xref: /freebsd/bin/sh/expand.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1997-2005
5  *	Herbert Xu <herbert@gondor.apana.org.au>.  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  * 4. 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 #ifndef lint
36 #if 0
37 static char sccsid[] = "@(#)expand.c	8.5 (Berkeley) 5/15/95";
38 #endif
39 #endif /* not lint */
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/types.h>
44 #include <sys/time.h>
45 #include <sys/stat.h>
46 #include <dirent.h>
47 #include <errno.h>
48 #include <inttypes.h>
49 #include <limits.h>
50 #include <pwd.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 #include <wchar.h>
56 #include <wctype.h>
57 
58 /*
59  * Routines to expand arguments to commands.  We have to deal with
60  * backquotes, shell variables, and file metacharacters.
61  */
62 
63 #include "shell.h"
64 #include "main.h"
65 #include "nodes.h"
66 #include "eval.h"
67 #include "expand.h"
68 #include "syntax.h"
69 #include "parser.h"
70 #include "jobs.h"
71 #include "options.h"
72 #include "var.h"
73 #include "input.h"
74 #include "output.h"
75 #include "memalloc.h"
76 #include "error.h"
77 #include "mystring.h"
78 #include "arith.h"
79 #include "show.h"
80 #include "builtins.h"
81 
82 /*
83  * Structure specifying which parts of the string should be searched
84  * for IFS characters.
85  */
86 
87 struct ifsregion {
88 	struct ifsregion *next;	/* next region in list */
89 	int begoff;		/* offset of start of region */
90 	int endoff;		/* offset of end of region */
91 	int inquotes;		/* search for nul bytes only */
92 };
93 
94 
95 static char *expdest;			/* output of current string */
96 static struct nodelist *argbackq;	/* list of back quote expressions */
97 static struct ifsregion ifsfirst;	/* first struct in list of ifs regions */
98 static struct ifsregion *ifslastp;	/* last struct in list */
99 static struct arglist exparg;		/* holds expanded arg list */
100 
101 static void argstr(char *, int);
102 static char *exptilde(char *, int);
103 static void expbackq(union node *, int, int);
104 static int subevalvar(char *, char *, int, int, int, int, int);
105 static char *evalvar(char *, int);
106 static int varisset(char *, int);
107 static void varvalue(char *, int, int, int);
108 static void recordregion(int, int, int);
109 static void removerecordregions(int);
110 static void ifsbreakup(char *, struct arglist *);
111 static void expandmeta(struct strlist *, int);
112 static void expmeta(char *, char *);
113 static void addfname(char *);
114 static struct strlist *expsort(struct strlist *);
115 static struct strlist *msort(struct strlist *, int);
116 static int patmatch(const char *, const char *, int);
117 static char *cvtnum(int, char *);
118 static int collate_range_cmp(wchar_t, wchar_t);
119 
120 static int
121 collate_range_cmp(wchar_t c1, wchar_t c2)
122 {
123 	static wchar_t s1[2], s2[2];
124 
125 	s1[0] = c1;
126 	s2[0] = c2;
127 	return (wcscoll(s1, s2));
128 }
129 
130 static char *
131 stputs_quotes(const char *data, const char *syntax, char *p)
132 {
133 	while (*data) {
134 		CHECKSTRSPACE(2, p);
135 		if (syntax[(int)*data] == CCTL)
136 			USTPUTC(CTLESC, p);
137 		USTPUTC(*data++, p);
138 	}
139 	return (p);
140 }
141 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
142 
143 /*
144  * Perform expansions on an argument, placing the resulting list of arguments
145  * in arglist.  Parameter expansion, command substitution and arithmetic
146  * expansion are always performed; additional expansions can be requested
147  * via flag (EXP_*).
148  * The result is left in the stack string.
149  * When arglist is NULL, perform here document expansion.
150  *
151  * Caution: this function uses global state and is not reentrant.
152  * However, a new invocation after an interrupted invocation is safe
153  * and will reset the global state for the new call.
154  */
155 void
156 expandarg(union node *arg, struct arglist *arglist, int flag)
157 {
158 	struct strlist *sp;
159 	char *p;
160 
161 	argbackq = arg->narg.backquote;
162 	STARTSTACKSTR(expdest);
163 	ifsfirst.next = NULL;
164 	ifslastp = NULL;
165 	argstr(arg->narg.text, flag);
166 	if (arglist == NULL) {
167 		STACKSTRNUL(expdest);
168 		return;			/* here document expanded */
169 	}
170 	STPUTC('\0', expdest);
171 	p = grabstackstr(expdest);
172 	exparg.lastp = &exparg.list;
173 	/*
174 	 * TODO - EXP_REDIR
175 	 */
176 	if (flag & EXP_FULL) {
177 		ifsbreakup(p, &exparg);
178 		*exparg.lastp = NULL;
179 		exparg.lastp = &exparg.list;
180 		expandmeta(exparg.list, flag);
181 	} else {
182 		if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
183 			rmescapes(p);
184 		sp = (struct strlist *)stalloc(sizeof (struct strlist));
185 		sp->text = p;
186 		*exparg.lastp = sp;
187 		exparg.lastp = &sp->next;
188 	}
189 	while (ifsfirst.next != NULL) {
190 		struct ifsregion *ifsp;
191 		INTOFF;
192 		ifsp = ifsfirst.next->next;
193 		ckfree(ifsfirst.next);
194 		ifsfirst.next = ifsp;
195 		INTON;
196 	}
197 	*exparg.lastp = NULL;
198 	if (exparg.list) {
199 		*arglist->lastp = exparg.list;
200 		arglist->lastp = exparg.lastp;
201 	}
202 }
203 
204 
205 
206 /*
207  * Perform parameter expansion, command substitution and arithmetic
208  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
209  * Processing ends at a CTLENDVAR character as well as '\0'.
210  * This is used to expand word in ${var+word} etc.
211  * If EXP_FULL, EXP_CASE or EXP_REDIR are set, keep and/or generate CTLESC
212  * characters to allow for further processing.
213  * If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
214  */
215 static void
216 argstr(char *p, int flag)
217 {
218 	char c;
219 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);	/* do CTLESC */
220 	int firsteq = 1;
221 	int split_lit;
222 	int lit_quoted;
223 
224 	split_lit = flag & EXP_SPLIT_LIT;
225 	lit_quoted = flag & EXP_LIT_QUOTED;
226 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
227 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
228 		p = exptilde(p, flag);
229 	for (;;) {
230 		CHECKSTRSPACE(2, expdest);
231 		switch (c = *p++) {
232 		case '\0':
233 		case CTLENDVAR:
234 			goto breakloop;
235 		case CTLQUOTEMARK:
236 			lit_quoted = 1;
237 			/* "$@" syntax adherence hack */
238 			if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
239 				break;
240 			if ((flag & EXP_FULL) != 0)
241 				USTPUTC(c, expdest);
242 			break;
243 		case CTLQUOTEEND:
244 			lit_quoted = 0;
245 			break;
246 		case CTLESC:
247 			if (quotes)
248 				USTPUTC(c, expdest);
249 			c = *p++;
250 			USTPUTC(c, expdest);
251 			if (split_lit && !lit_quoted)
252 				recordregion(expdest - stackblock() -
253 				    (quotes ? 2 : 1),
254 				    expdest - stackblock(), 0);
255 			break;
256 		case CTLVAR:
257 			p = evalvar(p, flag);
258 			break;
259 		case CTLBACKQ:
260 		case CTLBACKQ|CTLQUOTE:
261 			expbackq(argbackq->n, c & CTLQUOTE, flag);
262 			argbackq = argbackq->next;
263 			break;
264 		case CTLENDARI:
265 			expari(flag);
266 			break;
267 		case ':':
268 		case '=':
269 			/*
270 			 * sort of a hack - expand tildes in variable
271 			 * assignments (after the first '=' and after ':'s).
272 			 */
273 			USTPUTC(c, expdest);
274 			if (split_lit && !lit_quoted)
275 				recordregion(expdest - stackblock() - 1,
276 				    expdest - stackblock(), 0);
277 			if (flag & EXP_VARTILDE && *p == '~' &&
278 			    (c != '=' || firsteq)) {
279 				if (c == '=')
280 					firsteq = 0;
281 				p = exptilde(p, flag);
282 			}
283 			break;
284 		default:
285 			USTPUTC(c, expdest);
286 			if (split_lit && !lit_quoted)
287 				recordregion(expdest - stackblock() - 1,
288 				    expdest - stackblock(), 0);
289 		}
290 	}
291 breakloop:;
292 }
293 
294 /*
295  * Perform tilde expansion, placing the result in the stack string and
296  * returning the next position in the input string to process.
297  */
298 static char *
299 exptilde(char *p, int flag)
300 {
301 	char c, *startp = p;
302 	struct passwd *pw;
303 	char *home;
304 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
305 
306 	while ((c = *p) != '\0') {
307 		switch(c) {
308 		case CTLESC: /* This means CTL* are always considered quoted. */
309 		case CTLVAR:
310 		case CTLBACKQ:
311 		case CTLBACKQ | CTLQUOTE:
312 		case CTLARI:
313 		case CTLENDARI:
314 		case CTLQUOTEMARK:
315 			return (startp);
316 		case ':':
317 			if (flag & EXP_VARTILDE)
318 				goto done;
319 			break;
320 		case '/':
321 		case CTLENDVAR:
322 			goto done;
323 		}
324 		p++;
325 	}
326 done:
327 	*p = '\0';
328 	if (*(startp+1) == '\0') {
329 		if ((home = lookupvar("HOME")) == NULL)
330 			goto lose;
331 	} else {
332 		if ((pw = getpwnam(startp+1)) == NULL)
333 			goto lose;
334 		home = pw->pw_dir;
335 	}
336 	if (*home == '\0')
337 		goto lose;
338 	*p = c;
339 	if (quotes)
340 		STPUTS_QUOTES(home, SQSYNTAX, expdest);
341 	else
342 		STPUTS(home, expdest);
343 	return (p);
344 lose:
345 	*p = c;
346 	return (startp);
347 }
348 
349 
350 static void
351 removerecordregions(int endoff)
352 {
353 	if (ifslastp == NULL)
354 		return;
355 
356 	if (ifsfirst.endoff > endoff) {
357 		while (ifsfirst.next != NULL) {
358 			struct ifsregion *ifsp;
359 			INTOFF;
360 			ifsp = ifsfirst.next->next;
361 			ckfree(ifsfirst.next);
362 			ifsfirst.next = ifsp;
363 			INTON;
364 		}
365 		if (ifsfirst.begoff > endoff)
366 			ifslastp = NULL;
367 		else {
368 			ifslastp = &ifsfirst;
369 			ifsfirst.endoff = endoff;
370 		}
371 		return;
372 	}
373 
374 	ifslastp = &ifsfirst;
375 	while (ifslastp->next && ifslastp->next->begoff < endoff)
376 		ifslastp=ifslastp->next;
377 	while (ifslastp->next != NULL) {
378 		struct ifsregion *ifsp;
379 		INTOFF;
380 		ifsp = ifslastp->next->next;
381 		ckfree(ifslastp->next);
382 		ifslastp->next = ifsp;
383 		INTON;
384 	}
385 	if (ifslastp->endoff > endoff)
386 		ifslastp->endoff = endoff;
387 }
388 
389 /*
390  * Expand arithmetic expression.  Backup to start of expression,
391  * evaluate, place result in (backed up) result, adjust string position.
392  */
393 void
394 expari(int flag)
395 {
396 	char *p, *q, *start;
397 	arith_t result;
398 	int begoff;
399 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
400 	int quoted;
401 
402 	/*
403 	 * This routine is slightly over-complicated for
404 	 * efficiency.  First we make sure there is
405 	 * enough space for the result, which may be bigger
406 	 * than the expression.  Next we
407 	 * scan backwards looking for the start of arithmetic.  If the
408 	 * next previous character is a CTLESC character, then we
409 	 * have to rescan starting from the beginning since CTLESC
410 	 * characters have to be processed left to right.
411 	 */
412 	CHECKSTRSPACE(DIGITS(result) - 2, expdest);
413 	USTPUTC('\0', expdest);
414 	start = stackblock();
415 	p = expdest - 2;
416 	while (p >= start && *p != CTLARI)
417 		--p;
418 	if (p < start || *p != CTLARI)
419 		error("missing CTLARI (shouldn't happen)");
420 	if (p > start && *(p - 1) == CTLESC)
421 		for (p = start; *p != CTLARI; p++)
422 			if (*p == CTLESC)
423 				p++;
424 
425 	if (p[1] == '"')
426 		quoted=1;
427 	else
428 		quoted=0;
429 	begoff = p - start;
430 	removerecordregions(begoff);
431 	if (quotes)
432 		rmescapes(p+2);
433 	q = grabstackstr(expdest);
434 	result = arith(p+2);
435 	ungrabstackstr(q, expdest);
436 	fmtstr(p, DIGITS(result), ARITH_FORMAT_STR, result);
437 	while (*p++)
438 		;
439 	if (quoted == 0)
440 		recordregion(begoff, p - 1 - start, 0);
441 	result = expdest - p + 1;
442 	STADJUST(-result, expdest);
443 }
444 
445 
446 /*
447  * Perform command substitution.
448  */
449 static void
450 expbackq(union node *cmd, int quoted, int flag)
451 {
452 	struct backcmd in;
453 	int i;
454 	char buf[128];
455 	char *p;
456 	char *dest = expdest;
457 	struct ifsregion saveifs, *savelastp;
458 	struct nodelist *saveargbackq;
459 	char lastc;
460 	int startloc = dest - stackblock();
461 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
462 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
463 	size_t nnl;
464 
465 	INTOFF;
466 	saveifs = ifsfirst;
467 	savelastp = ifslastp;
468 	saveargbackq = argbackq;
469 	p = grabstackstr(dest);
470 	evalbackcmd(cmd, &in);
471 	ungrabstackstr(p, dest);
472 	ifsfirst = saveifs;
473 	ifslastp = savelastp;
474 	argbackq = saveargbackq;
475 
476 	p = in.buf;
477 	lastc = '\0';
478 	nnl = 0;
479 	/* Don't copy trailing newlines */
480 	for (;;) {
481 		if (--in.nleft < 0) {
482 			if (in.fd < 0)
483 				break;
484 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
485 			TRACE(("expbackq: read returns %d\n", i));
486 			if (i <= 0)
487 				break;
488 			p = buf;
489 			in.nleft = i - 1;
490 		}
491 		lastc = *p++;
492 		if (lastc != '\0') {
493 			if (lastc == '\n') {
494 				nnl++;
495 			} else {
496 				CHECKSTRSPACE(nnl + 2, dest);
497 				while (nnl > 0) {
498 					nnl--;
499 					USTPUTC('\n', dest);
500 				}
501 				if (quotes && syntax[(int)lastc] == CCTL)
502 					USTPUTC(CTLESC, dest);
503 				USTPUTC(lastc, dest);
504 			}
505 		}
506 	}
507 
508 	if (in.fd >= 0)
509 		close(in.fd);
510 	if (in.buf)
511 		ckfree(in.buf);
512 	if (in.jp)
513 		exitstatus = waitforjob(in.jp, (int *)NULL);
514 	if (quoted == 0)
515 		recordregion(startloc, dest - stackblock(), 0);
516 	TRACE(("expbackq: size=%td: \"%.*s\"\n",
517 		((dest - stackblock()) - startloc),
518 		(int)((dest - stackblock()) - startloc),
519 		stackblock() + startloc));
520 	expdest = dest;
521 	INTON;
522 }
523 
524 
525 
526 static int
527 subevalvar(char *p, char *str, int strloc, int subtype, int startloc,
528   int varflags, int quotes)
529 {
530 	char *startp;
531 	char *loc = NULL;
532 	char *q;
533 	int c = 0;
534 	struct nodelist *saveargbackq = argbackq;
535 	int amount;
536 
537 	argstr(p, (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
538 	    subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX ?
539 	    EXP_CASE : 0) | EXP_TILDE);
540 	STACKSTRNUL(expdest);
541 	argbackq = saveargbackq;
542 	startp = stackblock() + startloc;
543 	if (str == NULL)
544 	    str = stackblock() + strloc;
545 
546 	switch (subtype) {
547 	case VSASSIGN:
548 		setvar(str, startp, 0);
549 		amount = startp - expdest;
550 		STADJUST(amount, expdest);
551 		varflags &= ~VSNUL;
552 		return 1;
553 
554 	case VSQUESTION:
555 		if (*p != CTLENDVAR) {
556 			outfmt(out2, "%s\n", startp);
557 			error((char *)NULL);
558 		}
559 		error("%.*s: parameter %snot set", (int)(p - str - 1),
560 		      str, (varflags & VSNUL) ? "null or "
561 					      : nullstr);
562 		return 0;
563 
564 	case VSTRIMLEFT:
565 		for (loc = startp; loc < str; loc++) {
566 			c = *loc;
567 			*loc = '\0';
568 			if (patmatch(str, startp, quotes)) {
569 				*loc = c;
570 				goto recordleft;
571 			}
572 			*loc = c;
573 			if (quotes && *loc == CTLESC)
574 				loc++;
575 		}
576 		return 0;
577 
578 	case VSTRIMLEFTMAX:
579 		for (loc = str - 1; loc >= startp;) {
580 			c = *loc;
581 			*loc = '\0';
582 			if (patmatch(str, startp, quotes)) {
583 				*loc = c;
584 				goto recordleft;
585 			}
586 			*loc = c;
587 			loc--;
588 			if (quotes && loc > startp && *(loc - 1) == CTLESC) {
589 				for (q = startp; q < loc; q++)
590 					if (*q == CTLESC)
591 						q++;
592 				if (q > loc)
593 					loc--;
594 			}
595 		}
596 		return 0;
597 
598 	case VSTRIMRIGHT:
599 		for (loc = str - 1; loc >= startp;) {
600 			if (patmatch(str, loc, quotes)) {
601 				amount = loc - expdest;
602 				STADJUST(amount, expdest);
603 				return 1;
604 			}
605 			loc--;
606 			if (quotes && loc > startp && *(loc - 1) == CTLESC) {
607 				for (q = startp; q < loc; q++)
608 					if (*q == CTLESC)
609 						q++;
610 				if (q > loc)
611 					loc--;
612 			}
613 		}
614 		return 0;
615 
616 	case VSTRIMRIGHTMAX:
617 		for (loc = startp; loc < str - 1; loc++) {
618 			if (patmatch(str, loc, quotes)) {
619 				amount = loc - expdest;
620 				STADJUST(amount, expdest);
621 				return 1;
622 			}
623 			if (quotes && *loc == CTLESC)
624 				loc++;
625 		}
626 		return 0;
627 
628 
629 	default:
630 		abort();
631 	}
632 
633 recordleft:
634 	amount = ((str - 1) - (loc - startp)) - expdest;
635 	STADJUST(amount, expdest);
636 	while (loc != str - 1)
637 		*startp++ = *loc++;
638 	return 1;
639 }
640 
641 
642 /*
643  * Expand a variable, and return a pointer to the next character in the
644  * input string.
645  */
646 
647 static char *
648 evalvar(char *p, int flag)
649 {
650 	int subtype;
651 	int varflags;
652 	char *var;
653 	char *val;
654 	int patloc;
655 	int c;
656 	int set;
657 	int special;
658 	int startloc;
659 	int varlen;
660 	int varlenb;
661 	int easy;
662 	int quotes = flag & (EXP_FULL | EXP_CASE | EXP_REDIR);
663 
664 	varflags = (unsigned char)*p++;
665 	subtype = varflags & VSTYPE;
666 	var = p;
667 	special = 0;
668 	if (! is_name(*p))
669 		special = 1;
670 	p = strchr(p, '=') + 1;
671 again: /* jump here after setting a variable with ${var=text} */
672 	if (varflags & VSLINENO) {
673 		set = 1;
674 		special = 0;
675 		val = var;
676 		p[-1] = '\0';	/* temporarily overwrite '=' to have \0
677 				   terminated string */
678 	} else if (special) {
679 		set = varisset(var, varflags & VSNUL);
680 		val = NULL;
681 	} else {
682 		val = bltinlookup(var, 1);
683 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
684 			val = NULL;
685 			set = 0;
686 		} else
687 			set = 1;
688 	}
689 	varlen = 0;
690 	startloc = expdest - stackblock();
691 	if (!set && uflag && *var != '@' && *var != '*') {
692 		switch (subtype) {
693 		case VSNORMAL:
694 		case VSTRIMLEFT:
695 		case VSTRIMLEFTMAX:
696 		case VSTRIMRIGHT:
697 		case VSTRIMRIGHTMAX:
698 		case VSLENGTH:
699 			error("%.*s: parameter not set", (int)(p - var - 1),
700 			    var);
701 		}
702 	}
703 	if (set && subtype != VSPLUS) {
704 		/* insert the value of the variable */
705 		if (special) {
706 			varvalue(var, varflags & VSQUOTE, subtype, flag);
707 			if (subtype == VSLENGTH) {
708 				varlenb = expdest - stackblock() - startloc;
709 				varlen = varlenb;
710 				if (localeisutf8) {
711 					val = stackblock() + startloc;
712 					for (;val != expdest; val++)
713 						if ((*val & 0xC0) == 0x80)
714 							varlen--;
715 				}
716 				STADJUST(-varlenb, expdest);
717 			}
718 		} else {
719 			char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
720 								  : BASESYNTAX;
721 
722 			if (subtype == VSLENGTH) {
723 				for (;*val; val++)
724 					if (!localeisutf8 ||
725 					    (*val & 0xC0) != 0x80)
726 						varlen++;
727 			}
728 			else {
729 				if (quotes)
730 					STPUTS_QUOTES(val, syntax, expdest);
731 				else
732 					STPUTS(val, expdest);
733 
734 			}
735 		}
736 	}
737 
738 	if (subtype == VSPLUS)
739 		set = ! set;
740 
741 	easy = ((varflags & VSQUOTE) == 0 ||
742 		(*var == '@' && shellparam.nparam != 1));
743 
744 
745 	switch (subtype) {
746 	case VSLENGTH:
747 		expdest = cvtnum(varlen, expdest);
748 		goto record;
749 
750 	case VSNORMAL:
751 		if (!easy)
752 			break;
753 record:
754 		recordregion(startloc, expdest - stackblock(),
755 		    varflags & VSQUOTE || (ifsset() && ifsval()[0] == '\0' &&
756 		    (*var == '@' || *var == '*')));
757 		break;
758 
759 	case VSPLUS:
760 	case VSMINUS:
761 		if (!set) {
762 			argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) |
763 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0));
764 			break;
765 		}
766 		if (easy)
767 			goto record;
768 		break;
769 
770 	case VSTRIMLEFT:
771 	case VSTRIMLEFTMAX:
772 	case VSTRIMRIGHT:
773 	case VSTRIMRIGHTMAX:
774 		if (!set)
775 			break;
776 		/*
777 		 * Terminate the string and start recording the pattern
778 		 * right after it
779 		 */
780 		STPUTC('\0', expdest);
781 		patloc = expdest - stackblock();
782 		if (subevalvar(p, NULL, patloc, subtype,
783 		    startloc, varflags, quotes) == 0) {
784 			int amount = (expdest - stackblock() - patloc) + 1;
785 			STADJUST(-amount, expdest);
786 		}
787 		/* Remove any recorded regions beyond start of variable */
788 		removerecordregions(startloc);
789 		goto record;
790 
791 	case VSASSIGN:
792 	case VSQUESTION:
793 		if (!set) {
794 			if (subevalvar(p, var, 0, subtype, startloc, varflags,
795 			    quotes)) {
796 				varflags &= ~VSNUL;
797 				/*
798 				 * Remove any recorded regions beyond
799 				 * start of variable
800 				 */
801 				removerecordregions(startloc);
802 				goto again;
803 			}
804 			break;
805 		}
806 		if (easy)
807 			goto record;
808 		break;
809 
810 	case VSERROR:
811 		c = p - var - 1;
812 		error("${%.*s%s}: Bad substitution", c, var,
813 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
814 
815 	default:
816 		abort();
817 	}
818 	p[-1] = '=';	/* recover overwritten '=' */
819 
820 	if (subtype != VSNORMAL) {	/* skip to end of alternative */
821 		int nesting = 1;
822 		for (;;) {
823 			if ((c = *p++) == CTLESC)
824 				p++;
825 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
826 				if (set)
827 					argbackq = argbackq->next;
828 			} else if (c == CTLVAR) {
829 				if ((*p++ & VSTYPE) != VSNORMAL)
830 					nesting++;
831 			} else if (c == CTLENDVAR) {
832 				if (--nesting == 0)
833 					break;
834 			}
835 		}
836 	}
837 	return p;
838 }
839 
840 
841 
842 /*
843  * Test whether a specialized variable is set.
844  */
845 
846 static int
847 varisset(char *name, int nulok)
848 {
849 
850 	if (*name == '!')
851 		return backgndpidset();
852 	else if (*name == '@' || *name == '*') {
853 		if (*shellparam.p == NULL)
854 			return 0;
855 
856 		if (nulok) {
857 			char **av;
858 
859 			for (av = shellparam.p; *av; av++)
860 				if (**av != '\0')
861 					return 1;
862 			return 0;
863 		}
864 	} else if (is_digit(*name)) {
865 		char *ap;
866 		int num = atoi(name);
867 
868 		if (num > shellparam.nparam)
869 			return 0;
870 
871 		if (num == 0)
872 			ap = arg0;
873 		else
874 			ap = shellparam.p[num - 1];
875 
876 		if (nulok && (ap == NULL || *ap == '\0'))
877 			return 0;
878 	}
879 	return 1;
880 }
881 
882 static void
883 strtodest(const char *p, int flag, int subtype, int quoted)
884 {
885 	if (flag & (EXP_FULL | EXP_CASE) && subtype != VSLENGTH)
886 		STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
887 	else
888 		STPUTS(p, expdest);
889 }
890 
891 /*
892  * Add the value of a specialized variable to the stack string.
893  */
894 
895 static void
896 varvalue(char *name, int quoted, int subtype, int flag)
897 {
898 	int num;
899 	char *p;
900 	int i;
901 	char sep;
902 	char **ap;
903 
904 	switch (*name) {
905 	case '$':
906 		num = rootpid;
907 		goto numvar;
908 	case '?':
909 		num = oexitstatus;
910 		goto numvar;
911 	case '#':
912 		num = shellparam.nparam;
913 		goto numvar;
914 	case '!':
915 		num = backgndpidval();
916 numvar:
917 		expdest = cvtnum(num, expdest);
918 		break;
919 	case '-':
920 		for (i = 0 ; i < NOPTS ; i++) {
921 			if (optlist[i].val)
922 				STPUTC(optlist[i].letter, expdest);
923 		}
924 		break;
925 	case '@':
926 		if (flag & EXP_FULL && quoted) {
927 			for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
928 				strtodest(p, flag, subtype, quoted);
929 				if (*ap)
930 					STPUTC('\0', expdest);
931 			}
932 			break;
933 		}
934 		/* FALLTHROUGH */
935 	case '*':
936 		if (ifsset())
937 			sep = ifsval()[0];
938 		else
939 			sep = ' ';
940 		for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
941 			strtodest(p, flag, subtype, quoted);
942 			if (!*ap)
943 				break;
944 			if (sep || (flag & EXP_FULL && !quoted && **ap != '\0'))
945 				STPUTC(sep, expdest);
946 		}
947 		break;
948 	case '0':
949 		p = arg0;
950 		strtodest(p, flag, subtype, quoted);
951 		break;
952 	default:
953 		if (is_digit(*name)) {
954 			num = atoi(name);
955 			if (num > 0 && num <= shellparam.nparam) {
956 				p = shellparam.p[num - 1];
957 				strtodest(p, flag, subtype, quoted);
958 			}
959 		}
960 		break;
961 	}
962 }
963 
964 
965 
966 /*
967  * Record the fact that we have to scan this region of the
968  * string for IFS characters.
969  */
970 
971 static void
972 recordregion(int start, int end, int inquotes)
973 {
974 	struct ifsregion *ifsp;
975 
976 	if (ifslastp == NULL) {
977 		ifsp = &ifsfirst;
978 	} else {
979 		if (ifslastp->endoff == start
980 		    && ifslastp->inquotes == inquotes) {
981 			/* extend previous area */
982 			ifslastp->endoff = end;
983 			return;
984 		}
985 		ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
986 		ifslastp->next = ifsp;
987 	}
988 	ifslastp = ifsp;
989 	ifslastp->next = NULL;
990 	ifslastp->begoff = start;
991 	ifslastp->endoff = end;
992 	ifslastp->inquotes = inquotes;
993 }
994 
995 
996 
997 /*
998  * Break the argument string into pieces based upon IFS and add the
999  * strings to the argument list.  The regions of the string to be
1000  * searched for IFS characters have been stored by recordregion.
1001  * CTLESC characters are preserved but have little effect in this pass
1002  * other than escaping CTL* characters.  In particular, they do not escape
1003  * IFS characters: that should be done with the ifsregion mechanism.
1004  * CTLQUOTEMARK characters are used to preserve empty quoted strings.
1005  * This pass treats them as a regular character, making the string non-empty.
1006  * Later, they are removed along with the other CTL* characters.
1007  */
1008 static void
1009 ifsbreakup(char *string, struct arglist *arglist)
1010 {
1011 	struct ifsregion *ifsp;
1012 	struct strlist *sp;
1013 	char *start;
1014 	char *p;
1015 	char *q;
1016 	const char *ifs;
1017 	const char *ifsspc;
1018 	int had_param_ch = 0;
1019 
1020 	start = string;
1021 
1022 	if (ifslastp == NULL) {
1023 		/* Return entire argument, IFS doesn't apply to any of it */
1024 		sp = (struct strlist *)stalloc(sizeof *sp);
1025 		sp->text = start;
1026 		*arglist->lastp = sp;
1027 		arglist->lastp = &sp->next;
1028 		return;
1029 	}
1030 
1031 	ifs = ifsset() ? ifsval() : " \t\n";
1032 
1033 	for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
1034 		p = string + ifsp->begoff;
1035 		while (p < string + ifsp->endoff) {
1036 			q = p;
1037 			if (*p == CTLESC)
1038 				p++;
1039 			if (ifsp->inquotes) {
1040 				/* Only NULs (should be from "$@") end args */
1041 				had_param_ch = 1;
1042 				if (*p != 0) {
1043 					p++;
1044 					continue;
1045 				}
1046 				ifsspc = NULL;
1047 			} else {
1048 				if (!strchr(ifs, *p)) {
1049 					had_param_ch = 1;
1050 					p++;
1051 					continue;
1052 				}
1053 				ifsspc = strchr(" \t\n", *p);
1054 
1055 				/* Ignore IFS whitespace at start */
1056 				if (q == start && ifsspc != NULL) {
1057 					p++;
1058 					start = p;
1059 					continue;
1060 				}
1061 				had_param_ch = 0;
1062 			}
1063 
1064 			/* Save this argument... */
1065 			*q = '\0';
1066 			sp = (struct strlist *)stalloc(sizeof *sp);
1067 			sp->text = start;
1068 			*arglist->lastp = sp;
1069 			arglist->lastp = &sp->next;
1070 			p++;
1071 
1072 			if (ifsspc != NULL) {
1073 				/* Ignore further trailing IFS whitespace */
1074 				for (; p < string + ifsp->endoff; p++) {
1075 					q = p;
1076 					if (*p == CTLESC)
1077 						p++;
1078 					if (strchr(ifs, *p) == NULL) {
1079 						p = q;
1080 						break;
1081 					}
1082 					if (strchr(" \t\n", *p) == NULL) {
1083 						p++;
1084 						break;
1085 					}
1086 				}
1087 			}
1088 			start = p;
1089 		}
1090 	}
1091 
1092 	/*
1093 	 * Save anything left as an argument.
1094 	 * Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1095 	 * generating 2 arguments, the second of which is empty.
1096 	 * Some recent clarification of the Posix spec say that it
1097 	 * should only generate one....
1098 	 */
1099 	if (had_param_ch || *start != 0) {
1100 		sp = (struct strlist *)stalloc(sizeof *sp);
1101 		sp->text = start;
1102 		*arglist->lastp = sp;
1103 		arglist->lastp = &sp->next;
1104 	}
1105 }
1106 
1107 
1108 static char expdir[PATH_MAX];
1109 #define expdir_end (expdir + sizeof(expdir))
1110 
1111 /*
1112  * Perform pathname generation and remove control characters.
1113  * At this point, the only control characters should be CTLESC and CTLQUOTEMARK.
1114  * The results are stored in the list exparg.
1115  */
1116 static void
1117 expandmeta(struct strlist *str, int flag __unused)
1118 {
1119 	char *p;
1120 	struct strlist **savelastp;
1121 	struct strlist *sp;
1122 	char c;
1123 	/* TODO - EXP_REDIR */
1124 
1125 	while (str) {
1126 		if (fflag)
1127 			goto nometa;
1128 		p = str->text;
1129 		for (;;) {			/* fast check for meta chars */
1130 			if ((c = *p++) == '\0')
1131 				goto nometa;
1132 			if (c == '*' || c == '?' || c == '[')
1133 				break;
1134 		}
1135 		savelastp = exparg.lastp;
1136 		INTOFF;
1137 		expmeta(expdir, str->text);
1138 		INTON;
1139 		if (exparg.lastp == savelastp) {
1140 			/*
1141 			 * no matches
1142 			 */
1143 nometa:
1144 			*exparg.lastp = str;
1145 			rmescapes(str->text);
1146 			exparg.lastp = &str->next;
1147 		} else {
1148 			*exparg.lastp = NULL;
1149 			*savelastp = sp = expsort(*savelastp);
1150 			while (sp->next != NULL)
1151 				sp = sp->next;
1152 			exparg.lastp = &sp->next;
1153 		}
1154 		str = str->next;
1155 	}
1156 }
1157 
1158 
1159 /*
1160  * Do metacharacter (i.e. *, ?, [...]) expansion.
1161  */
1162 
1163 static void
1164 expmeta(char *enddir, char *name)
1165 {
1166 	const char *p;
1167 	const char *q;
1168 	const char *start;
1169 	char *endname;
1170 	int metaflag;
1171 	struct stat statb;
1172 	DIR *dirp;
1173 	struct dirent *dp;
1174 	int atend;
1175 	int matchdot;
1176 	int esc;
1177 	int namlen;
1178 
1179 	metaflag = 0;
1180 	start = name;
1181 	for (p = name; esc = 0, *p; p += esc + 1) {
1182 		if (*p == '*' || *p == '?')
1183 			metaflag = 1;
1184 		else if (*p == '[') {
1185 			q = p + 1;
1186 			if (*q == '!' || *q == '^')
1187 				q++;
1188 			for (;;) {
1189 				while (*q == CTLQUOTEMARK)
1190 					q++;
1191 				if (*q == CTLESC)
1192 					q++;
1193 				if (*q == '/' || *q == '\0')
1194 					break;
1195 				if (*++q == ']') {
1196 					metaflag = 1;
1197 					break;
1198 				}
1199 			}
1200 		} else if (*p == '\0')
1201 			break;
1202 		else if (*p == CTLQUOTEMARK)
1203 			continue;
1204 		else {
1205 			if (*p == CTLESC)
1206 				esc++;
1207 			if (p[esc] == '/') {
1208 				if (metaflag)
1209 					break;
1210 				start = p + esc + 1;
1211 			}
1212 		}
1213 	}
1214 	if (metaflag == 0) {	/* we've reached the end of the file name */
1215 		if (enddir != expdir)
1216 			metaflag++;
1217 		for (p = name ; ; p++) {
1218 			if (*p == CTLQUOTEMARK)
1219 				continue;
1220 			if (*p == CTLESC)
1221 				p++;
1222 			*enddir++ = *p;
1223 			if (*p == '\0')
1224 				break;
1225 			if (enddir == expdir_end)
1226 				return;
1227 		}
1228 		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1229 			addfname(expdir);
1230 		return;
1231 	}
1232 	endname = name + (p - name);
1233 	if (start != name) {
1234 		p = name;
1235 		while (p < start) {
1236 			while (*p == CTLQUOTEMARK)
1237 				p++;
1238 			if (*p == CTLESC)
1239 				p++;
1240 			*enddir++ = *p++;
1241 			if (enddir == expdir_end)
1242 				return;
1243 		}
1244 	}
1245 	if (enddir == expdir) {
1246 		p = ".";
1247 	} else if (enddir == expdir + 1 && *expdir == '/') {
1248 		p = "/";
1249 	} else {
1250 		p = expdir;
1251 		enddir[-1] = '\0';
1252 	}
1253 	if ((dirp = opendir(p)) == NULL)
1254 		return;
1255 	if (enddir != expdir)
1256 		enddir[-1] = '/';
1257 	if (*endname == 0) {
1258 		atend = 1;
1259 	} else {
1260 		atend = 0;
1261 		*endname = '\0';
1262 		endname += esc + 1;
1263 	}
1264 	matchdot = 0;
1265 	p = start;
1266 	while (*p == CTLQUOTEMARK)
1267 		p++;
1268 	if (*p == CTLESC)
1269 		p++;
1270 	if (*p == '.')
1271 		matchdot++;
1272 	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1273 		if (dp->d_name[0] == '.' && ! matchdot)
1274 			continue;
1275 		if (patmatch(start, dp->d_name, 0)) {
1276 			namlen = dp->d_namlen;
1277 			if (enddir + namlen + 1 > expdir_end)
1278 				continue;
1279 			memcpy(enddir, dp->d_name, namlen + 1);
1280 			if (atend)
1281 				addfname(expdir);
1282 			else {
1283 				if (dp->d_type != DT_UNKNOWN &&
1284 				    dp->d_type != DT_DIR &&
1285 				    dp->d_type != DT_LNK)
1286 					continue;
1287 				if (enddir + namlen + 2 > expdir_end)
1288 					continue;
1289 				enddir[namlen] = '/';
1290 				enddir[namlen + 1] = '\0';
1291 				expmeta(enddir + namlen + 1, endname);
1292 			}
1293 		}
1294 	}
1295 	closedir(dirp);
1296 	if (! atend)
1297 		endname[-esc - 1] = esc ? CTLESC : '/';
1298 }
1299 
1300 
1301 /*
1302  * Add a file name to the list.
1303  */
1304 
1305 static void
1306 addfname(char *name)
1307 {
1308 	char *p;
1309 	struct strlist *sp;
1310 
1311 	p = stalloc(strlen(name) + 1);
1312 	scopy(name, p);
1313 	sp = (struct strlist *)stalloc(sizeof *sp);
1314 	sp->text = p;
1315 	*exparg.lastp = sp;
1316 	exparg.lastp = &sp->next;
1317 }
1318 
1319 
1320 /*
1321  * Sort the results of file name expansion.  It calculates the number of
1322  * strings to sort and then calls msort (short for merge sort) to do the
1323  * work.
1324  */
1325 
1326 static struct strlist *
1327 expsort(struct strlist *str)
1328 {
1329 	int len;
1330 	struct strlist *sp;
1331 
1332 	len = 0;
1333 	for (sp = str ; sp ; sp = sp->next)
1334 		len++;
1335 	return msort(str, len);
1336 }
1337 
1338 
1339 static struct strlist *
1340 msort(struct strlist *list, int len)
1341 {
1342 	struct strlist *p, *q = NULL;
1343 	struct strlist **lpp;
1344 	int half;
1345 	int n;
1346 
1347 	if (len <= 1)
1348 		return list;
1349 	half = len >> 1;
1350 	p = list;
1351 	for (n = half ; --n >= 0 ; ) {
1352 		q = p;
1353 		p = p->next;
1354 	}
1355 	q->next = NULL;			/* terminate first half of list */
1356 	q = msort(list, half);		/* sort first half of list */
1357 	p = msort(p, len - half);		/* sort second half */
1358 	lpp = &list;
1359 	for (;;) {
1360 		if (strcmp(p->text, q->text) < 0) {
1361 			*lpp = p;
1362 			lpp = &p->next;
1363 			if ((p = *lpp) == NULL) {
1364 				*lpp = q;
1365 				break;
1366 			}
1367 		} else {
1368 			*lpp = q;
1369 			lpp = &q->next;
1370 			if ((q = *lpp) == NULL) {
1371 				*lpp = p;
1372 				break;
1373 			}
1374 		}
1375 	}
1376 	return list;
1377 }
1378 
1379 
1380 
1381 static wchar_t
1382 get_wc(const char **p)
1383 {
1384 	wchar_t c;
1385 	int chrlen;
1386 
1387 	chrlen = mbtowc(&c, *p, 4);
1388 	if (chrlen == 0)
1389 		return 0;
1390 	else if (chrlen == -1)
1391 		c = 0;
1392 	else
1393 		*p += chrlen;
1394 	return c;
1395 }
1396 
1397 
1398 /*
1399  * See if a character matches a character class, starting at the first colon
1400  * of "[:class:]".
1401  * If a valid character class is recognized, a pointer to the next character
1402  * after the final closing bracket is stored into *end, otherwise a null
1403  * pointer is stored into *end.
1404  */
1405 static int
1406 match_charclass(const char *p, wchar_t chr, const char **end)
1407 {
1408 	char name[20];
1409 	const char *nameend;
1410 	wctype_t cclass;
1411 
1412 	*end = NULL;
1413 	p++;
1414 	nameend = strstr(p, ":]");
1415 	if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1416 	    nameend == p)
1417 		return 0;
1418 	memcpy(name, p, nameend - p);
1419 	name[nameend - p] = '\0';
1420 	*end = nameend + 2;
1421 	cclass = wctype(name);
1422 	/* An unknown class matches nothing but is valid nevertheless. */
1423 	if (cclass == 0)
1424 		return 0;
1425 	return iswctype(chr, cclass);
1426 }
1427 
1428 
1429 /*
1430  * Returns true if the pattern matches the string.
1431  */
1432 
1433 static int
1434 patmatch(const char *pattern, const char *string, int squoted)
1435 {
1436 	const char *p, *q, *end;
1437 	const char *bt_p, *bt_q;
1438 	char c;
1439 	wchar_t wc, wc2;
1440 
1441 	p = pattern;
1442 	q = string;
1443 	bt_p = NULL;
1444 	bt_q = NULL;
1445 	for (;;) {
1446 		switch (c = *p++) {
1447 		case '\0':
1448 			if (*q != '\0')
1449 				goto backtrack;
1450 			return 1;
1451 		case CTLESC:
1452 			if (squoted && *q == CTLESC)
1453 				q++;
1454 			if (*q++ != *p++)
1455 				goto backtrack;
1456 			break;
1457 		case CTLQUOTEMARK:
1458 			continue;
1459 		case '?':
1460 			if (squoted && *q == CTLESC)
1461 				q++;
1462 			if (*q == '\0')
1463 				return 0;
1464 			if (localeisutf8) {
1465 				wc = get_wc(&q);
1466 				/*
1467 				 * A '?' does not match invalid UTF-8 but a
1468 				 * '*' does, so backtrack.
1469 				 */
1470 				if (wc == 0)
1471 					goto backtrack;
1472 			} else
1473 				wc = (unsigned char)*q++;
1474 			break;
1475 		case '*':
1476 			c = *p;
1477 			while (c == CTLQUOTEMARK || c == '*')
1478 				c = *++p;
1479 			/*
1480 			 * If the pattern ends here, we know the string
1481 			 * matches without needing to look at the rest of it.
1482 			 */
1483 			if (c == '\0')
1484 				return 1;
1485 			/*
1486 			 * First try the shortest match for the '*' that
1487 			 * could work. We can forget any earlier '*' since
1488 			 * there is no way having it match more characters
1489 			 * can help us, given that we are already here.
1490 			 */
1491 			bt_p = p;
1492 			bt_q = q;
1493 			break;
1494 		case '[': {
1495 			const char *endp;
1496 			int invert, found;
1497 			wchar_t chr;
1498 
1499 			endp = p;
1500 			if (*endp == '!' || *endp == '^')
1501 				endp++;
1502 			for (;;) {
1503 				while (*endp == CTLQUOTEMARK)
1504 					endp++;
1505 				if (*endp == 0)
1506 					goto dft;		/* no matching ] */
1507 				if (*endp == CTLESC)
1508 					endp++;
1509 				if (*++endp == ']')
1510 					break;
1511 			}
1512 			invert = 0;
1513 			if (*p == '!' || *p == '^') {
1514 				invert++;
1515 				p++;
1516 			}
1517 			found = 0;
1518 			if (squoted && *q == CTLESC)
1519 				q++;
1520 			if (*q == '\0')
1521 				return 0;
1522 			if (localeisutf8) {
1523 				chr = get_wc(&q);
1524 				if (chr == 0)
1525 					goto backtrack;
1526 			} else
1527 				chr = (unsigned char)*q++;
1528 			c = *p++;
1529 			do {
1530 				if (c == CTLQUOTEMARK)
1531 					continue;
1532 				if (c == '[' && *p == ':') {
1533 					found |= match_charclass(p, chr, &end);
1534 					if (end != NULL)
1535 						p = end;
1536 				}
1537 				if (c == CTLESC)
1538 					c = *p++;
1539 				if (localeisutf8 && c & 0x80) {
1540 					p--;
1541 					wc = get_wc(&p);
1542 					if (wc == 0) /* bad utf-8 */
1543 						return 0;
1544 				} else
1545 					wc = (unsigned char)c;
1546 				if (*p == '-' && p[1] != ']') {
1547 					p++;
1548 					while (*p == CTLQUOTEMARK)
1549 						p++;
1550 					if (*p == CTLESC)
1551 						p++;
1552 					if (localeisutf8) {
1553 						wc2 = get_wc(&p);
1554 						if (wc2 == 0) /* bad utf-8 */
1555 							return 0;
1556 					} else
1557 						wc2 = (unsigned char)*p++;
1558 					if (   collate_range_cmp(chr, wc) >= 0
1559 					    && collate_range_cmp(chr, wc2) <= 0
1560 					   )
1561 						found = 1;
1562 				} else {
1563 					if (chr == wc)
1564 						found = 1;
1565 				}
1566 			} while ((c = *p++) != ']');
1567 			if (found == invert)
1568 				goto backtrack;
1569 			break;
1570 		}
1571 dft:	        default:
1572 			if (squoted && *q == CTLESC)
1573 				q++;
1574 			if (*q == '\0')
1575 				return 0;
1576 			if (*q++ == c)
1577 				break;
1578 backtrack:
1579 			/*
1580 			 * If we have a mismatch (other than hitting the end
1581 			 * of the string), go back to the last '*' seen and
1582 			 * have it match one additional character.
1583 			 */
1584 			if (bt_p == NULL)
1585 				return 0;
1586 			if (squoted && *bt_q == CTLESC)
1587 				bt_q++;
1588 			if (*bt_q == '\0')
1589 				return 0;
1590 			bt_q++;
1591 			p = bt_p;
1592 			q = bt_q;
1593 			break;
1594 		}
1595 	}
1596 }
1597 
1598 
1599 
1600 /*
1601  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1602  */
1603 
1604 void
1605 rmescapes(char *str)
1606 {
1607 	char *p, *q;
1608 
1609 	p = str;
1610 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1611 		if (*p++ == '\0')
1612 			return;
1613 	}
1614 	q = p;
1615 	while (*p) {
1616 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1617 			p++;
1618 			continue;
1619 		}
1620 		if (*p == CTLESC)
1621 			p++;
1622 		*q++ = *p++;
1623 	}
1624 	*q = '\0';
1625 }
1626 
1627 
1628 
1629 /*
1630  * See if a pattern matches in a case statement.
1631  */
1632 
1633 int
1634 casematch(union node *pattern, const char *val)
1635 {
1636 	struct stackmark smark;
1637 	int result;
1638 	char *p;
1639 
1640 	setstackmark(&smark);
1641 	argbackq = pattern->narg.backquote;
1642 	STARTSTACKSTR(expdest);
1643 	ifslastp = NULL;
1644 	argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
1645 	STPUTC('\0', expdest);
1646 	p = grabstackstr(expdest);
1647 	result = patmatch(p, val, 0);
1648 	popstackmark(&smark);
1649 	return result;
1650 }
1651 
1652 /*
1653  * Our own itoa().
1654  */
1655 
1656 static char *
1657 cvtnum(int num, char *buf)
1658 {
1659 	char temp[32];
1660 	int neg = num < 0;
1661 	char *p = temp + 31;
1662 
1663 	temp[31] = '\0';
1664 
1665 	do {
1666 		*--p = num % 10 + '0';
1667 	} while ((num /= 10) != 0);
1668 
1669 	if (neg)
1670 		*--p = '-';
1671 
1672 	STPUTS(p, buf);
1673 	return buf;
1674 }
1675 
1676 /*
1677  * Do most of the work for wordexp(3).
1678  */
1679 
1680 int
1681 wordexpcmd(int argc, char **argv)
1682 {
1683 	size_t len;
1684 	int i;
1685 
1686 	out1fmt("%08x", argc - 1);
1687 	for (i = 1, len = 0; i < argc; i++)
1688 		len += strlen(argv[i]);
1689 	out1fmt("%08x", (int)len);
1690 	for (i = 1; i < argc; i++)
1691 		outbin(argv[i], strlen(argv[i]) + 1, out1);
1692         return (0);
1693 }
1694