1/*-
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/bin/sh/expand.c 198454 2009-10-24 21:20:04Z jilles $");
40
41#include <sys/types.h>
42#include <sys/time.h>
43#include <sys/stat.h>
44#include <errno.h>
45#include <dirent.h>
46#include <unistd.h>
47#include <pwd.h>
48#include <stdlib.h>
49#include <limits.h>
50#include <stdio.h>
51#include <string.h>
52
53/*
54 * Routines to expand arguments to commands. We have to deal with
55 * backquotes, shell variables, and file metacharacters.
56 */
57
58#include "shell.h"
59#include "main.h"
60#include "nodes.h"
61#include "eval.h"
62#include "expand.h"
63#include "syntax.h"
64#include "parser.h"
65#include "jobs.h"
66#include "options.h"
67#include "var.h"
68#include "input.h"
69#include "output.h"
70#include "memalloc.h"
71#include "error.h"
72#include "mystring.h"
73#include "arith.h"
74#include "show.h"
75
76/*
77 * Structure specifying which parts of the string should be searched
78 * for IFS characters.
79 */
80
81struct ifsregion {
82 struct ifsregion *next; /* next region in list */
83 int begoff; /* offset of start of region */
84 int endoff; /* offset of end of region */
85 int inquotes; /* search for nul bytes only */
86};
87
88
89STATIC char *expdest; /* output of current string */
90STATIC struct nodelist *argbackq; /* list of back quote expressions */
91STATIC struct ifsregion ifsfirst; /* first struct in list of ifs regions */
92STATIC struct ifsregion *ifslastp; /* last struct in list */
93STATIC struct arglist exparg; /* holds expanded arg list */
94
95STATIC void argstr(char *, int);
96STATIC char *exptilde(char *, int);
97STATIC void expbackq(union node *, int, int);
98STATIC int subevalvar(char *, char *, int, int, int, int);
99STATIC char *evalvar(char *, int);
100STATIC int varisset(char *, int);
101STATIC void varvalue(char *, int, int, int);
102STATIC void recordregion(int, int, int);
103STATIC void removerecordregions(int);
104STATIC void ifsbreakup(char *, struct arglist *);
105STATIC void expandmeta(struct strlist *, int);
106STATIC void expmeta(char *, char *);
107STATIC void addfname(char *);
108STATIC struct strlist *expsort(struct strlist *);
109STATIC struct strlist *msort(struct strlist *, int);
110STATIC int pmatch(char *, char *, int);
111STATIC char *cvtnum(int, char *);
112STATIC int collate_range_cmp(int, int);
113
114STATIC int
115collate_range_cmp(int c1, int c2)
116{
117 static char s1[2], s2[2];
118
119 s1[0] = c1;
120 s2[0] = c2;
121 return (strcoll(s1, s2));
122}
123
124/*
125 * Expand shell variables and backquotes inside a here document.
126 * union node *arg the document
127 * int fd; where to write the expanded version
128 */
129
130void
131expandhere(union node *arg, int fd)
132{
133 herefd = fd;
134 expandarg(arg, (struct arglist *)NULL, 0);
135 xwrite(fd, stackblock(), expdest - stackblock());
136}
137
138
139/*
140 * Perform variable substitution and command substitution on an argument,
141 * placing the resulting list of arguments in arglist. If EXP_FULL is true,
142 * perform splitting and file name expansion. When arglist is NULL, perform
143 * here document expansion.
144 */
145
146void
147expandarg(union node *arg, struct arglist *arglist, int flag)
148{
149 struct strlist *sp;
150 char *p;
151
152 argbackq = arg->narg.backquote;
153 STARTSTACKSTR(expdest);
154 ifsfirst.next = NULL;
155 ifslastp = NULL;
156 argstr(arg->narg.text, flag);
157 if (arglist == NULL) {
158 return; /* here document expanded */
159 }
160 STPUTC('\0', expdest);
161 p = grabstackstr(expdest);
162 exparg.lastp = &exparg.list;
163 /*
164 * TODO - EXP_REDIR
165 */
166 if (flag & EXP_FULL) {
167 ifsbreakup(p, &exparg);
168 *exparg.lastp = NULL;
169 exparg.lastp = &exparg.list;
170 expandmeta(exparg.list, flag);
171 } else {
172 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
173 rmescapes(p);
174 sp = (struct strlist *)stalloc(sizeof (struct strlist));
175 sp->text = p;
176 *exparg.lastp = sp;
177 exparg.lastp = &sp->next;
178 }
179 while (ifsfirst.next != NULL) {
180 struct ifsregion *ifsp;
181 INTOFF;
182 ifsp = ifsfirst.next->next;
183 ckfree(ifsfirst.next);
184 ifsfirst.next = ifsp;
185 INTON;
186 }
187 *exparg.lastp = NULL;
188 if (exparg.list) {
189 *arglist->lastp = exparg.list;
190 arglist->lastp = exparg.lastp;
191 }
192}
193
194
195
196/*
197 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC
198 * characters to allow for further processing. Otherwise treat
199 * $@ like $* since no splitting will be performed.
200 */
201
202STATIC void
203argstr(char *p, int flag)
204{
205 char c;
206 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */
207 int firsteq = 1;
208
209 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
210 p = exptilde(p, flag);
211 for (;;) {
212 switch (c = *p++) {
213 case '\0':
214 case CTLENDVAR: /* ??? */
215 goto breakloop;
216 case CTLQUOTEMARK:
217 /* "$@" syntax adherence hack */
218 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
219 break;
220 if ((flag & EXP_FULL) != 0)
221 STPUTC(c, expdest);
222 break;
223 case CTLESC:
224 if (quotes)
225 STPUTC(c, expdest);
226 c = *p++;
227 STPUTC(c, expdest);
228 break;
229 case CTLVAR:
230 p = evalvar(p, flag);
231 break;
232 case CTLBACKQ:
233 case CTLBACKQ|CTLQUOTE:
234 expbackq(argbackq->n, c & CTLQUOTE, flag);
235 argbackq = argbackq->next;
236 break;
237 case CTLENDARI:
238 expari(flag);
239 break;
240 case ':':
241 case '=':
242 /*
243 * sort of a hack - expand tildes in variable
244 * assignments (after the first '=' and after ':'s).
245 */
246 STPUTC(c, expdest);
247 if (flag & EXP_VARTILDE && *p == '~') {
248 if (c == '=') {
249 if (firsteq)
250 firsteq = 0;
251 else
252 break;
253 }
254 p = exptilde(p, flag);
255 }
256 break;
257 default:
258 STPUTC(c, expdest);
259 }
260 }
261breakloop:;
262}
263
264STATIC char *
265exptilde(char *p, int flag)
266{
267 char c, *startp = p;
268 struct passwd *pw;
269 char *home;
270 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
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 * Expand arithmetic expression. Backup to start of expression,
353 * evaluate, place result in (backed up) result, adjust string position.
354 */
355void
356expari(int flag)
357{
358 char *p, *start;
359 arith_t result;
360 int begoff;
361 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
362 int quoted;
363
364
365 /*
366 * This routine is slightly over-complicated for
367 * efficiency. First we make sure there is
368 * enough space for the result, which may be bigger
369 * than the expression if we add exponentiation. Next we
370 * scan backwards looking for the start of arithmetic. If the
371 * next previous character is a CTLESC character, then we
372 * have to rescan starting from the beginning since CTLESC
373 * characters have to be processed left to right.
374 */
375 CHECKSTRSPACE(DIGITS(result) - 2, expdest);
376 USTPUTC('\0', expdest);
377 start = stackblock();
378 p = expdest - 2;
379 while (p >= start && *p != CTLARI)
380 --p;
381 if (p < start || *p != CTLARI)
382 error("missing CTLARI (shouldn't happen)");
383 if (p > start && *(p - 1) == CTLESC)
384 for (p = start; *p != CTLARI; p++)
385 if (*p == CTLESC)
386 p++;
387
388 if (p[1] == '"')
389 quoted=1;
390 else
391 quoted=0;
392 begoff = p - start;
393 removerecordregions(begoff);
394 if (quotes)
395 rmescapes(p+2);
396 result = arith(p+2);
397 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
398 while (*p++)
399 ;
400 if (quoted == 0)
401 recordregion(begoff, p - 1 - start, 0);
402 result = expdest - p + 1;
403 STADJUST(-result, expdest);
404}
405
406
407/*
408 * Expand stuff in backwards quotes.
409 */
410
411STATIC void
412expbackq(union node *cmd, int quoted, int flag)
413{
414 struct backcmd in;
415 int i;
416 char buf[128];
417 char *p;
418 char *dest = expdest;
419 struct ifsregion saveifs, *savelastp;
420 struct nodelist *saveargbackq;
421 char lastc;
422 int startloc = dest - stackblock();
423 char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
424 int saveherefd;
425 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
426 int nnl;
427
428 INTOFF;
429 saveifs = ifsfirst;
430 savelastp = ifslastp;
431 saveargbackq = argbackq;
432 saveherefd = herefd;
433 herefd = -1;
434 p = grabstackstr(dest);
435 evalbackcmd(cmd, &in);
436 ungrabstackstr(p, dest);
437 ifsfirst = saveifs;
438 ifslastp = savelastp;
439 argbackq = saveargbackq;
440 herefd = saveherefd;
441
442 p = in.buf;
443 lastc = '\0';
444 nnl = 0;
445 /* Don't copy trailing newlines */
446 for (;;) {
447 if (--in.nleft < 0) {
448 if (in.fd < 0)
449 break;
450 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
451 TRACE(("expbackq: read returns %d\n", i));
452 if (i <= 0)
453 break;
454 p = buf;
455 in.nleft = i - 1;
456 }
457 lastc = *p++;
458 if (lastc != '\0') {
459 if (quotes && syntax[(int)lastc] == CCTL)
460 STPUTC(CTLESC, dest);
461 if (lastc == '\n') {
462 nnl++;
463 } else {
464 while (nnl > 0) {
465 nnl--;
466 STPUTC('\n', dest);
467 }
468 STPUTC(lastc, dest);
469 }
470 }
471 }
472
473 if (in.fd >= 0)
474 close(in.fd);
475 if (in.buf)
476 ckfree(in.buf);
477 if (in.jp)
478 exitstatus = waitforjob(in.jp, (int *)NULL);
479 if (quoted == 0)
480 recordregion(startloc, dest - stackblock(), 0);
481 TRACE(("evalbackq: size=%d: \"%.*s\"\n",
482 (dest - stackblock()) - startloc,
483 (dest - stackblock()) - startloc,
484 stackblock() + startloc));
485 expdest = dest;
486 INTON;
487}
488
489
490
491STATIC int
492subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
493 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", (int)(p - str - 1),
528 str, (varflags & VSNUL) ? "null or "
529 : nullstr);
530 return 0;
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 *loc = c;
538 goto recordleft;
539 }
540 *loc = c;
541 if ((varflags & VSQUOTE) && *loc == CTLESC)
542 loc++;
543 }
544 return 0;
545
546 case VSTRIMLEFTMAX:
547 for (loc = str - 1; loc >= startp;) {
548 c = *loc;
549 *loc = '\0';
550 if (patmatch(str, startp, varflags & VSQUOTE)) {
551 *loc = c;
552 goto recordleft;
553 }
554 *loc = c;
555 loc--;
556 if ((varflags & VSQUOTE) && loc > startp &&
557 *(loc - 1) == CTLESC) {
558 for (q = startp; q < loc; q++)
559 if (*q == CTLESC)
560 q++;
561 if (q > loc)
562 loc--;
563 }
564 }
565 return 0;
566
567 case VSTRIMRIGHT:
568 for (loc = str - 1; loc >= startp;) {
569 if (patmatch(str, loc, varflags & VSQUOTE)) {
570 amount = loc - expdest;
571 STADJUST(amount, expdest);
572 return 1;
573 }
574 loc--;
575 if ((varflags & VSQUOTE) && loc > startp &&
576 *(loc - 1) == CTLESC) {
577 for (q = startp; q < loc; q++)
578 if (*q == CTLESC)
579 q++;
580 if (q > loc)
581 loc--;
582 }
583 }
584 return 0;
585
586 case VSTRIMRIGHTMAX:
587 for (loc = startp; loc < str - 1; loc++) {
588 if (patmatch(str, loc, varflags & VSQUOTE)) {
589 amount = loc - expdest;
590 STADJUST(amount, expdest);
591 return 1;
592 }
593 if ((varflags & VSQUOTE) && *loc == CTLESC)
594 loc++;
595 }
596 return 0;
597
598
599 default:
600 abort();
601 }
602
603recordleft:
604 amount = ((str - 1) - (loc - startp)) - expdest;
605 STADJUST(amount, expdest);
606 while (loc != str - 1)
607 *startp++ = *loc++;
608 return 1;
609}
610
611
612/*
613 * Expand a variable, and return a pointer to the next character in the
614 * input string.
615 */
616
617STATIC char *
618evalvar(char *p, int flag)
619{
620 int subtype;
621 int varflags;
622 char *var;
623 char *val;
624 int patloc;
625 int c;
626 int set;
627 int special;
628 int startloc;
629 int varlen;
630 int easy;
631 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
632
633 varflags = (unsigned char)*p++;
634 subtype = varflags & VSTYPE;
635 var = p;
636 special = 0;
637 if (! is_name(*p))
638 special = 1;
639 p = strchr(p, '=') + 1;
640again: /* jump here after setting a variable with ${var=text} */
641 if (varflags & VSLINENO) {
642 set = 1;
643 special = 0;
644 val = var;
645 p[-1] = '\0'; /* temporarily overwrite '=' to have \0
646 terminated string */
647 } else if (special) {
648 set = varisset(var, varflags & VSNUL);
649 val = NULL;
650 } else {
651 val = bltinlookup(var, 1);
652 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
653 val = NULL;
654 set = 0;
655 } else
656 set = 1;
657 }
658 varlen = 0;
659 startloc = expdest - stackblock();
660 if (!set && uflag && *var != '@' && *var != '*') {
661 switch (subtype) {
662 case VSNORMAL:
663 case VSTRIMLEFT:
664 case VSTRIMLEFTMAX:
665 case VSTRIMRIGHT:
666 case VSTRIMRIGHTMAX:
667 case VSLENGTH:
668 error("%.*s: parameter not set", (int)(p - var - 1),
669 var);
670 }
671 }
672 if (set && subtype != VSPLUS) {
673 /* insert the value of the variable */
674 if (special) {
675 varvalue(var, varflags & VSQUOTE, subtype, flag);
676 if (subtype == VSLENGTH) {
677 varlen = expdest - stackblock() - startloc;
678 STADJUST(-varlen, expdest);
679 }
680 } else {
681 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
682 : BASESYNTAX;
683
684 if (subtype == VSLENGTH) {
685 for (;*val; val++)
686 varlen++;
687 }
688 else {
689 while (*val) {
690 if (quotes &&
691 syntax[(int)*val] == CCTL)
692 STPUTC(CTLESC, expdest);
693 STPUTC(*val++, expdest);
694 }
695
696 }
697 }
698 }
699
700 if (subtype == VSPLUS)
701 set = ! set;
702
703 easy = ((varflags & VSQUOTE) == 0 ||
704 (*var == '@' && shellparam.nparam != 1));
705
706
707 switch (subtype) {
708 case VSLENGTH:
709 expdest = cvtnum(varlen, expdest);
710 goto record;
711
712 case VSNORMAL:
713 if (!easy)
714 break;
715record:
716 recordregion(startloc, expdest - stackblock(),
717 varflags & VSQUOTE);
718 break;
719
720 case VSPLUS:
721 case VSMINUS:
722 if (!set) {
723 argstr(p, flag);
724 break;
725 }
726 if (easy)
727 goto record;
728 break;
729
730 case VSTRIMLEFT:
731 case VSTRIMLEFTMAX:
732 case VSTRIMRIGHT:
733 case VSTRIMRIGHTMAX:
734 if (!set)
735 break;
736 /*
737 * Terminate the string and start recording the pattern
738 * right after it
739 */
740 STPUTC('\0', expdest);
741 patloc = expdest - stackblock();
742 if (subevalvar(p, NULL, patloc, subtype,
743 startloc, varflags) == 0) {
744 int amount = (expdest - stackblock() - patloc) + 1;
745 STADJUST(-amount, expdest);
746 }
747 /* Remove any recorded regions beyond start of variable */
748 removerecordregions(startloc);
749 goto record;
750
751 case VSASSIGN:
752 case VSQUESTION:
753 if (!set) {
754 if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
755 varflags &= ~VSNUL;
756 /*
757 * Remove any recorded regions beyond
758 * start of variable
759 */
760 removerecordregions(startloc);
761 goto again;
762 }
763 break;
764 }
765 if (easy)
766 goto record;
767 break;
768
769 case VSERROR:
770 c = p - var - 1;
771 error("${%.*s%s}: Bad substitution", c, var,
772 (c > 0 && *p != CTLENDVAR) ? "..." : "");
773
774 default:
775 abort();
776 }
777 p[-1] = '='; /* recover overwritten '=' */
778
779 if (subtype != VSNORMAL) { /* skip to end of alternative */
780 int nesting = 1;
781 for (;;) {
782 if ((c = *p++) == CTLESC)
783 p++;
784 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
785 if (set)
786 argbackq = argbackq->next;
787 } else if (c == CTLVAR) {
788 if ((*p++ & VSTYPE) != VSNORMAL)
789 nesting++;
790 } else if (c == CTLENDVAR) {
791 if (--nesting == 0)
792 break;
793 }
794 }
795 }
796 return p;
797}
798
799
800
801/*
802 * Test whether a specialized variable is set.
803 */
804
805STATIC int
806varisset(char *name, int nulok)
807{
808
809 if (*name == '!')
810 return backgndpid != -1;
811 else if (*name == '@' || *name == '*') {
812 if (*shellparam.p == NULL)
813 return 0;
814
815 if (nulok) {
816 char **av;
817
818 for (av = shellparam.p; *av; av++)
819 if (**av != '\0')
820 return 1;
821 return 0;
822 }
823 } else if (is_digit(*name)) {
824 char *ap;
825 int num = atoi(name);
826
827 if (num > shellparam.nparam)
828 return 0;
829
830 if (num == 0)
831 ap = arg0;
832 else
833 ap = shellparam.p[num - 1];
834
835 if (nulok && (ap == NULL || *ap == '\0'))
836 return 0;
837 }
838 return 1;
839}
840
841
842
843/*
844 * Add the value of a specialized variable to the stack string.
845 */
846
847STATIC void
848varvalue(char *name, int quoted, int subtype, int flag)
849{
850 int num;
851 char *p;
852 int i;
853 extern int oexitstatus;
854 char sep;
855 char **ap;
856 char const *syntax;
857
858#define STRTODEST(p) \
859 do {\
860 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
861 syntax = quoted? DQSYNTAX : BASESYNTAX; \
862 while (*p) { \
863 if (syntax[(int)*p] == CCTL) \
864 STPUTC(CTLESC, expdest); \
865 STPUTC(*p++, expdest); \
866 } \
867 } else \
868 while (*p) \
869 STPUTC(*p++, expdest); \
870 } while (0)
871
872
873 switch (*name) {
874 case '$':
875 num = rootpid;
876 goto numvar;
877 case '?':
878 num = oexitstatus;
879 goto numvar;
880 case '#':
881 num = shellparam.nparam;
882 goto numvar;
883 case '!':
884 num = backgndpid;
885numvar:
886 expdest = cvtnum(num, expdest);
887 break;
888 case '-':
889 for (i = 0 ; i < NOPTS ; i++) {
890 if (optlist[i].val)
891 STPUTC(optlist[i].letter, expdest);
892 }
893 break;
894 case '@':
895 if (flag & EXP_FULL && quoted) {
896 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
897 STRTODEST(p);
898 if (*ap)
899 STPUTC('\0', expdest);
900 }
901 break;
902 }
903 /* FALLTHROUGH */
904 case '*':
905 if (ifsset())
906 sep = ifsval()[0];
907 else
908 sep = ' ';
909 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
910 STRTODEST(p);
911 if (*ap && sep)
912 STPUTC(sep, expdest);
913 }
914 break;
915 case '0':
916 p = arg0;
917 STRTODEST(p);
918 break;
919 default:
920 if (is_digit(*name)) {
921 num = atoi(name);
922 if (num > 0 && num <= shellparam.nparam) {
923 p = shellparam.p[num - 1];
924 STRTODEST(p);
925 }
926 }
927 break;
928 }
929}
930
931
932
933/*
934 * Record the the fact that we have to scan this region of the
935 * string for IFS characters.
936 */
937
938STATIC void
939recordregion(int start, int end, int inquotes)
940{
941 struct ifsregion *ifsp;
942
943 if (ifslastp == NULL) {
944 ifsp = &ifsfirst;
945 } else {
946 if (ifslastp->endoff == start
947 && ifslastp->inquotes == inquotes) {
948 /* extend previous area */
949 ifslastp->endoff = end;
950 return;
951 }
952 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
953 ifslastp->next = ifsp;
954 }
955 ifslastp = ifsp;
956 ifslastp->next = NULL;
957 ifslastp->begoff = start;
958 ifslastp->endoff = end;
959 ifslastp->inquotes = inquotes;
960}
961
962
963
964/*
965 * Break the argument string into pieces based upon IFS and add the
966 * strings to the argument list. The regions of the string to be
967 * searched for IFS characters have been stored by recordregion.
968 */
969STATIC void
970ifsbreakup(char *string, struct arglist *arglist)
971{
972 struct ifsregion *ifsp;
973 struct strlist *sp;
974 char *start;
975 char *p;
976 char *q;
977 char *ifs;
978 const char *ifsspc;
979 int had_param_ch = 0;
980
981 start = string;
982
983 if (ifslastp == NULL) {
984 /* Return entire argument, IFS doesn't apply to any of it */
985 sp = (struct strlist *)stalloc(sizeof *sp);
986 sp->text = start;
987 *arglist->lastp = sp;
988 arglist->lastp = &sp->next;
989 return;
990 }
991
992 ifs = ifsset() ? ifsval() : " \t\n";
993
994 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
995 p = string + ifsp->begoff;
996 while (p < string + ifsp->endoff) {
997 q = p;
998 if (*p == CTLESC)
999 p++;
1000 if (ifsp->inquotes) {
1001 /* Only NULs (should be from "$@") end args */
1002 had_param_ch = 1;
1003 if (*p != 0) {
1004 p++;
1005 continue;
1006 }
1007 ifsspc = NULL;
1008 } else {
1009 if (!strchr(ifs, *p)) {
1010 had_param_ch = 1;
1011 p++;
1012 continue;
1013 }
1014 ifsspc = strchr(" \t\n", *p);
1015
1016 /* Ignore IFS whitespace at start */
1017 if (q == start && ifsspc != NULL) {
1018 p++;
1019 start = p;
1020 continue;
1021 }
1022 had_param_ch = 0;
1023 }
1024
1025 /* Save this argument... */
1026 *q = '\0';
1027 sp = (struct strlist *)stalloc(sizeof *sp);
1028 sp->text = start;
1029 *arglist->lastp = sp;
1030 arglist->lastp = &sp->next;
1031 p++;
1032
1033 if (ifsspc != NULL) {
1034 /* Ignore further trailing IFS whitespace */
1035 for (; p < string + ifsp->endoff; p++) {
1036 q = p;
1037 if (*p == CTLESC)
1038 p++;
1039 if (strchr(ifs, *p) == NULL) {
1040 p = q;
1041 break;
1042 }
1043 if (strchr(" \t\n", *p) == NULL) {
1044 p++;
1045 break;
1046 }
1047 }
1048 }
1049 start = p;
1050 }
1051 }
1052
1053 /*
1054 * Save anything left as an argument.
1055 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1056 * generating 2 arguments, the second of which is empty.
1057 * Some recent clarification of the Posix spec say that it
1058 * should only generate one....
1059 */
1060 if (had_param_ch || *start != 0) {
1061 sp = (struct strlist *)stalloc(sizeof *sp);
1062 sp->text = start;
1063 *arglist->lastp = sp;
1064 arglist->lastp = &sp->next;
1065 }
1066}
1067
1068
1069
1070/*
1071 * Expand shell metacharacters. At this point, the only control characters
1072 * should be escapes. The results are stored in the list exparg.
1073 */
1074
1075STATIC char *expdir;
1076
1077
1078STATIC void
1079expandmeta(struct strlist *str, int flag __unused)
1080{
1081 char *p;
1082 struct strlist **savelastp;
1083 struct strlist *sp;
1084 char c;
1085 /* TODO - EXP_REDIR */
1086
1087 while (str) {
1088 if (fflag)
1089 goto nometa;
1090 p = str->text;
1091 for (;;) { /* fast check for meta chars */
1092 if ((c = *p++) == '\0')
1093 goto nometa;
1094 if (c == '*' || c == '?' || c == '[' || c == '!')
1095 break;
1096 }
1097 savelastp = exparg.lastp;
1098 INTOFF;
1099 if (expdir == NULL) {
1100 int i = strlen(str->text);
1101 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1102 }
1103
1104 expmeta(expdir, str->text);
1105 ckfree(expdir);
1106 expdir = NULL;
1107 INTON;
1108 if (exparg.lastp == savelastp) {
1109 /*
1110 * no matches
1111 */
1112nometa:
1113 *exparg.lastp = str;
1114 rmescapes(str->text);
1115 exparg.lastp = &str->next;
1116 } else {
1117 *exparg.lastp = NULL;
1118 *savelastp = sp = expsort(*savelastp);
1119 while (sp->next != NULL)
1120 sp = sp->next;
1121 exparg.lastp = &sp->next;
1122 }
1123 str = str->next;
1124 }
1125}
1126
1127
1128/*
1129 * Do metacharacter (i.e. *, ?, [...]) expansion.
1130 */
1131
1132STATIC void
1133expmeta(char *enddir, char *name)
1134{
1135 char *p;
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 == '!' || *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 p = ".";
1210 } else if (enddir == expdir + 1 && *expdir == '/') {
1211 p = "/";
1212 } else {
1213 p = expdir;
1214 enddir[-1] = '\0';
1215 }
1216 if ((dirp = opendir(p)) == 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, q = dp->d_name;
1243 (*p++ = *q++) != '\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 == '!' || *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 == '!' || *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 ( collate_range_cmp(chr, c) >= 0
1444 && collate_range_cmp(chr, *p) <= 0
1445 )
1446 found = 1;
1447 p++;
1448 } else {
1449 if (chr == c)
1450 found = 1;
1451 }
1452 } while ((c = *p++) != ']');
1453 if (found == invert)
1454 return 0;
1455 break;
1456 }
1457dft: default:
1458 if (squoted && *q == CTLESC)
1459 q++;
1460 if (*q++ != c)
1461 return 0;
1462 break;
1463 }
1464 }
1465breakloop:
1466 if (*q != '\0')
1467 return 0;
1468 return 1;
1469}
1470
1471
1472
1473/*
1474 * Remove any CTLESC characters from a string.
1475 */
1476
1477void
1478rmescapes(char *str)
1479{
1480 char *p, *q;
1481
1482 p = str;
1483 while (*p != CTLESC && *p != CTLQUOTEMARK) {
1484 if (*p++ == '\0')
1485 return;
1486 }
1487 q = p;
1488 while (*p) {
1489 if (*p == CTLQUOTEMARK) {
1490 p++;
1491 continue;
1492 }
1493 if (*p == CTLESC)
1494 p++;
1495 *q++ = *p++;
1496 }
1497 *q = '\0';
1498}
1499
1500
1501
1502/*
1503 * See if a pattern matches in a case statement.
1504 */
1505
1506int
1507casematch(union node *pattern, char *val)
1508{
1509 struct stackmark smark;
1510 int result;
1511 char *p;
1512
1513 setstackmark(&smark);
1514 argbackq = pattern->narg.backquote;
1515 STARTSTACKSTR(expdest);
1516 ifslastp = NULL;
1517 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1518 STPUTC('\0', expdest);
1519 p = grabstackstr(expdest);
1520 result = patmatch(p, val, 0);
1521 popstackmark(&smark);
1522 return result;
1523}
1524
1525/*
1526 * Our own itoa().
1527 */
1528
1529STATIC char *
1530cvtnum(int num, char *buf)
1531{
1532 char temp[32];
1533 int neg = num < 0;
1534 char *p = temp + 31;
1535
1536 temp[31] = '\0';
1537
1538 do {
1539 *--p = num % 10 + '0';
1540 } while ((num /= 10) != 0);
1541
1542 if (neg)
1543 *--p = '-';
1544
1545 while (*p)
1546 STPUTC(*p++, buf);
1547 return buf;
1548}
1549
1550/*
1551 * Do most of the work for wordexp(3).
1552 */
1553
1554int
1555wordexpcmd(int argc, char **argv)
1556{
1557 size_t len;
1558 int i;
1559
1560 out1fmt("%08x", argc - 1);
1561 for (i = 1, len = 0; i < argc; i++)
1562 len += strlen(argv[i]);
1563 out1fmt("%08x", (int)len);
1564 for (i = 1; i < argc; i++) {
1565 out1str(argv[i]);
1566 out1c('\0');
1567 }
1568 return (0);
1569}
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
36#endif
37#endif /* not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/bin/sh/expand.c 198454 2009-10-24 21:20:04Z jilles $");
40
41#include <sys/types.h>
42#include <sys/time.h>
43#include <sys/stat.h>
44#include <errno.h>
45#include <dirent.h>
46#include <unistd.h>
47#include <pwd.h>
48#include <stdlib.h>
49#include <limits.h>
50#include <stdio.h>
51#include <string.h>
52
53/*
54 * Routines to expand arguments to commands. We have to deal with
55 * backquotes, shell variables, and file metacharacters.
56 */
57
58#include "shell.h"
59#include "main.h"
60#include "nodes.h"
61#include "eval.h"
62#include "expand.h"
63#include "syntax.h"
64#include "parser.h"
65#include "jobs.h"
66#include "options.h"
67#include "var.h"
68#include "input.h"
69#include "output.h"
70#include "memalloc.h"
71#include "error.h"
72#include "mystring.h"
73#include "arith.h"
74#include "show.h"
75
76/*
77 * Structure specifying which parts of the string should be searched
78 * for IFS characters.
79 */
80
81struct ifsregion {
82 struct ifsregion *next; /* next region in list */
83 int begoff; /* offset of start of region */
84 int endoff; /* offset of end of region */
85 int inquotes; /* search for nul bytes only */
86};
87
88
89STATIC char *expdest; /* output of current string */
90STATIC struct nodelist *argbackq; /* list of back quote expressions */
91STATIC struct ifsregion ifsfirst; /* first struct in list of ifs regions */
92STATIC struct ifsregion *ifslastp; /* last struct in list */
93STATIC struct arglist exparg; /* holds expanded arg list */
94
95STATIC void argstr(char *, int);
96STATIC char *exptilde(char *, int);
97STATIC void expbackq(union node *, int, int);
98STATIC int subevalvar(char *, char *, int, int, int, int);
99STATIC char *evalvar(char *, int);
100STATIC int varisset(char *, int);
101STATIC void varvalue(char *, int, int, int);
102STATIC void recordregion(int, int, int);
103STATIC void removerecordregions(int);
104STATIC void ifsbreakup(char *, struct arglist *);
105STATIC void expandmeta(struct strlist *, int);
106STATIC void expmeta(char *, char *);
107STATIC void addfname(char *);
108STATIC struct strlist *expsort(struct strlist *);
109STATIC struct strlist *msort(struct strlist *, int);
110STATIC int pmatch(char *, char *, int);
111STATIC char *cvtnum(int, char *);
112STATIC int collate_range_cmp(int, int);
113
114STATIC int
115collate_range_cmp(int c1, int c2)
116{
117 static char s1[2], s2[2];
118
119 s1[0] = c1;
120 s2[0] = c2;
121 return (strcoll(s1, s2));
122}
123
124/*
125 * Expand shell variables and backquotes inside a here document.
126 * union node *arg the document
127 * int fd; where to write the expanded version
128 */
129
130void
131expandhere(union node *arg, int fd)
132{
133 herefd = fd;
134 expandarg(arg, (struct arglist *)NULL, 0);
135 xwrite(fd, stackblock(), expdest - stackblock());
136}
137
138
139/*
140 * Perform variable substitution and command substitution on an argument,
141 * placing the resulting list of arguments in arglist. If EXP_FULL is true,
142 * perform splitting and file name expansion. When arglist is NULL, perform
143 * here document expansion.
144 */
145
146void
147expandarg(union node *arg, struct arglist *arglist, int flag)
148{
149 struct strlist *sp;
150 char *p;
151
152 argbackq = arg->narg.backquote;
153 STARTSTACKSTR(expdest);
154 ifsfirst.next = NULL;
155 ifslastp = NULL;
156 argstr(arg->narg.text, flag);
157 if (arglist == NULL) {
158 return; /* here document expanded */
159 }
160 STPUTC('\0', expdest);
161 p = grabstackstr(expdest);
162 exparg.lastp = &exparg.list;
163 /*
164 * TODO - EXP_REDIR
165 */
166 if (flag & EXP_FULL) {
167 ifsbreakup(p, &exparg);
168 *exparg.lastp = NULL;
169 exparg.lastp = &exparg.list;
170 expandmeta(exparg.list, flag);
171 } else {
172 if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
173 rmescapes(p);
174 sp = (struct strlist *)stalloc(sizeof (struct strlist));
175 sp->text = p;
176 *exparg.lastp = sp;
177 exparg.lastp = &sp->next;
178 }
179 while (ifsfirst.next != NULL) {
180 struct ifsregion *ifsp;
181 INTOFF;
182 ifsp = ifsfirst.next->next;
183 ckfree(ifsfirst.next);
184 ifsfirst.next = ifsp;
185 INTON;
186 }
187 *exparg.lastp = NULL;
188 if (exparg.list) {
189 *arglist->lastp = exparg.list;
190 arglist->lastp = exparg.lastp;
191 }
192}
193
194
195
196/*
197 * Perform variable and command substitution. If EXP_FULL is set, output CTLESC
198 * characters to allow for further processing. Otherwise treat
199 * $@ like $* since no splitting will be performed.
200 */
201
202STATIC void
203argstr(char *p, int flag)
204{
205 char c;
206 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR); /* do CTLESC */
207 int firsteq = 1;
208
209 if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
210 p = exptilde(p, flag);
211 for (;;) {
212 switch (c = *p++) {
213 case '\0':
214 case CTLENDVAR: /* ??? */
215 goto breakloop;
216 case CTLQUOTEMARK:
217 /* "$@" syntax adherence hack */
218 if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
219 break;
220 if ((flag & EXP_FULL) != 0)
221 STPUTC(c, expdest);
222 break;
223 case CTLESC:
224 if (quotes)
225 STPUTC(c, expdest);
226 c = *p++;
227 STPUTC(c, expdest);
228 break;
229 case CTLVAR:
230 p = evalvar(p, flag);
231 break;
232 case CTLBACKQ:
233 case CTLBACKQ|CTLQUOTE:
234 expbackq(argbackq->n, c & CTLQUOTE, flag);
235 argbackq = argbackq->next;
236 break;
237 case CTLENDARI:
238 expari(flag);
239 break;
240 case ':':
241 case '=':
242 /*
243 * sort of a hack - expand tildes in variable
244 * assignments (after the first '=' and after ':'s).
245 */
246 STPUTC(c, expdest);
247 if (flag & EXP_VARTILDE && *p == '~') {
248 if (c == '=') {
249 if (firsteq)
250 firsteq = 0;
251 else
252 break;
253 }
254 p = exptilde(p, flag);
255 }
256 break;
257 default:
258 STPUTC(c, expdest);
259 }
260 }
261breakloop:;
262}
263
264STATIC char *
265exptilde(char *p, int flag)
266{
267 char c, *startp = p;
268 struct passwd *pw;
269 char *home;
270 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
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 * Expand arithmetic expression. Backup to start of expression,
353 * evaluate, place result in (backed up) result, adjust string position.
354 */
355void
356expari(int flag)
357{
358 char *p, *start;
359 arith_t result;
360 int begoff;
361 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
362 int quoted;
363
364
365 /*
366 * This routine is slightly over-complicated for
367 * efficiency. First we make sure there is
368 * enough space for the result, which may be bigger
369 * than the expression if we add exponentiation. Next we
370 * scan backwards looking for the start of arithmetic. If the
371 * next previous character is a CTLESC character, then we
372 * have to rescan starting from the beginning since CTLESC
373 * characters have to be processed left to right.
374 */
375 CHECKSTRSPACE(DIGITS(result) - 2, expdest);
376 USTPUTC('\0', expdest);
377 start = stackblock();
378 p = expdest - 2;
379 while (p >= start && *p != CTLARI)
380 --p;
381 if (p < start || *p != CTLARI)
382 error("missing CTLARI (shouldn't happen)");
383 if (p > start && *(p - 1) == CTLESC)
384 for (p = start; *p != CTLARI; p++)
385 if (*p == CTLESC)
386 p++;
387
388 if (p[1] == '"')
389 quoted=1;
390 else
391 quoted=0;
392 begoff = p - start;
393 removerecordregions(begoff);
394 if (quotes)
395 rmescapes(p+2);
396 result = arith(p+2);
397 fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
398 while (*p++)
399 ;
400 if (quoted == 0)
401 recordregion(begoff, p - 1 - start, 0);
402 result = expdest - p + 1;
403 STADJUST(-result, expdest);
404}
405
406
407/*
408 * Expand stuff in backwards quotes.
409 */
410
411STATIC void
412expbackq(union node *cmd, int quoted, int flag)
413{
414 struct backcmd in;
415 int i;
416 char buf[128];
417 char *p;
418 char *dest = expdest;
419 struct ifsregion saveifs, *savelastp;
420 struct nodelist *saveargbackq;
421 char lastc;
422 int startloc = dest - stackblock();
423 char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
424 int saveherefd;
425 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
426 int nnl;
427
428 INTOFF;
429 saveifs = ifsfirst;
430 savelastp = ifslastp;
431 saveargbackq = argbackq;
432 saveherefd = herefd;
433 herefd = -1;
434 p = grabstackstr(dest);
435 evalbackcmd(cmd, &in);
436 ungrabstackstr(p, dest);
437 ifsfirst = saveifs;
438 ifslastp = savelastp;
439 argbackq = saveargbackq;
440 herefd = saveherefd;
441
442 p = in.buf;
443 lastc = '\0';
444 nnl = 0;
445 /* Don't copy trailing newlines */
446 for (;;) {
447 if (--in.nleft < 0) {
448 if (in.fd < 0)
449 break;
450 while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
451 TRACE(("expbackq: read returns %d\n", i));
452 if (i <= 0)
453 break;
454 p = buf;
455 in.nleft = i - 1;
456 }
457 lastc = *p++;
458 if (lastc != '\0') {
459 if (quotes && syntax[(int)lastc] == CCTL)
460 STPUTC(CTLESC, dest);
461 if (lastc == '\n') {
462 nnl++;
463 } else {
464 while (nnl > 0) {
465 nnl--;
466 STPUTC('\n', dest);
467 }
468 STPUTC(lastc, dest);
469 }
470 }
471 }
472
473 if (in.fd >= 0)
474 close(in.fd);
475 if (in.buf)
476 ckfree(in.buf);
477 if (in.jp)
478 exitstatus = waitforjob(in.jp, (int *)NULL);
479 if (quoted == 0)
480 recordregion(startloc, dest - stackblock(), 0);
481 TRACE(("evalbackq: size=%d: \"%.*s\"\n",
482 (dest - stackblock()) - startloc,
483 (dest - stackblock()) - startloc,
484 stackblock() + startloc));
485 expdest = dest;
486 INTON;
487}
488
489
490
491STATIC int
492subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
493 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", (int)(p - str - 1),
528 str, (varflags & VSNUL) ? "null or "
529 : nullstr);
530 return 0;
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 *loc = c;
538 goto recordleft;
539 }
540 *loc = c;
541 if ((varflags & VSQUOTE) && *loc == CTLESC)
542 loc++;
543 }
544 return 0;
545
546 case VSTRIMLEFTMAX:
547 for (loc = str - 1; loc >= startp;) {
548 c = *loc;
549 *loc = '\0';
550 if (patmatch(str, startp, varflags & VSQUOTE)) {
551 *loc = c;
552 goto recordleft;
553 }
554 *loc = c;
555 loc--;
556 if ((varflags & VSQUOTE) && loc > startp &&
557 *(loc - 1) == CTLESC) {
558 for (q = startp; q < loc; q++)
559 if (*q == CTLESC)
560 q++;
561 if (q > loc)
562 loc--;
563 }
564 }
565 return 0;
566
567 case VSTRIMRIGHT:
568 for (loc = str - 1; loc >= startp;) {
569 if (patmatch(str, loc, varflags & VSQUOTE)) {
570 amount = loc - expdest;
571 STADJUST(amount, expdest);
572 return 1;
573 }
574 loc--;
575 if ((varflags & VSQUOTE) && loc > startp &&
576 *(loc - 1) == CTLESC) {
577 for (q = startp; q < loc; q++)
578 if (*q == CTLESC)
579 q++;
580 if (q > loc)
581 loc--;
582 }
583 }
584 return 0;
585
586 case VSTRIMRIGHTMAX:
587 for (loc = startp; loc < str - 1; loc++) {
588 if (patmatch(str, loc, varflags & VSQUOTE)) {
589 amount = loc - expdest;
590 STADJUST(amount, expdest);
591 return 1;
592 }
593 if ((varflags & VSQUOTE) && *loc == CTLESC)
594 loc++;
595 }
596 return 0;
597
598
599 default:
600 abort();
601 }
602
603recordleft:
604 amount = ((str - 1) - (loc - startp)) - expdest;
605 STADJUST(amount, expdest);
606 while (loc != str - 1)
607 *startp++ = *loc++;
608 return 1;
609}
610
611
612/*
613 * Expand a variable, and return a pointer to the next character in the
614 * input string.
615 */
616
617STATIC char *
618evalvar(char *p, int flag)
619{
620 int subtype;
621 int varflags;
622 char *var;
623 char *val;
624 int patloc;
625 int c;
626 int set;
627 int special;
628 int startloc;
629 int varlen;
630 int easy;
631 int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
632
633 varflags = (unsigned char)*p++;
634 subtype = varflags & VSTYPE;
635 var = p;
636 special = 0;
637 if (! is_name(*p))
638 special = 1;
639 p = strchr(p, '=') + 1;
640again: /* jump here after setting a variable with ${var=text} */
641 if (varflags & VSLINENO) {
642 set = 1;
643 special = 0;
644 val = var;
645 p[-1] = '\0'; /* temporarily overwrite '=' to have \0
646 terminated string */
647 } else if (special) {
648 set = varisset(var, varflags & VSNUL);
649 val = NULL;
650 } else {
651 val = bltinlookup(var, 1);
652 if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
653 val = NULL;
654 set = 0;
655 } else
656 set = 1;
657 }
658 varlen = 0;
659 startloc = expdest - stackblock();
660 if (!set && uflag && *var != '@' && *var != '*') {
661 switch (subtype) {
662 case VSNORMAL:
663 case VSTRIMLEFT:
664 case VSTRIMLEFTMAX:
665 case VSTRIMRIGHT:
666 case VSTRIMRIGHTMAX:
667 case VSLENGTH:
668 error("%.*s: parameter not set", (int)(p - var - 1),
669 var);
670 }
671 }
672 if (set && subtype != VSPLUS) {
673 /* insert the value of the variable */
674 if (special) {
675 varvalue(var, varflags & VSQUOTE, subtype, flag);
676 if (subtype == VSLENGTH) {
677 varlen = expdest - stackblock() - startloc;
678 STADJUST(-varlen, expdest);
679 }
680 } else {
681 char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
682 : BASESYNTAX;
683
684 if (subtype == VSLENGTH) {
685 for (;*val; val++)
686 varlen++;
687 }
688 else {
689 while (*val) {
690 if (quotes &&
691 syntax[(int)*val] == CCTL)
692 STPUTC(CTLESC, expdest);
693 STPUTC(*val++, expdest);
694 }
695
696 }
697 }
698 }
699
700 if (subtype == VSPLUS)
701 set = ! set;
702
703 easy = ((varflags & VSQUOTE) == 0 ||
704 (*var == '@' && shellparam.nparam != 1));
705
706
707 switch (subtype) {
708 case VSLENGTH:
709 expdest = cvtnum(varlen, expdest);
710 goto record;
711
712 case VSNORMAL:
713 if (!easy)
714 break;
715record:
716 recordregion(startloc, expdest - stackblock(),
717 varflags & VSQUOTE);
718 break;
719
720 case VSPLUS:
721 case VSMINUS:
722 if (!set) {
723 argstr(p, flag);
724 break;
725 }
726 if (easy)
727 goto record;
728 break;
729
730 case VSTRIMLEFT:
731 case VSTRIMLEFTMAX:
732 case VSTRIMRIGHT:
733 case VSTRIMRIGHTMAX:
734 if (!set)
735 break;
736 /*
737 * Terminate the string and start recording the pattern
738 * right after it
739 */
740 STPUTC('\0', expdest);
741 patloc = expdest - stackblock();
742 if (subevalvar(p, NULL, patloc, subtype,
743 startloc, varflags) == 0) {
744 int amount = (expdest - stackblock() - patloc) + 1;
745 STADJUST(-amount, expdest);
746 }
747 /* Remove any recorded regions beyond start of variable */
748 removerecordregions(startloc);
749 goto record;
750
751 case VSASSIGN:
752 case VSQUESTION:
753 if (!set) {
754 if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
755 varflags &= ~VSNUL;
756 /*
757 * Remove any recorded regions beyond
758 * start of variable
759 */
760 removerecordregions(startloc);
761 goto again;
762 }
763 break;
764 }
765 if (easy)
766 goto record;
767 break;
768
769 case VSERROR:
770 c = p - var - 1;
771 error("${%.*s%s}: Bad substitution", c, var,
772 (c > 0 && *p != CTLENDVAR) ? "..." : "");
773
774 default:
775 abort();
776 }
777 p[-1] = '='; /* recover overwritten '=' */
778
779 if (subtype != VSNORMAL) { /* skip to end of alternative */
780 int nesting = 1;
781 for (;;) {
782 if ((c = *p++) == CTLESC)
783 p++;
784 else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
785 if (set)
786 argbackq = argbackq->next;
787 } else if (c == CTLVAR) {
788 if ((*p++ & VSTYPE) != VSNORMAL)
789 nesting++;
790 } else if (c == CTLENDVAR) {
791 if (--nesting == 0)
792 break;
793 }
794 }
795 }
796 return p;
797}
798
799
800
801/*
802 * Test whether a specialized variable is set.
803 */
804
805STATIC int
806varisset(char *name, int nulok)
807{
808
809 if (*name == '!')
810 return backgndpid != -1;
811 else if (*name == '@' || *name == '*') {
812 if (*shellparam.p == NULL)
813 return 0;
814
815 if (nulok) {
816 char **av;
817
818 for (av = shellparam.p; *av; av++)
819 if (**av != '\0')
820 return 1;
821 return 0;
822 }
823 } else if (is_digit(*name)) {
824 char *ap;
825 int num = atoi(name);
826
827 if (num > shellparam.nparam)
828 return 0;
829
830 if (num == 0)
831 ap = arg0;
832 else
833 ap = shellparam.p[num - 1];
834
835 if (nulok && (ap == NULL || *ap == '\0'))
836 return 0;
837 }
838 return 1;
839}
840
841
842
843/*
844 * Add the value of a specialized variable to the stack string.
845 */
846
847STATIC void
848varvalue(char *name, int quoted, int subtype, int flag)
849{
850 int num;
851 char *p;
852 int i;
853 extern int oexitstatus;
854 char sep;
855 char **ap;
856 char const *syntax;
857
858#define STRTODEST(p) \
859 do {\
860 if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH) { \
861 syntax = quoted? DQSYNTAX : BASESYNTAX; \
862 while (*p) { \
863 if (syntax[(int)*p] == CCTL) \
864 STPUTC(CTLESC, expdest); \
865 STPUTC(*p++, expdest); \
866 } \
867 } else \
868 while (*p) \
869 STPUTC(*p++, expdest); \
870 } while (0)
871
872
873 switch (*name) {
874 case '$':
875 num = rootpid;
876 goto numvar;
877 case '?':
878 num = oexitstatus;
879 goto numvar;
880 case '#':
881 num = shellparam.nparam;
882 goto numvar;
883 case '!':
884 num = backgndpid;
885numvar:
886 expdest = cvtnum(num, expdest);
887 break;
888 case '-':
889 for (i = 0 ; i < NOPTS ; i++) {
890 if (optlist[i].val)
891 STPUTC(optlist[i].letter, expdest);
892 }
893 break;
894 case '@':
895 if (flag & EXP_FULL && quoted) {
896 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
897 STRTODEST(p);
898 if (*ap)
899 STPUTC('\0', expdest);
900 }
901 break;
902 }
903 /* FALLTHROUGH */
904 case '*':
905 if (ifsset())
906 sep = ifsval()[0];
907 else
908 sep = ' ';
909 for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
910 STRTODEST(p);
911 if (*ap && sep)
912 STPUTC(sep, expdest);
913 }
914 break;
915 case '0':
916 p = arg0;
917 STRTODEST(p);
918 break;
919 default:
920 if (is_digit(*name)) {
921 num = atoi(name);
922 if (num > 0 && num <= shellparam.nparam) {
923 p = shellparam.p[num - 1];
924 STRTODEST(p);
925 }
926 }
927 break;
928 }
929}
930
931
932
933/*
934 * Record the the fact that we have to scan this region of the
935 * string for IFS characters.
936 */
937
938STATIC void
939recordregion(int start, int end, int inquotes)
940{
941 struct ifsregion *ifsp;
942
943 if (ifslastp == NULL) {
944 ifsp = &ifsfirst;
945 } else {
946 if (ifslastp->endoff == start
947 && ifslastp->inquotes == inquotes) {
948 /* extend previous area */
949 ifslastp->endoff = end;
950 return;
951 }
952 ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
953 ifslastp->next = ifsp;
954 }
955 ifslastp = ifsp;
956 ifslastp->next = NULL;
957 ifslastp->begoff = start;
958 ifslastp->endoff = end;
959 ifslastp->inquotes = inquotes;
960}
961
962
963
964/*
965 * Break the argument string into pieces based upon IFS and add the
966 * strings to the argument list. The regions of the string to be
967 * searched for IFS characters have been stored by recordregion.
968 */
969STATIC void
970ifsbreakup(char *string, struct arglist *arglist)
971{
972 struct ifsregion *ifsp;
973 struct strlist *sp;
974 char *start;
975 char *p;
976 char *q;
977 char *ifs;
978 const char *ifsspc;
979 int had_param_ch = 0;
980
981 start = string;
982
983 if (ifslastp == NULL) {
984 /* Return entire argument, IFS doesn't apply to any of it */
985 sp = (struct strlist *)stalloc(sizeof *sp);
986 sp->text = start;
987 *arglist->lastp = sp;
988 arglist->lastp = &sp->next;
989 return;
990 }
991
992 ifs = ifsset() ? ifsval() : " \t\n";
993
994 for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
995 p = string + ifsp->begoff;
996 while (p < string + ifsp->endoff) {
997 q = p;
998 if (*p == CTLESC)
999 p++;
1000 if (ifsp->inquotes) {
1001 /* Only NULs (should be from "$@") end args */
1002 had_param_ch = 1;
1003 if (*p != 0) {
1004 p++;
1005 continue;
1006 }
1007 ifsspc = NULL;
1008 } else {
1009 if (!strchr(ifs, *p)) {
1010 had_param_ch = 1;
1011 p++;
1012 continue;
1013 }
1014 ifsspc = strchr(" \t\n", *p);
1015
1016 /* Ignore IFS whitespace at start */
1017 if (q == start && ifsspc != NULL) {
1018 p++;
1019 start = p;
1020 continue;
1021 }
1022 had_param_ch = 0;
1023 }
1024
1025 /* Save this argument... */
1026 *q = '\0';
1027 sp = (struct strlist *)stalloc(sizeof *sp);
1028 sp->text = start;
1029 *arglist->lastp = sp;
1030 arglist->lastp = &sp->next;
1031 p++;
1032
1033 if (ifsspc != NULL) {
1034 /* Ignore further trailing IFS whitespace */
1035 for (; p < string + ifsp->endoff; p++) {
1036 q = p;
1037 if (*p == CTLESC)
1038 p++;
1039 if (strchr(ifs, *p) == NULL) {
1040 p = q;
1041 break;
1042 }
1043 if (strchr(" \t\n", *p) == NULL) {
1044 p++;
1045 break;
1046 }
1047 }
1048 }
1049 start = p;
1050 }
1051 }
1052
1053 /*
1054 * Save anything left as an argument.
1055 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1056 * generating 2 arguments, the second of which is empty.
1057 * Some recent clarification of the Posix spec say that it
1058 * should only generate one....
1059 */
1060 if (had_param_ch || *start != 0) {
1061 sp = (struct strlist *)stalloc(sizeof *sp);
1062 sp->text = start;
1063 *arglist->lastp = sp;
1064 arglist->lastp = &sp->next;
1065 }
1066}
1067
1068
1069
1070/*
1071 * Expand shell metacharacters. At this point, the only control characters
1072 * should be escapes. The results are stored in the list exparg.
1073 */
1074
1075STATIC char *expdir;
1076
1077
1078STATIC void
1079expandmeta(struct strlist *str, int flag __unused)
1080{
1081 char *p;
1082 struct strlist **savelastp;
1083 struct strlist *sp;
1084 char c;
1085 /* TODO - EXP_REDIR */
1086
1087 while (str) {
1088 if (fflag)
1089 goto nometa;
1090 p = str->text;
1091 for (;;) { /* fast check for meta chars */
1092 if ((c = *p++) == '\0')
1093 goto nometa;
1094 if (c == '*' || c == '?' || c == '[' || c == '!')
1095 break;
1096 }
1097 savelastp = exparg.lastp;
1098 INTOFF;
1099 if (expdir == NULL) {
1100 int i = strlen(str->text);
1101 expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1102 }
1103
1104 expmeta(expdir, str->text);
1105 ckfree(expdir);
1106 expdir = NULL;
1107 INTON;
1108 if (exparg.lastp == savelastp) {
1109 /*
1110 * no matches
1111 */
1112nometa:
1113 *exparg.lastp = str;
1114 rmescapes(str->text);
1115 exparg.lastp = &str->next;
1116 } else {
1117 *exparg.lastp = NULL;
1118 *savelastp = sp = expsort(*savelastp);
1119 while (sp->next != NULL)
1120 sp = sp->next;
1121 exparg.lastp = &sp->next;
1122 }
1123 str = str->next;
1124 }
1125}
1126
1127
1128/*
1129 * Do metacharacter (i.e. *, ?, [...]) expansion.
1130 */
1131
1132STATIC void
1133expmeta(char *enddir, char *name)
1134{
1135 char *p;
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 == '!' || *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 p = ".";
1210 } else if (enddir == expdir + 1 && *expdir == '/') {
1211 p = "/";
1212 } else {
1213 p = expdir;
1214 enddir[-1] = '\0';
1215 }
1216 if ((dirp = opendir(p)) == 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, q = dp->d_name;
1243 (*p++ = *q++) != '\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 == '!' || *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 == '!' || *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 ( collate_range_cmp(chr, c) >= 0
1444 && collate_range_cmp(chr, *p) <= 0
1445 )
1446 found = 1;
1447 p++;
1448 } else {
1449 if (chr == c)
1450 found = 1;
1451 }
1452 } while ((c = *p++) != ']');
1453 if (found == invert)
1454 return 0;
1455 break;
1456 }
1457dft: default:
1458 if (squoted && *q == CTLESC)
1459 q++;
1460 if (*q++ != c)
1461 return 0;
1462 break;
1463 }
1464 }
1465breakloop:
1466 if (*q != '\0')
1467 return 0;
1468 return 1;
1469}
1470
1471
1472
1473/*
1474 * Remove any CTLESC characters from a string.
1475 */
1476
1477void
1478rmescapes(char *str)
1479{
1480 char *p, *q;
1481
1482 p = str;
1483 while (*p != CTLESC && *p != CTLQUOTEMARK) {
1484 if (*p++ == '\0')
1485 return;
1486 }
1487 q = p;
1488 while (*p) {
1489 if (*p == CTLQUOTEMARK) {
1490 p++;
1491 continue;
1492 }
1493 if (*p == CTLESC)
1494 p++;
1495 *q++ = *p++;
1496 }
1497 *q = '\0';
1498}
1499
1500
1501
1502/*
1503 * See if a pattern matches in a case statement.
1504 */
1505
1506int
1507casematch(union node *pattern, char *val)
1508{
1509 struct stackmark smark;
1510 int result;
1511 char *p;
1512
1513 setstackmark(&smark);
1514 argbackq = pattern->narg.backquote;
1515 STARTSTACKSTR(expdest);
1516 ifslastp = NULL;
1517 argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1518 STPUTC('\0', expdest);
1519 p = grabstackstr(expdest);
1520 result = patmatch(p, val, 0);
1521 popstackmark(&smark);
1522 return result;
1523}
1524
1525/*
1526 * Our own itoa().
1527 */
1528
1529STATIC char *
1530cvtnum(int num, char *buf)
1531{
1532 char temp[32];
1533 int neg = num < 0;
1534 char *p = temp + 31;
1535
1536 temp[31] = '\0';
1537
1538 do {
1539 *--p = num % 10 + '0';
1540 } while ((num /= 10) != 0);
1541
1542 if (neg)
1543 *--p = '-';
1544
1545 while (*p)
1546 STPUTC(*p++, buf);
1547 return buf;
1548}
1549
1550/*
1551 * Do most of the work for wordexp(3).
1552 */
1553
1554int
1555wordexpcmd(int argc, char **argv)
1556{
1557 size_t len;
1558 int i;
1559
1560 out1fmt("%08x", argc - 1);
1561 for (i = 1, len = 0; i < argc; i++)
1562 len += strlen(argv[i]);
1563 out1fmt("%08x", (int)len);
1564 for (i = 1; i < argc; i++) {
1565 out1str(argv[i]);
1566 out1c('\0');
1567 }
1568 return (0);
1569}