(c))
472 c -= 'A' - 10; /* todo: assumes ascii */
473 else
474 c = -1; /* _: force error */
475 if (c < 0 || c >= base)
476 return -1;
477 num = num * base + c;
478 } else
479 return -1;
480 }
481 if (neg)
482 num = -num;
483 *nump = num;
484 return base;
485}
486
487/* convert variable vq to integer variable, setting its value from vp
488 * (vq and vp may be the same)
489 */
490struct tbl *
491setint_v(struct tbl *vq, struct tbl *vp, bool arith)
492{
493 int base;
494 int64_t num;
495
496 if ((base = getint(vp, &num, arith)) == -1)
497 return NULL;
498 if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
499 vq->flag &= ~ALLOC;
500 afree(vq->val.s, vq->areap);
501 }
502 vq->val.i = num;
503 if (vq->type == 0) /* default base */
504 vq->type = base;
505 vq->flag |= ISSET|INTEGER;
506 if (vq->flag&SPECIAL)
507 setspec(vq);
508 return vq;
509}
510
511static char *
512formatstr(struct tbl *vp, const char *s)
513{
514 int olen, nlen;
515 char *p, *q;
516
517 olen = strlen(s);
518
519 if (vp->flag & (RJUST|LJUST)) {
520 if (!vp->u2.field) /* default field width */
521 vp->u2.field = olen;
522 nlen = vp->u2.field;
523 } else
524 nlen = olen;
525
526 p = alloc(nlen + 1, ATEMP);
527 if (vp->flag & (RJUST|LJUST)) {
528 int slen;
529
530 if (vp->flag & RJUST) {
531 const char *r = s + olen;
532 /* strip trailing spaces (at&t ksh uses r[-1] == ' ') */
533 while (r > s && isspace((unsigned char)r[-1]))
534 --r;
535 slen = r - s;
536 if (slen > vp->u2.field) {
537 s += slen - vp->u2.field;
538 slen = vp->u2.field;
539 }
540 shf_snprintf(p, nlen + 1,
541 ((vp->flag & ZEROFIL) && digit(*s)) ?
542 "%0*s%.*s" : "%*s%.*s",
543 vp->u2.field - slen, null, slen, s);
544 } else {
545 /* strip leading spaces/zeros */
546 while (isspace((unsigned char)*s))
547 s++;
548 if (vp->flag & ZEROFIL)
549 while (*s == '0')
550 s++;
551 shf_snprintf(p, nlen + 1, "%-*.*s",
552 vp->u2.field, vp->u2.field, s);
553 }
554 } else
555 memcpy(p, s, olen + 1);
556
557 if (vp->flag & UCASEV_AL) {
558 for (q = p; *q; q++)
559 if (islower((unsigned char)*q))
560 *q = toupper((unsigned char)*q);
561 } else if (vp->flag & LCASEV) {
562 for (q = p; *q; q++)
563 if (isupper((unsigned char)*q))
564 *q = tolower((unsigned char)*q);
565 }
566
567 return p;
568}
569
570/*
571 * make vp->val.s be "name=value" for quick exporting.
572 */
573static void
574export(struct tbl *vp, const char *val)
575{
576 char *xp;
577 char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
578 int namelen = strlen(vp->name);
579 int vallen = strlen(val) + 1;
580
581 vp->flag |= ALLOC;
582 xp = alloc(namelen + 1 + vallen, vp->areap);
583 memcpy(vp->val.s = xp, vp->name, namelen);
584 xp += namelen;
585 *xp++ = '=';
586 vp->type = xp - vp->val.s; /* offset to value */
587 memcpy(xp, val, vallen);
588 afree(op, vp->areap);
589}
590
591/*
592 * lookup variable (according to (set&LOCAL)),
593 * set its attributes (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL,
594 * LCASEV, UCASEV_AL), and optionally set its value if an assignment.
595 */
596struct tbl *
597typeset(const char *var, int set, int clr, int field, int base)
598{
599 struct tbl *vp;
600 struct tbl *vpbase, *t;
601 char *tvar;
602 const char *val;
603
604 /* check for valid variable name, search for value */
605 val = skip_varname(var, false);
606 if (val == var)
607 return NULL;
608 if (*val == '[') {
609 int len;
610
611 len = array_ref_len(val);
612 if (len == 0)
613 return NULL;
614 /* IMPORT is only used when the shell starts up and is
615 * setting up its environment. Allow only simple array
616 * references at this time since parameter/command substitution
617 * is preformed on the [expression], which would be a major
618 * security hole.
619 */
620 if (set & IMPORT) {
621 int i;
622 for (i = 1; i < len - 1; i++)
623 if (!digit(val[i]))
624 return NULL;
625 }
626 val += len;
627 }
628 if (*val == '=')
629 tvar = str_nsave(var, val++ - var, ATEMP);
630 else {
631 /* Importing from original environment: must have an = */
632 if (set & IMPORT)
633 return NULL;
634 tvar = (char *) var;
635 val = NULL;
636 }
637
638 /* Prevent typeset from creating a local PATH/ENV/SHELL */
639 if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 ||
640 strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0))
641 errorf("%s: restricted", tvar);
642
643 vp = (set&LOCAL) ? local(tvar, (set & LOCAL_COPY) ? true : false) :
644 global(tvar);
645 set &= ~(LOCAL|LOCAL_COPY);
646
647 vpbase = (vp->flag & ARRAY) ? global(arrayname(tvar)) : vp;
648
649 /* only allow export flag to be set. at&t ksh allows any attribute to
650 * be changed, which means it can be truncated or modified
651 * (-L/-R/-Z/-i).
652 */
653 if ((vpbase->flag&RDONLY) &&
654 (val || clr || (set & ~EXPORT)))
655 /* XXX check calls - is error here ok by POSIX? */
656 errorf("%s: is read only", tvar);
657 if (val)
658 afree(tvar, ATEMP);
659
660 /* most calls are with set/clr == 0 */
661 if (set | clr) {
662 int ok = 1;
663 /* XXX if x[0] isn't set, there will be problems: need to have
664 * one copy of attributes for arrays...
665 */
666 for (t = vpbase; t; t = t->u.array) {
667 int fake_assign;
668 int error_ok = KSH_RETURN_ERROR;
669 char *s = NULL;
670 char *free_me = NULL;
671
672 fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
673 ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
674 ((t->flag & INTEGER) && (clr & INTEGER)) ||
675 (!(t->flag & INTEGER) && (set & INTEGER)));
676 if (fake_assign) {
677 if (t->flag & INTEGER) {
678 s = str_val(t);
679 free_me = NULL;
680 } else {
681 s = t->val.s + t->type;
682 free_me = (t->flag & ALLOC) ? t->val.s :
683 NULL;
684 }
685 t->flag &= ~ALLOC;
686 }
687 if (!(t->flag & INTEGER) && (set & INTEGER)) {
688 t->type = 0;
689 t->flag &= ~ALLOC;
690 }
691 if (!(t->flag & RDONLY) && (set & RDONLY)) {
692 /* allow var to be initialized read-only */
693 error_ok |= KSH_IGNORE_RDONLY;
694 }
695 t->flag = (t->flag | set) & ~clr;
696 /* Don't change base if assignment is to be done,
697 * in case assignment fails.
698 */
699 if ((set & INTEGER) && base > 0 && (!val || t != vp))
700 t->type = base;
701 if (set & (LJUST|RJUST|ZEROFIL))
702 t->u2.field = field;
703 if (fake_assign) {
704 if (!setstr(t, s, error_ok)) {
705 /* Somewhat arbitrary action here:
706 * zap contents of variable, but keep
707 * the flag settings.
708 */
709 ok = 0;
710 if (t->flag & INTEGER)
711 t->flag &= ~ISSET;
712 else {
713 if (t->flag & ALLOC)
714 afree(t->val.s, t->areap);
715 t->flag &= ~(ISSET|ALLOC);
716 t->type = 0;
717 }
718 }
719 afree(free_me, t->areap);
720 }
721 }
722 if (!ok)
723 errorf(NULL);
724 }
725
726 if (val != NULL) {
727 if (vp->flag&INTEGER) {
728 /* do not zero base before assignment */
729 setstr(vp, val, KSH_UNWIND_ERROR | KSH_IGNORE_RDONLY);
730 /* Done after assignment to override default */
731 if (base > 0)
732 vp->type = base;
733 } else
734 /* setstr can't fail (readonly check already done) */
735 setstr(vp, val, KSH_RETURN_ERROR | KSH_IGNORE_RDONLY);
736 }
737
738 /* only x[0] is ever exported, so use vpbase */
739 if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
740 vpbase->type == 0)
741 export(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
742
743 return vp;
744}
745
746/* Unset a variable. array_ref is set if there was an array reference in
747 * the name lookup (eg, x[2]).
748 */
749void
750unset(struct tbl *vp, int array_ref)
751{
752 if (vp->flag & ALLOC)
753 afree(vp->val.s, vp->areap);
754 if ((vp->flag & ARRAY) && !array_ref) {
755 struct tbl *a, *tmp;
756
757 /* Free up entire array */
758 for (a = vp->u.array; a; ) {
759 tmp = a;
760 a = a->u.array;
761 if (tmp->flag & ALLOC)
762 afree(tmp->val.s, tmp->areap);
763 afree(tmp, tmp->areap);
764 }
765 vp->u.array = NULL;
766 }
767 /* If foo[0] is being unset, the remainder of the array is kept... */
768 vp->flag &= SPECIAL | (array_ref ? ARRAY|DEFINED : 0);
769 if (vp->flag & SPECIAL)
770 unsetspec(vp); /* responsible for `unspecial'ing var */
771}
772
773/* return a pointer to the first char past a legal variable name (returns the
774 * argument if there is no legal name, returns * a pointer to the terminating
775 * null if whole string is legal).
776 */
777char *
778skip_varname(const char *s, int aok)
779{
780 int alen;
781
782 if (s && letter(*s)) {
783 while (*++s && letnum(*s))
784 ;
785 if (aok && *s == '[' && (alen = array_ref_len(s)))
786 s += alen;
787 }
788 return (char *) s;
789}
790
791/* Return a pointer to the first character past any legal variable name. */
792char *
793skip_wdvarname(const char *s,
794 int aok) /* skip array de-reference? */
795{
796 if (s[0] == CHAR && letter(s[1])) {
797 do {
798 s += 2;
799 } while (s[0] == CHAR && letnum(s[1]));
800 if (aok && s[0] == CHAR && s[1] == '[') {
801 /* skip possible array de-reference */
802 const char *p = s;
803 char c;
804 int depth = 0;
805
806 while (1) {
807 if (p[0] != CHAR)
808 break;
809 c = p[1];
810 p += 2;
811 if (c == '[')
812 depth++;
813 else if (c == ']' && --depth == 0) {
814 s = p;
815 break;
816 }
817 }
818 }
819 }
820 return (char *) s;
821}
822
823/* Check if coded string s is a variable name */
824int
825is_wdvarname(const char *s, int aok)
826{
827 char *p = skip_wdvarname(s, aok);
828
829 return p != s && p[0] == EOS;
830}
831
832/* Check if coded string s is a variable assignment */
833int
834is_wdvarassign(const char *s)
835{
836 char *p = skip_wdvarname(s, true);
837
838 return p != s && p[0] == CHAR && p[1] == '=';
839}
840
841/*
842 * Make the exported environment from the exported names in the dictionary.
843 */
844char **
845makenv(void)
846{
847 struct block *l;
848 XPtrV env;
849 struct tbl *vp, **vpp;
850 int i;
851
852 XPinit(env, 64);
853 for (l = genv->loc; l != NULL; l = l->next)
854 for (vpp = l->vars.tbls, i = l->vars.size; --i >= 0; )
855 if ((vp = *vpp++) != NULL &&
856 (vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
857 struct block *l2;
858 struct tbl *vp2;
859 unsigned int h = hash(vp->name);
860
861 /* unexport any redefined instances */
862 for (l2 = l->next; l2 != NULL; l2 = l2->next) {
863 vp2 = ktsearch(&l2->vars, vp->name, h);
864 if (vp2 != NULL)
865 vp2->flag &= ~EXPORT;
866 }
867 if ((vp->flag&INTEGER)) {
868 /* integer to string */
869 char *val;
870 val = str_val(vp);
871 vp->flag &= ~(INTEGER|RDONLY);
872 /* setstr can't fail here */
873 setstr(vp, val, KSH_RETURN_ERROR);
874 }
875 XPput(env, vp->val.s);
876 }
877 XPput(env, NULL);
878 return (char **) XPclose(env);
879}
880
881/*
882 * Called after a fork in parent to bump the random number generator.
883 * Done to ensure children will not get the same random number sequence
884 * if the parent doesn't use $RANDOM.
885 */
886void
887change_random(void)
888{
889 rand();
890}
891
892/*
893 * handle special variables with side effects - PATH, SECONDS.
894 */
895
896/* Test if name is a special parameter */
897static int
898special(const char *name)
899{
900 struct tbl *tp;
901
902 tp = ktsearch(&specials, name, hash(name));
903 return tp && (tp->flag & ISSET) ? tp->type : V_NONE;
904}
905
906/* Make a variable non-special */
907static void
908unspecial(const char *name)
909{
910 struct tbl *tp;
911
912 tp = ktsearch(&specials, name, hash(name));
913 if (tp)
914 ktdelete(tp);
915}
916
917static struct timespec seconds; /* time SECONDS last set */
918static int user_lineno; /* what user set $LINENO to */
919
920static void
921getspec(struct tbl *vp)
922{
923 switch (special(vp->name)) {
924 case V_SECONDS:
925 vp->flag &= ~SPECIAL;
926 /* On start up the value of SECONDS is used before seconds
927 * has been set - don't do anything in this case
928 * (see initcoms[] in main.c).
929 */
930 if (vp->flag & ISSET) {
931 struct timespec difference, now;
932
933 clock_gettime(CLOCK_MONOTONIC, &now);
934 timespecsub(&now, &seconds, &difference);
935 setint(vp, (int64_t)difference.tv_sec);
936 }
937 vp->flag |= SPECIAL;
938 break;
939 case V_RANDOM:
940 vp->flag &= ~SPECIAL;
941 setint(vp, (int64_t) (rand() & 0x7fff));
942 vp->flag |= SPECIAL;
943 break;
944 case V_HISTSIZE:
945 vp->flag &= ~SPECIAL;
946 setint(vp, (int64_t) histsize);
947 vp->flag |= SPECIAL;
948 break;
949 case V_OPTIND:
950 vp->flag &= ~SPECIAL;
951 setint(vp, (int64_t) user_opt.uoptind);
952 vp->flag |= SPECIAL;
953 break;
954 case V_LINENO:
955 vp->flag &= ~SPECIAL;
956 setint(vp, (int64_t) current_lineno + user_lineno);
957 vp->flag |= SPECIAL;
958 break;
959 }
960}
961
962static void
963setspec(struct tbl *vp)
964{
965 char *s;
966
967 switch (special(vp->name)) {
968 case V_PATH:
969 afree(search_path, APERM);
970 search_path = str_save(str_val(vp), APERM);
971 flushcom(1); /* clear tracked aliases */
972 break;
973 case V_IFS:
974 setctypes(s = str_val(vp), C_IFS);
975 ifs0 = *s;
976 break;
977 case V_OPTIND:
978 vp->flag &= ~SPECIAL;
979 getopts_reset((int) intval(vp));
980 vp->flag |= SPECIAL;
981 break;
982 case V_POSIXLY_CORRECT:
983 change_flag(FPOSIX, OF_SPECIAL, 1);
984 break;
985 case V_TMPDIR:
986 afree(tmpdir, APERM);
987 tmpdir = NULL;
988 /* Use tmpdir iff it is an absolute path, is writable and
989 * searchable and is a directory...
990 */
991 {
992 struct stat statb;
993
994 s = str_val(vp);
995 if (s[0] == '/' && access(s, W_OK|X_OK) == 0 &&
996 stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
997 tmpdir = str_save(s, APERM);
998 }
999 break;
1000 case V_HISTCONTROL:
1001 sethistcontrol(str_val(vp));
1002 break;
1003 case V_HISTSIZE:
1004 vp->flag &= ~SPECIAL;
1005 sethistsize((int) intval(vp));
1006 vp->flag |= SPECIAL;
1007 break;
1008 case V_HISTFILE:
1009 sethistfile(str_val(vp));
1010 break;
1011 case V_VISUAL:
1012 set_editmode(str_val(vp));
1013 break;
1014 case V_EDITOR:
1015 if (!(global("VISUAL")->flag & ISSET))
1016 set_editmode(str_val(vp));
1017 break;
1018 case V_COLUMNS:
1019 {
1020 int64_t l;
1021
1022 if (getint(vp, &l, false) == -1) {
1023 x_cols = MIN_COLS;
1024 break;
1025 }
1026 if (l <= MIN_COLS || l > INT_MAX)
1027 x_cols = MIN_COLS;
1028 else
1029 x_cols = l;
1030 }
1031 break;
1032 case V_MAIL:
1033 mbset(str_val(vp));
1034 break;
1035 case V_MAILPATH:
1036 mpset(str_val(vp));
1037 break;
1038 case V_MAILCHECK:
1039 vp->flag &= ~SPECIAL;
1040 mcset(intval(vp));
1041 vp->flag |= SPECIAL;
1042 break;
1043 case V_RANDOM:
1044 vp->flag &= ~SPECIAL;
1045 srand_deterministic((unsigned int)intval(vp));
1046 vp->flag |= SPECIAL;
1047 break;
1048 case V_SECONDS:
1049 vp->flag &= ~SPECIAL;
1050 clock_gettime(CLOCK_MONOTONIC, &seconds);
1051 seconds.tv_sec -= intval(vp);
1052 vp->flag |= SPECIAL;
1053 break;
1054 case V_TMOUT:
1055 /* Enforce integer to avoid command execution from initcoms[] */
1056 vp->flag &= ~SPECIAL;
1057 intval(vp);
1058 vp->flag |= SPECIAL;
1059 /* at&t ksh seems to do this (only listen if integer) */
1060 if (vp->flag & INTEGER)
1061 ksh_tmout = vp->val.i >= 0 ? vp->val.i : 0;
1062 break;
1063 case V_LINENO:
1064 vp->flag &= ~SPECIAL;
1065 /* The -1 is because line numbering starts at 1. */
1066 user_lineno = (unsigned int) intval(vp) - current_lineno - 1;
1067 vp->flag |= SPECIAL;
1068 break;
1069 case V_TERM:
1070#ifndef SMALL
1071 {
1072 int ret;
1073
1074 vp->flag &= ~SPECIAL;
1075 if (setupterm(str_val(vp), shl_out->fd, &ret) == ERR)
1076 del_curterm(cur_term);
1077 vp->flag |= SPECIAL;
1078 }
1079#endif
1080 break;
1081 }
1082}
1083
1084static void
1085unsetspec(struct tbl *vp)
1086{
1087 switch (special(vp->name)) {
1088 case V_PATH:
1089 afree(search_path, APERM);
1090 search_path = str_save(def_path, APERM);
1091 flushcom(1); /* clear tracked aliases */
1092 break;
1093 case V_IFS:
1094 setctypes(" \t\n", C_IFS);
1095 ifs0 = ' ';
1096 break;
1097 case V_TMPDIR:
1098 /* should not become unspecial */
1099 afree(tmpdir, APERM);
1100 tmpdir = NULL;
1101 break;
1102 case V_MAIL:
1103 mbset(NULL);
1104 break;
1105 case V_MAILPATH:
1106 mpset(NULL);
1107 break;
1108 case V_HISTCONTROL:
1109 sethistcontrol(NULL);
1110 break;
1111 case V_LINENO:
1112 case V_MAILCHECK: /* at&t ksh leaves previous value in place */
1113 case V_RANDOM:
1114 case V_SECONDS:
1115 case V_TMOUT: /* at&t ksh leaves previous value in place */
1116 unspecial(vp->name);
1117 break;
1118
1119 /* at&t ksh man page says OPTIND, OPTARG and _ lose special meaning,
1120 * but OPTARG does not (still set by getopts) and _ is also still
1121 * set in various places.
1122 * Don't know what at&t does for:
1123 * MAIL, MAILPATH, HISTSIZE, HISTFILE,
1124 * Unsetting these in at&t ksh does not loose the `specialness':
1125 * no effect: IFS, COLUMNS, PATH, TMPDIR,
1126 * VISUAL, EDITOR,
1127 * pdkshisms: no effect:
1128 * POSIXLY_CORRECT (use set +o posix instead)
1129 */
1130 }
1131}
1132
1133/*
1134 * Search for (and possibly create) a table entry starting with
1135 * vp, indexed by val.
1136 */
1137static struct tbl *
1138arraysearch(struct tbl *vp, int val)
1139{
1140 struct tbl *prev, *curr, *new;
1141 size_t namelen = strlen(vp->name) + 1;
1142
1143 vp->flag |= ARRAY|DEFINED;
1144 vp->index = 0;
1145 /* The table entry is always [0] */
1146 if (val == 0)
1147 return vp;
1148 prev = vp;
1149 curr = vp->u.array;
1150 while (curr && curr->index < val) {
1151 prev = curr;
1152 curr = curr->u.array;
1153 }
1154 if (curr && curr->index == val) {
1155 if (curr->flag&ISSET)
1156 return curr;
1157 else
1158 new = curr;
1159 } else
1160 new = alloc(sizeof(struct tbl) + namelen,
1161 vp->areap);
1162 strlcpy(new->name, vp->name, namelen);
1163 new->flag = vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL);
1164 new->type = vp->type;
1165 new->areap = vp->areap;
1166 new->u2.field = vp->u2.field;
1167 new->index = val;
1168 if (curr != new) { /* not reusing old array entry */
1169 prev->u.array = new;
1170 new->u.array = curr;
1171 }
1172 return new;
1173}
1174
1175/* Return the length of an array reference (eg, [1+2]) - cp is assumed
1176 * to point to the open bracket. Returns 0 if there is no matching closing
1177 * bracket.
1178 */
1179int
1180array_ref_len(const char *cp)
1181{
1182 const char *s = cp;
1183 int c;
1184 int depth = 0;
1185
1186 while ((c = *s++) && (c != ']' || --depth))
1187 if (c == '[')
1188 depth++;
1189 if (!c)
1190 return 0;
1191 return s - cp;
1192}
1193
1194/*
1195 * Make a copy of the base of an array name
1196 */
1197char *
1198arrayname(const char *str)
1199{
1200 const char *p;
1201
1202 if ((p = strchr(str, '[')) == 0)
1203 /* Shouldn't happen, but why worry? */
1204 return (char *) str;
1205
1206 return str_nsave(str, p - str, ATEMP);
1207}
1208
1209/* Set (or overwrite, if !reset) the array variable var to the values in vals.
1210 */
1211void
1212set_array(const char *var, int reset, char **vals)
1213{
1214 struct tbl *vp, *vq;
1215 int i;
1216
1217 /* to get local array, use "typeset foo; set -A foo" */
1218 vp = global(var);
1219
1220 /* Note: at&t ksh allows set -A but not set +A of a read-only var */
1221 if ((vp->flag&RDONLY))
1222 errorf("%s: is read only", var);
1223 /* This code is quite non-optimal */
1224 if (reset > 0)
1225 /* trash existing values and attributes */
1226 unset(vp, 0);
1227 /* todo: would be nice for assignment to completely succeed or
1228 * completely fail. Only really effects integer arrays:
1229 * evaluation of some of vals[] may fail...
1230 */
1231 for (i = 0; vals[i]; i++) {
1232 vq = arraysearch(vp, i);
1233 /* would be nice to deal with errors here... (see above) */
1234 setstr(vq, vals[i], KSH_RETURN_ERROR);
1235 }
1236}
