1 /* $OpenBSD: var.c,v 1.73 2023/07/23 23:42:03 kn 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 */
30 static struct tbl vtemp;
31 static struct table specials;
32 static char *formatstr(struct tbl *, const char *);
33 static void export(struct tbl *, const char *);
34 static int special(const char *);
35 static void unspecial(const char *);
36 static void getspec(struct tbl *);
37 static void setspec(struct tbl *);
38 static void unsetspec(struct tbl *);
39 static 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 */
45 void
newblock(void)46 newblock(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 */
71 void
popblock(void)72 popblock(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 */
93 void
initvar(void)94 initvar(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 #ifndef SMALL
112 { "MAIL", V_MAIL },
113 { "MAILCHECK", V_MAILCHECK },
114 { "MAILPATH", V_MAILPATH },
115 #endif /* SMALL */
116 { "RANDOM", V_RANDOM },
117 { "SECONDS", V_SECONDS },
118 { "TMOUT", V_TMOUT },
119 { "LINENO", V_LINENO },
120 { "TERM", V_TERM },
121 { NULL, 0 }
122 };
123 int i;
124 struct tbl *tp;
125
126 ktinit(&specials, APERM, 32); /* must be 2^n (currently 19 specials) */
127 for (i = 0; names[i].name; i++) {
128 tp = ktenter(&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 static const char *
array_index_calc(const char * n,bool * arrayp,int * valp)139 array_index_calc(const char *n, bool *arrayp, int *valp)
140 {
141 const char *p;
142 int len;
143
144 *arrayp = false;
145 p = skip_varname(n, false);
146 if (p != n && *p == '[' && (len = array_ref_len(p))) {
147 char *sub, *tmp;
148 int64_t rval;
149
150 /* Calculate the value of the subscript */
151 *arrayp = true;
152 tmp = str_nsave(p+1, len-2, ATEMP);
153 sub = substitute(tmp, 0);
154 afree(tmp, ATEMP);
155 n = str_nsave(n, p - n, ATEMP);
156 evaluate(sub, &rval, KSH_UNWIND_ERROR, true);
157 if (rval < 0 || rval > INT_MAX)
158 errorf("%s: subscript %" PRIi64 " out of range",
159 n, rval);
160 *valp = rval;
161 afree(sub, ATEMP);
162 }
163 return n;
164 }
165
166 /*
167 * Search for variable, if not found create globally.
168 */
169 struct tbl *
global(const char * n)170 global(const char *n)
171 {
172 struct block *l = genv->loc;
173 struct tbl *vp;
174 long num;
175 int c;
176 unsigned int h;
177 bool array;
178 int val;
179
180 /* Check to see if this is an array */
181 n = array_index_calc(n, &array, &val);
182 h = hash(n);
183 c = (unsigned char)n[0];
184 if (!letter(c)) {
185 if (array)
186 errorf("bad substitution");
187 vp = &vtemp;
188 vp->flag = DEFINED;
189 vp->type = 0;
190 vp->areap = ATEMP;
191 *vp->name = c;
192 if (digit(c)) {
193 errno = 0;
194 num = strtol(n, NULL, 10);
195 if (errno == 0 && num <= l->argc)
196 /* setstr can't fail here */
197 setstr(vp, l->argv[num], KSH_RETURN_ERROR);
198 vp->flag |= RDONLY;
199 return vp;
200 }
201 vp->flag |= RDONLY;
202 if (n[1] != '\0')
203 return vp;
204 vp->flag |= ISSET|INTEGER;
205 switch (c) {
206 case '$':
207 vp->val.i = kshpid;
208 break;
209 case '!':
210 /* If no job, expand to nothing */
211 if ((vp->val.i = j_async()) == 0)
212 vp->flag &= ~(ISSET|INTEGER);
213 break;
214 case '?':
215 vp->val.i = exstat;
216 break;
217 case '#':
218 vp->val.i = l->argc;
219 break;
220 case '-':
221 vp->flag &= ~INTEGER;
222 vp->val.s = getoptions();
223 break;
224 default:
225 vp->flag &= ~(ISSET|INTEGER);
226 }
227 return vp;
228 }
229 for (l = genv->loc; ; l = l->next) {
230 vp = ktsearch(&l->vars, n, h);
231 if (vp != NULL) {
232 if (array)
233 return arraysearch(vp, val);
234 else
235 return vp;
236 }
237 if (l->next == NULL)
238 break;
239 }
240 vp = ktenter(&l->vars, n, h);
241 if (array)
242 vp = arraysearch(vp, val);
243 vp->flag |= DEFINED;
244 if (special(n))
245 vp->flag |= SPECIAL;
246 return vp;
247 }
248
249 /*
250 * Search for local variable, if not found create locally.
251 */
252 struct tbl *
local(const char * n,bool copy)253 local(const char *n, bool copy)
254 {
255 struct block *l = genv->loc;
256 struct tbl *vp;
257 unsigned int h;
258 bool array;
259 int val;
260
261 /* Check to see if this is an array */
262 n = array_index_calc(n, &array, &val);
263 h = hash(n);
264 if (!letter(*n)) {
265 vp = &vtemp;
266 vp->flag = DEFINED|RDONLY;
267 vp->type = 0;
268 vp->areap = ATEMP;
269 return vp;
270 }
271 vp = ktenter(&l->vars, n, h);
272 if (copy && !(vp->flag & DEFINED)) {
273 struct block *ll = l;
274 struct tbl *vq = NULL;
275
276 while ((ll = ll->next) && !(vq = ktsearch(&ll->vars, n, h)))
277 ;
278 if (vq) {
279 vp->flag |= vq->flag &
280 (EXPORT | INTEGER | RDONLY | LJUST | RJUST |
281 ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
282 if (vq->flag & INTEGER)
283 vp->type = vq->type;
284 vp->u2.field = vq->u2.field;
285 }
286 }
287 if (array)
288 vp = arraysearch(vp, val);
289 vp->flag |= DEFINED;
290 if (special(n))
291 vp->flag |= SPECIAL;
292 return vp;
293 }
294
295 /* get variable string value */
296 char *
str_val(struct tbl * vp)297 str_val(struct tbl *vp)
298 {
299 char *s;
300
301 if ((vp->flag&SPECIAL))
302 getspec(vp);
303 if (!(vp->flag&ISSET))
304 s = null; /* special to dollar() */
305 else if (!(vp->flag&INTEGER)) /* string source */
306 s = vp->val.s + vp->type;
307 else { /* integer source */
308 /* worst case number length is when base=2, so use
309 * minus base # number BITS(int64_t) NUL */
310 char strbuf[1 + 2 + 1 + BITS(int64_t) + 1];
311 const char *digits = (vp->flag & UCASEV_AL) ?
312 "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" :
313 "0123456789abcdefghijklmnopqrstuvwxyz";
314 uint64_t n;
315 unsigned int base;
316
317 s = strbuf + sizeof(strbuf);
318 if (vp->flag & INT_U)
319 n = (uint64_t) vp->val.i;
320 else
321 n = (vp->val.i < 0) ? -vp->val.i : vp->val.i;
322 base = (vp->type == 0) ? 10 : vp->type;
323 if (base < 2 || base > strlen(digits))
324 base = 10;
325
326 *--s = '\0';
327 do {
328 *--s = digits[n % base];
329 n /= base;
330 } while (n != 0);
331 if (base != 10) {
332 *--s = '#';
333 *--s = digits[base % 10];
334 if (base >= 10)
335 *--s = digits[base / 10];
336 }
337 if (!(vp->flag & INT_U) && vp->val.i < 0)
338 *--s = '-';
339 if (vp->flag & (RJUST|LJUST)) /* case already dealt with */
340 s = formatstr(vp, s);
341 else
342 s = str_save(s, ATEMP);
343 }
344 return s;
345 }
346
347 /* get variable integer value, with error checking */
348 int64_t
intval(struct tbl * vp)349 intval(struct tbl *vp)
350 {
351 int64_t num;
352 int base;
353
354 base = getint(vp, &num, false);
355 if (base == -1)
356 /* XXX check calls - is error here ok by POSIX? */
357 errorf("%s: bad number", str_val(vp));
358 return num;
359 }
360
361 /* set variable to string value */
362 int
setstr(struct tbl * vq,const char * s,int error_ok)363 setstr(struct tbl *vq, const char *s, int error_ok)
364 {
365 const char *fs = NULL;
366 int no_ro_check = error_ok & KSH_IGNORE_RDONLY;
367 error_ok &= ~KSH_IGNORE_RDONLY;
368 if ((vq->flag & RDONLY) && !no_ro_check) {
369 warningf(true, "%s: is read only", vq->name);
370 if (!error_ok)
371 errorf(NULL);
372 return 0;
373 }
374 if (!(vq->flag&INTEGER)) { /* string dest */
375 if ((vq->flag&ALLOC)) {
376 /* debugging */
377 if (s >= vq->val.s &&
378 s <= vq->val.s + strlen(vq->val.s))
379 internal_errorf("%s: %s=%s: assigning to self",
380 __func__, vq->name, s);
381 afree(vq->val.s, vq->areap);
382 }
383 vq->flag &= ~(ISSET|ALLOC);
384 vq->type = 0;
385 if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
386 fs = s = formatstr(vq, s);
387 if ((vq->flag&EXPORT))
388 export(vq, s);
389 else {
390 vq->val.s = str_save(s, vq->areap);
391 vq->flag |= ALLOC;
392 }
393 } else { /* integer dest */
394 if (!v_evaluate(vq, s, error_ok, true))
395 return 0;
396 }
397 vq->flag |= ISSET;
398 if ((vq->flag&SPECIAL))
399 setspec(vq);
400 afree((void *)fs, ATEMP);
401 return 1;
402 }
403
404 /* set variable to integer */
405 void
setint(struct tbl * vq,int64_t n)406 setint(struct tbl *vq, int64_t n)
407 {
408 if (!(vq->flag&INTEGER)) {
409 struct tbl *vp = &vtemp;
410 vp->flag = (ISSET|INTEGER);
411 vp->type = 0;
412 vp->areap = ATEMP;
413 vp->val.i = n;
414 /* setstr can't fail here */
415 setstr(vq, str_val(vp), KSH_RETURN_ERROR);
416 } else
417 vq->val.i = n;
418 vq->flag |= ISSET;
419 if ((vq->flag&SPECIAL))
420 setspec(vq);
421 }
422
423 int
getint(struct tbl * vp,int64_t * nump,bool arith)424 getint(struct tbl *vp, int64_t *nump, bool arith)
425 {
426 char *s;
427 int c;
428 int base, neg;
429 int have_base = 0;
430 int64_t num;
431
432 if (vp->flag&SPECIAL)
433 getspec(vp);
434 /* XXX is it possible for ISSET to be set and val.s to be 0? */
435 if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
436 return -1;
437 if (vp->flag&INTEGER) {
438 *nump = vp->val.i;
439 return vp->type;
440 }
441 s = vp->val.s + vp->type;
442 if (s == NULL) /* redundant given initial test */
443 s = null;
444 base = 10;
445 num = 0;
446 neg = 0;
447 if (arith && *s == '0' && *(s+1)) {
448 s++;
449 if (*s == 'x' || *s == 'X') {
450 s++;
451 base = 16;
452 } else if (vp->flag & ZEROFIL) {
453 while (*s == '0')
454 s++;
455 } else
456 base = 8;
457 have_base++;
458 }
459 for (c = (unsigned char)*s++; c ; c = (unsigned char)*s++) {
460 if (c == '-') {
461 neg++;
462 } else if (c == '#') {
463 base = (int) num;
464 if (have_base || base < 2 || base > 36)
465 return -1;
466 num = 0;
467 have_base = 1;
468 } else if (letnum(c)) {
469 if (isdigit(c))
470 c -= '0';
471 else if (islower(c))
472 c -= 'a' - 10; /* todo: assumes ascii */
473 else if (isupper(c))
474 c -= 'A' - 10; /* todo: assumes ascii */
475 else
476 c = -1; /* _: force error */
477 if (c < 0 || c >= base)
478 return -1;
479 num = num * base + c;
480 } else
481 return -1;
482 }
483 if (neg)
484 num = -num;
485 *nump = num;
486 return base;
487 }
488
489 /* convert variable vq to integer variable, setting its value from vp
490 * (vq and vp may be the same)
491 */
492 struct tbl *
setint_v(struct tbl * vq,struct tbl * vp,bool arith)493 setint_v(struct tbl *vq, struct tbl *vp, bool arith)
494 {
495 int base;
496 int64_t num;
497
498 if ((base = getint(vp, &num, arith)) == -1)
499 return NULL;
500 if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
501 vq->flag &= ~ALLOC;
502 afree(vq->val.s, vq->areap);
503 }
504 vq->val.i = num;
505 if (vq->type == 0) /* default base */
506 vq->type = base;
507 vq->flag |= ISSET|INTEGER;
508 if (vq->flag&SPECIAL)
509 setspec(vq);
510 return vq;
511 }
512
513 static char *
formatstr(struct tbl * vp,const char * s)514 formatstr(struct tbl *vp, const char *s)
515 {
516 int olen, nlen;
517 char *p, *q;
518
519 olen = strlen(s);
520
521 if (vp->flag & (RJUST|LJUST)) {
522 if (!vp->u2.field) /* default field width */
523 vp->u2.field = olen;
524 nlen = vp->u2.field;
525 } else
526 nlen = olen;
527
528 p = alloc(nlen + 1, ATEMP);
529 if (vp->flag & (RJUST|LJUST)) {
530 int slen;
531
532 if (vp->flag & RJUST) {
533 const char *r = s + olen;
534 /* strip trailing spaces (at&t ksh uses r[-1] == ' ') */
535 while (r > s && isspace((unsigned char)r[-1]))
536 --r;
537 slen = r - s;
538 if (slen > vp->u2.field) {
539 s += slen - vp->u2.field;
540 slen = vp->u2.field;
541 }
542 shf_snprintf(p, nlen + 1,
543 ((vp->flag & ZEROFIL) && digit(*s)) ?
544 "%0*s%.*s" : "%*s%.*s",
545 vp->u2.field - slen, null, slen, s);
546 } else {
547 /* strip leading spaces/zeros */
548 while (isspace((unsigned char)*s))
549 s++;
550 if (vp->flag & ZEROFIL)
551 while (*s == '0')
552 s++;
553 shf_snprintf(p, nlen + 1, "%-*.*s",
554 vp->u2.field, vp->u2.field, s);
555 }
556 } else
557 memcpy(p, s, olen + 1);
558
559 if (vp->flag & UCASEV_AL) {
560 for (q = p; *q; q++)
561 if (islower((unsigned char)*q))
562 *q = toupper((unsigned char)*q);
563 } else if (vp->flag & LCASEV) {
564 for (q = p; *q; q++)
565 if (isupper((unsigned char)*q))
566 *q = tolower((unsigned char)*q);
567 }
568
569 return p;
570 }
571
572 /*
573 * make vp->val.s be "name=value" for quick exporting.
574 */
575 static void
export(struct tbl * vp,const char * val)576 export(struct tbl *vp, const char *val)
577 {
578 char *xp;
579 char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
580 int namelen = strlen(vp->name);
581 int vallen = strlen(val) + 1;
582
583 vp->flag |= ALLOC;
584 xp = alloc(namelen + 1 + vallen, vp->areap);
585 memcpy(vp->val.s = xp, vp->name, namelen);
586 xp += namelen;
587 *xp++ = '=';
588 vp->type = xp - vp->val.s; /* offset to value */
589 memcpy(xp, val, vallen);
590 afree(op, vp->areap);
591 }
592
593 /*
594 * lookup variable (according to (set&LOCAL)),
595 * set its attributes (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL,
596 * LCASEV, UCASEV_AL), and optionally set its value if an assignment.
597 */
598 struct tbl *
typeset(const char * var,int set,int clr,int field,int base)599 typeset(const char *var, int set, int clr, int field, int base)
600 {
601 struct tbl *vp;
602 struct tbl *vpbase, *t;
603 char *tvar;
604 const char *val;
605
606 /* check for valid variable name, search for value */
607 val = skip_varname(var, false);
608 if (val == var)
609 return NULL;
610 if (*val == '[') {
611 int len;
612
613 len = array_ref_len(val);
614 if (len == 0)
615 return NULL;
616 /* IMPORT is only used when the shell starts up and is
617 * setting up its environment. Allow only simple array
618 * references at this time since parameter/command substitution
619 * is preformed on the [expression], which would be a major
620 * security hole.
621 */
622 if (set & IMPORT) {
623 int i;
624 for (i = 1; i < len - 1; i++)
625 if (!digit(val[i]))
626 return NULL;
627 }
628 val += len;
629 }
630 if (*val == '=')
631 tvar = str_nsave(var, val++ - var, ATEMP);
632 else {
633 /* Importing from original environment: must have an = */
634 if (set & IMPORT)
635 return NULL;
636 tvar = (char *) var;
637 val = NULL;
638 }
639
640 /* Prevent typeset from creating a local PATH/ENV/SHELL */
641 if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 ||
642 strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0))
643 errorf("%s: restricted", tvar);
644
645 vp = (set&LOCAL) ? local(tvar, (set & LOCAL_COPY) ? true : false) :
646 global(tvar);
647 set &= ~(LOCAL|LOCAL_COPY);
648
649 vpbase = (vp->flag & ARRAY) ? global(arrayname(tvar)) : vp;
650
651 /* only allow export flag to be set. at&t ksh allows any attribute to
652 * be changed, which means it can be truncated or modified
653 * (-L/-R/-Z/-i).
654 */
655 if ((vpbase->flag&RDONLY) &&
656 (val || clr || (set & ~EXPORT)))
657 /* XXX check calls - is error here ok by POSIX? */
658 errorf("%s: is read only", tvar);
659 if (val)
660 afree(tvar, ATEMP);
661
662 /* most calls are with set/clr == 0 */
663 if (set | clr) {
664 int ok = 1;
665 /* XXX if x[0] isn't set, there will be problems: need to have
666 * one copy of attributes for arrays...
667 */
668 for (t = vpbase; t; t = t->u.array) {
669 int fake_assign;
670 int error_ok = KSH_RETURN_ERROR;
671 char *s = NULL;
672 char *free_me = NULL;
673
674 fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
675 ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
676 ((t->flag & INTEGER) && (clr & INTEGER)) ||
677 (!(t->flag & INTEGER) && (set & INTEGER)));
678 if (fake_assign) {
679 if (t->flag & INTEGER) {
680 s = str_val(t);
681 free_me = NULL;
682 } else {
683 s = t->val.s + t->type;
684 free_me = (t->flag & ALLOC) ? t->val.s :
685 NULL;
686 }
687 t->flag &= ~ALLOC;
688 }
689 if (!(t->flag & INTEGER) && (set & INTEGER)) {
690 t->type = 0;
691 t->flag &= ~ALLOC;
692 }
693 if (!(t->flag & RDONLY) && (set & RDONLY)) {
694 /* allow var to be initialized read-only */
695 error_ok |= KSH_IGNORE_RDONLY;
696 }
697 t->flag = (t->flag | set) & ~clr;
698 /* Don't change base if assignment is to be done,
699 * in case assignment fails.
700 */
701 if ((set & INTEGER) && base > 0 && (!val || t != vp))
702 t->type = base;
703 if (set & (LJUST|RJUST|ZEROFIL))
704 t->u2.field = field;
705 if (fake_assign) {
706 if (!setstr(t, s, error_ok)) {
707 /* Somewhat arbitrary action here:
708 * zap contents of variable, but keep
709 * the flag settings.
710 */
711 ok = 0;
712 if (t->flag & INTEGER)
713 t->flag &= ~ISSET;
714 else {
715 if (t->flag & ALLOC)
716 afree(t->val.s, t->areap);
717 t->flag &= ~(ISSET|ALLOC);
718 t->type = 0;
719 }
720 }
721 afree(free_me, t->areap);
722 }
723 }
724 if (!ok)
725 errorf(NULL);
726 }
727
728 if (val != NULL) {
729 if (vp->flag&INTEGER) {
730 /* do not zero base before assignment */
731 setstr(vp, val, KSH_UNWIND_ERROR | KSH_IGNORE_RDONLY);
732 /* Done after assignment to override default */
733 if (base > 0)
734 vp->type = base;
735 } else
736 /* setstr can't fail (readonly check already done) */
737 setstr(vp, val, KSH_RETURN_ERROR | KSH_IGNORE_RDONLY);
738 }
739
740 /* only x[0] is ever exported, so use vpbase */
741 if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
742 vpbase->type == 0)
743 export(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
744
745 return vp;
746 }
747
748 /* Unset a variable. array_ref is set if there was an array reference in
749 * the name lookup (eg, x[2]).
750 */
751 void
unset(struct tbl * vp,int array_ref)752 unset(struct tbl *vp, int array_ref)
753 {
754 if (vp->flag & ALLOC)
755 afree(vp->val.s, vp->areap);
756 if ((vp->flag & ARRAY) && !array_ref) {
757 struct tbl *a, *tmp;
758
759 /* Free up entire array */
760 for (a = vp->u.array; a; ) {
761 tmp = a;
762 a = a->u.array;
763 if (tmp->flag & ALLOC)
764 afree(tmp->val.s, tmp->areap);
765 afree(tmp, tmp->areap);
766 }
767 vp->u.array = NULL;
768 }
769 /* If foo[0] is being unset, the remainder of the array is kept... */
770 vp->flag &= SPECIAL | (array_ref ? ARRAY|DEFINED : 0);
771 if (vp->flag & SPECIAL)
772 unsetspec(vp); /* responsible for `unspecial'ing var */
773 }
774
775 /* return a pointer to the first char past a legal variable name (returns the
776 * argument if there is no legal name, returns * a pointer to the terminating
777 * null if whole string is legal).
778 */
779 char *
skip_varname(const char * s,int aok)780 skip_varname(const char *s, int aok)
781 {
782 int alen;
783
784 if (s && letter(*s)) {
785 while (*++s && letnum(*s))
786 ;
787 if (aok && *s == '[' && (alen = array_ref_len(s)))
788 s += alen;
789 }
790 return (char *) s;
791 }
792
793 /* Return a pointer to the first character past any legal variable name. */
794 char *
skip_wdvarname(const char * s,int aok)795 skip_wdvarname(const char *s,
796 int aok) /* skip array de-reference? */
797 {
798 if (s[0] == CHAR && letter(s[1])) {
799 do {
800 s += 2;
801 } while (s[0] == CHAR && letnum(s[1]));
802 if (aok && s[0] == CHAR && s[1] == '[') {
803 /* skip possible array de-reference */
804 const char *p = s;
805 char c;
806 int depth = 0;
807
808 while (1) {
809 if (p[0] != CHAR)
810 break;
811 c = p[1];
812 p += 2;
813 if (c == '[')
814 depth++;
815 else if (c == ']' && --depth == 0) {
816 s = p;
817 break;
818 }
819 }
820 }
821 }
822 return (char *) s;
823 }
824
825 /* Check if coded string s is a variable name */
826 int
is_wdvarname(const char * s,int aok)827 is_wdvarname(const char *s, int aok)
828 {
829 char *p = skip_wdvarname(s, aok);
830
831 return p != s && p[0] == EOS;
832 }
833
834 /* Check if coded string s is a variable assignment */
835 int
is_wdvarassign(const char * s)836 is_wdvarassign(const char *s)
837 {
838 char *p = skip_wdvarname(s, true);
839
840 return p != s && p[0] == CHAR && p[1] == '=';
841 }
842
843 /*
844 * Make the exported environment from the exported names in the dictionary.
845 */
846 char **
makenv(void)847 makenv(void)
848 {
849 struct block *l;
850 XPtrV env;
851 struct tbl *vp, **vpp;
852 int i;
853
854 XPinit(env, 64);
855 for (l = genv->loc; l != NULL; l = l->next)
856 for (vpp = l->vars.tbls, i = l->vars.size; --i >= 0; )
857 if ((vp = *vpp++) != NULL &&
858 (vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
859 struct block *l2;
860 struct tbl *vp2;
861 unsigned int h = hash(vp->name);
862
863 /* unexport any redefined instances */
864 for (l2 = l->next; l2 != NULL; l2 = l2->next) {
865 vp2 = ktsearch(&l2->vars, vp->name, h);
866 if (vp2 != NULL)
867 vp2->flag &= ~EXPORT;
868 }
869 if ((vp->flag&INTEGER)) {
870 /* integer to string */
871 char *val;
872 val = str_val(vp);
873 vp->flag &= ~(INTEGER|RDONLY);
874 /* setstr can't fail here */
875 setstr(vp, val, KSH_RETURN_ERROR);
876 }
877 XPput(env, vp->val.s);
878 }
879 XPput(env, NULL);
880 return (char **) XPclose(env);
881 }
882
883 /*
884 * Called after a fork in parent to bump the random number generator.
885 * Done to ensure children will not get the same random number sequence
886 * if the parent doesn't use $RANDOM.
887 */
888 void
change_random(void)889 change_random(void)
890 {
891 rand();
892 }
893
894 /*
895 * handle special variables with side effects - PATH, SECONDS.
896 */
897
898 /* Test if name is a special parameter */
899 static int
special(const char * name)900 special(const char *name)
901 {
902 struct tbl *tp;
903
904 tp = ktsearch(&specials, name, hash(name));
905 return tp && (tp->flag & ISSET) ? tp->type : V_NONE;
906 }
907
908 /* Make a variable non-special */
909 static void
unspecial(const char * name)910 unspecial(const char *name)
911 {
912 struct tbl *tp;
913
914 tp = ktsearch(&specials, name, hash(name));
915 if (tp)
916 ktdelete(tp);
917 }
918
919 static struct timespec seconds; /* time SECONDS last set */
920 static int user_lineno; /* what user set $LINENO to */
921
922 static void
getspec(struct tbl * vp)923 getspec(struct tbl *vp)
924 {
925 switch (special(vp->name)) {
926 case V_SECONDS:
927 vp->flag &= ~SPECIAL;
928 /* On start up the value of SECONDS is used before seconds
929 * has been set - don't do anything in this case
930 * (see initcoms[] in main.c).
931 */
932 if (vp->flag & ISSET) {
933 struct timespec difference, now;
934
935 clock_gettime(CLOCK_MONOTONIC, &now);
936 timespecsub(&now, &seconds, &difference);
937 setint(vp, (int64_t)difference.tv_sec);
938 }
939 vp->flag |= SPECIAL;
940 break;
941 case V_RANDOM:
942 vp->flag &= ~SPECIAL;
943 setint(vp, (int64_t) (rand() & 0x7fff));
944 vp->flag |= SPECIAL;
945 break;
946 case V_HISTSIZE:
947 vp->flag &= ~SPECIAL;
948 setint(vp, (int64_t) histsize);
949 vp->flag |= SPECIAL;
950 break;
951 case V_OPTIND:
952 vp->flag &= ~SPECIAL;
953 setint(vp, (int64_t) user_opt.uoptind);
954 vp->flag |= SPECIAL;
955 break;
956 case V_LINENO:
957 vp->flag &= ~SPECIAL;
958 setint(vp, (int64_t) current_lineno + user_lineno);
959 vp->flag |= SPECIAL;
960 break;
961 }
962 }
963
964 static void
setspec(struct tbl * vp)965 setspec(struct tbl *vp)
966 {
967 char *s;
968
969 switch (special(vp->name)) {
970 case V_PATH:
971 afree(search_path, APERM);
972 search_path = str_save(str_val(vp), APERM);
973 flushcom(1); /* clear tracked aliases */
974 break;
975 case V_IFS:
976 setctypes(s = str_val(vp), C_IFS);
977 ifs0 = *s;
978 break;
979 case V_OPTIND:
980 vp->flag &= ~SPECIAL;
981 getopts_reset((int) intval(vp));
982 vp->flag |= SPECIAL;
983 break;
984 case V_POSIXLY_CORRECT:
985 change_flag(FPOSIX, OF_SPECIAL, 1);
986 break;
987 case V_TMPDIR:
988 afree(tmpdir, APERM);
989 tmpdir = NULL;
990 /* Use tmpdir iff it is an absolute path, is writable and
991 * searchable and is a directory...
992 */
993 {
994 struct stat statb;
995
996 s = str_val(vp);
997 if (s[0] == '/' && access(s, W_OK|X_OK) == 0 &&
998 stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
999 tmpdir = str_save(s, APERM);
1000 }
1001 break;
1002 case V_HISTCONTROL:
1003 sethistcontrol(str_val(vp));
1004 break;
1005 case V_HISTSIZE:
1006 vp->flag &= ~SPECIAL;
1007 sethistsize((int) intval(vp));
1008 vp->flag |= SPECIAL;
1009 break;
1010 case V_HISTFILE:
1011 sethistfile(str_val(vp));
1012 break;
1013 case V_VISUAL:
1014 set_editmode(str_val(vp));
1015 break;
1016 case V_EDITOR:
1017 if (!(global("VISUAL")->flag & ISSET))
1018 set_editmode(str_val(vp));
1019 break;
1020 case V_COLUMNS:
1021 {
1022 int64_t l;
1023
1024 if (getint(vp, &l, false) == -1) {
1025 x_cols = MIN_COLS;
1026 break;
1027 }
1028 if (l <= MIN_COLS || l > INT_MAX)
1029 x_cols = MIN_COLS;
1030 else
1031 x_cols = l;
1032 }
1033 break;
1034 #ifndef SMALL
1035 case V_MAIL:
1036 mbset(str_val(vp));
1037 break;
1038 case V_MAILPATH:
1039 mpset(str_val(vp));
1040 break;
1041 case V_MAILCHECK:
1042 vp->flag &= ~SPECIAL;
1043 mcset(intval(vp));
1044 vp->flag |= SPECIAL;
1045 break;
1046 #endif /* SMALL */
1047 case V_RANDOM:
1048 vp->flag &= ~SPECIAL;
1049 srand_deterministic((unsigned int)intval(vp));
1050 vp->flag |= SPECIAL;
1051 break;
1052 case V_SECONDS:
1053 vp->flag &= ~SPECIAL;
1054 clock_gettime(CLOCK_MONOTONIC, &seconds);
1055 seconds.tv_sec -= intval(vp);
1056 vp->flag |= SPECIAL;
1057 break;
1058 case V_TMOUT:
1059 /* Enforce integer to avoid command execution from initcoms[] */
1060 vp->flag &= ~SPECIAL;
1061 intval(vp);
1062 vp->flag |= SPECIAL;
1063 /* at&t ksh seems to do this (only listen if integer) */
1064 if (vp->flag & INTEGER)
1065 ksh_tmout = vp->val.i >= 0 ? vp->val.i : 0;
1066 break;
1067 case V_LINENO:
1068 vp->flag &= ~SPECIAL;
1069 /* The -1 is because line numbering starts at 1. */
1070 user_lineno = (unsigned int) intval(vp) - current_lineno - 1;
1071 vp->flag |= SPECIAL;
1072 break;
1073 case V_TERM:
1074 #ifndef SMALL
1075 {
1076 int ret;
1077
1078 vp->flag &= ~SPECIAL;
1079 if (setupterm(str_val(vp), shl_out->fd, &ret) == ERR)
1080 del_curterm(cur_term);
1081 vp->flag |= SPECIAL;
1082 }
1083 #endif
1084 break;
1085 }
1086 }
1087
1088 static void
unsetspec(struct tbl * vp)1089 unsetspec(struct tbl *vp)
1090 {
1091 switch (special(vp->name)) {
1092 case V_PATH:
1093 afree(search_path, APERM);
1094 search_path = str_save(def_path, APERM);
1095 flushcom(1); /* clear tracked aliases */
1096 break;
1097 case V_IFS:
1098 setctypes(" \t\n", C_IFS);
1099 ifs0 = ' ';
1100 break;
1101 case V_TMPDIR:
1102 /* should not become unspecial */
1103 afree(tmpdir, APERM);
1104 tmpdir = NULL;
1105 break;
1106 #ifndef SMALL
1107 case V_MAIL:
1108 mbset(NULL);
1109 break;
1110 case V_MAILPATH:
1111 mpset(NULL);
1112 break;
1113 #endif /* SMALL */
1114 case V_HISTCONTROL:
1115 sethistcontrol(NULL);
1116 break;
1117 case V_LINENO:
1118 #ifndef SMALL
1119 case V_MAILCHECK: /* at&t ksh leaves previous value in place */
1120 #endif /* SMALL */
1121 case V_RANDOM:
1122 case V_SECONDS:
1123 case V_TMOUT: /* at&t ksh leaves previous value in place */
1124 unspecial(vp->name);
1125 break;
1126
1127 /* at&t ksh man page says OPTIND, OPTARG and _ lose special meaning,
1128 * but OPTARG does not (still set by getopts) and _ is also still
1129 * set in various places.
1130 * Don't know what at&t does for:
1131 * MAIL, MAILPATH, HISTSIZE, HISTFILE,
1132 * Unsetting these in at&t ksh does not loose the `specialness':
1133 * no effect: IFS, COLUMNS, PATH, TMPDIR,
1134 * VISUAL, EDITOR,
1135 * pdkshisms: no effect:
1136 * POSIXLY_CORRECT (use set +o posix instead)
1137 */
1138 }
1139 }
1140
1141 /*
1142 * Search for (and possibly create) a table entry starting with
1143 * vp, indexed by val.
1144 */
1145 static struct tbl *
arraysearch(struct tbl * vp,int val)1146 arraysearch(struct tbl *vp, int val)
1147 {
1148 struct tbl *prev, *curr, *new;
1149 size_t namelen = strlen(vp->name) + 1;
1150
1151 vp->flag |= ARRAY|DEFINED;
1152 vp->index = 0;
1153 /* The table entry is always [0] */
1154 if (val == 0)
1155 return vp;
1156 prev = vp;
1157 curr = vp->u.array;
1158 while (curr && curr->index < val) {
1159 prev = curr;
1160 curr = curr->u.array;
1161 }
1162 if (curr && curr->index == val) {
1163 if (curr->flag&ISSET)
1164 return curr;
1165 else
1166 new = curr;
1167 } else
1168 new = alloc(sizeof(struct tbl) + namelen,
1169 vp->areap);
1170 strlcpy(new->name, vp->name, namelen);
1171 new->flag = vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL);
1172 new->type = vp->type;
1173 new->areap = vp->areap;
1174 new->u2.field = vp->u2.field;
1175 new->index = val;
1176 if (curr != new) { /* not reusing old array entry */
1177 prev->u.array = new;
1178 new->u.array = curr;
1179 }
1180 return new;
1181 }
1182
1183 /* Return the length of an array reference (eg, [1+2]) - cp is assumed
1184 * to point to the open bracket. Returns 0 if there is no matching closing
1185 * bracket.
1186 */
1187 int
array_ref_len(const char * cp)1188 array_ref_len(const char *cp)
1189 {
1190 const char *s = cp;
1191 int c;
1192 int depth = 0;
1193
1194 while ((c = *s++) && (c != ']' || --depth))
1195 if (c == '[')
1196 depth++;
1197 if (!c)
1198 return 0;
1199 return s - cp;
1200 }
1201
1202 /*
1203 * Make a copy of the base of an array name
1204 */
1205 char *
arrayname(const char * str)1206 arrayname(const char *str)
1207 {
1208 const char *p;
1209
1210 if ((p = strchr(str, '[')) == 0)
1211 /* Shouldn't happen, but why worry? */
1212 return (char *) str;
1213
1214 return str_nsave(str, p - str, ATEMP);
1215 }
1216
1217 /* Set (or overwrite, if !reset) the array variable var to the values in vals.
1218 */
1219 void
set_array(const char * var,int reset,char ** vals)1220 set_array(const char *var, int reset, char **vals)
1221 {
1222 struct tbl *vp, *vq;
1223 int i;
1224
1225 /* to get local array, use "typeset foo; set -A foo" */
1226 vp = global(var);
1227
1228 /* Note: at&t ksh allows set -A but not set +A of a read-only var */
1229 if ((vp->flag&RDONLY))
1230 errorf("%s: is read only", var);
1231 /* This code is quite non-optimal */
1232 if (reset > 0)
1233 /* trash existing values and attributes */
1234 unset(vp, 0);
1235 /* todo: would be nice for assignment to completely succeed or
1236 * completely fail. Only really effects integer arrays:
1237 * evaluation of some of vals[] may fail...
1238 */
1239 for (i = 0; vals[i]; i++) {
1240 vq = arraysearch(vp, i);
1241 /* would be nice to deal with errors here... (see above) */
1242 setstr(vq, vals[i], KSH_RETURN_ERROR);
1243 }
1244 }
1245