source: trunk/src/ash/expand.c@ 2311

Last change on this file since 2311 was 809, checked in by bird, 19 years ago

Solaris + cleanup.
  • Property svn:eol-style set to native
File size: 30.6 KB
Line 
1/* $NetBSD: expand.c,v 1.71 2005/06/01 15:41:19 lukem Exp $ */
2
3/*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#ifdef HAVE_SYS_CDEFS_H
36#include <sys/cdefs.h>
37#endif
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
41#else
42__RCSID("$NetBSD: expand.c,v 1.71 2005/06/01 15:41:19 lukem Exp $");
43#endif
44#endif /* not lint */
45
46#include <sys/types.h>
47#include <sys/time.h>
48#include <sys/stat.h>
49#include <errno.h>
50#include <dirent.h>
51#include <unistd.h>
52#include <pwd.h>
53#include <stdlib.h>
54#include <stdio.h>
55#ifdef __sun__
56#include <iso/limits_iso.h>
57#endif
58
59/*
60 * Routines to expand arguments to commands. We have to deal with
61 * backquotes, shell variables, and file metacharacters.
62 */
63
64#include "shell.h"
65#include "main.h"
66#include "nodes.h"
67#include "eval.h"
68#include "expand.h"
69#include "syntax.h"
70#include "parser.h"
71#include "jobs.h"
72#include "options.h"
73#include "var.h"
74#include "input.h"
75#include "output.h"
76#include "memalloc.h"
77#include "error.h"
78#include "mystring.h"
79#include "show.h"
80
81/*
82 * Structure specifying which parts of the string should be searched
83 * for IFS characters.
84 */
85
86struct ifsregion {
87 struct ifsregion *next; /* next region in list */
88 int begoff; /* offset of start of region */
89 int endoff; /* offset of end of region */
90 int inquotes; /* search for nul bytes only */
91};
92
93
94char *expdest; /* output of current string */
95struct nodelist *argbackq; /* list of back quote expressions */
96struct ifsregion ifsfirst; /* first struct in list of ifs regions */
97struct ifsregion *ifslastp; /* last struct in list */
98struct arglist exparg; /* holds expanded arg list */
99
100STATIC void argstr(char *, int);
101STATIC char *exptilde(char *, int);
102STATIC void expbackq(union node *, int, int);
103STATIC int subevalvar(char *, char *, int, int, int, int);
104STATIC char *evalvar(char *, int);
105STATIC int varisset(char *, int);
106STATIC void varvalue(char *, int, int, int);
107STATIC void recordregion(int, int, int);
108STATIC void removerecordregions(int);
109STATIC void ifsbreakup(char *, struct arglist *);
110STATIC void ifsfree(void);
111STATIC void expandmeta(struct strlist *, int);
112STATIC void expmeta(char *, char *);
113STATIC void addfname(char *);
114STATIC struct strlist *expsort(struct strlist *);
115STATIC struct strlist *msort(struct strlist *, int);
116STATIC int pmatch(char *, char *, int);
117STATIC char *cvtnum(int, char *);
118
119/*
120 * Expand shell variables and backquotes inside a here document.
121 */
122
123void
124expandhere(union node *arg, int fd)
125{
126 herefd = fd;
127 expandarg(arg, (struct arglist *)NULL, 0);
128 xwrite(fd, stackblock(), expdest - stackblock());
129}
130
131
132/*
133 * Perform variable substitution and command substitution on an argument,
134 * placing the resulting list of arguments in arglist. If EXP_FULL is true,
135 * perform splitting and file name expansion. When arglist is NULL, perform
136 * here document expansion.
137 */
138
139void
140expandarg(union node *arg, struct arglist *arglist, int flag)
141{
142 struct strlist *sp;
143 char *p;
144
145 argbackq = arg->narg.backquote;
146 STARTSTACKSTR(expdest);
147 ifsfirst.next = NULL;
148 ifslastp = NULL;
149 argstr(arg->narg.text, flag);
150 if (arglist == NULL) {
151 return; /* here document expanded */
152 }
153 STPUTC('\0', expdest);
154 p = grabstackstr(expdest);
155 exparg.lastp = &exparg.list;
156 /*
157 * TODO - EXP_REDIR
158 */
159 if (flag & EXP_FULL) {
160 ifsbreakup(p, &exparg);
161 *exparg.lastp = NULL;
162 exparg.lastp = &exparg.list;
163 expandmeta(exparg.list, flag);
164 } else {
165 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
166 rmescapes(p);
167 sp = (struct strlist *)stalloc(sizeof (struct strlist));
168 sp->text = p;
169 *exparg.lastp = sp;
170 exparg.lastp = &sp->next;
171 }
172 ifsfree();
173 *exparg.lastp = NULL;
174 if (exparg.list) {
175 *arglist->lastp = exparg.list;
176 arglist->lastp = exparg.lastp;
177 }
178}
179
180
181
182/*
183 * Perform variable and command substitution.
184 * If EXP_FULL is set, output CTLESC characters to allow for further processing.
185 * Otherwise treat $@ like $* since no splitting will be performed.
186 */
187
188STATIC void
189argstr(char *p, int flag)
190{
191 char c;
192 int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */
193 int firsteq = 1;
194 const char *ifs = NULL;
195 int ifs_split = EXP_IFS_SPLIT;
196
197 if (flag & EXP_IFS_SPLIT)
198 ifs = ifsset() ? ifsval() : " \t\n";
199
200 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
201 p = exptilde(p, flag);
202 for (;;) {
203 switch (c = *p++) {
204 case '\0':
205 case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */
206 return;
207 case CTLQUOTEMARK:
208 /* "$@" syntax adherence hack */
209 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
210 break;
211 if ((flag & EXP_FULL) != 0)
212 STPUTC(c, expdest);
213 ifs_split = 0;
214 break;
215 case CTLQUOTEEND:
216 ifs_split = EXP_IFS_SPLIT;
217 break;
218 case CTLESC:
219 if (quotes)
220 STPUTC(c, expdest);
221 c = *p++;
222 STPUTC(c, expdest);
223 break;
224 case CTLVAR:
225 p = evalvar(p, (flag & ~EXP_IFS_SPLIT) | (flag & ifs_split));
226 break;
227 case CTLBACKQ:
228 case CTLBACKQ|CTLQUOTE:
229 expbackq(argbackq->n, c & CTLQUOTE, flag);
230 argbackq = argbackq->next;
231 break;
232 case CTLENDARI:
233 expari(flag);
234 break;
235 case ':':
236 case '=':
237 /*
238 * sort of a hack - expand tildes in variable
239 * assignments (after the first '=' and after ':'s).
240 */
241 STPUTC(c, expdest);
242 if (flag & EXP_VARTILDE && *p == '~') {
243 if (c == '=') {
244 if (firsteq)
245 firsteq = 0;
246 else
247 break;
248 }
249 p = exptilde(p, flag);
250 }
251 break;
252 default:
253 STPUTC(c, expdest);
254 if (flag & EXP_IFS_SPLIT & ifs_split && strchr(ifs, c) != NULL) {
255 /* We need to get the output split here... */
256 recordregion(expdest - stackblock() - 1,
257 expdest - stackblock(), 0);
258 }
259 break;
260 }
261 }
262}
263
264STATIC char *
265exptilde(char *p, int flag)
266{
267 char c, *startp = p;
268 struct passwd *pw;
269 const char *home;
270 int quotes = flag & (EXP_FULL | EXP_CASE);
271
272 while ((c = *p) != '\0') {
273 switch(c) {
274 case CTLESC:
275 return (startp);
276 case CTLQUOTEMARK:
277 return (startp);
278 case ':':
279 if (flag & EXP_VARTILDE)
280 goto done;
281 break;
282 case '/':
283 goto done;
284 }
285 p++;
286 }
287done:
288 *p = '\0';
289 if (*(startp+1) == '\0') {
290 if ((home = lookupvar("HOME")) == NULL)
291 goto lose;
292 } else {
293 if ((pw = getpwnam(startp+1)) == NULL)
294 goto lose;
295 home = pw->pw_dir;
296 }
297 if (*home == '\0')
298 goto lose;
299 *p = c;
300 while ((c = *home++) != '\0') {
301 if (quotes && SQSYNTAX[(int)c] == CCTL)
302 STPUTC(CTLESC, expdest);
303 STPUTC(c, expdest);
304 }
305 return (p);
306lose:
307 *p = c;
308 return (startp);
309}
310
311
312STATIC void
313removerecordregions(int endoff)
314{
315 if (ifslastp == NULL)
316 return;
317
318 if (ifsfirst.endoff > endoff) {
319 while (ifsfirst.next != NULL) {
320 struct ifsregion *ifsp;
321 INTOFF;
322 ifsp = ifsfirst.next->next;
323 ckfree(ifsfirst.next);
324 ifsfirst.next = ifsp;
325 INTON;
326 }
327 if (ifsfirst.begoff > endoff)
328 ifslastp = NULL;
329 else {
330 ifslastp = &ifsfirst;
331 ifsfirst.endoff = endoff;
332 }
333 return;
334 }
335
336 ifslastp = &ifsfirst;
337 while (ifslastp->next && ifslastp->next->begoff < endoff)
338 ifslastp=ifslastp->next;
339 while (ifslastp->next != NULL) {
340 struct ifsregion *ifsp;
341 INTOFF;
342 ifsp = ifslastp->next->next;
343 ckfree(ifslastp->next);
344 ifslastp->next = ifsp;
345 INTON;
346 }
347 if (ifslastp->endoff > endoff)
348 ifslastp->endoff = endoff;
349}
350
351
352/*
353 * Expand arithmetic expression. Backup to start of expression,
354 * evaluate, place result in (backed up) result, adjust string position.
355 */
356void
357expari(int flag)
358{
359 char *p, *start;
360 int result;
361 int begoff;
362 int quotes = flag & (EXP_FULL | EXP_CASE);
363 int quoted;
364
365 /* ifsfree(); */
366
367 /*
368 * This routine is slightly over-complicated for
369 * efficiency. First we make sure there is
370 * enough space for the result, which may be bigger
371 * than the expression if we add exponentation. Next we
372 * scan backwards looking for the start of arithmetic. If the
373 * next previous character is a CTLESC character, then we
374 * have to rescan starting from the beginning since CTLESC
375 * characters have to be processed left to right.
376 */
377#if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10
378#error "integers with more than 10 digits are not supported"
379#endif
380 CHECKSTRSPACE(12 - 2, expdest);
381 USTPUTC('\0', expdest);
382 start = stackblock();
383 p = expdest - 1;
384 while (*p != CTLARI && p >= start)
385 --p;
386 if (*p != CTLARI)
387 error("missing CTLARI (shouldn't happen)");
388 if (p > start && *(p-1) == CTLESC)
389 for (p = start; *p != CTLARI; p++)
390 if (*p == CTLESC)
391 p++;
392
393 if (p[1] == '"')
394 quoted=1;
395 else
396 quoted=0;
397 begoff = p - start;
398 removerecordregions(begoff);
399 if (quotes)
400 rmescapes(p+2);
401 result = arith(p+2);
402 fmtstr(p, 12, "%d", result);
403
404 while (*p++)
405 ;
406
407 if (quoted == 0)
408 recordregion(begoff, p - 1 - start, 0);
409 result = expdest - p + 1;
410 STADJUST(-result, expdest);
411}
412
413
414/*
415 * Expand stuff in backwards quotes.
416 */
417
418STATIC void
419expbackq(union node *cmd, int quoted, int flag)
420{
421 struct backcmd in;
422 int i;
423 char buf[128];
424 char *p;
425 char *dest = expdest;
426 struct ifsregion saveifs, *savelastp;
427 struct nodelist *saveargbackq;
428 char lastc;
429 int startloc = dest - stackblock();
430 char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
431 int saveherefd;
432 int quotes = flag & (EXP_FULL | EXP_CASE);
433
434 INTOFF;
435 saveifs = ifsfirst;
436 savelastp = ifslastp;
437 saveargbackq = argbackq;
438 saveherefd = herefd;
439 herefd = -1;
440 p = grabstackstr(dest);
441 evalbackcmd(cmd, &in);
442 ungrabstackstr(p, dest);
443 ifsfirst = saveifs;
444 ifslastp = savelastp;
445 argbackq = saveargbackq;
446 herefd = saveherefd;
447
448 p = in.buf;
449 lastc = '\0';
450 for (;;) {
451 if (--in.nleft < 0) {
452 if (in.fd < 0)
453 break;
454 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
455 TRACE(("expbackq: read returns %d\n", i));
456 if (i <= 0)
457 break;
458 p = buf;
459 in.nleft = i - 1;
460 }
461 lastc = *p++;
462 if (lastc != '\0') {
463 if (quotes && syntax[(int)lastc] == CCTL)
464 STPUTC(CTLESC, dest);
465 STPUTC(lastc, dest);
466 }
467 }
468
469 /* Eat all trailing newlines */
470 p = stackblock() + startloc;
471 while (dest > p && dest[-1] == '\n')
472 STUNPUTC(dest);
473
474 if (in.fd >= 0)
475 close(in.fd);
476 if (in.buf)
477 ckfree(in.buf);
478 if (in.jp)
479 back_exitstatus = waitforjob(in.jp);
480 if (quoted == 0)
481 recordregion(startloc, dest - stackblock(), 0);
482 TRACE(("evalbackq: size=%d: \"%.*s\"\n",
483 (dest - stackblock()) - startloc,
484 (dest - stackblock()) - startloc,
485 stackblock() + startloc));
486 expdest = dest;
487 INTON;
488}
489
490
491
492STATIC int
493subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags)
494{
495 char *startp;
496 char *loc = NULL;
497 char *q;
498 int c = 0;
499 int saveherefd = herefd;
500 struct nodelist *saveargbackq = argbackq;
501 int amount;
502
503 herefd = -1;
504 argstr(p, 0);
505 STACKSTRNUL(expdest);
506 herefd = saveherefd;
507 argbackq = saveargbackq;
508 startp = stackblock() + startloc;
509 if (str == NULL)
510 str = stackblock() + strloc;
511
512 switch (subtype) {
513 case VSASSIGN:
514 setvar(str, startp, 0);
515 amount = startp - expdest;
516 STADJUST(amount, expdest);
517 varflags &= ~VSNUL;
518 if (c != 0)
519 *loc = c;
520 return 1;
521
522 case VSQUESTION:
523 if (*p != CTLENDVAR) {
524 outfmt(&errout, "%s\n", startp);
525 error((char *)NULL);
526 }
527 error("%.*s: parameter %snot set", p - str - 1,
528 str, (varflags & VSNUL) ? "null or "
529 : nullstr);
530 /* NOTREACHED */
531
532 case VSTRIMLEFT:
533 for (loc = startp; loc < str; loc++) {
534 c = *loc;
535 *loc = '\0';
536 if (patmatch(str, startp, varflags & VSQUOTE))
537 goto recordleft;
538 *loc = c;
539 if ((varflags & VSQUOTE) && *loc == CTLESC)
540 loc++;
541 }
542 return 0;
543
544 case VSTRIMLEFTMAX:
545 for (loc = str - 1; loc >= startp;) {
546 c = *loc;
547 *loc = '\0';
548 if (patmatch(str, startp, varflags & VSQUOTE))
549 goto recordleft;
550 *loc = c;
551 loc--;
552 if ((varflags & VSQUOTE) && loc > startp &&
553 *(loc - 1) == CTLESC) {
554 for (q = startp; q < loc; q++)
555 if (*q == CTLESC)
556 q++;
557 if (q > loc)
558 loc--;
559 }
560 }
561 return 0;
562
563 case VSTRIMRIGHT:
564 for (loc = str - 1; loc >= startp;) {
565 if (patmatch(str, loc, varflags & VSQUOTE))
566 goto recordright;
567 loc--;
568 if ((varflags & VSQUOTE) && loc > startp &&
569 *(loc - 1) == CTLESC) {
570 for (q = startp; q < loc; q++)
571 if (*q == CTLESC)
572 q++;
573 if (q > loc)
574 loc--;
575 }
576 }
577 return 0;
578
579 case VSTRIMRIGHTMAX:
580 for (loc = startp; loc < str - 1; loc++) {
581 if (patmatch(str, loc, varflags & VSQUOTE))
582 goto recordright;
583 if ((varflags & VSQUOTE) && *loc == CTLESC)
584 loc++;
585 }
586 return 0;
587
588 default:
589 abort();
590 }
591
592recordleft:
593 *loc = c;
594 amount = ((str - 1) - (loc - startp)) - expdest;
595 STADJUST(amount, expdest);
596 while (loc != str - 1)
597 *startp++ = *loc++;
598 return 1;
599
600recordright:
601 amount = loc - expdest;
602 STADJUST(amount, expdest);
603 STPUTC('\0', expdest);
604 STADJUST(-1, expdest);
605 return 1;
606}
607
608
609/*
610 * Expand a variable, and return a pointer to the next character in the
611 * input string.
612 */
613
614STATIC char *
615evalvar(char *p, int flag)
616{
617 int subtype;
618 int varflags;
619 char *var;
620 char *val;
621 int patloc;
622 int c;
623 int set;
624 int special;
625 int startloc;
626 int varlen;
627 int apply_ifs;
628 int quotes = flag & (EXP_FULL | EXP_CASE);
629
630 varflags = (unsigned char)*p++;
631 subtype = varflags & VSTYPE;
632 var = p;
633 special = !is_name(*p);
634 p = strchr(p, '=') + 1;
635
636again: /* jump here after setting a variable with ${var=text} */
637 if (special) {
638 set = varisset(var, varflags & VSNUL);
639 val = NULL;
640 } else {
641 val = lookupvar(var);
642 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
643 val = NULL;
644 set = 0;
645 } else
646 set = 1;
647 }
648
649 varlen = 0;
650 startloc = expdest - stackblock();
651
652 if (!set && uflag) {
653 switch (subtype) {
654 case VSNORMAL:
655 case VSTRIMLEFT:
656 case VSTRIMLEFTMAX:
657 case VSTRIMRIGHT:
658 case VSTRIMRIGHTMAX:
659 case VSLENGTH:
660 error("%.*s: parameter not set", p - var - 1, var);
661 /* NOTREACHED */
662 }
663 }
664
665 if (set && subtype != VSPLUS) {
666 /* insert the value of the variable */
667 if (special) {
668 varvalue(var, varflags & VSQUOTE, subtype, flag);
669 if (subtype == VSLENGTH) {
670 varlen = expdest - stackblock() - startloc;
671 STADJUST(-varlen, expdest);
672 }
673 } else {
674 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
675 : BASESYNTAX;
676
677 if (subtype == VSLENGTH) {
678 for (;*val; val++)
679 varlen++;
680 } else {
681 while (*val) {
682 if (quotes && syntax[(int)*val] == CCTL)
683 STPUTC(CTLESC, expdest);
684 STPUTC(*val++, expdest);
685 }
686
687 }
688 }
689 }
690
691
692 apply_ifs = ((varflags & VSQUOTE) == 0 ||
693 (*var == '@' && shellparam.nparam != 1));
694
695 switch (subtype) {
696 case VSLENGTH:
697 expdest = cvtnum(varlen, expdest);
698 break;
699
700 case VSNORMAL:
701 break;
702
703 case VSPLUS:
704 set = !set;
705 /* FALLTHROUGH */
706 case VSMINUS:
707 if (!set) {
708 argstr(p, flag | (apply_ifs ? EXP_IFS_SPLIT : 0));
709 /*
710 * ${x-a b c} doesn't get split, but removing the
711 * 'apply_ifs = 0' apparantly breaks ${1+"$@"}..
712 * ${x-'a b' c} should generate 2 args.
713 */
714 /* We should have marked stuff already */
715 apply_ifs = 0;
716 }
717 break;
718
719 case VSTRIMLEFT:
720 case VSTRIMLEFTMAX:
721 case VSTRIMRIGHT:
722 case VSTRIMRIGHTMAX:
723 if (!set)
724 break;
725 /*
726 * Terminate the string and start recording the pattern
727 * right after it
728 */
729 STPUTC('\0', expdest);
730 patloc = expdest - stackblock();
731 if (subevalvar(p, NULL, patloc, subtype,
732 startloc, varflags) == 0) {
733 int amount = (expdest - stackblock() - patloc) + 1;
734 STADJUST(-amount, expdest);
735 }
736 /* Remove any recorded regions beyond start of variable */
737 removerecordregions(startloc);
738 apply_ifs = 1;
739 break;
740
741 case VSASSIGN:
742 case VSQUESTION:
743 if (set)
744 break;
745 if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
746 varflags &= ~VSNUL;
747 /*
748 * Remove any recorded regions beyond
749 * start of variable
750 */
751 removerecordregions(startloc);
752 goto again;
753 }
754 apply_ifs = 0;
755 break;
756
757 default:
758 abort();
759 }
760
761 if (apply_ifs)
762 recordregion(startloc, expdest - stackblock(),
763 varflags & VSQUOTE);
764
765 if (subtype != VSNORMAL) { /* skip to end of alternative */
766 int nesting = 1;
767 for (;;) {
768 if ((c = *p++) == CTLESC)
769 p++;
770 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
771 if (set)
772 argbackq = argbackq->next;
773 } else if (c == CTLVAR) {
774 if ((*p++ & VSTYPE) != VSNORMAL)
775 nesting++;
776 } else if (c == CTLENDVAR) {
777 if (--nesting == 0)
778 break;
779 }
780 }
781 }
782 return p;
783}
784
785
786
787/*
788 * Test whether a specialized variable is set.
789 */
790
791STATIC int
792varisset(char *name, int nulok)
793{
794 if (*name == '!')
795 return backgndpid != -1;
796 else if (*name == '@' || *name == '*') {
797 if (*shellparam.p == NULL)
798 return 0;
799
800 if (nulok) {
801 char **av;
802
803 for (av = shellparam.p; *av; av++)
804 if (**av != '\0')
805 return 1;
806 return 0;
807 }
808 } else if (is_digit(*name)) {
809 char *ap;
810 int num = atoi(name);
811
812 if (num > shellparam.nparam)
813 return 0;
814
815 if (num == 0)
816 ap = arg0;
817 else
818 ap = shellparam.p[num - 1];
819
820 if (nulok && (ap == NULL || *ap == '\0'))
821 return 0;
822 }
823 return 1;
824}
825
826
827
828/*
829 * Add the value of a specialized variable to the stack string.
830 */
831
832STATIC void
833varvalue(char *name, int quoted, int subtype, int flag)
834{
835 int num;
836 char *p;
837 int i;
838 char sep;
839 char **ap;
840 char const *syntax;
841
842#define STRTODEST(p) \
843 do {\
844 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
845 syntax = quoted? DQSYNTAX : BASESYNTAX; \
846 while (*p) { \
847 if (syntax[(int)*p] == CCTL) \
848 STPUTC(CTLESC, expdest); \
849 STPUTC(*p++, expdest); \
850 } \
851 } else \
852 while (*p) \
853 STPUTC(*p++, expdest); \
854 } while (0)
855
856
857 switch (*name) {
858 case '$':
859 num = rootpid;
860 goto numvar;
861 case '?':
862 num = exitstatus;
863 goto numvar;
864 case '#':
865 num = shellparam.nparam;
866 goto numvar;
867 case '!':
868 num = backgndpid;
869numvar:
870 expdest = cvtnum(num, expdest);
871 break;
872 case '-':
873 for (i = 0; optlist[i].name; i++) {
874 if (optlist[i].val)
875 STPUTC(optlist[i].letter, expdest);
876 }
877 break;
878 case '@':
879 if (flag & EXP_FULL && quoted) {
880 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
881 STRTODEST(p);
882 if (*ap)
883 STPUTC('\0', expdest);
884 }
885 break;
886 }
887 /* fall through */
888 case '*':
889 if (ifsset() != 0)
890 sep = ifsval()[0];
891 else
892 sep = ' ';
893 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
894 STRTODEST(p);
895 if (*ap && sep)
896 STPUTC(sep, expdest);
897 }
898 break;
899 case '0':
900 p = arg0;
901 STRTODEST(p);
902 break;
903 default:
904 if (is_digit(*name)) {
905 num = atoi(name);
906 if (num > 0 && num <= shellparam.nparam) {
907 p = shellparam.p[num - 1];
908 STRTODEST(p);
909 }
910 }
911 break;
912 }
913}
914
915
916
917/*
918 * Record the fact that we have to scan this region of the
919 * string for IFS characters.
920 */
921
922STATIC void
923recordregion(int start, int end, int inquotes)
924{
925 struct ifsregion *ifsp;
926
927 if (ifslastp == NULL) {
928 ifsp = &ifsfirst;
929 } else {
930 if (ifslastp->endoff == start
931 && ifslastp->inquotes == inquotes) {
932 /* extend previous area */
933 ifslastp->endoff = end;
934 return;
935 }
936 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
937 ifslastp->next = ifsp;
938 }
939 ifslastp = ifsp;
940 ifslastp->next = NULL;
941 ifslastp->begoff = start;
942 ifslastp->endoff = end;
943 ifslastp->inquotes = inquotes;
944}
945
946
947
948/*
949 * Break the argument string into pieces based upon IFS and add the
950 * strings to the argument list. The regions of the string to be
951 * searched for IFS characters have been stored by recordregion.
952 */
953STATIC void
954ifsbreakup(char *string, struct arglist *arglist)
955{
956 struct ifsregion *ifsp;
957 struct strlist *sp;
958 char *start;
959 char *p;
960 char *q;
961 const char *ifs;
962 const char *ifsspc;
963 int inquotes;
964
965 start = string;
966 ifsspc = NULL;
967 inquotes = 0;
968
969 if (ifslastp == NULL) {
970 /* Return entire argument, IFS doesn't apply to any of it */
971 sp = (struct strlist *)stalloc(sizeof *sp);
972 sp->text = start;
973 *arglist->lastp = sp;
974 arglist->lastp = &sp->next;
975 return;
976 }
977
978 ifs = ifsset() ? ifsval() : " \t\n";
979
980 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
981 p = string + ifsp->begoff;
982 inquotes = ifsp->inquotes;
983 ifsspc = NULL;
984 while (p < string + ifsp->endoff) {
985 q = p;
986 if (*p == CTLESC)
987 p++;
988 if (inquotes) {
989 /* Only NULs (probably from "$@") end args */
990 if (*p != 0) {
991 p++;
992 continue;
993 }
994 } else {
995 if (!strchr(ifs, *p)) {
996 p++;
997 continue;
998 }
999 ifsspc = strchr(" \t\n", *p);
1000
1001 /* Ignore IFS whitespace at start */
1002 if (q == start && ifsspc != NULL) {
1003 p++;
1004 start = p;
1005 continue;
1006 }
1007 }
1008
1009 /* Save this argument... */
1010 *q = '\0';
1011 sp = (struct strlist *)stalloc(sizeof *sp);
1012 sp->text = start;
1013 *arglist->lastp = sp;
1014 arglist->lastp = &sp->next;
1015 p++;
1016
1017 if (ifsspc != NULL) {
1018 /* Ignore further trailing IFS whitespace */
1019 for (; p < string + ifsp->endoff; p++) {
1020 q = p;
1021 if (*p == CTLESC)
1022 p++;
1023 if (strchr(ifs, *p) == NULL) {
1024 p = q;
1025 break;
1026 }
1027 if (strchr(" \t\n", *p) == NULL) {
1028 p++;
1029 break;
1030 }
1031 }
1032 }
1033 start = p;
1034 }
1035 }
1036
1037 /*
1038 * Save anything left as an argument.
1039 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1040 * generating 2 arguments, the second of which is empty.
1041 * Some recent clarification of the Posix spec say that it
1042 * should only generate one....
1043 */
1044 if (*start /* || (!ifsspc && start > string) */) {
1045 sp = (struct strlist *)stalloc(sizeof *sp);
1046 sp->text = start;
1047 *arglist->lastp = sp;
1048 arglist->lastp = &sp->next;
1049 }
1050}
1051
1052STATIC void
1053ifsfree(void)
1054{
1055 while (ifsfirst.next != NULL) {
1056 struct ifsregion *ifsp;
1057 INTOFF;
1058 ifsp = ifsfirst.next->next;
1059 ckfree(ifsfirst.next);
1060 ifsfirst.next = ifsp;
1061 INTON;
1062 }
1063 ifslastp = NULL;
1064 ifsfirst.next = NULL;
1065}
1066
1067
1068
1069/*
1070 * Expand shell metacharacters. At this point, the only control characters
1071 * should be escapes. The results are stored in the list exparg.
1072 */
1073
1074char *expdir;
1075
1076
1077STATIC void
1078expandmeta(struct strlist *str, int flag)
1079{
1080 char *p;
1081 struct strlist **savelastp;
1082 struct strlist *sp;
1083 char c;
1084 /* TODO - EXP_REDIR */
1085
1086 while (str) {
1087 if (fflag)
1088 goto nometa;
1089 p = str->text;
1090 for (;;) { /* fast check for meta chars */
1091 if ((c = *p++) == '\0')
1092 goto nometa;
1093 if (c == '*' || c == '?' || c == '[' || c == '!')
1094 break;
1095 }
1096 savelastp = exparg.lastp;
1097 INTOFF;
1098 if (expdir == NULL) {
1099 int i = strlen(str->text);
1100 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1101 }
1102
1103 expmeta(expdir, str->text);
1104 ckfree(expdir);
1105 expdir = NULL;
1106 INTON;
1107 if (exparg.lastp == savelastp) {
1108 /*
1109 * no matches
1110 */
1111nometa:
1112 *exparg.lastp = str;
1113 rmescapes(str->text);
1114 exparg.lastp = &str->next;
1115 } else {
1116 *exparg.lastp = NULL;
1117 *savelastp = sp = expsort(*savelastp);
1118 while (sp->next != NULL)
1119 sp = sp->next;
1120 exparg.lastp = &sp->next;
1121 }
1122 str = str->next;
1123 }
1124}
1125
1126
1127/*
1128 * Do metacharacter (i.e. *, ?, [...]) expansion.
1129 */
1130
1131STATIC void
1132expmeta(char *enddir, char *name)
1133{
1134 char *p;
1135 const char *cp;
1136 char *q;
1137 char *start;
1138 char *endname;
1139 int metaflag;
1140 struct stat statb;
1141 DIR *dirp;
1142 struct dirent *dp;
1143 int atend;
1144 int matchdot;
1145
1146 metaflag = 0;
1147 start = name;
1148 for (p = name ; ; p++) {
1149 if (*p == '*' || *p == '?')
1150 metaflag = 1;
1151 else if (*p == '[') {
1152 q = p + 1;
1153 if (*q == '!')
1154 q++;
1155 for (;;) {
1156 while (*q == CTLQUOTEMARK)
1157 q++;
1158 if (*q == CTLESC)
1159 q++;
1160 if (*q == '/' || *q == '\0')
1161 break;
1162 if (*++q == ']') {
1163 metaflag = 1;
1164 break;
1165 }
1166 }
1167 } else if (*p == '!' && p[1] == '!' && (p == name || p[-1] == '/')) {
1168 metaflag = 1;
1169 } else if (*p == '\0')
1170 break;
1171 else if (*p == CTLQUOTEMARK)
1172 continue;
1173 else if (*p == CTLESC)
1174 p++;
1175 if (*p == '/') {
1176 if (metaflag)
1177 break;
1178 start = p + 1;
1179 }
1180 }
1181 if (metaflag == 0) { /* we've reached the end of the file name */
1182 if (enddir != expdir)
1183 metaflag++;
1184 for (p = name ; ; p++) {
1185 if (*p == CTLQUOTEMARK)
1186 continue;
1187 if (*p == CTLESC)
1188 p++;
1189 *enddir++ = *p;
1190 if (*p == '\0')
1191 break;
1192 }
1193 if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1194 addfname(expdir);
1195 return;
1196 }
1197 endname = p;
1198 if (start != name) {
1199 p = name;
1200 while (p < start) {
1201 while (*p == CTLQUOTEMARK)
1202 p++;
1203 if (*p == CTLESC)
1204 p++;
1205 *enddir++ = *p++;
1206 }
1207 }
1208 if (enddir == expdir) {
1209 cp = ".";
1210 } else if (enddir == expdir + 1 && *expdir == '/') {
1211 cp = "/";
1212 } else {
1213 cp = expdir;
1214 enddir[-1] = '\0';
1215 }
1216 if ((dirp = opendir(cp)) == NULL)
1217 return;
1218 if (enddir != expdir)
1219 enddir[-1] = '/';
1220 if (*endname == 0) {
1221 atend = 1;
1222 } else {
1223 atend = 0;
1224 *endname++ = '\0';
1225 }
1226 matchdot = 0;
1227 p = start;
1228 while (*p == CTLQUOTEMARK)
1229 p++;
1230 if (*p == CTLESC)
1231 p++;
1232 if (*p == '.')
1233 matchdot++;
1234 while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1235 if (dp->d_name[0] == '.' && ! matchdot)
1236 continue;
1237 if (patmatch(start, dp->d_name, 0)) {
1238 if (atend) {
1239 scopy(dp->d_name, enddir);
1240 addfname(expdir);
1241 } else {
1242 for (p = enddir, cp = dp->d_name;
1243 (*p++ = *cp++) != '\0';)
1244 continue;
1245 p[-1] = '/';
1246 expmeta(p, endname);
1247 }
1248 }
1249 }
1250 closedir(dirp);
1251 if (! atend)
1252 endname[-1] = '/';
1253}
1254
1255
1256/*
1257 * Add a file name to the list.
1258 */
1259
1260STATIC void
1261addfname(char *name)
1262{
1263 char *p;
1264 struct strlist *sp;
1265
1266 p = stalloc(strlen(name) + 1);
1267 scopy(name, p);
1268 sp = (struct strlist *)stalloc(sizeof *sp);
1269 sp->text = p;
1270 *exparg.lastp = sp;
1271 exparg.lastp = &sp->next;
1272}
1273
1274
1275/*
1276 * Sort the results of file name expansion. It calculates the number of
1277 * strings to sort and then calls msort (short for merge sort) to do the
1278 * work.
1279 */
1280
1281STATIC struct strlist *
1282expsort(struct strlist *str)
1283{
1284 int len;
1285 struct strlist *sp;
1286
1287 len = 0;
1288 for (sp = str ; sp ; sp = sp->next)
1289 len++;
1290 return msort(str, len);
1291}
1292
1293
1294STATIC struct strlist *
1295msort(struct strlist *list, int len)
1296{
1297 struct strlist *p, *q = NULL;
1298 struct strlist **lpp;
1299 int half;
1300 int n;
1301
1302 if (len <= 1)
1303 return list;
1304 half = len >> 1;
1305 p = list;
1306 for (n = half ; --n >= 0 ; ) {
1307 q = p;
1308 p = p->next;
1309 }
1310 q->next = NULL; /* terminate first half of list */
1311 q = msort(list, half); /* sort first half of list */
1312 p = msort(p, len - half); /* sort second half */
1313 lpp = &list;
1314 for (;;) {
1315 if (strcmp(p->text, q->text) < 0) {
1316 *lpp = p;
1317 lpp = &p->next;
1318 if ((p = *lpp) == NULL) {
1319 *lpp = q;
1320 break;
1321 }
1322 } else {
1323 *lpp = q;
1324 lpp = &q->next;
1325 if ((q = *lpp) == NULL) {
1326 *lpp = p;
1327 break;
1328 }
1329 }
1330 }
1331 return list;
1332}
1333
1334
1335
1336/*
1337 * Returns true if the pattern matches the string.
1338 */
1339
1340int
1341patmatch(char *pattern, char *string, int squoted)
1342{
1343#ifdef notdef
1344 if (pattern[0] == '!' && pattern[1] == '!')
1345 return 1 - pmatch(pattern + 2, string);
1346 else
1347#endif
1348 return pmatch(pattern, string, squoted);
1349}
1350
1351
1352STATIC int
1353pmatch(char *pattern, char *string, int squoted)
1354{
1355 char *p, *q;
1356 char c;
1357
1358 p = pattern;
1359 q = string;
1360 for (;;) {
1361 switch (c = *p++) {
1362 case '\0':
1363 goto breakloop;
1364 case CTLESC:
1365 if (squoted && *q == CTLESC)
1366 q++;
1367 if (*q++ != *p++)
1368 return 0;
1369 break;
1370 case CTLQUOTEMARK:
1371 continue;
1372 case '?':
1373 if (squoted && *q == CTLESC)
1374 q++;
1375 if (*q++ == '\0')
1376 return 0;
1377 break;
1378 case '*':
1379 c = *p;
1380 while (c == CTLQUOTEMARK || c == '*')
1381 c = *++p;
1382 if (c != CTLESC && c != CTLQUOTEMARK &&
1383 c != '?' && c != '*' && c != '[') {
1384 while (*q != c) {
1385 if (squoted && *q == CTLESC &&
1386 q[1] == c)
1387 break;
1388 if (*q == '\0')
1389 return 0;
1390 if (squoted && *q == CTLESC)
1391 q++;
1392 q++;
1393 }
1394 }
1395 do {
1396 if (pmatch(p, q, squoted))
1397 return 1;
1398 if (squoted && *q == CTLESC)
1399 q++;
1400 } while (*q++ != '\0');
1401 return 0;
1402 case '[': {
1403 char *endp;
1404 int invert, found;
1405 char chr;
1406
1407 endp = p;
1408 if (*endp == '!')
1409 endp++;
1410 for (;;) {
1411 while (*endp == CTLQUOTEMARK)
1412 endp++;
1413 if (*endp == '\0')
1414 goto dft; /* no matching ] */
1415 if (*endp == CTLESC)
1416 endp++;
1417 if (*++endp == ']')
1418 break;
1419 }
1420 invert = 0;
1421 if (*p == '!') {
1422 invert++;
1423 p++;
1424 }
1425 found = 0;
1426 chr = *q++;
1427 if (squoted && chr == CTLESC)
1428 chr = *q++;
1429 if (chr == '\0')
1430 return 0;
1431 c = *p++;
1432 do {
1433 if (c == CTLQUOTEMARK)
1434 continue;
1435 if (c == CTLESC)
1436 c = *p++;
1437 if (*p == '-' && p[1] != ']') {
1438 p++;
1439 while (*p == CTLQUOTEMARK)
1440 p++;
1441 if (*p == CTLESC)
1442 p++;
1443 if (chr >= c && chr <= *p)
1444 found = 1;
1445 p++;
1446 } else {
1447 if (chr == c)
1448 found = 1;
1449 }
1450 } while ((c = *p++) != ']');
1451 if (found == invert)
1452 return 0;
1453 break;
1454 }
1455dft: default:
1456 if (squoted && *q == CTLESC)
1457 q++;
1458 if (*q++ != c)
1459 return 0;
1460 break;
1461 }
1462 }
1463breakloop:
1464 if (*q != '\0')
1465 return 0;
1466 return 1;
1467}
1468
1469
1470
1471/*
1472 * Remove any CTLESC characters from a string.
1473 */
1474
1475void
1476rmescapes(char *str)
1477{
1478 char *p, *q;
1479
1480 p = str;
1481 while (*p != CTLESC && *p != CTLQUOTEMARK) {
1482 if (*p++ == '\0')
1483 return;
1484 }
1485 q = p;
1486 while (*p) {
1487 if (*p == CTLQUOTEMARK) {
1488 p++;
1489 continue;
1490 }
1491 if (*p == CTLESC)
1492 p++;
1493 *q++ = *p++;
1494 }
1495 *q = '\0';
1496}
1497
1498
1499
1500/*
1501 * See if a pattern matches in a case statement.
1502 */
1503
1504int
1505casematch(union node *pattern, char *val)
1506{
1507 struct stackmark smark;
1508 int result;
1509 char *p;
1510
1511 setstackmark(&smark);
1512 argbackq = pattern->narg.backquote;
1513 STARTSTACKSTR(expdest);
1514 ifslastp = NULL;
1515 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1516 STPUTC('\0', expdest);
1517 p = grabstackstr(expdest);
1518 result = patmatch(p, val, 0);
1519 popstackmark(&smark);
1520 return result;
1521}
1522
1523/*
1524 * Our own itoa().
1525 */
1526
1527STATIC char *
1528cvtnum(int num, char *buf)
1529{
1530 char temp[32];
1531 int neg = num < 0;
1532 char *p = temp + 31;
1533
1534 temp[31] = '\0';
1535
1536 do {
1537 *--p = num % 10 + '0';
1538 } while ((num /= 10) != 0);
1539
1540 if (neg)
1541 *--p = '-';
1542
1543 while (*p)
1544 STPUTC(*p++, buf);
1545 return buf;
1546}
1547
1548/*
1549 * Do most of the work for wordexp(3).
1550 */
1551
1552int
1553wordexpcmd(int argc, char **argv)
1554{
1555 size_t len;
1556 int i;
1557
1558 out1fmt("%d", argc - 1);
1559 out1c('\0');
1560 for (i = 1, len = 0; i < argc; i++)
1561 len += strlen(argv[i]);
1562 out1fmt("%zd", len);
1563 out1c('\0');
1564 for (i = 1; i < argc; i++) {
1565 out1str(argv[i]);
1566 out1c('\0');
1567 }
1568 return (0);
1569}
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