xref: /freebsd/bin/sh/expand.c (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
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 __FBSDID("$FreeBSD$");
44 
45 #include <sys/types.h>
46 #include <sys/time.h>
47 #include <sys/stat.h>
48 #include <dirent.h>
49 #include <errno.h>
50 #include <inttypes.h>
51 #include <limits.h>
52 #include <pwd.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 #include <wchar.h>
58 #include <wctype.h>
59 
60 /*
61  * Routines to expand arguments to commands.  We have to deal with
62  * backquotes, shell variables, and file metacharacters.
63  */
64 
65 #include "shell.h"
66 #include "main.h"
67 #include "nodes.h"
68 #include "eval.h"
69 #include "expand.h"
70 #include "syntax.h"
71 #include "parser.h"
72 #include "jobs.h"
73 #include "options.h"
74 #include "var.h"
75 #include "input.h"
76 #include "output.h"
77 #include "memalloc.h"
78 #include "error.h"
79 #include "mystring.h"
80 #include "arith.h"
81 #include "show.h"
82 #include "builtins.h"
83 
84 enum wordstate { WORD_IDLE, WORD_WS_DELIMITED, WORD_QUOTEMARK };
85 
86 struct worddest {
87 	struct arglist *list;
88 	enum wordstate state;
89 };
90 
91 static char *expdest;			/* output of current string */
92 
93 static const char *argstr(const char *, struct nodelist **restrict, int,
94     struct worddest *);
95 static const char *exptilde(const char *, int);
96 static const char *expari(const char *, struct nodelist **restrict, int,
97     struct worddest *);
98 static void expbackq(union node *, int, int, struct worddest *);
99 static const char *subevalvar_trim(const char *, struct nodelist **restrict,
100     int, int, int);
101 static const char *subevalvar_misc(const char *, struct nodelist **restrict,
102     const char *, int, int, int);
103 static const char *evalvar(const char *, struct nodelist **restrict, int,
104     struct worddest *);
105 static int varisset(const char *, int);
106 static void strtodest(const char *, int, int, int, struct worddest *);
107 static void reprocess(int, int, int, int, struct worddest *);
108 static void varvalue(const char *, int, int, int, struct worddest *);
109 static void expandmeta(char *, struct arglist *);
110 static void expmeta(char *, char *, struct arglist *);
111 static int expsortcmp(const void *, const void *);
112 static int patmatch(const char *, const char *);
113 static void cvtnum(int, char *);
114 static int collate_range_cmp(wchar_t, wchar_t);
115 
116 void
117 emptyarglist(struct arglist *list)
118 {
119 
120 	list->args = list->smallarg;
121 	list->count = 0;
122 	list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
123 }
124 
125 void
126 appendarglist(struct arglist *list, char *str)
127 {
128 	char **newargs;
129 	int newcapacity;
130 
131 	if (list->count >= list->capacity) {
132 		newcapacity = list->capacity * 2;
133 		if (newcapacity < 16)
134 			newcapacity = 16;
135 		if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
136 			error("Too many entries in arglist");
137 		newargs = stalloc(newcapacity * sizeof(newargs[0]));
138 		memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
139 		list->args = newargs;
140 		list->capacity = newcapacity;
141 	}
142 	list->args[list->count++] = str;
143 }
144 
145 static int
146 collate_range_cmp(wchar_t c1, wchar_t c2)
147 {
148 	wchar_t s1[2], s2[2];
149 
150 	s1[0] = c1;
151 	s1[1] = L'\0';
152 	s2[0] = c2;
153 	s2[1] = L'\0';
154 	return (wcscoll(s1, s2));
155 }
156 
157 static char *
158 stputs_quotes(const char *data, const char *syntax, char *p)
159 {
160 	while (*data) {
161 		CHECKSTRSPACE(2, p);
162 		if (syntax[(int)*data] == CCTL)
163 			USTPUTC(CTLESC, p);
164 		USTPUTC(*data++, p);
165 	}
166 	return (p);
167 }
168 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
169 
170 static char *
171 nextword(char c, int flag, char *p, struct worddest *dst)
172 {
173 	int is_ws;
174 
175 	is_ws = c == '\t' || c == '\n' || c == ' ';
176 	if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
177 	    dst->state != WORD_WS_DELIMITED) || c == '\0') {
178 		STPUTC('\0', p);
179 		if (flag & EXP_GLOB)
180 			expandmeta(grabstackstr(p), dst->list);
181 		else
182 			appendarglist(dst->list, grabstackstr(p));
183 		dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
184 	} else if (!is_ws && dst->state == WORD_WS_DELIMITED)
185 		dst->state = WORD_IDLE;
186 	/* Reserve space while the stack string is empty. */
187 	appendarglist(dst->list, NULL);
188 	dst->list->count--;
189 	STARTSTACKSTR(p);
190 	return p;
191 }
192 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
193 
194 static char *
195 stputs_split(const char *data, const char *syntax, int flag, char *p,
196     struct worddest *dst)
197 {
198 	const char *ifs;
199 	char c;
200 
201 	ifs = ifsset() ? ifsval() : " \t\n";
202 	while (*data) {
203 		CHECKSTRSPACE(2, p);
204 		c = *data++;
205 		if (strchr(ifs, c) != NULL) {
206 			NEXTWORD(c, flag, p, dst);
207 			continue;
208 		}
209 		if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
210 			USTPUTC(CTLESC, p);
211 		USTPUTC(c, p);
212 	}
213 	return (p);
214 }
215 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
216 
217 /*
218  * Perform expansions on an argument, placing the resulting list of arguments
219  * in arglist.  Parameter expansion, command substitution and arithmetic
220  * expansion are always performed; additional expansions can be requested
221  * via flag (EXP_*).
222  * The result is left in the stack string.
223  * When arglist is NULL, perform here document expansion.
224  *
225  * When doing something that may cause this to be re-entered, make sure
226  * the stack string is empty via grabstackstr() and do not assume expdest
227  * remains valid.
228  */
229 void
230 expandarg(union node *arg, struct arglist *arglist, int flag)
231 {
232 	struct worddest exparg;
233 	struct nodelist *argbackq;
234 
235 	if (fflag)
236 		flag &= ~EXP_GLOB;
237 	argbackq = arg->narg.backquote;
238 	exparg.list = arglist;
239 	exparg.state = WORD_IDLE;
240 	STARTSTACKSTR(expdest);
241 	argstr(arg->narg.text, &argbackq, flag, &exparg);
242 	if (arglist == NULL) {
243 		STACKSTRNUL(expdest);
244 		return;			/* here document expanded */
245 	}
246 	if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
247 	    exparg.state == WORD_QUOTEMARK) {
248 		STPUTC('\0', expdest);
249 		if (flag & EXP_SPLIT) {
250 			if (flag & EXP_GLOB)
251 				expandmeta(grabstackstr(expdest), exparg.list);
252 			else
253 				appendarglist(exparg.list, grabstackstr(expdest));
254 		}
255 	}
256 	if ((flag & EXP_SPLIT) == 0)
257 		appendarglist(arglist, grabstackstr(expdest));
258 }
259 
260 
261 
262 /*
263  * Perform parameter expansion, command substitution and arithmetic
264  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
265  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
266  * This is used to expand word in ${var+word} etc.
267  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
268  * characters to allow for further processing.
269  *
270  * If EXP_SPLIT is set, dst receives any complete words produced.
271  */
272 static const char *
273 argstr(const char *p, struct nodelist **restrict argbackq, int flag,
274     struct worddest *dst)
275 {
276 	char c;
277 	int quotes = flag & (EXP_GLOB | EXP_CASE);	/* do CTLESC */
278 	int firsteq = 1;
279 	int split_lit;
280 	int lit_quoted;
281 
282 	split_lit = flag & EXP_SPLIT_LIT;
283 	lit_quoted = flag & EXP_LIT_QUOTED;
284 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
285 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
286 		p = exptilde(p, flag);
287 	for (;;) {
288 		CHECKSTRSPACE(2, expdest);
289 		switch (c = *p++) {
290 		case '\0':
291 			return (p - 1);
292 		case CTLENDVAR:
293 		case CTLENDARI:
294 			return (p);
295 		case CTLQUOTEMARK:
296 			lit_quoted = 1;
297 			/* "$@" syntax adherence hack */
298 			if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
299 			    p[2] == '@' && p[3] == '=')
300 				break;
301 			if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
302 				dst->state = WORD_QUOTEMARK;
303 			break;
304 		case CTLQUOTEEND:
305 			lit_quoted = 0;
306 			break;
307 		case CTLESC:
308 			c = *p++;
309 			if (split_lit && !lit_quoted &&
310 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
311 				NEXTWORD(c, flag, expdest, dst);
312 				break;
313 			}
314 			if (quotes)
315 				USTPUTC(CTLESC, expdest);
316 			USTPUTC(c, expdest);
317 			break;
318 		case CTLVAR:
319 			p = evalvar(p, argbackq, flag, dst);
320 			break;
321 		case CTLBACKQ:
322 		case CTLBACKQ|CTLQUOTE:
323 			expbackq((*argbackq)->n, c & CTLQUOTE, flag, dst);
324 			*argbackq = (*argbackq)->next;
325 			break;
326 		case CTLARI:
327 			p = expari(p, argbackq, flag, dst);
328 			break;
329 		case ':':
330 		case '=':
331 			/*
332 			 * sort of a hack - expand tildes in variable
333 			 * assignments (after the first '=' and after ':'s).
334 			 */
335 			if (split_lit && !lit_quoted &&
336 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
337 				NEXTWORD(c, flag, expdest, dst);
338 				break;
339 			}
340 			USTPUTC(c, expdest);
341 			if (flag & EXP_VARTILDE && *p == '~' &&
342 			    (c != '=' || firsteq)) {
343 				if (c == '=')
344 					firsteq = 0;
345 				p = exptilde(p, flag);
346 			}
347 			break;
348 		default:
349 			if (split_lit && !lit_quoted &&
350 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
351 				NEXTWORD(c, flag, expdest, dst);
352 				break;
353 			}
354 			USTPUTC(c, expdest);
355 		}
356 	}
357 }
358 
359 /*
360  * Perform tilde expansion, placing the result in the stack string and
361  * returning the next position in the input string to process.
362  */
363 static const char *
364 exptilde(const char *p, int flag)
365 {
366 	char c;
367 	const char *startp = p;
368 	const char *user;
369 	struct passwd *pw;
370 	char *home;
371 	int len;
372 
373 	for (;;) {
374 		c = *p;
375 		switch(c) {
376 		case CTLESC: /* This means CTL* are always considered quoted. */
377 		case CTLVAR:
378 		case CTLBACKQ:
379 		case CTLBACKQ | CTLQUOTE:
380 		case CTLARI:
381 		case CTLENDARI:
382 		case CTLQUOTEMARK:
383 			return (startp);
384 		case ':':
385 			if ((flag & EXP_VARTILDE) == 0)
386 				break;
387 			/* FALLTHROUGH */
388 		case '\0':
389 		case '/':
390 		case CTLENDVAR:
391 			len = p - startp - 1;
392 			STPUTBIN(startp + 1, len, expdest);
393 			STACKSTRNUL(expdest);
394 			user = expdest - len;
395 			if (*user == '\0') {
396 				home = lookupvar("HOME");
397 			} else {
398 				pw = getpwnam(user);
399 				home = pw != NULL ? pw->pw_dir : NULL;
400 			}
401 			STADJUST(-len, expdest);
402 			if (home == NULL || *home == '\0')
403 				return (startp);
404 			strtodest(home, flag, VSNORMAL, 1, NULL);
405 			return (p);
406 		}
407 		p++;
408 	}
409 }
410 
411 
412 /*
413  * Expand arithmetic expression.
414  */
415 static const char *
416 expari(const char *p, struct nodelist **restrict argbackq, int flag,
417     struct worddest *dst)
418 {
419 	char *q, *start;
420 	arith_t result;
421 	int begoff;
422 	int quoted;
423 	int adj;
424 
425 	quoted = *p++ == '"';
426 	begoff = expdest - stackblock();
427 	p = argstr(p, argbackq, 0, NULL);
428 	STPUTC('\0', expdest);
429 	start = stackblock() + begoff;
430 
431 	q = grabstackstr(expdest);
432 	result = arith(start);
433 	ungrabstackstr(q, expdest);
434 
435 	start = stackblock() + begoff;
436 	adj = start - expdest;
437 	STADJUST(adj, expdest);
438 
439 	CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
440 	fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
441 	adj = strlen(expdest);
442 	STADJUST(adj, expdest);
443 	/*
444 	 * If this is quoted, a '-' must not indicate a range in [...].
445 	 * If this is not quoted, splitting may occur.
446 	 */
447 	if (quoted ?
448 	    result < 0 && begoff > 1 && flag & (EXP_GLOB | EXP_CASE) :
449 	    flag & EXP_SPLIT)
450 		reprocess(expdest - adj - stackblock(), flag, VSNORMAL, quoted,
451 		    dst);
452 	return p;
453 }
454 
455 
456 /*
457  * Perform command substitution.
458  */
459 static void
460 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
461 {
462 	struct backcmd in;
463 	int i;
464 	char buf[128];
465 	char *p;
466 	char *dest = expdest;
467 	char lastc;
468 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
469 	int quotes = flag & (EXP_GLOB | EXP_CASE);
470 	size_t nnl;
471 	const char *ifs;
472 	int startloc;
473 
474 	INTOFF;
475 	p = grabstackstr(dest);
476 	evalbackcmd(cmd, &in);
477 	ungrabstackstr(p, dest);
478 
479 	p = in.buf;
480 	startloc = dest - stackblock();
481 	nnl = 0;
482 	if (!quoted && flag & EXP_SPLIT)
483 		ifs = ifsset() ? ifsval() : " \t\n";
484 	else
485 		ifs = "";
486 	/* Remove trailing newlines */
487 	for (;;) {
488 		if (--in.nleft < 0) {
489 			if (in.fd < 0)
490 				break;
491 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
492 				;
493 			TRACE(("expbackq: read returns %d\n", i));
494 			if (i <= 0)
495 				break;
496 			p = buf;
497 			in.nleft = i - 1;
498 		}
499 		lastc = *p++;
500 		if (lastc == '\0')
501 			continue;
502 		if (nnl > 0 && lastc != '\n') {
503 			NEXTWORD('\n', flag, dest, dst);
504 			nnl = 0;
505 		}
506 		if (strchr(ifs, lastc) != NULL) {
507 			if (lastc == '\n')
508 				nnl++;
509 			else
510 				NEXTWORD(lastc, flag, dest, dst);
511 		} else {
512 			CHECKSTRSPACE(2, dest);
513 			if (quotes && syntax[(int)lastc] == CCTL)
514 				USTPUTC(CTLESC, dest);
515 			USTPUTC(lastc, dest);
516 		}
517 	}
518 	while (dest > stackblock() + startloc && STTOPC(dest) == '\n')
519 		STUNPUTC(dest);
520 
521 	if (in.fd >= 0)
522 		close(in.fd);
523 	if (in.buf)
524 		ckfree(in.buf);
525 	if (in.jp) {
526 		p = grabstackstr(dest);
527 		exitstatus = waitforjob(in.jp, (int *)NULL);
528 		ungrabstackstr(p, dest);
529 	}
530 	TRACE(("expbackq: done\n"));
531 	expdest = dest;
532 	INTON;
533 }
534 
535 
536 
537 static void
538 recordleft(const char *str, const char *loc, char *startp)
539 {
540 	int amount;
541 
542 	amount = ((str - 1) - (loc - startp)) - expdest;
543 	STADJUST(amount, expdest);
544 	while (loc != str - 1)
545 		*startp++ = *loc++;
546 }
547 
548 static const char *
549 subevalvar_trim(const char *p, struct nodelist **restrict argbackq, int strloc,
550     int subtype, int startloc)
551 {
552 	char *startp;
553 	char *loc = NULL;
554 	char *str;
555 	int c = 0;
556 	int amount;
557 
558 	p = argstr(p, argbackq, EXP_CASE | EXP_TILDE, NULL);
559 	STACKSTRNUL(expdest);
560 	startp = stackblock() + startloc;
561 	str = stackblock() + strloc;
562 
563 	switch (subtype) {
564 	case VSTRIMLEFT:
565 		for (loc = startp; loc < str; loc++) {
566 			c = *loc;
567 			*loc = '\0';
568 			if (patmatch(str, startp)) {
569 				*loc = c;
570 				recordleft(str, loc, startp);
571 				return p;
572 			}
573 			*loc = c;
574 		}
575 		break;
576 
577 	case VSTRIMLEFTMAX:
578 		for (loc = str - 1; loc >= startp;) {
579 			c = *loc;
580 			*loc = '\0';
581 			if (patmatch(str, startp)) {
582 				*loc = c;
583 				recordleft(str, loc, startp);
584 				return p;
585 			}
586 			*loc = c;
587 			loc--;
588 		}
589 		break;
590 
591 	case VSTRIMRIGHT:
592 		for (loc = str - 1; loc >= startp;) {
593 			if (patmatch(str, loc)) {
594 				amount = loc - expdest;
595 				STADJUST(amount, expdest);
596 				return p;
597 			}
598 			loc--;
599 		}
600 		break;
601 
602 	case VSTRIMRIGHTMAX:
603 		for (loc = startp; loc < str - 1; loc++) {
604 			if (patmatch(str, loc)) {
605 				amount = loc - expdest;
606 				STADJUST(amount, expdest);
607 				return p;
608 			}
609 		}
610 		break;
611 
612 
613 	default:
614 		abort();
615 	}
616 	amount = (expdest - stackblock() - strloc) + 1;
617 	STADJUST(-amount, expdest);
618 	return p;
619 }
620 
621 
622 static const char *
623 subevalvar_misc(const char *p, struct nodelist **restrict argbackq,
624     const char *var, int subtype, int startloc, int varflags)
625 {
626 	char *startp;
627 	int amount;
628 
629 	p = argstr(p, argbackq, EXP_TILDE, NULL);
630 	STACKSTRNUL(expdest);
631 	startp = stackblock() + startloc;
632 
633 	switch (subtype) {
634 	case VSASSIGN:
635 		setvar(var, startp, 0);
636 		amount = startp - expdest;
637 		STADJUST(amount, expdest);
638 		return p;
639 
640 	case VSQUESTION:
641 		if (*p != CTLENDVAR) {
642 			outfmt(out2, "%s\n", startp);
643 			error((char *)NULL);
644 		}
645 		error("%.*s: parameter %snot set", (int)(p - var - 1),
646 		      var, (varflags & VSNUL) ? "null or " : "");
647 
648 	default:
649 		abort();
650 	}
651 }
652 
653 
654 /*
655  * Expand a variable, and return a pointer to the next character in the
656  * input string.
657  */
658 
659 static const char *
660 evalvar(const char *p, struct nodelist **restrict argbackq, int flag,
661     struct worddest *dst)
662 {
663 	int subtype;
664 	int varflags;
665 	const char *var;
666 	const char *val;
667 	int patloc;
668 	int c;
669 	int set;
670 	int special;
671 	int startloc;
672 	int varlen;
673 	int varlenb;
674 	char buf[21];
675 
676 	varflags = (unsigned char)*p++;
677 	subtype = varflags & VSTYPE;
678 	var = p;
679 	special = 0;
680 	if (! is_name(*p))
681 		special = 1;
682 	p = strchr(p, '=') + 1;
683 	if (varflags & VSLINENO) {
684 		set = 1;
685 		special = 1;
686 		val = NULL;
687 	} else if (special) {
688 		set = varisset(var, varflags & VSNUL);
689 		val = NULL;
690 	} else {
691 		val = bltinlookup(var, 1);
692 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
693 			val = NULL;
694 			set = 0;
695 		} else
696 			set = 1;
697 	}
698 	varlen = 0;
699 	startloc = expdest - stackblock();
700 	if (!set && uflag && *var != '@' && *var != '*') {
701 		switch (subtype) {
702 		case VSNORMAL:
703 		case VSTRIMLEFT:
704 		case VSTRIMLEFTMAX:
705 		case VSTRIMRIGHT:
706 		case VSTRIMRIGHTMAX:
707 		case VSLENGTH:
708 			error("%.*s: parameter not set", (int)(p - var - 1),
709 			    var);
710 		}
711 	}
712 	if (set && subtype != VSPLUS) {
713 		/* insert the value of the variable */
714 		if (special) {
715 			if (varflags & VSLINENO) {
716 				if (p - var > (ptrdiff_t)sizeof(buf))
717 					abort();
718 				memcpy(buf, var, p - var - 1);
719 				buf[p - var - 1] = '\0';
720 				strtodest(buf, flag, subtype,
721 				    varflags & VSQUOTE, dst);
722 			} else
723 				varvalue(var, varflags & VSQUOTE, subtype, flag,
724 				    dst);
725 			if (subtype == VSLENGTH) {
726 				varlenb = expdest - stackblock() - startloc;
727 				varlen = varlenb;
728 				if (localeisutf8) {
729 					val = stackblock() + startloc;
730 					for (;val != expdest; val++)
731 						if ((*val & 0xC0) == 0x80)
732 							varlen--;
733 				}
734 				STADJUST(-varlenb, expdest);
735 			}
736 		} else {
737 			if (subtype == VSLENGTH) {
738 				for (;*val; val++)
739 					if (!localeisutf8 ||
740 					    (*val & 0xC0) != 0x80)
741 						varlen++;
742 			}
743 			else
744 				strtodest(val, flag, subtype,
745 				    varflags & VSQUOTE, dst);
746 		}
747 	}
748 
749 	if (subtype == VSPLUS)
750 		set = ! set;
751 
752 	switch (subtype) {
753 	case VSLENGTH:
754 		cvtnum(varlen, buf);
755 		strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
756 		break;
757 
758 	case VSNORMAL:
759 		return p;
760 
761 	case VSPLUS:
762 	case VSMINUS:
763 		if (!set) {
764 			return argstr(p, argbackq,
765 			    flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
766 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
767 		}
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 		p = subevalvar_trim(p, argbackq, patloc, subtype, startloc);
783 		reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
784 		if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
785 			dst->state = WORD_QUOTEMARK;
786 		return p;
787 
788 	case VSASSIGN:
789 	case VSQUESTION:
790 		if (!set) {
791 			p = subevalvar_misc(p, argbackq, var, subtype,
792 			    startloc, varflags);
793 			/* assert(subtype == VSASSIGN); */
794 			val = lookupvar(var);
795 			strtodest(val, flag, subtype, varflags & VSQUOTE, dst);
796 			return p;
797 		}
798 		break;
799 
800 	case VSERROR:
801 		c = p - var - 1;
802 		error("${%.*s%s}: Bad substitution", c, var,
803 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
804 
805 	default:
806 		abort();
807 	}
808 
809 	{	/* skip to end of alternative */
810 		int nesting = 1;
811 		for (;;) {
812 			if ((c = *p++) == CTLESC)
813 				p++;
814 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE))
815 				*argbackq = (*argbackq)->next;
816 			else if (c == CTLVAR) {
817 				if ((*p++ & VSTYPE) != VSNORMAL)
818 					nesting++;
819 			} else if (c == CTLENDVAR) {
820 				if (--nesting == 0)
821 					break;
822 			}
823 		}
824 	}
825 	return p;
826 }
827 
828 
829 
830 /*
831  * Test whether a special or positional parameter is set.
832  */
833 
834 static int
835 varisset(const char *name, int nulok)
836 {
837 
838 	if (*name == '!')
839 		return backgndpidset();
840 	else if (*name == '@' || *name == '*') {
841 		if (*shellparam.p == NULL)
842 			return 0;
843 
844 		if (nulok) {
845 			char **av;
846 
847 			for (av = shellparam.p; *av; av++)
848 				if (**av != '\0')
849 					return 1;
850 			return 0;
851 		}
852 	} else if (is_digit(*name)) {
853 		char *ap;
854 		long num;
855 
856 		errno = 0;
857 		num = strtol(name, NULL, 10);
858 		if (errno != 0 || num > shellparam.nparam)
859 			return 0;
860 
861 		if (num == 0)
862 			ap = arg0;
863 		else
864 			ap = shellparam.p[num - 1];
865 
866 		if (nulok && (ap == NULL || *ap == '\0'))
867 			return 0;
868 	}
869 	return 1;
870 }
871 
872 static void
873 strtodest(const char *p, int flag, int subtype, int quoted,
874     struct worddest *dst)
875 {
876 	if (subtype == VSLENGTH || subtype == VSTRIMLEFT ||
877 	    subtype == VSTRIMLEFTMAX || subtype == VSTRIMRIGHT ||
878 	    subtype == VSTRIMRIGHTMAX)
879 		STPUTS(p, expdest);
880 	else if (flag & EXP_SPLIT && !quoted && dst != NULL)
881 		STPUTS_SPLIT(p, BASESYNTAX, flag, expdest, dst);
882 	else if (flag & (EXP_GLOB | EXP_CASE))
883 		STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
884 	else
885 		STPUTS(p, expdest);
886 }
887 
888 static void
889 reprocess(int startloc, int flag, int subtype, int quoted,
890     struct worddest *dst)
891 {
892 	static char *buf = NULL;
893 	static size_t buflen = 0;
894 	char *startp;
895 	size_t len, zpos, zlen;
896 
897 	startp = stackblock() + startloc;
898 	len = expdest - startp;
899 	if (len >= SIZE_MAX / 2)
900 		abort();
901 	INTOFF;
902 	if (len >= buflen) {
903 		ckfree(buf);
904 		buf = NULL;
905 	}
906 	if (buflen < 128)
907 		buflen = 128;
908 	while (len >= buflen)
909 		buflen <<= 1;
910 	if (buf == NULL)
911 		buf = ckmalloc(buflen);
912 	INTON;
913 	memcpy(buf, startp, len);
914 	buf[len] = '\0';
915 	STADJUST(-len, expdest);
916 	for (zpos = 0;;) {
917 		zlen = strlen(buf + zpos);
918 		strtodest(buf + zpos, flag, subtype, quoted, dst);
919 		zpos += zlen + 1;
920 		if (zpos == len + 1)
921 			break;
922 		if (flag & EXP_SPLIT && (quoted || (zlen > 0 && zpos < len)))
923 			NEXTWORD('\0', flag, expdest, dst);
924 	}
925 }
926 
927 /*
928  * Add the value of a special or positional parameter to the stack string.
929  */
930 
931 static void
932 varvalue(const char *name, int quoted, int subtype, int flag,
933     struct worddest *dst)
934 {
935 	int num;
936 	char *p;
937 	int i;
938 	int splitlater;
939 	char sep[2];
940 	char **ap;
941 	char buf[(NSHORTOPTS > 10 ? NSHORTOPTS : 10) + 1];
942 
943 	if (subtype == VSLENGTH)
944 		flag &= ~EXP_FULL;
945 	splitlater = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
946 		subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX;
947 
948 	switch (*name) {
949 	case '$':
950 		num = rootpid;
951 		break;
952 	case '?':
953 		num = oexitstatus;
954 		break;
955 	case '#':
956 		num = shellparam.nparam;
957 		break;
958 	case '!':
959 		num = backgndpidval();
960 		break;
961 	case '-':
962 		p = buf;
963 		for (i = 0 ; i < NSHORTOPTS ; i++) {
964 			if (optval[i])
965 				*p++ = optletter[i];
966 		}
967 		*p = '\0';
968 		strtodest(buf, flag, subtype, quoted, dst);
969 		return;
970 	case '@':
971 		if (flag & EXP_SPLIT && quoted) {
972 			for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
973 				strtodest(p, flag, subtype, quoted, dst);
974 				if (*ap) {
975 					if (splitlater)
976 						STPUTC('\0', expdest);
977 					else
978 						NEXTWORD('\0', flag, expdest,
979 						    dst);
980 				}
981 			}
982 			if (shellparam.nparam > 0)
983 				dst->state = WORD_QUOTEMARK;
984 			return;
985 		}
986 		/* FALLTHROUGH */
987 	case '*':
988 		if (ifsset())
989 			sep[0] = ifsval()[0];
990 		else
991 			sep[0] = ' ';
992 		sep[1] = '\0';
993 		for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
994 			strtodest(p, flag, subtype, quoted, dst);
995 			if (!*ap)
996 				break;
997 			if (sep[0])
998 				strtodest(sep, flag, subtype, quoted, dst);
999 			else if (flag & EXP_SPLIT && !quoted && **ap != '\0') {
1000 				if (splitlater)
1001 					STPUTC('\0', expdest);
1002 				else
1003 					NEXTWORD('\0', flag, expdest, dst);
1004 			}
1005 		}
1006 		return;
1007 	default:
1008 		if (is_digit(*name)) {
1009 			num = atoi(name);
1010 			if (num == 0)
1011 				p = arg0;
1012 			else if (num > 0 && num <= shellparam.nparam)
1013 				p = shellparam.p[num - 1];
1014 			else
1015 				return;
1016 			strtodest(p, flag, subtype, quoted, dst);
1017 		}
1018 		return;
1019 	}
1020 	cvtnum(num, buf);
1021 	strtodest(buf, flag, subtype, quoted, dst);
1022 }
1023 
1024 
1025 
1026 static char expdir[PATH_MAX];
1027 #define expdir_end (expdir + sizeof(expdir))
1028 
1029 /*
1030  * Perform pathname generation and remove control characters.
1031  * At this point, the only control characters should be CTLESC.
1032  * The results are stored in the list dstlist.
1033  */
1034 static void
1035 expandmeta(char *pattern, struct arglist *dstlist)
1036 {
1037 	char *p;
1038 	int firstmatch;
1039 	char c;
1040 
1041 	firstmatch = dstlist->count;
1042 	p = pattern;
1043 	for (; (c = *p) != '\0'; p++) {
1044 		/* fast check for meta chars */
1045 		if (c == '*' || c == '?' || c == '[') {
1046 			INTOFF;
1047 			expmeta(expdir, pattern, dstlist);
1048 			INTON;
1049 			break;
1050 		}
1051 	}
1052 	if (dstlist->count == firstmatch) {
1053 		/*
1054 		 * no matches
1055 		 */
1056 		rmescapes(pattern);
1057 		appendarglist(dstlist, pattern);
1058 	} else {
1059 		qsort(&dstlist->args[firstmatch],
1060 		    dstlist->count - firstmatch,
1061 		    sizeof(dstlist->args[0]), expsortcmp);
1062 	}
1063 }
1064 
1065 
1066 /*
1067  * Do metacharacter (i.e. *, ?, [...]) expansion.
1068  */
1069 
1070 static void
1071 expmeta(char *enddir, char *name, struct arglist *arglist)
1072 {
1073 	const char *p;
1074 	const char *q;
1075 	const char *start;
1076 	char *endname;
1077 	int metaflag;
1078 	struct stat statb;
1079 	DIR *dirp;
1080 	struct dirent *dp;
1081 	int atend;
1082 	int matchdot;
1083 	int esc;
1084 	int namlen;
1085 
1086 	metaflag = 0;
1087 	start = name;
1088 	for (p = name; esc = 0, *p; p += esc + 1) {
1089 		if (*p == '*' || *p == '?')
1090 			metaflag = 1;
1091 		else if (*p == '[') {
1092 			q = p + 1;
1093 			if (*q == '!' || *q == '^')
1094 				q++;
1095 			for (;;) {
1096 				if (*q == CTLESC)
1097 					q++;
1098 				if (*q == '/' || *q == '\0')
1099 					break;
1100 				if (*++q == ']') {
1101 					metaflag = 1;
1102 					break;
1103 				}
1104 			}
1105 		} else if (*p == '\0')
1106 			break;
1107 		else {
1108 			if (*p == CTLESC)
1109 				esc++;
1110 			if (p[esc] == '/') {
1111 				if (metaflag)
1112 					break;
1113 				start = p + esc + 1;
1114 			}
1115 		}
1116 	}
1117 	if (metaflag == 0) {	/* we've reached the end of the file name */
1118 		if (enddir != expdir)
1119 			metaflag++;
1120 		for (p = name ; ; p++) {
1121 			if (*p == CTLESC)
1122 				p++;
1123 			*enddir++ = *p;
1124 			if (*p == '\0')
1125 				break;
1126 			if (enddir == expdir_end)
1127 				return;
1128 		}
1129 		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1130 			appendarglist(arglist, stsavestr(expdir));
1131 		return;
1132 	}
1133 	endname = name + (p - name);
1134 	if (start != name) {
1135 		p = name;
1136 		while (p < start) {
1137 			if (*p == CTLESC)
1138 				p++;
1139 			*enddir++ = *p++;
1140 			if (enddir == expdir_end)
1141 				return;
1142 		}
1143 	}
1144 	if (enddir == expdir) {
1145 		p = ".";
1146 	} else if (enddir == expdir + 1 && *expdir == '/') {
1147 		p = "/";
1148 	} else {
1149 		p = expdir;
1150 		enddir[-1] = '\0';
1151 	}
1152 	if ((dirp = opendir(p)) == NULL)
1153 		return;
1154 	if (enddir != expdir)
1155 		enddir[-1] = '/';
1156 	if (*endname == 0) {
1157 		atend = 1;
1158 	} else {
1159 		atend = 0;
1160 		*endname = '\0';
1161 		endname += esc + 1;
1162 	}
1163 	matchdot = 0;
1164 	p = start;
1165 	if (*p == CTLESC)
1166 		p++;
1167 	if (*p == '.')
1168 		matchdot++;
1169 	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1170 		if (dp->d_name[0] == '.' && ! matchdot)
1171 			continue;
1172 		if (patmatch(start, dp->d_name)) {
1173 			namlen = dp->d_namlen;
1174 			if (enddir + namlen + 1 > expdir_end)
1175 				continue;
1176 			memcpy(enddir, dp->d_name, namlen + 1);
1177 			if (atend)
1178 				appendarglist(arglist, stsavestr(expdir));
1179 			else {
1180 				if (dp->d_type != DT_UNKNOWN &&
1181 				    dp->d_type != DT_DIR &&
1182 				    dp->d_type != DT_LNK)
1183 					continue;
1184 				if (enddir + namlen + 2 > expdir_end)
1185 					continue;
1186 				enddir[namlen] = '/';
1187 				enddir[namlen + 1] = '\0';
1188 				expmeta(enddir + namlen + 1, endname, arglist);
1189 			}
1190 		}
1191 	}
1192 	closedir(dirp);
1193 	if (! atend)
1194 		endname[-esc - 1] = esc ? CTLESC : '/';
1195 }
1196 
1197 
1198 static int
1199 expsortcmp(const void *p1, const void *p2)
1200 {
1201 	const char *s1 = *(const char * const *)p1;
1202 	const char *s2 = *(const char * const *)p2;
1203 
1204 	return (strcoll(s1, s2));
1205 }
1206 
1207 
1208 
1209 static wchar_t
1210 get_wc(const char **p)
1211 {
1212 	wchar_t c;
1213 	int chrlen;
1214 
1215 	chrlen = mbtowc(&c, *p, 4);
1216 	if (chrlen == 0)
1217 		return 0;
1218 	else if (chrlen == -1)
1219 		c = 0;
1220 	else
1221 		*p += chrlen;
1222 	return c;
1223 }
1224 
1225 
1226 /*
1227  * See if a character matches a character class, starting at the first colon
1228  * of "[:class:]".
1229  * If a valid character class is recognized, a pointer to the next character
1230  * after the final closing bracket is stored into *end, otherwise a null
1231  * pointer is stored into *end.
1232  */
1233 static int
1234 match_charclass(const char *p, wchar_t chr, const char **end)
1235 {
1236 	char name[20];
1237 	const char *nameend;
1238 	wctype_t cclass;
1239 
1240 	*end = NULL;
1241 	p++;
1242 	nameend = strstr(p, ":]");
1243 	if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1244 	    nameend == p)
1245 		return 0;
1246 	memcpy(name, p, nameend - p);
1247 	name[nameend - p] = '\0';
1248 	*end = nameend + 2;
1249 	cclass = wctype(name);
1250 	/* An unknown class matches nothing but is valid nevertheless. */
1251 	if (cclass == 0)
1252 		return 0;
1253 	return iswctype(chr, cclass);
1254 }
1255 
1256 
1257 /*
1258  * Returns true if the pattern matches the string.
1259  */
1260 
1261 static int
1262 patmatch(const char *pattern, const char *string)
1263 {
1264 	const char *p, *q, *end;
1265 	const char *bt_p, *bt_q;
1266 	char c;
1267 	wchar_t wc, wc2;
1268 
1269 	p = pattern;
1270 	q = string;
1271 	bt_p = NULL;
1272 	bt_q = NULL;
1273 	for (;;) {
1274 		switch (c = *p++) {
1275 		case '\0':
1276 			if (*q != '\0')
1277 				goto backtrack;
1278 			return 1;
1279 		case CTLESC:
1280 			if (*q++ != *p++)
1281 				goto backtrack;
1282 			break;
1283 		case '?':
1284 			if (*q == '\0')
1285 				return 0;
1286 			if (localeisutf8) {
1287 				wc = get_wc(&q);
1288 				/*
1289 				 * A '?' does not match invalid UTF-8 but a
1290 				 * '*' does, so backtrack.
1291 				 */
1292 				if (wc == 0)
1293 					goto backtrack;
1294 			} else
1295 				q++;
1296 			break;
1297 		case '*':
1298 			c = *p;
1299 			while (c == '*')
1300 				c = *++p;
1301 			/*
1302 			 * If the pattern ends here, we know the string
1303 			 * matches without needing to look at the rest of it.
1304 			 */
1305 			if (c == '\0')
1306 				return 1;
1307 			/*
1308 			 * First try the shortest match for the '*' that
1309 			 * could work. We can forget any earlier '*' since
1310 			 * there is no way having it match more characters
1311 			 * can help us, given that we are already here.
1312 			 */
1313 			bt_p = p;
1314 			bt_q = q;
1315 			break;
1316 		case '[': {
1317 			const char *savep, *saveq;
1318 			int invert, found;
1319 			wchar_t chr;
1320 
1321 			savep = p, saveq = q;
1322 			invert = 0;
1323 			if (*p == '!' || *p == '^') {
1324 				invert++;
1325 				p++;
1326 			}
1327 			found = 0;
1328 			if (*q == '\0')
1329 				return 0;
1330 			if (localeisutf8) {
1331 				chr = get_wc(&q);
1332 				if (chr == 0)
1333 					goto backtrack;
1334 			} else
1335 				chr = (unsigned char)*q++;
1336 			c = *p++;
1337 			do {
1338 				if (c == '\0') {
1339 					p = savep, q = saveq;
1340 					c = '[';
1341 					goto dft;
1342 				}
1343 				if (c == '[' && *p == ':') {
1344 					found |= match_charclass(p, chr, &end);
1345 					if (end != NULL) {
1346 						p = end;
1347 						continue;
1348 					}
1349 				}
1350 				if (c == CTLESC)
1351 					c = *p++;
1352 				if (localeisutf8 && c & 0x80) {
1353 					p--;
1354 					wc = get_wc(&p);
1355 					if (wc == 0) /* bad utf-8 */
1356 						return 0;
1357 				} else
1358 					wc = (unsigned char)c;
1359 				if (*p == '-' && p[1] != ']') {
1360 					p++;
1361 					if (*p == CTLESC)
1362 						p++;
1363 					if (localeisutf8) {
1364 						wc2 = get_wc(&p);
1365 						if (wc2 == 0) /* bad utf-8 */
1366 							return 0;
1367 					} else
1368 						wc2 = (unsigned char)*p++;
1369 					if (   collate_range_cmp(chr, wc) >= 0
1370 					    && collate_range_cmp(chr, wc2) <= 0
1371 					   )
1372 						found = 1;
1373 				} else {
1374 					if (chr == wc)
1375 						found = 1;
1376 				}
1377 			} while ((c = *p++) != ']');
1378 			if (found == invert)
1379 				goto backtrack;
1380 			break;
1381 		}
1382 dft:	        default:
1383 			if (*q == '\0')
1384 				return 0;
1385 			if (*q++ == c)
1386 				break;
1387 backtrack:
1388 			/*
1389 			 * If we have a mismatch (other than hitting the end
1390 			 * of the string), go back to the last '*' seen and
1391 			 * have it match one additional character.
1392 			 */
1393 			if (bt_p == NULL)
1394 				return 0;
1395 			if (*bt_q == '\0')
1396 				return 0;
1397 			bt_q++;
1398 			p = bt_p;
1399 			q = bt_q;
1400 			break;
1401 		}
1402 	}
1403 }
1404 
1405 
1406 
1407 /*
1408  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1409  */
1410 
1411 void
1412 rmescapes(char *str)
1413 {
1414 	char *p, *q;
1415 
1416 	p = str;
1417 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1418 		if (*p++ == '\0')
1419 			return;
1420 	}
1421 	q = p;
1422 	while (*p) {
1423 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1424 			p++;
1425 			continue;
1426 		}
1427 		if (*p == CTLESC)
1428 			p++;
1429 		*q++ = *p++;
1430 	}
1431 	*q = '\0';
1432 }
1433 
1434 
1435 
1436 /*
1437  * See if a pattern matches in a case statement.
1438  */
1439 
1440 int
1441 casematch(union node *pattern, const char *val)
1442 {
1443 	struct stackmark smark;
1444 	struct nodelist *argbackq;
1445 	int result;
1446 	char *p;
1447 
1448 	setstackmark(&smark);
1449 	argbackq = pattern->narg.backquote;
1450 	STARTSTACKSTR(expdest);
1451 	argstr(pattern->narg.text, &argbackq, EXP_TILDE | EXP_CASE, NULL);
1452 	STPUTC('\0', expdest);
1453 	p = grabstackstr(expdest);
1454 	result = patmatch(p, val);
1455 	popstackmark(&smark);
1456 	return result;
1457 }
1458 
1459 /*
1460  * Our own itoa().
1461  */
1462 
1463 static void
1464 cvtnum(int num, char *buf)
1465 {
1466 	char temp[32];
1467 	int neg = num < 0;
1468 	char *p = temp + 31;
1469 
1470 	temp[31] = '\0';
1471 
1472 	do {
1473 		*--p = num % 10 + '0';
1474 	} while ((num /= 10) != 0);
1475 
1476 	if (neg)
1477 		*--p = '-';
1478 
1479 	memcpy(buf, p, temp + 32 - p);
1480 }
1481 
1482 /*
1483  * Do most of the work for wordexp(3).
1484  */
1485 
1486 int
1487 wordexpcmd(int argc, char **argv)
1488 {
1489 	size_t len;
1490 	int i;
1491 
1492 	out1fmt("%08x", argc - 1);
1493 	for (i = 1, len = 0; i < argc; i++)
1494 		len += strlen(argv[i]);
1495 	out1fmt("%08x", (int)len);
1496 	for (i = 1; i < argc; i++)
1497 		outbin(argv[i], strlen(argv[i]) + 1, out1);
1498         return (0);
1499 }
1500 
1501 /*
1502  * Do most of the work for wordexp(3), new version.
1503  */
1504 
1505 int
1506 freebsd_wordexpcmd(int argc __unused, char **argv __unused)
1507 {
1508 	struct arglist arglist;
1509 	union node *args, *n;
1510 	size_t len;
1511 	int ch;
1512 	int protected = 0;
1513 	int fd = -1;
1514 	int i;
1515 
1516 	while ((ch = nextopt("f:p")) != '\0') {
1517 		switch (ch) {
1518 		case 'f':
1519 			fd = number(shoptarg);
1520 			break;
1521 		case 'p':
1522 			protected = 1;
1523 			break;
1524 		}
1525 	}
1526 	if (*argptr != NULL)
1527 		error("wrong number of arguments");
1528 	if (fd < 0)
1529 		error("missing fd");
1530 	INTOFF;
1531 	setinputfd(fd, 1);
1532 	INTON;
1533 	args = parsewordexp();
1534 	popfile(); /* will also close fd */
1535 	if (protected)
1536 		for (n = args; n != NULL; n = n->narg.next) {
1537 			if (n->narg.backquote != NULL) {
1538 				outcslow('C', out1);
1539 				error("command substitution disabled");
1540 			}
1541 		}
1542 	outcslow(' ', out1);
1543 	emptyarglist(&arglist);
1544 	for (n = args; n != NULL; n = n->narg.next)
1545 		expandarg(n, &arglist, EXP_FULL | EXP_TILDE);
1546 	for (i = 0, len = 0; i < arglist.count; i++)
1547 		len += strlen(arglist.args[i]);
1548 	out1fmt("%016x %016zx", arglist.count, len);
1549 	for (i = 0; i < arglist.count; i++)
1550 		outbin(arglist.args[i], strlen(arglist.args[i]) + 1, out1);
1551 	return (0);
1552 }
1553