xref: /freebsd/bin/sh/expand.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
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  * Copyright (c) 2010-2015
7  *	Jilles Tjoelker <jilles@stack.nl>.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * Kenneth Almquist.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)expand.c	8.5 (Berkeley) 5/15/95";
40 #endif
41 #endif /* not lint */
42 #include <sys/cdefs.h>
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 enum wordstate { WORD_IDLE, WORD_WS_DELIMITED, WORD_QUOTEMARK };
83 
84 struct worddest {
85 	struct arglist *list;
86 	enum wordstate state;
87 };
88 
89 static char *expdest;			/* output of current string */
90 
91 static const char *argstr(const char *, struct nodelist **restrict, int,
92     struct worddest *);
93 static const char *exptilde(const char *, int);
94 static const char *expari(const char *, struct nodelist **restrict, int,
95     struct worddest *);
96 static void expbackq(union node *, int, int, struct worddest *);
97 static const char *subevalvar_trim(const char *, struct nodelist **restrict,
98     int, int, int);
99 static const char *subevalvar_misc(const char *, struct nodelist **restrict,
100     const char *, int, int, int);
101 static const char *evalvar(const char *, struct nodelist **restrict, int,
102     struct worddest *);
103 static int varisset(const char *, int);
104 static void strtodest(const char *, int, int, int, struct worddest *);
105 static void reprocess(int, int, int, int, struct worddest *);
106 static void varvalue(const char *, int, int, int, struct worddest *);
107 static void expandmeta(char *, struct arglist *);
108 static void expmeta(char *, char *, struct arglist *);
109 static int expsortcmp(const void *, const void *);
110 static int patmatch(const char *, const char *);
111 static void cvtnum(int, char *);
112 static int collate_range_cmp(wchar_t, wchar_t);
113 
114 void
115 emptyarglist(struct arglist *list)
116 {
117 
118 	list->args = list->smallarg;
119 	list->count = 0;
120 	list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
121 }
122 
123 void
124 appendarglist(struct arglist *list, char *str)
125 {
126 	char **newargs;
127 	int newcapacity;
128 
129 	if (list->count >= list->capacity) {
130 		newcapacity = list->capacity * 2;
131 		if (newcapacity < 16)
132 			newcapacity = 16;
133 		if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
134 			error("Too many entries in arglist");
135 		newargs = stalloc(newcapacity * sizeof(newargs[0]));
136 		memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
137 		list->args = newargs;
138 		list->capacity = newcapacity;
139 	}
140 	list->args[list->count++] = str;
141 }
142 
143 static int
144 collate_range_cmp(wchar_t c1, wchar_t c2)
145 {
146 	wchar_t s1[2], s2[2];
147 
148 	s1[0] = c1;
149 	s1[1] = L'\0';
150 	s2[0] = c2;
151 	s2[1] = L'\0';
152 	return (wcscoll(s1, s2));
153 }
154 
155 static char *
156 stputs_quotes(const char *data, const char *syntax, char *p)
157 {
158 	while (*data) {
159 		CHECKSTRSPACE(2, p);
160 		if (syntax[(int)*data] == CCTL)
161 			USTPUTC(CTLESC, p);
162 		USTPUTC(*data++, p);
163 	}
164 	return (p);
165 }
166 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
167 
168 static char *
169 nextword(char c, int flag, char *p, struct worddest *dst)
170 {
171 	int is_ws;
172 
173 	is_ws = c == '\t' || c == '\n' || c == ' ';
174 	if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
175 	    dst->state != WORD_WS_DELIMITED) || c == '\0') {
176 		STPUTC('\0', p);
177 		if (flag & EXP_GLOB)
178 			expandmeta(grabstackstr(p), dst->list);
179 		else
180 			appendarglist(dst->list, grabstackstr(p));
181 		dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
182 	} else if (!is_ws && dst->state == WORD_WS_DELIMITED)
183 		dst->state = WORD_IDLE;
184 	/* Reserve space while the stack string is empty. */
185 	appendarglist(dst->list, NULL);
186 	dst->list->count--;
187 	STARTSTACKSTR(p);
188 	return p;
189 }
190 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
191 
192 static char *
193 stputs_split(const char *data, const char *syntax, int flag, char *p,
194     struct worddest *dst)
195 {
196 	const char *ifs;
197 	char c;
198 
199 	ifs = ifsset() ? ifsval() : " \t\n";
200 	while (*data) {
201 		CHECKSTRSPACE(2, p);
202 		c = *data++;
203 		if (strchr(ifs, c) != NULL) {
204 			NEXTWORD(c, flag, p, dst);
205 			continue;
206 		}
207 		if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
208 			USTPUTC(CTLESC, p);
209 		USTPUTC(c, p);
210 	}
211 	return (p);
212 }
213 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
214 
215 /*
216  * Perform expansions on an argument, placing the resulting list of arguments
217  * in arglist.  Parameter expansion, command substitution and arithmetic
218  * expansion are always performed; additional expansions can be requested
219  * via flag (EXP_*).
220  * The result is left in the stack string.
221  * When arglist is NULL, perform here document expansion.
222  *
223  * When doing something that may cause this to be re-entered, make sure
224  * the stack string is empty via grabstackstr() and do not assume expdest
225  * remains valid.
226  */
227 void
228 expandarg(union node *arg, struct arglist *arglist, int flag)
229 {
230 	struct worddest exparg;
231 	struct nodelist *argbackq;
232 
233 	if (fflag)
234 		flag &= ~EXP_GLOB;
235 	argbackq = arg->narg.backquote;
236 	exparg.list = arglist;
237 	exparg.state = WORD_IDLE;
238 	STARTSTACKSTR(expdest);
239 	argstr(arg->narg.text, &argbackq, flag, &exparg);
240 	if (arglist == NULL) {
241 		STACKSTRNUL(expdest);
242 		return;			/* here document expanded */
243 	}
244 	if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
245 	    exparg.state == WORD_QUOTEMARK) {
246 		STPUTC('\0', expdest);
247 		if (flag & EXP_SPLIT) {
248 			if (flag & EXP_GLOB)
249 				expandmeta(grabstackstr(expdest), exparg.list);
250 			else
251 				appendarglist(exparg.list, grabstackstr(expdest));
252 		}
253 	}
254 	if ((flag & EXP_SPLIT) == 0)
255 		appendarglist(arglist, grabstackstr(expdest));
256 }
257 
258 
259 
260 /*
261  * Perform parameter expansion, command substitution and arithmetic
262  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
263  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
264  * This is used to expand word in ${var+word} etc.
265  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
266  * characters to allow for further processing.
267  *
268  * If EXP_SPLIT is set, dst receives any complete words produced.
269  */
270 static const char *
271 argstr(const char *p, struct nodelist **restrict argbackq, int flag,
272     struct worddest *dst)
273 {
274 	char c;
275 	int quotes = flag & (EXP_GLOB | EXP_CASE);	/* do CTLESC */
276 	int firsteq = 1;
277 	int split_lit;
278 	int lit_quoted;
279 
280 	split_lit = flag & EXP_SPLIT_LIT;
281 	lit_quoted = flag & EXP_LIT_QUOTED;
282 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
283 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
284 		p = exptilde(p, flag);
285 	for (;;) {
286 		CHECKSTRSPACE(2, expdest);
287 		switch (c = *p++) {
288 		case '\0':
289 			return (p - 1);
290 		case CTLENDVAR:
291 		case CTLENDARI:
292 			return (p);
293 		case CTLQUOTEMARK:
294 			lit_quoted = 1;
295 			/* "$@" syntax adherence hack */
296 			if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
297 			    p[2] == '@' && p[3] == '=')
298 				break;
299 			if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
300 				dst->state = WORD_QUOTEMARK;
301 			break;
302 		case CTLQUOTEEND:
303 			lit_quoted = 0;
304 			break;
305 		case CTLESC:
306 			c = *p++;
307 			if (split_lit && !lit_quoted &&
308 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
309 				NEXTWORD(c, flag, expdest, dst);
310 				break;
311 			}
312 			if (quotes)
313 				USTPUTC(CTLESC, expdest);
314 			USTPUTC(c, expdest);
315 			break;
316 		case CTLVAR:
317 			p = evalvar(p, argbackq, flag, dst);
318 			break;
319 		case CTLBACKQ:
320 		case CTLBACKQ|CTLQUOTE:
321 			expbackq((*argbackq)->n, c & CTLQUOTE, flag, dst);
322 			*argbackq = (*argbackq)->next;
323 			break;
324 		case CTLARI:
325 			p = expari(p, argbackq, flag, dst);
326 			break;
327 		case ':':
328 		case '=':
329 			/*
330 			 * sort of a hack - expand tildes in variable
331 			 * assignments (after the first '=' and after ':'s).
332 			 */
333 			if (split_lit && !lit_quoted &&
334 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
335 				NEXTWORD(c, flag, expdest, dst);
336 				break;
337 			}
338 			USTPUTC(c, expdest);
339 			if (flag & EXP_VARTILDE && *p == '~' &&
340 			    (c != '=' || firsteq)) {
341 				if (c == '=')
342 					firsteq = 0;
343 				p = exptilde(p, flag);
344 			}
345 			break;
346 		default:
347 			if (split_lit && !lit_quoted &&
348 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
349 				NEXTWORD(c, flag, expdest, dst);
350 				break;
351 			}
352 			USTPUTC(c, expdest);
353 		}
354 	}
355 }
356 
357 /*
358  * Perform tilde expansion, placing the result in the stack string and
359  * returning the next position in the input string to process.
360  */
361 static const char *
362 exptilde(const char *p, int flag)
363 {
364 	char c;
365 	const char *startp = p;
366 	const char *user;
367 	struct passwd *pw;
368 	char *home;
369 	int len;
370 
371 	for (;;) {
372 		c = *p;
373 		switch(c) {
374 		case CTLESC: /* This means CTL* are always considered quoted. */
375 		case CTLVAR:
376 		case CTLBACKQ:
377 		case CTLBACKQ | CTLQUOTE:
378 		case CTLARI:
379 		case CTLENDARI:
380 		case CTLQUOTEMARK:
381 			return (startp);
382 		case ':':
383 			if ((flag & EXP_VARTILDE) == 0)
384 				break;
385 			/* FALLTHROUGH */
386 		case '\0':
387 		case '/':
388 		case CTLENDVAR:
389 			len = p - startp - 1;
390 			STPUTBIN(startp + 1, len, expdest);
391 			STACKSTRNUL(expdest);
392 			user = expdest - len;
393 			if (*user == '\0') {
394 				home = lookupvar("HOME");
395 			} else {
396 				pw = getpwnam(user);
397 				home = pw != NULL ? pw->pw_dir : NULL;
398 			}
399 			STADJUST(-len, expdest);
400 			if (home == NULL || *home == '\0')
401 				return (startp);
402 			strtodest(home, flag, VSNORMAL, 1, NULL);
403 			return (p);
404 		}
405 		p++;
406 	}
407 }
408 
409 
410 /*
411  * Expand arithmetic expression.
412  */
413 static const char *
414 expari(const char *p, struct nodelist **restrict argbackq, int flag,
415     struct worddest *dst)
416 {
417 	char *q, *start;
418 	arith_t result;
419 	int begoff;
420 	int quoted;
421 	int adj;
422 
423 	quoted = *p++ == '"';
424 	begoff = expdest - stackblock();
425 	p = argstr(p, argbackq, 0, NULL);
426 	STPUTC('\0', expdest);
427 	start = stackblock() + begoff;
428 
429 	q = grabstackstr(expdest);
430 	result = arith(start);
431 	ungrabstackstr(q, expdest);
432 
433 	start = stackblock() + begoff;
434 	adj = start - expdest;
435 	STADJUST(adj, expdest);
436 
437 	CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
438 	fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
439 	adj = strlen(expdest);
440 	STADJUST(adj, expdest);
441 	/*
442 	 * If this is quoted, a '-' must not indicate a range in [...].
443 	 * If this is not quoted, splitting may occur.
444 	 */
445 	if (quoted ?
446 	    result < 0 && begoff > 1 && flag & (EXP_GLOB | EXP_CASE) :
447 	    flag & EXP_SPLIT)
448 		reprocess(expdest - adj - stackblock(), flag, VSNORMAL, quoted,
449 		    dst);
450 	return p;
451 }
452 
453 
454 /*
455  * Perform command substitution.
456  */
457 static void
458 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
459 {
460 	struct backcmd in;
461 	int i;
462 	char buf[128];
463 	char *p;
464 	char *dest = expdest;
465 	char lastc;
466 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
467 	int quotes = flag & (EXP_GLOB | EXP_CASE);
468 	size_t nnl;
469 	const char *ifs;
470 	int startloc;
471 
472 	INTOFF;
473 	p = grabstackstr(dest);
474 	evalbackcmd(cmd, &in);
475 	ungrabstackstr(p, dest);
476 
477 	p = in.buf;
478 	startloc = dest - stackblock();
479 	nnl = 0;
480 	if (!quoted && flag & EXP_SPLIT)
481 		ifs = ifsset() ? ifsval() : " \t\n";
482 	else
483 		ifs = "";
484 	/* Remove trailing newlines */
485 	for (;;) {
486 		if (--in.nleft < 0) {
487 			if (in.fd < 0)
488 				break;
489 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
490 				;
491 			TRACE(("expbackq: read returns %d\n", i));
492 			if (i <= 0)
493 				break;
494 			p = buf;
495 			in.nleft = i - 1;
496 		}
497 		lastc = *p++;
498 		if (lastc == '\0')
499 			continue;
500 		if (nnl > 0 && lastc != '\n') {
501 			NEXTWORD('\n', flag, dest, dst);
502 			nnl = 0;
503 		}
504 		if (strchr(ifs, lastc) != NULL) {
505 			if (lastc == '\n')
506 				nnl++;
507 			else
508 				NEXTWORD(lastc, flag, dest, dst);
509 		} else {
510 			CHECKSTRSPACE(2, dest);
511 			if (quotes && syntax[(int)lastc] == CCTL)
512 				USTPUTC(CTLESC, dest);
513 			USTPUTC(lastc, dest);
514 		}
515 	}
516 	while (dest > stackblock() + startloc && STTOPC(dest) == '\n')
517 		STUNPUTC(dest);
518 
519 	if (in.fd >= 0)
520 		close(in.fd);
521 	if (in.buf)
522 		ckfree(in.buf);
523 	if (in.jp) {
524 		p = grabstackstr(dest);
525 		exitstatus = waitforjob(in.jp, (int *)NULL);
526 		ungrabstackstr(p, dest);
527 	}
528 	TRACE(("expbackq: done\n"));
529 	expdest = dest;
530 	INTON;
531 }
532 
533 
534 
535 static void
536 recordleft(const char *str, const char *loc, char *startp)
537 {
538 	int amount;
539 
540 	amount = ((str - 1) - (loc - startp)) - expdest;
541 	STADJUST(amount, expdest);
542 	while (loc != str - 1)
543 		*startp++ = *loc++;
544 }
545 
546 static const char *
547 subevalvar_trim(const char *p, struct nodelist **restrict argbackq, int strloc,
548     int subtype, int startloc)
549 {
550 	char *startp;
551 	char *loc = NULL;
552 	char *str;
553 	int c = 0;
554 	int amount;
555 
556 	p = argstr(p, argbackq, EXP_CASE | EXP_TILDE, NULL);
557 	STACKSTRNUL(expdest);
558 	startp = stackblock() + startloc;
559 	str = stackblock() + strloc;
560 
561 	switch (subtype) {
562 	case VSTRIMLEFT:
563 		for (loc = startp; loc < str; loc++) {
564 			c = *loc;
565 			*loc = '\0';
566 			if (patmatch(str, startp)) {
567 				*loc = c;
568 				recordleft(str, loc, startp);
569 				return p;
570 			}
571 			*loc = c;
572 		}
573 		break;
574 
575 	case VSTRIMLEFTMAX:
576 		for (loc = str - 1; loc >= startp;) {
577 			c = *loc;
578 			*loc = '\0';
579 			if (patmatch(str, startp)) {
580 				*loc = c;
581 				recordleft(str, loc, startp);
582 				return p;
583 			}
584 			*loc = c;
585 			loc--;
586 		}
587 		break;
588 
589 	case VSTRIMRIGHT:
590 		for (loc = str - 1; loc >= startp;) {
591 			if (patmatch(str, loc)) {
592 				amount = loc - expdest;
593 				STADJUST(amount, expdest);
594 				return p;
595 			}
596 			loc--;
597 		}
598 		break;
599 
600 	case VSTRIMRIGHTMAX:
601 		for (loc = startp; loc < str - 1; loc++) {
602 			if (patmatch(str, loc)) {
603 				amount = loc - expdest;
604 				STADJUST(amount, expdest);
605 				return p;
606 			}
607 		}
608 		break;
609 
610 
611 	default:
612 		abort();
613 	}
614 	amount = (expdest - stackblock() - strloc) + 1;
615 	STADJUST(-amount, expdest);
616 	return p;
617 }
618 
619 
620 static const char *
621 subevalvar_misc(const char *p, struct nodelist **restrict argbackq,
622     const char *var, int subtype, int startloc, int varflags)
623 {
624 	const char *end;
625 	char *startp;
626 	int amount;
627 
628 	end = argstr(p, argbackq, EXP_TILDE, NULL);
629 	STACKSTRNUL(expdest);
630 	startp = stackblock() + startloc;
631 
632 	switch (subtype) {
633 	case VSASSIGN:
634 		setvar(var, startp, 0);
635 		amount = startp - expdest;
636 		STADJUST(amount, expdest);
637 		return end;
638 
639 	case VSQUESTION:
640 		if (*p != CTLENDVAR) {
641 			outfmt(out2, "%s\n", startp);
642 			error((char *)NULL);
643 		}
644 		error("%.*s: parameter %snot set", (int)(p - var - 1),
645 		      var, (varflags & VSNUL) ? "null or " : "");
646 
647 	default:
648 		abort();
649 	}
650 }
651 
652 
653 /*
654  * Expand a variable, and return a pointer to the next character in the
655  * input string.
656  */
657 
658 static const char *
659 evalvar(const char *p, struct nodelist **restrict argbackq, int flag,
660     struct worddest *dst)
661 {
662 	int subtype;
663 	int varflags;
664 	const char *var;
665 	const char *val;
666 	int patloc;
667 	int c;
668 	int set;
669 	int special;
670 	int startloc;
671 	int varlen;
672 	int varlenb;
673 	char buf[21];
674 
675 	varflags = (unsigned char)*p++;
676 	subtype = varflags & VSTYPE;
677 	var = p;
678 	special = 0;
679 	if (! is_name(*p))
680 		special = 1;
681 	p = strchr(p, '=') + 1;
682 	if (varflags & VSLINENO) {
683 		set = 1;
684 		special = 1;
685 		val = NULL;
686 	} else if (special) {
687 		set = varisset(var, varflags & VSNUL);
688 		val = NULL;
689 	} else {
690 		val = bltinlookup(var, 1);
691 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
692 			val = NULL;
693 			set = 0;
694 		} else
695 			set = 1;
696 	}
697 	varlen = 0;
698 	startloc = expdest - stackblock();
699 	if (!set && uflag && *var != '@' && *var != '*') {
700 		switch (subtype) {
701 		case VSNORMAL:
702 		case VSTRIMLEFT:
703 		case VSTRIMLEFTMAX:
704 		case VSTRIMRIGHT:
705 		case VSTRIMRIGHTMAX:
706 		case VSLENGTH:
707 			error("%.*s: parameter not set", (int)(p - var - 1),
708 			    var);
709 		}
710 	}
711 	if (set && subtype != VSPLUS) {
712 		/* insert the value of the variable */
713 		if (special) {
714 			if (varflags & VSLINENO) {
715 				if (p - var > (ptrdiff_t)sizeof(buf))
716 					abort();
717 				memcpy(buf, var, p - var - 1);
718 				buf[p - var - 1] = '\0';
719 				strtodest(buf, flag, subtype,
720 				    varflags & VSQUOTE, dst);
721 			} else
722 				varvalue(var, varflags & VSQUOTE, subtype, flag,
723 				    dst);
724 			if (subtype == VSLENGTH) {
725 				varlenb = expdest - stackblock() - startloc;
726 				varlen = varlenb;
727 				if (localeisutf8) {
728 					val = stackblock() + startloc;
729 					for (;val != expdest; val++)
730 						if ((*val & 0xC0) == 0x80)
731 							varlen--;
732 				}
733 				STADJUST(-varlenb, expdest);
734 			}
735 		} else {
736 			if (subtype == VSLENGTH) {
737 				for (;*val; val++)
738 					if (!localeisutf8 ||
739 					    (*val & 0xC0) != 0x80)
740 						varlen++;
741 			}
742 			else
743 				strtodest(val, flag, subtype,
744 				    varflags & VSQUOTE, dst);
745 		}
746 	}
747 
748 	if (subtype == VSPLUS)
749 		set = ! set;
750 
751 	switch (subtype) {
752 	case VSLENGTH:
753 		cvtnum(varlen, buf);
754 		strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
755 		break;
756 
757 	case VSNORMAL:
758 		return p;
759 
760 	case VSPLUS:
761 	case VSMINUS:
762 		if (!set) {
763 			return argstr(p, argbackq,
764 			    flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
765 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
766 		}
767 		break;
768 
769 	case VSTRIMLEFT:
770 	case VSTRIMLEFTMAX:
771 	case VSTRIMRIGHT:
772 	case VSTRIMRIGHTMAX:
773 		if (!set)
774 			break;
775 		/*
776 		 * Terminate the string and start recording the pattern
777 		 * right after it
778 		 */
779 		STPUTC('\0', expdest);
780 		patloc = expdest - stackblock();
781 		p = subevalvar_trim(p, argbackq, patloc, subtype, startloc);
782 		reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
783 		if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
784 			dst->state = WORD_QUOTEMARK;
785 		return p;
786 
787 	case VSASSIGN:
788 	case VSQUESTION:
789 		if (!set) {
790 			p = subevalvar_misc(p, argbackq, var, subtype,
791 			    startloc, varflags);
792 			/* assert(subtype == VSASSIGN); */
793 			val = lookupvar(var);
794 			strtodest(val, flag, subtype, varflags & VSQUOTE, dst);
795 			return p;
796 		}
797 		break;
798 
799 	case VSERROR:
800 		c = p - var - 1;
801 		error("${%.*s%s}: Bad substitution", c, var,
802 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
803 
804 	default:
805 		abort();
806 	}
807 
808 	{	/* skip to end of alternative */
809 		int nesting = 1;
810 		for (;;) {
811 			if ((c = *p++) == CTLESC)
812 				p++;
813 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE))
814 				*argbackq = (*argbackq)->next;
815 			else if (c == CTLVAR) {
816 				if ((*p++ & VSTYPE) != VSNORMAL)
817 					nesting++;
818 			} else if (c == CTLENDVAR) {
819 				if (--nesting == 0)
820 					break;
821 			}
822 		}
823 	}
824 	return p;
825 }
826 
827 
828 
829 /*
830  * Test whether a special or positional parameter is set.
831  */
832 
833 static int
834 varisset(const char *name, int nulok)
835 {
836 
837 	if (*name == '!')
838 		return backgndpidset();
839 	else if (*name == '@' || *name == '*') {
840 		if (*shellparam.p == NULL)
841 			return 0;
842 
843 		if (nulok) {
844 			char **av;
845 
846 			for (av = shellparam.p; *av; av++)
847 				if (**av != '\0')
848 					return 1;
849 			return 0;
850 		}
851 	} else if (is_digit(*name)) {
852 		char *ap;
853 		long num;
854 
855 		errno = 0;
856 		num = strtol(name, NULL, 10);
857 		if (errno != 0 || num > shellparam.nparam)
858 			return 0;
859 
860 		if (num == 0)
861 			ap = arg0;
862 		else
863 			ap = shellparam.p[num - 1];
864 
865 		if (nulok && (ap == NULL || *ap == '\0'))
866 			return 0;
867 	}
868 	return 1;
869 }
870 
871 static void
872 strtodest(const char *p, int flag, int subtype, int quoted,
873     struct worddest *dst)
874 {
875 	if (subtype == VSLENGTH || subtype == VSTRIMLEFT ||
876 	    subtype == VSTRIMLEFTMAX || subtype == VSTRIMRIGHT ||
877 	    subtype == VSTRIMRIGHTMAX)
878 		STPUTS(p, expdest);
879 	else if (flag & EXP_SPLIT && !quoted && dst != NULL)
880 		STPUTS_SPLIT(p, BASESYNTAX, flag, expdest, dst);
881 	else if (flag & (EXP_GLOB | EXP_CASE))
882 		STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
883 	else
884 		STPUTS(p, expdest);
885 }
886 
887 static void
888 reprocess(int startloc, int flag, int subtype, int quoted,
889     struct worddest *dst)
890 {
891 	static char *buf = NULL;
892 	static size_t buflen = 0;
893 	char *startp;
894 	size_t len, zpos, zlen;
895 
896 	startp = stackblock() + startloc;
897 	len = expdest - startp;
898 	if (len >= SIZE_MAX / 2 || len > PTRDIFF_MAX)
899 		abort();
900 	INTOFF;
901 	if (len >= buflen) {
902 		ckfree(buf);
903 		buf = NULL;
904 	}
905 	if (buflen < 128)
906 		buflen = 128;
907 	while (len >= buflen)
908 		buflen <<= 1;
909 	if (buf == NULL)
910 		buf = ckmalloc(buflen);
911 	INTON;
912 	memcpy(buf, startp, len);
913 	buf[len] = '\0';
914 	STADJUST(-(ptrdiff_t)len, expdest);
915 	for (zpos = 0;;) {
916 		zlen = strlen(buf + zpos);
917 		strtodest(buf + zpos, flag, subtype, quoted, dst);
918 		zpos += zlen + 1;
919 		if (zpos == len + 1)
920 			break;
921 		if (flag & EXP_SPLIT && (quoted || (zlen > 0 && zpos < len)))
922 			NEXTWORD('\0', flag, expdest, dst);
923 	}
924 }
925 
926 /*
927  * Add the value of a special or positional parameter to the stack string.
928  */
929 
930 static void
931 varvalue(const char *name, int quoted, int subtype, int flag,
932     struct worddest *dst)
933 {
934 	int num;
935 	char *p;
936 	int i;
937 	int splitlater;
938 	char sep[2];
939 	char **ap;
940 	char buf[(NSHORTOPTS > 10 ? NSHORTOPTS : 10) + 1];
941 
942 	if (subtype == VSLENGTH)
943 		flag &= ~EXP_FULL;
944 	splitlater = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
945 		subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX;
946 
947 	switch (*name) {
948 	case '$':
949 		num = rootpid;
950 		break;
951 	case '?':
952 		num = oexitstatus;
953 		break;
954 	case '#':
955 		num = shellparam.nparam;
956 		break;
957 	case '!':
958 		num = backgndpidval();
959 		break;
960 	case '-':
961 		p = buf;
962 		for (i = 0 ; i < NSHORTOPTS ; i++) {
963 			if (optval[i])
964 				*p++ = optletter[i];
965 		}
966 		*p = '\0';
967 		strtodest(buf, flag, subtype, quoted, dst);
968 		return;
969 	case '@':
970 		if (flag & EXP_SPLIT && quoted) {
971 			for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
972 				strtodest(p, flag, subtype, quoted, dst);
973 				if (*ap) {
974 					if (splitlater)
975 						STPUTC('\0', expdest);
976 					else
977 						NEXTWORD('\0', flag, expdest,
978 						    dst);
979 				}
980 			}
981 			if (shellparam.nparam > 0)
982 				dst->state = WORD_QUOTEMARK;
983 			return;
984 		}
985 		/* FALLTHROUGH */
986 	case '*':
987 		if (ifsset())
988 			sep[0] = ifsval()[0];
989 		else
990 			sep[0] = ' ';
991 		sep[1] = '\0';
992 		for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
993 			strtodest(p, flag, subtype, quoted, dst);
994 			if (!*ap)
995 				break;
996 			if (sep[0])
997 				strtodest(sep, flag, subtype, quoted, dst);
998 			else if (flag & EXP_SPLIT && !quoted && **ap != '\0') {
999 				if (splitlater)
1000 					STPUTC('\0', expdest);
1001 				else
1002 					NEXTWORD('\0', flag, expdest, dst);
1003 			}
1004 		}
1005 		return;
1006 	default:
1007 		if (is_digit(*name)) {
1008 			num = atoi(name);
1009 			if (num == 0)
1010 				p = arg0;
1011 			else if (num > 0 && num <= shellparam.nparam)
1012 				p = shellparam.p[num - 1];
1013 			else
1014 				return;
1015 			strtodest(p, flag, subtype, quoted, dst);
1016 		}
1017 		return;
1018 	}
1019 	cvtnum(num, buf);
1020 	strtodest(buf, flag, subtype, quoted, dst);
1021 }
1022 
1023 
1024 
1025 static char expdir[PATH_MAX];
1026 #define expdir_end (expdir + sizeof(expdir))
1027 
1028 /*
1029  * Perform pathname generation and remove control characters.
1030  * At this point, the only control characters should be CTLESC.
1031  * The results are stored in the list dstlist.
1032  */
1033 static void
1034 expandmeta(char *pattern, struct arglist *dstlist)
1035 {
1036 	char *p;
1037 	int firstmatch;
1038 	char c;
1039 
1040 	firstmatch = dstlist->count;
1041 	p = pattern;
1042 	for (; (c = *p) != '\0'; p++) {
1043 		/* fast check for meta chars */
1044 		if (c == '*' || c == '?' || c == '[') {
1045 			INTOFF;
1046 			expmeta(expdir, pattern, dstlist);
1047 			INTON;
1048 			break;
1049 		}
1050 	}
1051 	if (dstlist->count == firstmatch) {
1052 		/*
1053 		 * no matches
1054 		 */
1055 		rmescapes(pattern);
1056 		appendarglist(dstlist, pattern);
1057 	} else {
1058 		qsort(&dstlist->args[firstmatch],
1059 		    dstlist->count - firstmatch,
1060 		    sizeof(dstlist->args[0]), expsortcmp);
1061 	}
1062 }
1063 
1064 
1065 /*
1066  * Do metacharacter (i.e. *, ?, [...]) expansion.
1067  */
1068 
1069 static void
1070 expmeta(char *enddir, char *name, struct arglist *arglist)
1071 {
1072 	const char *p;
1073 	const char *q;
1074 	const char *start;
1075 	char *endname;
1076 	int metaflag;
1077 	struct stat statb;
1078 	DIR *dirp;
1079 	struct dirent *dp;
1080 	int atend;
1081 	int matchdot;
1082 	int esc;
1083 	int namlen;
1084 
1085 	metaflag = 0;
1086 	start = name;
1087 	for (p = name; esc = 0, *p; p += esc + 1) {
1088 		if (*p == '*' || *p == '?')
1089 			metaflag = 1;
1090 		else if (*p == '[') {
1091 			q = p + 1;
1092 			if (*q == '!' || *q == '^')
1093 				q++;
1094 			for (;;) {
1095 				if (*q == CTLESC)
1096 					q++;
1097 				if (*q == '/' || *q == '\0')
1098 					break;
1099 				if (*++q == ']') {
1100 					metaflag = 1;
1101 					break;
1102 				}
1103 			}
1104 		} else if (*p == '\0')
1105 			break;
1106 		else {
1107 			if (*p == CTLESC)
1108 				esc++;
1109 			if (p[esc] == '/') {
1110 				if (metaflag)
1111 					break;
1112 				start = p + esc + 1;
1113 			}
1114 		}
1115 	}
1116 	if (metaflag == 0) {	/* we've reached the end of the file name */
1117 		if (enddir != expdir)
1118 			metaflag++;
1119 		for (p = name ; ; p++) {
1120 			if (*p == CTLESC)
1121 				p++;
1122 			*enddir++ = *p;
1123 			if (*p == '\0')
1124 				break;
1125 			if (enddir == expdir_end)
1126 				return;
1127 		}
1128 		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1129 			appendarglist(arglist, stsavestr(expdir));
1130 		return;
1131 	}
1132 	endname = name + (p - name);
1133 	if (start != name) {
1134 		p = name;
1135 		while (p < start) {
1136 			if (*p == CTLESC)
1137 				p++;
1138 			*enddir++ = *p++;
1139 			if (enddir == expdir_end)
1140 				return;
1141 		}
1142 	}
1143 	if (enddir == expdir) {
1144 		p = ".";
1145 	} else if (enddir == expdir + 1 && *expdir == '/') {
1146 		p = "/";
1147 	} else {
1148 		p = expdir;
1149 		enddir[-1] = '\0';
1150 	}
1151 	if ((dirp = opendir(p)) == NULL)
1152 		return;
1153 	if (enddir != expdir)
1154 		enddir[-1] = '/';
1155 	if (*endname == 0) {
1156 		atend = 1;
1157 	} else {
1158 		atend = 0;
1159 		*endname = '\0';
1160 		endname += esc + 1;
1161 	}
1162 	matchdot = 0;
1163 	p = start;
1164 	if (*p == CTLESC)
1165 		p++;
1166 	if (*p == '.')
1167 		matchdot++;
1168 	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1169 		if (dp->d_name[0] == '.' && ! matchdot)
1170 			continue;
1171 		if (patmatch(start, dp->d_name)) {
1172 			namlen = dp->d_namlen;
1173 			if (enddir + namlen + 1 > expdir_end)
1174 				continue;
1175 			memcpy(enddir, dp->d_name, namlen + 1);
1176 			if (atend)
1177 				appendarglist(arglist, stsavestr(expdir));
1178 			else {
1179 				if (dp->d_type != DT_UNKNOWN &&
1180 				    dp->d_type != DT_DIR &&
1181 				    dp->d_type != DT_LNK)
1182 					continue;
1183 				if (enddir + namlen + 2 > expdir_end)
1184 					continue;
1185 				enddir[namlen] = '/';
1186 				enddir[namlen + 1] = '\0';
1187 				expmeta(enddir + namlen + 1, endname, arglist);
1188 			}
1189 		}
1190 	}
1191 	closedir(dirp);
1192 	if (! atend)
1193 		endname[-esc - 1] = esc ? CTLESC : '/';
1194 }
1195 
1196 
1197 static int
1198 expsortcmp(const void *p1, const void *p2)
1199 {
1200 	const char *s1 = *(const char * const *)p1;
1201 	const char *s2 = *(const char * const *)p2;
1202 
1203 	return (strcoll(s1, s2));
1204 }
1205 
1206 
1207 
1208 static wchar_t
1209 get_wc(const char **p)
1210 {
1211 	wchar_t c;
1212 	int chrlen;
1213 
1214 	chrlen = mbtowc(&c, *p, 4);
1215 	if (chrlen == 0)
1216 		return 0;
1217 	else if (chrlen == -1)
1218 		c = 0;
1219 	else
1220 		*p += chrlen;
1221 	return c;
1222 }
1223 
1224 
1225 /*
1226  * See if a character matches a character class, starting at the first colon
1227  * of "[:class:]".
1228  * If a valid character class is recognized, a pointer to the next character
1229  * after the final closing bracket is stored into *end, otherwise a null
1230  * pointer is stored into *end.
1231  */
1232 static int
1233 match_charclass(const char *p, wchar_t chr, const char **end)
1234 {
1235 	char name[20];
1236 	const char *nameend;
1237 	wctype_t cclass;
1238 
1239 	*end = NULL;
1240 	p++;
1241 	nameend = strstr(p, ":]");
1242 	if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1243 	    nameend == p)
1244 		return 0;
1245 	memcpy(name, p, nameend - p);
1246 	name[nameend - p] = '\0';
1247 	*end = nameend + 2;
1248 	cclass = wctype(name);
1249 	/* An unknown class matches nothing but is valid nevertheless. */
1250 	if (cclass == 0)
1251 		return 0;
1252 	return iswctype(chr, cclass);
1253 }
1254 
1255 
1256 /*
1257  * Returns true if the pattern matches the string.
1258  */
1259 
1260 static int
1261 patmatch(const char *pattern, const char *string)
1262 {
1263 	const char *p, *q, *end;
1264 	const char *bt_p, *bt_q;
1265 	char c;
1266 	wchar_t wc, wc2;
1267 
1268 	p = pattern;
1269 	q = string;
1270 	bt_p = NULL;
1271 	bt_q = NULL;
1272 	for (;;) {
1273 		switch (c = *p++) {
1274 		case '\0':
1275 			if (*q != '\0')
1276 				goto backtrack;
1277 			return 1;
1278 		case CTLESC:
1279 			if (*q++ != *p++)
1280 				goto backtrack;
1281 			break;
1282 		case '?':
1283 			if (*q == '\0')
1284 				return 0;
1285 			if (localeisutf8) {
1286 				wc = get_wc(&q);
1287 				/*
1288 				 * A '?' does not match invalid UTF-8 but a
1289 				 * '*' does, so backtrack.
1290 				 */
1291 				if (wc == 0)
1292 					goto backtrack;
1293 			} else
1294 				q++;
1295 			break;
1296 		case '*':
1297 			c = *p;
1298 			while (c == '*')
1299 				c = *++p;
1300 			/*
1301 			 * If the pattern ends here, we know the string
1302 			 * matches without needing to look at the rest of it.
1303 			 */
1304 			if (c == '\0')
1305 				return 1;
1306 			/*
1307 			 * First try the shortest match for the '*' that
1308 			 * could work. We can forget any earlier '*' since
1309 			 * there is no way having it match more characters
1310 			 * can help us, given that we are already here.
1311 			 */
1312 			bt_p = p;
1313 			bt_q = q;
1314 			break;
1315 		case '[': {
1316 			const char *savep, *saveq;
1317 			int invert, found;
1318 			wchar_t chr;
1319 
1320 			savep = p, saveq = q;
1321 			invert = 0;
1322 			if (*p == '!' || *p == '^') {
1323 				invert++;
1324 				p++;
1325 			}
1326 			found = 0;
1327 			if (*q == '\0')
1328 				return 0;
1329 			if (localeisutf8) {
1330 				chr = get_wc(&q);
1331 				if (chr == 0)
1332 					goto backtrack;
1333 			} else
1334 				chr = (unsigned char)*q++;
1335 			c = *p++;
1336 			do {
1337 				if (c == '\0') {
1338 					p = savep, q = saveq;
1339 					c = '[';
1340 					goto dft;
1341 				}
1342 				if (c == '[' && *p == ':') {
1343 					found |= match_charclass(p, chr, &end);
1344 					if (end != NULL) {
1345 						p = end;
1346 						continue;
1347 					}
1348 				}
1349 				if (c == CTLESC)
1350 					c = *p++;
1351 				if (localeisutf8 && c & 0x80) {
1352 					p--;
1353 					wc = get_wc(&p);
1354 					if (wc == 0) /* bad utf-8 */
1355 						return 0;
1356 				} else
1357 					wc = (unsigned char)c;
1358 				if (*p == '-' && p[1] != ']') {
1359 					p++;
1360 					if (*p == CTLESC)
1361 						p++;
1362 					if (localeisutf8) {
1363 						wc2 = get_wc(&p);
1364 						if (wc2 == 0) /* bad utf-8 */
1365 							return 0;
1366 					} else
1367 						wc2 = (unsigned char)*p++;
1368 					if (   collate_range_cmp(chr, wc) >= 0
1369 					    && collate_range_cmp(chr, wc2) <= 0
1370 					   )
1371 						found = 1;
1372 				} else {
1373 					if (chr == wc)
1374 						found = 1;
1375 				}
1376 			} while ((c = *p++) != ']');
1377 			if (found == invert)
1378 				goto backtrack;
1379 			break;
1380 		}
1381 dft:	        default:
1382 			if (*q == '\0')
1383 				return 0;
1384 			if (*q++ == c)
1385 				break;
1386 backtrack:
1387 			/*
1388 			 * If we have a mismatch (other than hitting the end
1389 			 * of the string), go back to the last '*' seen and
1390 			 * have it match one additional character.
1391 			 */
1392 			if (bt_p == NULL)
1393 				return 0;
1394 			if (*bt_q == '\0')
1395 				return 0;
1396 			bt_q++;
1397 			p = bt_p;
1398 			q = bt_q;
1399 			break;
1400 		}
1401 	}
1402 }
1403 
1404 
1405 
1406 /*
1407  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1408  */
1409 
1410 void
1411 rmescapes(char *str)
1412 {
1413 	char *p, *q;
1414 
1415 	p = str;
1416 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1417 		if (*p++ == '\0')
1418 			return;
1419 	}
1420 	q = p;
1421 	while (*p) {
1422 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1423 			p++;
1424 			continue;
1425 		}
1426 		if (*p == CTLESC)
1427 			p++;
1428 		*q++ = *p++;
1429 	}
1430 	*q = '\0';
1431 }
1432 
1433 
1434 
1435 /*
1436  * See if a pattern matches in a case statement.
1437  */
1438 
1439 int
1440 casematch(union node *pattern, const char *val)
1441 {
1442 	struct stackmark smark;
1443 	struct nodelist *argbackq;
1444 	int result;
1445 	char *p;
1446 
1447 	setstackmark(&smark);
1448 	argbackq = pattern->narg.backquote;
1449 	STARTSTACKSTR(expdest);
1450 	argstr(pattern->narg.text, &argbackq, EXP_TILDE | EXP_CASE, NULL);
1451 	STPUTC('\0', expdest);
1452 	p = grabstackstr(expdest);
1453 	result = patmatch(p, val);
1454 	popstackmark(&smark);
1455 	return result;
1456 }
1457 
1458 /*
1459  * Our own itoa().
1460  */
1461 
1462 static void
1463 cvtnum(int num, char *buf)
1464 {
1465 	char temp[32];
1466 	int neg = num < 0;
1467 	char *p = temp + 31;
1468 
1469 	temp[31] = '\0';
1470 
1471 	do {
1472 		*--p = num % 10 + '0';
1473 	} while ((num /= 10) != 0);
1474 
1475 	if (neg)
1476 		*--p = '-';
1477 
1478 	memcpy(buf, p, temp + 32 - p);
1479 }
1480 
1481 /*
1482  * Do most of the work for wordexp(3).
1483  */
1484 
1485 int
1486 wordexpcmd(int argc, char **argv)
1487 {
1488 	size_t len;
1489 	int i;
1490 
1491 	out1fmt("%08x", argc - 1);
1492 	for (i = 1, len = 0; i < argc; i++)
1493 		len += strlen(argv[i]);
1494 	out1fmt("%08x", (int)len);
1495 	for (i = 1; i < argc; i++)
1496 		outbin(argv[i], strlen(argv[i]) + 1, out1);
1497         return (0);
1498 }
1499 
1500 /*
1501  * Do most of the work for wordexp(3), new version.
1502  */
1503 
1504 int
1505 freebsd_wordexpcmd(int argc __unused, char **argv __unused)
1506 {
1507 	struct arglist arglist;
1508 	union node *args, *n;
1509 	size_t len;
1510 	int ch;
1511 	int protected = 0;
1512 	int fd = -1;
1513 	int i;
1514 
1515 	while ((ch = nextopt("f:p")) != '\0') {
1516 		switch (ch) {
1517 		case 'f':
1518 			fd = number(shoptarg);
1519 			break;
1520 		case 'p':
1521 			protected = 1;
1522 			break;
1523 		}
1524 	}
1525 	if (*argptr != NULL)
1526 		error("wrong number of arguments");
1527 	if (fd < 0)
1528 		error("missing fd");
1529 	INTOFF;
1530 	setinputfd(fd, 1);
1531 	INTON;
1532 	args = parsewordexp();
1533 	popfile(); /* will also close fd */
1534 	if (protected)
1535 		for (n = args; n != NULL; n = n->narg.next) {
1536 			if (n->narg.backquote != NULL) {
1537 				outcslow('C', out1);
1538 				error("command substitution disabled");
1539 			}
1540 		}
1541 	outcslow(' ', out1);
1542 	emptyarglist(&arglist);
1543 	for (n = args; n != NULL; n = n->narg.next)
1544 		expandarg(n, &arglist, EXP_FULL | EXP_TILDE);
1545 	for (i = 0, len = 0; i < arglist.count; i++)
1546 		len += strlen(arglist.args[i]);
1547 	out1fmt("%016x %016zx", arglist.count, len);
1548 	for (i = 0; i < arglist.count; i++)
1549 		outbin(arglist.args[i], strlen(arglist.args[i]) + 1, out1);
1550 	return (0);
1551 }
1552