xref: /freebsd/bin/sh/expand.c (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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 #include <sys/types.h>
38 #include <sys/time.h>
39 #include <sys/stat.h>
40 #include <dirent.h>
41 #include <errno.h>
42 #include <inttypes.h>
43 #include <limits.h>
44 #include <pwd.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <wchar.h>
50 #include <wctype.h>
51 
52 /*
53  * Routines to expand arguments to commands.  We have to deal with
54  * backquotes, shell variables, and file metacharacters.
55  */
56 
57 #include "shell.h"
58 #include "main.h"
59 #include "nodes.h"
60 #include "eval.h"
61 #include "expand.h"
62 #include "syntax.h"
63 #include "parser.h"
64 #include "jobs.h"
65 #include "options.h"
66 #include "var.h"
67 #include "input.h"
68 #include "output.h"
69 #include "memalloc.h"
70 #include "error.h"
71 #include "mystring.h"
72 #include "arith.h"
73 #include "show.h"
74 #include "builtins.h"
75 
76 enum wordstate { WORD_IDLE, WORD_WS_DELIMITED, WORD_QUOTEMARK };
77 
78 struct worddest {
79 	struct arglist *list;
80 	enum wordstate state;
81 };
82 
83 static char *expdest;			/* output of current string */
84 
85 static const char *argstr(const char *, struct nodelist **restrict, int,
86     struct worddest *);
87 static const char *exptilde(const char *, int);
88 static const char *expari(const char *, struct nodelist **restrict, int,
89     struct worddest *);
90 static void expbackq(union node *, int, int, struct worddest *);
91 static const char *subevalvar_trim(const char *, struct nodelist **restrict,
92     int, int, int);
93 static const char *subevalvar_misc(const char *, struct nodelist **restrict,
94     const char *, int, int, int);
95 static const char *evalvar(const char *, struct nodelist **restrict, int,
96     struct worddest *);
97 static int varisset(const char *, int);
98 static void strtodest(const char *, int, int, int, struct worddest *);
99 static void reprocess(int, int, int, int, struct worddest *);
100 static void varvalue(const char *, int, int, int, struct worddest *);
101 static void expandmeta(char *, struct arglist *);
102 static void expmeta(char *, char *, struct arglist *);
103 static int expsortcmp(const void *, const void *);
104 static int patmatch(const char *, const char *);
105 static void cvtnum(int, char *);
106 static int collate_range_cmp(wchar_t, wchar_t);
107 
108 void
109 emptyarglist(struct arglist *list)
110 {
111 
112 	list->args = list->smallarg;
113 	list->count = 0;
114 	list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
115 }
116 
117 void
118 appendarglist(struct arglist *list, char *str)
119 {
120 	char **newargs;
121 	int newcapacity;
122 
123 	if (list->count >= list->capacity) {
124 		newcapacity = list->capacity * 2;
125 		if (newcapacity < 16)
126 			newcapacity = 16;
127 		if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
128 			error("Too many entries in arglist");
129 		newargs = stalloc(newcapacity * sizeof(newargs[0]));
130 		memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
131 		list->args = newargs;
132 		list->capacity = newcapacity;
133 	}
134 	list->args[list->count++] = str;
135 }
136 
137 static int
138 collate_range_cmp(wchar_t c1, wchar_t c2)
139 {
140 	wchar_t s1[2], s2[2];
141 
142 	s1[0] = c1;
143 	s1[1] = L'\0';
144 	s2[0] = c2;
145 	s2[1] = L'\0';
146 	return (wcscoll(s1, s2));
147 }
148 
149 static char *
150 stputs_quotes(const char *data, const char *syntax, char *p)
151 {
152 	while (*data) {
153 		CHECKSTRSPACE(2, p);
154 		if (syntax[(int)*data] == CCTL)
155 			USTPUTC(CTLESC, p);
156 		USTPUTC(*data++, p);
157 	}
158 	return (p);
159 }
160 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
161 
162 static char *
163 nextword(char c, int flag, char *p, struct worddest *dst)
164 {
165 	int is_ws;
166 
167 	is_ws = c == '\t' || c == '\n' || c == ' ';
168 	if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
169 	    dst->state != WORD_WS_DELIMITED) || c == '\0') {
170 		STPUTC('\0', p);
171 		if (flag & EXP_GLOB)
172 			expandmeta(grabstackstr(p), dst->list);
173 		else
174 			appendarglist(dst->list, grabstackstr(p));
175 		dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
176 	} else if (!is_ws && dst->state == WORD_WS_DELIMITED)
177 		dst->state = WORD_IDLE;
178 	/* Reserve space while the stack string is empty. */
179 	appendarglist(dst->list, NULL);
180 	dst->list->count--;
181 	STARTSTACKSTR(p);
182 	return p;
183 }
184 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
185 
186 static char *
187 stputs_split(const char *data, const char *syntax, int flag, char *p,
188     struct worddest *dst)
189 {
190 	const char *ifs;
191 	char c;
192 
193 	ifs = ifsset() ? ifsval() : " \t\n";
194 	while (*data) {
195 		CHECKSTRSPACE(2, p);
196 		c = *data++;
197 		if (strchr(ifs, c) != NULL) {
198 			NEXTWORD(c, flag, p, dst);
199 			continue;
200 		}
201 		if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
202 			USTPUTC(CTLESC, p);
203 		USTPUTC(c, p);
204 	}
205 	return (p);
206 }
207 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
208 
209 /*
210  * Perform expansions on an argument, placing the resulting list of arguments
211  * in arglist.  Parameter expansion, command substitution and arithmetic
212  * expansion are always performed; additional expansions can be requested
213  * via flag (EXP_*).
214  * The result is left in the stack string.
215  * When arglist is NULL, perform here document expansion.
216  *
217  * When doing something that may cause this to be re-entered, make sure
218  * the stack string is empty via grabstackstr() and do not assume expdest
219  * remains valid.
220  */
221 void
222 expandarg(union node *arg, struct arglist *arglist, int flag)
223 {
224 	struct worddest exparg;
225 	struct nodelist *argbackq;
226 
227 	if (fflag)
228 		flag &= ~EXP_GLOB;
229 	argbackq = arg->narg.backquote;
230 	exparg.list = arglist;
231 	exparg.state = WORD_IDLE;
232 	STARTSTACKSTR(expdest);
233 	argstr(arg->narg.text, &argbackq, flag, &exparg);
234 	if (arglist == NULL) {
235 		STACKSTRNUL(expdest);
236 		return;			/* here document expanded */
237 	}
238 	if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
239 	    exparg.state == WORD_QUOTEMARK) {
240 		STPUTC('\0', expdest);
241 		if (flag & EXP_SPLIT) {
242 			if (flag & EXP_GLOB)
243 				expandmeta(grabstackstr(expdest), exparg.list);
244 			else
245 				appendarglist(exparg.list, grabstackstr(expdest));
246 		}
247 	}
248 	if ((flag & EXP_SPLIT) == 0)
249 		appendarglist(arglist, grabstackstr(expdest));
250 }
251 
252 
253 
254 /*
255  * Perform parameter expansion, command substitution and arithmetic
256  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
257  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
258  * This is used to expand word in ${var+word} etc.
259  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
260  * characters to allow for further processing.
261  *
262  * If EXP_SPLIT is set, dst receives any complete words produced.
263  */
264 static const char *
265 argstr(const char *p, struct nodelist **restrict argbackq, int flag,
266     struct worddest *dst)
267 {
268 	char c;
269 	int quotes = flag & (EXP_GLOB | EXP_CASE);	/* do CTLESC */
270 	int firsteq = 1;
271 	int split_lit;
272 	int lit_quoted;
273 
274 	split_lit = flag & EXP_SPLIT_LIT;
275 	lit_quoted = flag & EXP_LIT_QUOTED;
276 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
277 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
278 		p = exptilde(p, flag);
279 	for (;;) {
280 		CHECKSTRSPACE(2, expdest);
281 		switch (c = *p++) {
282 		case '\0':
283 			return (p - 1);
284 		case CTLENDVAR:
285 		case CTLENDARI:
286 			return (p);
287 		case CTLQUOTEMARK:
288 			lit_quoted = 1;
289 			/* "$@" syntax adherence hack */
290 			if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
291 			    p[2] == '@' && p[3] == '=')
292 				break;
293 			if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
294 				dst->state = WORD_QUOTEMARK;
295 			break;
296 		case CTLQUOTEEND:
297 			lit_quoted = 0;
298 			break;
299 		case CTLESC:
300 			c = *p++;
301 			if (split_lit && !lit_quoted &&
302 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
303 				NEXTWORD(c, flag, expdest, dst);
304 				break;
305 			}
306 			if (quotes)
307 				USTPUTC(CTLESC, expdest);
308 			USTPUTC(c, expdest);
309 			break;
310 		case CTLVAR:
311 			p = evalvar(p, argbackq, flag, dst);
312 			break;
313 		case CTLBACKQ:
314 		case CTLBACKQ|CTLQUOTE:
315 			expbackq((*argbackq)->n, c & CTLQUOTE, flag, dst);
316 			*argbackq = (*argbackq)->next;
317 			break;
318 		case CTLARI:
319 			p = expari(p, argbackq, flag, dst);
320 			break;
321 		case ':':
322 		case '=':
323 			/*
324 			 * sort of a hack - expand tildes in variable
325 			 * assignments (after the first '=' and after ':'s).
326 			 */
327 			if (split_lit && !lit_quoted &&
328 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
329 				NEXTWORD(c, flag, expdest, dst);
330 				break;
331 			}
332 			USTPUTC(c, expdest);
333 			if (flag & EXP_VARTILDE && *p == '~' &&
334 			    (c != '=' || firsteq)) {
335 				if (c == '=')
336 					firsteq = 0;
337 				p = exptilde(p, flag);
338 			}
339 			break;
340 		default:
341 			if (split_lit && !lit_quoted &&
342 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
343 				NEXTWORD(c, flag, expdest, dst);
344 				break;
345 			}
346 			USTPUTC(c, expdest);
347 		}
348 	}
349 }
350 
351 /*
352  * Perform tilde expansion, placing the result in the stack string and
353  * returning the next position in the input string to process.
354  */
355 static const char *
356 exptilde(const char *p, int flag)
357 {
358 	char c;
359 	const char *startp = p;
360 	const char *user;
361 	struct passwd *pw;
362 	char *home;
363 	int len;
364 
365 	for (;;) {
366 		c = *p;
367 		switch(c) {
368 		case CTLESC: /* This means CTL* are always considered quoted. */
369 		case CTLVAR:
370 		case CTLBACKQ:
371 		case CTLBACKQ | CTLQUOTE:
372 		case CTLARI:
373 		case CTLENDARI:
374 		case CTLQUOTEMARK:
375 			return (startp);
376 		case ':':
377 			if ((flag & EXP_VARTILDE) == 0)
378 				break;
379 			/* FALLTHROUGH */
380 		case '\0':
381 		case '/':
382 		case CTLENDVAR:
383 			len = p - startp - 1;
384 			STPUTBIN(startp + 1, len, expdest);
385 			STACKSTRNUL(expdest);
386 			user = expdest - len;
387 			if (*user == '\0') {
388 				home = lookupvar("HOME");
389 			} else {
390 				pw = getpwnam(user);
391 				home = pw != NULL ? pw->pw_dir : NULL;
392 			}
393 			STADJUST(-len, expdest);
394 			if (home == NULL || *home == '\0')
395 				return (startp);
396 			strtodest(home, flag, VSNORMAL, 1, NULL);
397 			return (p);
398 		}
399 		p++;
400 	}
401 }
402 
403 
404 /*
405  * Expand arithmetic expression.
406  */
407 static const char *
408 expari(const char *p, struct nodelist **restrict argbackq, int flag,
409     struct worddest *dst)
410 {
411 	char *q, *start;
412 	arith_t result;
413 	int begoff;
414 	int quoted;
415 	int adj;
416 
417 	quoted = *p++ == '"';
418 	begoff = expdest - stackblock();
419 	p = argstr(p, argbackq, 0, NULL);
420 	STPUTC('\0', expdest);
421 	start = stackblock() + begoff;
422 
423 	q = grabstackstr(expdest);
424 	result = arith(start);
425 	ungrabstackstr(q, expdest);
426 
427 	start = stackblock() + begoff;
428 	adj = start - expdest;
429 	STADJUST(adj, expdest);
430 
431 	CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
432 	fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
433 	adj = strlen(expdest);
434 	STADJUST(adj, expdest);
435 	/*
436 	 * If this is quoted, a '-' must not indicate a range in [...].
437 	 * If this is not quoted, splitting may occur.
438 	 */
439 	if (quoted ?
440 	    result < 0 && begoff > 1 && flag & (EXP_GLOB | EXP_CASE) :
441 	    flag & EXP_SPLIT)
442 		reprocess(expdest - adj - stackblock(), flag, VSNORMAL, quoted,
443 		    dst);
444 	return p;
445 }
446 
447 
448 /*
449  * Perform command substitution.
450  */
451 static void
452 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
453 {
454 	struct backcmd in;
455 	int i;
456 	char buf[128];
457 	char *p;
458 	char *dest = expdest;
459 	char lastc;
460 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
461 	int quotes = flag & (EXP_GLOB | EXP_CASE);
462 	size_t nnl;
463 	const char *ifs;
464 	int startloc;
465 
466 	INTOFF;
467 	p = grabstackstr(dest);
468 	evalbackcmd(cmd, &in);
469 	ungrabstackstr(p, dest);
470 
471 	p = in.buf;
472 	startloc = dest - stackblock();
473 	nnl = 0;
474 	if (!quoted && flag & EXP_SPLIT)
475 		ifs = ifsset() ? ifsval() : " \t\n";
476 	else
477 		ifs = "";
478 	/* Remove trailing newlines */
479 	for (;;) {
480 		if (--in.nleft < 0) {
481 			if (in.fd < 0)
482 				break;
483 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
484 				;
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 			continue;
494 		if (nnl > 0 && lastc != '\n') {
495 			NEXTWORD('\n', flag, dest, dst);
496 			nnl = 0;
497 		}
498 		if (strchr(ifs, lastc) != NULL) {
499 			if (lastc == '\n')
500 				nnl++;
501 			else
502 				NEXTWORD(lastc, flag, dest, dst);
503 		} else {
504 			CHECKSTRSPACE(2, dest);
505 			if (quotes && syntax[(int)lastc] == CCTL)
506 				USTPUTC(CTLESC, dest);
507 			USTPUTC(lastc, dest);
508 		}
509 	}
510 	while (dest > stackblock() + startloc && STTOPC(dest) == '\n')
511 		STUNPUTC(dest);
512 
513 	if (in.fd >= 0)
514 		close(in.fd);
515 	if (in.buf)
516 		ckfree(in.buf);
517 	if (in.jp) {
518 		p = grabstackstr(dest);
519 		exitstatus = waitforjob(in.jp, (int *)NULL);
520 		ungrabstackstr(p, dest);
521 	}
522 	TRACE(("expbackq: done\n"));
523 	expdest = dest;
524 	INTON;
525 }
526 
527 
528 
529 static void
530 recordleft(const char *str, const char *loc, char *startp)
531 {
532 	int amount;
533 
534 	amount = ((str - 1) - (loc - startp)) - expdest;
535 	STADJUST(amount, expdest);
536 	while (loc != str - 1)
537 		*startp++ = *loc++;
538 }
539 
540 static const char *
541 subevalvar_trim(const char *p, struct nodelist **restrict argbackq, int strloc,
542     int subtype, int startloc)
543 {
544 	char *startp;
545 	char *loc = NULL;
546 	char *str;
547 	int c = 0;
548 	int amount;
549 
550 	p = argstr(p, argbackq, EXP_CASE | EXP_TILDE, NULL);
551 	STACKSTRNUL(expdest);
552 	startp = stackblock() + startloc;
553 	str = stackblock() + strloc;
554 
555 	switch (subtype) {
556 	case VSTRIMLEFT:
557 		for (loc = startp; loc < str; loc++) {
558 			c = *loc;
559 			*loc = '\0';
560 			if (patmatch(str, startp)) {
561 				*loc = c;
562 				recordleft(str, loc, startp);
563 				return p;
564 			}
565 			*loc = c;
566 		}
567 		break;
568 
569 	case VSTRIMLEFTMAX:
570 		for (loc = str - 1; loc >= startp;) {
571 			c = *loc;
572 			*loc = '\0';
573 			if (patmatch(str, startp)) {
574 				*loc = c;
575 				recordleft(str, loc, startp);
576 				return p;
577 			}
578 			*loc = c;
579 			loc--;
580 		}
581 		break;
582 
583 	case VSTRIMRIGHT:
584 		for (loc = str - 1; loc >= startp;) {
585 			if (patmatch(str, loc)) {
586 				amount = loc - expdest;
587 				STADJUST(amount, expdest);
588 				return p;
589 			}
590 			loc--;
591 		}
592 		break;
593 
594 	case VSTRIMRIGHTMAX:
595 		for (loc = startp; loc < str - 1; loc++) {
596 			if (patmatch(str, loc)) {
597 				amount = loc - expdest;
598 				STADJUST(amount, expdest);
599 				return p;
600 			}
601 		}
602 		break;
603 
604 
605 	default:
606 		abort();
607 	}
608 	amount = (expdest - stackblock() - strloc) + 1;
609 	STADJUST(-amount, expdest);
610 	return p;
611 }
612 
613 
614 static const char *
615 subevalvar_misc(const char *p, struct nodelist **restrict argbackq,
616     const char *var, int subtype, int startloc, int varflags)
617 {
618 	const char *end;
619 	char *startp;
620 	int amount;
621 
622 	end = argstr(p, argbackq, EXP_TILDE, NULL);
623 	STACKSTRNUL(expdest);
624 	startp = stackblock() + startloc;
625 
626 	switch (subtype) {
627 	case VSASSIGN:
628 		setvar(var, startp, 0);
629 		amount = startp - expdest;
630 		STADJUST(amount, expdest);
631 		return end;
632 
633 	case VSQUESTION:
634 		if (*p != CTLENDVAR) {
635 			outfmt(out2, "%s\n", startp);
636 			error((char *)NULL);
637 		}
638 		error("%.*s: parameter %snot set", (int)(p - var - 1),
639 		      var, (varflags & VSNUL) ? "null or " : "");
640 
641 	default:
642 		abort();
643 	}
644 }
645 
646 
647 /*
648  * Expand a variable, and return a pointer to the next character in the
649  * input string.
650  */
651 
652 static const char *
653 evalvar(const char *p, struct nodelist **restrict argbackq, int flag,
654     struct worddest *dst)
655 {
656 	int subtype;
657 	int varflags;
658 	const char *var;
659 	const char *val;
660 	int patloc;
661 	int c;
662 	int set;
663 	int special;
664 	int startloc;
665 	int varlen;
666 	int varlenb;
667 	char buf[21];
668 
669 	varflags = (unsigned char)*p++;
670 	subtype = varflags & VSTYPE;
671 	var = p;
672 	special = 0;
673 	if (! is_name(*p))
674 		special = 1;
675 	p = strchr(p, '=') + 1;
676 	if (varflags & VSLINENO) {
677 		set = 1;
678 		special = 1;
679 		val = NULL;
680 	} else if (special) {
681 		set = varisset(var, varflags & VSNUL);
682 		val = NULL;
683 	} else {
684 		val = bltinlookup(var, 1);
685 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
686 			val = NULL;
687 			set = 0;
688 		} else
689 			set = 1;
690 	}
691 	varlen = 0;
692 	startloc = expdest - stackblock();
693 	if (!set && uflag && *var != '@' && *var != '*') {
694 		switch (subtype) {
695 		case VSNORMAL:
696 		case VSTRIMLEFT:
697 		case VSTRIMLEFTMAX:
698 		case VSTRIMRIGHT:
699 		case VSTRIMRIGHTMAX:
700 		case VSLENGTH:
701 			error("%.*s: parameter not set", (int)(p - var - 1),
702 			    var);
703 		}
704 	}
705 	if (set && subtype != VSPLUS) {
706 		/* insert the value of the variable */
707 		if (special) {
708 			if (varflags & VSLINENO) {
709 				if (p - var > (ptrdiff_t)sizeof(buf))
710 					abort();
711 				memcpy(buf, var, p - var - 1);
712 				buf[p - var - 1] = '\0';
713 				strtodest(buf, flag, subtype,
714 				    varflags & VSQUOTE, dst);
715 			} else
716 				varvalue(var, varflags & VSQUOTE, subtype, flag,
717 				    dst);
718 			if (subtype == VSLENGTH) {
719 				varlenb = expdest - stackblock() - startloc;
720 				varlen = varlenb;
721 				if (localeisutf8) {
722 					val = stackblock() + startloc;
723 					for (;val != expdest; val++)
724 						if ((*val & 0xC0) == 0x80)
725 							varlen--;
726 				}
727 				STADJUST(-varlenb, expdest);
728 			}
729 		} else {
730 			if (subtype == VSLENGTH) {
731 				for (;*val; val++)
732 					if (!localeisutf8 ||
733 					    (*val & 0xC0) != 0x80)
734 						varlen++;
735 			}
736 			else
737 				strtodest(val, flag, subtype,
738 				    varflags & VSQUOTE, dst);
739 		}
740 	}
741 
742 	if (subtype == VSPLUS)
743 		set = ! set;
744 
745 	switch (subtype) {
746 	case VSLENGTH:
747 		cvtnum(varlen, buf);
748 		strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
749 		break;
750 
751 	case VSNORMAL:
752 		return p;
753 
754 	case VSPLUS:
755 	case VSMINUS:
756 		if (!set) {
757 			return argstr(p, argbackq,
758 			    flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
759 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
760 		}
761 		break;
762 
763 	case VSTRIMLEFT:
764 	case VSTRIMLEFTMAX:
765 	case VSTRIMRIGHT:
766 	case VSTRIMRIGHTMAX:
767 		if (!set)
768 			break;
769 		/*
770 		 * Terminate the string and start recording the pattern
771 		 * right after it
772 		 */
773 		STPUTC('\0', expdest);
774 		patloc = expdest - stackblock();
775 		p = subevalvar_trim(p, argbackq, patloc, subtype, startloc);
776 		reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
777 		if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
778 			dst->state = WORD_QUOTEMARK;
779 		return p;
780 
781 	case VSASSIGN:
782 	case VSQUESTION:
783 		if (!set) {
784 			p = subevalvar_misc(p, argbackq, var, subtype,
785 			    startloc, varflags);
786 			/* assert(subtype == VSASSIGN); */
787 			val = lookupvar(var);
788 			strtodest(val, flag, subtype, varflags & VSQUOTE, dst);
789 			return p;
790 		}
791 		break;
792 
793 	case VSERROR:
794 		c = p - var - 1;
795 		error("${%.*s%s}: Bad substitution", c, var,
796 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
797 
798 	default:
799 		abort();
800 	}
801 
802 	{	/* skip to end of alternative */
803 		int nesting = 1;
804 		for (;;) {
805 			if ((c = *p++) == CTLESC)
806 				p++;
807 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE))
808 				*argbackq = (*argbackq)->next;
809 			else if (c == CTLVAR) {
810 				if ((*p++ & VSTYPE) != VSNORMAL)
811 					nesting++;
812 			} else if (c == CTLENDVAR) {
813 				if (--nesting == 0)
814 					break;
815 			}
816 		}
817 	}
818 	return p;
819 }
820 
821 
822 
823 /*
824  * Test whether a special or positional parameter is set.
825  */
826 
827 static int
828 varisset(const char *name, int nulok)
829 {
830 
831 	if (*name == '!')
832 		return backgndpidset();
833 	else if (*name == '@' || *name == '*') {
834 		if (*shellparam.p == NULL)
835 			return 0;
836 
837 		if (nulok) {
838 			char **av;
839 
840 			for (av = shellparam.p; *av; av++)
841 				if (**av != '\0')
842 					return 1;
843 			return 0;
844 		}
845 	} else if (is_digit(*name)) {
846 		char *ap;
847 		long num;
848 
849 		errno = 0;
850 		num = strtol(name, NULL, 10);
851 		if (errno != 0 || num > shellparam.nparam)
852 			return 0;
853 
854 		if (num == 0)
855 			ap = arg0;
856 		else
857 			ap = shellparam.p[num - 1];
858 
859 		if (nulok && (ap == NULL || *ap == '\0'))
860 			return 0;
861 	}
862 	return 1;
863 }
864 
865 static void
866 strtodest(const char *p, int flag, int subtype, int quoted,
867     struct worddest *dst)
868 {
869 	if (subtype == VSLENGTH || subtype == VSTRIMLEFT ||
870 	    subtype == VSTRIMLEFTMAX || subtype == VSTRIMRIGHT ||
871 	    subtype == VSTRIMRIGHTMAX)
872 		STPUTS(p, expdest);
873 	else if (flag & EXP_SPLIT && !quoted && dst != NULL)
874 		STPUTS_SPLIT(p, BASESYNTAX, flag, expdest, dst);
875 	else if (flag & (EXP_GLOB | EXP_CASE))
876 		STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
877 	else
878 		STPUTS(p, expdest);
879 }
880 
881 static void
882 reprocess(int startloc, int flag, int subtype, int quoted,
883     struct worddest *dst)
884 {
885 	static char *buf = NULL;
886 	static size_t buflen = 0;
887 	char *startp;
888 	size_t len, zpos, zlen;
889 
890 	startp = stackblock() + startloc;
891 	len = expdest - startp;
892 	if (len >= SIZE_MAX / 2 || len > PTRDIFF_MAX)
893 		abort();
894 	INTOFF;
895 	if (len >= buflen) {
896 		ckfree(buf);
897 		buf = NULL;
898 	}
899 	if (buflen < 128)
900 		buflen = 128;
901 	while (len >= buflen)
902 		buflen <<= 1;
903 	if (buf == NULL)
904 		buf = ckmalloc(buflen);
905 	INTON;
906 	memcpy(buf, startp, len);
907 	buf[len] = '\0';
908 	STADJUST(-(ptrdiff_t)len, expdest);
909 	for (zpos = 0;;) {
910 		zlen = strlen(buf + zpos);
911 		strtodest(buf + zpos, flag, subtype, quoted, dst);
912 		zpos += zlen + 1;
913 		if (zpos == len + 1)
914 			break;
915 		if (flag & EXP_SPLIT && (quoted || (zlen > 0 && zpos < len)))
916 			NEXTWORD('\0', flag, expdest, dst);
917 	}
918 }
919 
920 /*
921  * Add the value of a special or positional parameter to the stack string.
922  */
923 
924 static void
925 varvalue(const char *name, int quoted, int subtype, int flag,
926     struct worddest *dst)
927 {
928 	int num;
929 	char *p;
930 	int i;
931 	int splitlater;
932 	char sep[2];
933 	char **ap;
934 	char buf[(NSHORTOPTS > 10 ? NSHORTOPTS : 10) + 1];
935 
936 	if (subtype == VSLENGTH)
937 		flag &= ~EXP_FULL;
938 	splitlater = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
939 		subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX;
940 
941 	switch (*name) {
942 	case '$':
943 		num = rootpid;
944 		break;
945 	case '?':
946 		num = oexitstatus;
947 		break;
948 	case '#':
949 		num = shellparam.nparam;
950 		break;
951 	case '!':
952 		num = backgndpidval();
953 		break;
954 	case '-':
955 		p = buf;
956 		for (i = 0 ; i < NSHORTOPTS ; i++) {
957 			if (optval[i])
958 				*p++ = optletter[i];
959 		}
960 		*p = '\0';
961 		strtodest(buf, flag, subtype, quoted, dst);
962 		return;
963 	case '@':
964 		if (flag & EXP_SPLIT && quoted) {
965 			for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
966 				strtodest(p, flag, subtype, quoted, dst);
967 				if (*ap) {
968 					if (splitlater)
969 						STPUTC('\0', expdest);
970 					else
971 						NEXTWORD('\0', flag, expdest,
972 						    dst);
973 				}
974 			}
975 			if (shellparam.nparam > 0)
976 				dst->state = WORD_QUOTEMARK;
977 			return;
978 		}
979 		/* FALLTHROUGH */
980 	case '*':
981 		if (ifsset())
982 			sep[0] = ifsval()[0];
983 		else
984 			sep[0] = ' ';
985 		sep[1] = '\0';
986 		for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
987 			strtodest(p, flag, subtype, quoted, dst);
988 			if (!*ap)
989 				break;
990 			if (sep[0])
991 				strtodest(sep, flag, subtype, quoted, dst);
992 			else if (flag & EXP_SPLIT && !quoted && **ap != '\0') {
993 				if (splitlater)
994 					STPUTC('\0', expdest);
995 				else
996 					NEXTWORD('\0', flag, expdest, dst);
997 			}
998 		}
999 		return;
1000 	default:
1001 		if (is_digit(*name)) {
1002 			num = atoi(name);
1003 			if (num == 0)
1004 				p = arg0;
1005 			else if (num > 0 && num <= shellparam.nparam)
1006 				p = shellparam.p[num - 1];
1007 			else
1008 				return;
1009 			strtodest(p, flag, subtype, quoted, dst);
1010 		}
1011 		return;
1012 	}
1013 	cvtnum(num, buf);
1014 	strtodest(buf, flag, subtype, quoted, dst);
1015 }
1016 
1017 
1018 
1019 static char expdir[PATH_MAX];
1020 #define expdir_end (expdir + sizeof(expdir))
1021 
1022 /*
1023  * Perform pathname generation and remove control characters.
1024  * At this point, the only control characters should be CTLESC.
1025  * The results are stored in the list dstlist.
1026  */
1027 static void
1028 expandmeta(char *pattern, struct arglist *dstlist)
1029 {
1030 	char *p;
1031 	int firstmatch;
1032 	char c;
1033 
1034 	firstmatch = dstlist->count;
1035 	p = pattern;
1036 	for (; (c = *p) != '\0'; p++) {
1037 		/* fast check for meta chars */
1038 		if (c == '*' || c == '?' || c == '[') {
1039 			INTOFF;
1040 			expmeta(expdir, pattern, dstlist);
1041 			INTON;
1042 			break;
1043 		}
1044 	}
1045 	if (dstlist->count == firstmatch) {
1046 		/*
1047 		 * no matches
1048 		 */
1049 		rmescapes(pattern);
1050 		appendarglist(dstlist, pattern);
1051 	} else {
1052 		qsort(&dstlist->args[firstmatch],
1053 		    dstlist->count - firstmatch,
1054 		    sizeof(dstlist->args[0]), expsortcmp);
1055 	}
1056 }
1057 
1058 
1059 /*
1060  * Do metacharacter (i.e. *, ?, [...]) expansion.
1061  */
1062 
1063 static void
1064 expmeta(char *enddir, char *name, struct arglist *arglist)
1065 {
1066 	const char *p;
1067 	const char *q;
1068 	const char *start;
1069 	char *endname;
1070 	int metaflag;
1071 	struct stat statb;
1072 	DIR *dirp;
1073 	struct dirent *dp;
1074 	int atend;
1075 	int matchdot;
1076 	int esc;
1077 	int namlen;
1078 
1079 	metaflag = 0;
1080 	start = name;
1081 	for (p = name; esc = 0, *p; p += esc + 1) {
1082 		if (*p == '*' || *p == '?')
1083 			metaflag = 1;
1084 		else if (*p == '[') {
1085 			q = p + 1;
1086 			if (*q == '!' || *q == '^')
1087 				q++;
1088 			for (;;) {
1089 				if (*q == CTLESC)
1090 					q++;
1091 				if (*q == '/' || *q == '\0')
1092 					break;
1093 				if (*++q == ']') {
1094 					metaflag = 1;
1095 					break;
1096 				}
1097 			}
1098 		} else if (*p == '\0')
1099 			break;
1100 		else {
1101 			if (*p == CTLESC)
1102 				esc++;
1103 			if (p[esc] == '/') {
1104 				if (metaflag)
1105 					break;
1106 				start = p + esc + 1;
1107 			}
1108 		}
1109 	}
1110 	if (metaflag == 0) {	/* we've reached the end of the file name */
1111 		if (enddir != expdir)
1112 			metaflag++;
1113 		for (p = name ; ; p++) {
1114 			if (*p == CTLESC)
1115 				p++;
1116 			*enddir++ = *p;
1117 			if (*p == '\0')
1118 				break;
1119 			if (enddir == expdir_end)
1120 				return;
1121 		}
1122 		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1123 			appendarglist(arglist, stsavestr(expdir));
1124 		return;
1125 	}
1126 	endname = name + (p - name);
1127 	if (start != name) {
1128 		p = name;
1129 		while (p < start) {
1130 			if (*p == CTLESC)
1131 				p++;
1132 			*enddir++ = *p++;
1133 			if (enddir == expdir_end)
1134 				return;
1135 		}
1136 	}
1137 	if (enddir == expdir) {
1138 		p = ".";
1139 	} else if (enddir == expdir + 1 && *expdir == '/') {
1140 		p = "/";
1141 	} else {
1142 		p = expdir;
1143 		enddir[-1] = '\0';
1144 	}
1145 	if ((dirp = opendir(p)) == NULL)
1146 		return;
1147 	if (enddir != expdir)
1148 		enddir[-1] = '/';
1149 	if (*endname == 0) {
1150 		atend = 1;
1151 	} else {
1152 		atend = 0;
1153 		*endname = '\0';
1154 		endname += esc + 1;
1155 	}
1156 	matchdot = 0;
1157 	p = start;
1158 	if (*p == CTLESC)
1159 		p++;
1160 	if (*p == '.')
1161 		matchdot++;
1162 	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1163 		if (dp->d_name[0] == '.' && ! matchdot)
1164 			continue;
1165 		if (patmatch(start, dp->d_name)) {
1166 			namlen = dp->d_namlen;
1167 			if (enddir + namlen + 1 > expdir_end)
1168 				continue;
1169 			memcpy(enddir, dp->d_name, namlen + 1);
1170 			if (atend)
1171 				appendarglist(arglist, stsavestr(expdir));
1172 			else {
1173 				if (dp->d_type != DT_UNKNOWN &&
1174 				    dp->d_type != DT_DIR &&
1175 				    dp->d_type != DT_LNK)
1176 					continue;
1177 				if (enddir + namlen + 2 > expdir_end)
1178 					continue;
1179 				enddir[namlen] = '/';
1180 				enddir[namlen + 1] = '\0';
1181 				expmeta(enddir + namlen + 1, endname, arglist);
1182 			}
1183 		}
1184 	}
1185 	closedir(dirp);
1186 	if (! atend)
1187 		endname[-esc - 1] = esc ? CTLESC : '/';
1188 }
1189 
1190 
1191 static int
1192 expsortcmp(const void *p1, const void *p2)
1193 {
1194 	const char *s1 = *(const char * const *)p1;
1195 	const char *s2 = *(const char * const *)p2;
1196 
1197 	return (strcoll(s1, s2));
1198 }
1199 
1200 
1201 
1202 static wchar_t
1203 get_wc(const char **p)
1204 {
1205 	wchar_t c;
1206 	int chrlen;
1207 
1208 	chrlen = mbtowc(&c, *p, 4);
1209 	if (chrlen == 0)
1210 		return 0;
1211 	else if (chrlen == -1)
1212 		c = 0;
1213 	else
1214 		*p += chrlen;
1215 	return c;
1216 }
1217 
1218 
1219 /*
1220  * See if a character matches a character class, starting at the first colon
1221  * of "[:class:]".
1222  * If a valid character class is recognized, a pointer to the next character
1223  * after the final closing bracket is stored into *end, otherwise a null
1224  * pointer is stored into *end.
1225  */
1226 static int
1227 match_charclass(const char *p, wchar_t chr, const char **end)
1228 {
1229 	char name[20];
1230 	const char *nameend;
1231 	wctype_t cclass;
1232 
1233 	*end = NULL;
1234 	p++;
1235 	nameend = strstr(p, ":]");
1236 	if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1237 	    nameend == p)
1238 		return 0;
1239 	memcpy(name, p, nameend - p);
1240 	name[nameend - p] = '\0';
1241 	*end = nameend + 2;
1242 	cclass = wctype(name);
1243 	/* An unknown class matches nothing but is valid nevertheless. */
1244 	if (cclass == 0)
1245 		return 0;
1246 	return iswctype(chr, cclass);
1247 }
1248 
1249 
1250 /*
1251  * Returns true if the pattern matches the string.
1252  */
1253 
1254 static int
1255 patmatch(const char *pattern, const char *string)
1256 {
1257 	const char *p, *q, *end;
1258 	const char *bt_p, *bt_q;
1259 	char c;
1260 	wchar_t wc, wc2;
1261 
1262 	p = pattern;
1263 	q = string;
1264 	bt_p = NULL;
1265 	bt_q = NULL;
1266 	for (;;) {
1267 		switch (c = *p++) {
1268 		case '\0':
1269 			if (*q != '\0')
1270 				goto backtrack;
1271 			return 1;
1272 		case CTLESC:
1273 			if (*q++ != *p++)
1274 				goto backtrack;
1275 			break;
1276 		case '?':
1277 			if (*q == '\0')
1278 				return 0;
1279 			if (localeisutf8) {
1280 				wc = get_wc(&q);
1281 				/*
1282 				 * A '?' does not match invalid UTF-8 but a
1283 				 * '*' does, so backtrack.
1284 				 */
1285 				if (wc == 0)
1286 					goto backtrack;
1287 			} else
1288 				q++;
1289 			break;
1290 		case '*':
1291 			c = *p;
1292 			while (c == '*')
1293 				c = *++p;
1294 			/*
1295 			 * If the pattern ends here, we know the string
1296 			 * matches without needing to look at the rest of it.
1297 			 */
1298 			if (c == '\0')
1299 				return 1;
1300 			/*
1301 			 * First try the shortest match for the '*' that
1302 			 * could work. We can forget any earlier '*' since
1303 			 * there is no way having it match more characters
1304 			 * can help us, given that we are already here.
1305 			 */
1306 			bt_p = p;
1307 			bt_q = q;
1308 			break;
1309 		case '[': {
1310 			const char *savep, *saveq;
1311 			int invert, found;
1312 			wchar_t chr;
1313 
1314 			savep = p, saveq = q;
1315 			invert = 0;
1316 			if (*p == '!' || *p == '^') {
1317 				invert++;
1318 				p++;
1319 			}
1320 			found = 0;
1321 			if (*q == '\0')
1322 				return 0;
1323 			if (localeisutf8) {
1324 				chr = get_wc(&q);
1325 				if (chr == 0)
1326 					goto backtrack;
1327 			} else
1328 				chr = (unsigned char)*q++;
1329 			c = *p++;
1330 			do {
1331 				if (c == '\0') {
1332 					p = savep, q = saveq;
1333 					c = '[';
1334 					goto dft;
1335 				}
1336 				if (c == '[' && *p == ':') {
1337 					found |= match_charclass(p, chr, &end);
1338 					if (end != NULL) {
1339 						p = end;
1340 						continue;
1341 					}
1342 				}
1343 				if (c == CTLESC)
1344 					c = *p++;
1345 				if (localeisutf8 && c & 0x80) {
1346 					p--;
1347 					wc = get_wc(&p);
1348 					if (wc == 0) /* bad utf-8 */
1349 						return 0;
1350 				} else
1351 					wc = (unsigned char)c;
1352 				if (*p == '-' && p[1] != ']') {
1353 					p++;
1354 					if (*p == CTLESC)
1355 						p++;
1356 					if (localeisutf8) {
1357 						wc2 = get_wc(&p);
1358 						if (wc2 == 0) /* bad utf-8 */
1359 							return 0;
1360 					} else
1361 						wc2 = (unsigned char)*p++;
1362 					if (   collate_range_cmp(chr, wc) >= 0
1363 					    && collate_range_cmp(chr, wc2) <= 0
1364 					   )
1365 						found = 1;
1366 				} else {
1367 					if (chr == wc)
1368 						found = 1;
1369 				}
1370 			} while ((c = *p++) != ']');
1371 			if (found == invert)
1372 				goto backtrack;
1373 			break;
1374 		}
1375 dft:	        default:
1376 			if (*q == '\0')
1377 				return 0;
1378 			if (*q++ == c)
1379 				break;
1380 backtrack:
1381 			/*
1382 			 * If we have a mismatch (other than hitting the end
1383 			 * of the string), go back to the last '*' seen and
1384 			 * have it match one additional character.
1385 			 */
1386 			if (bt_p == NULL)
1387 				return 0;
1388 			if (*bt_q == '\0')
1389 				return 0;
1390 			bt_q++;
1391 			p = bt_p;
1392 			q = bt_q;
1393 			break;
1394 		}
1395 	}
1396 }
1397 
1398 
1399 
1400 /*
1401  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1402  */
1403 
1404 void
1405 rmescapes(char *str)
1406 {
1407 	char *p, *q;
1408 
1409 	p = str;
1410 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1411 		if (*p++ == '\0')
1412 			return;
1413 	}
1414 	q = p;
1415 	while (*p) {
1416 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1417 			p++;
1418 			continue;
1419 		}
1420 		if (*p == CTLESC)
1421 			p++;
1422 		*q++ = *p++;
1423 	}
1424 	*q = '\0';
1425 }
1426 
1427 
1428 
1429 /*
1430  * See if a pattern matches in a case statement.
1431  */
1432 
1433 int
1434 casematch(union node *pattern, const char *val)
1435 {
1436 	struct stackmark smark;
1437 	struct nodelist *argbackq;
1438 	int result;
1439 	char *p;
1440 
1441 	setstackmark(&smark);
1442 	argbackq = pattern->narg.backquote;
1443 	STARTSTACKSTR(expdest);
1444 	argstr(pattern->narg.text, &argbackq, EXP_TILDE | EXP_CASE, NULL);
1445 	STPUTC('\0', expdest);
1446 	p = grabstackstr(expdest);
1447 	result = patmatch(p, val);
1448 	popstackmark(&smark);
1449 	return result;
1450 }
1451 
1452 /*
1453  * Our own itoa().
1454  */
1455 
1456 static void
1457 cvtnum(int num, char *buf)
1458 {
1459 	char temp[32];
1460 	int neg = num < 0;
1461 	char *p = temp + 31;
1462 
1463 	temp[31] = '\0';
1464 
1465 	do {
1466 		*--p = num % 10 + '0';
1467 	} while ((num /= 10) != 0);
1468 
1469 	if (neg)
1470 		*--p = '-';
1471 
1472 	memcpy(buf, p, temp + 32 - p);
1473 }
1474 
1475 /*
1476  * Do most of the work for wordexp(3).
1477  */
1478 
1479 int
1480 wordexpcmd(int argc, char **argv)
1481 {
1482 	size_t len;
1483 	int i;
1484 
1485 	out1fmt("%08x", argc - 1);
1486 	for (i = 1, len = 0; i < argc; i++)
1487 		len += strlen(argv[i]);
1488 	out1fmt("%08x", (int)len);
1489 	for (i = 1; i < argc; i++)
1490 		outbin(argv[i], strlen(argv[i]) + 1, out1);
1491         return (0);
1492 }
1493 
1494 /*
1495  * Do most of the work for wordexp(3), new version.
1496  */
1497 
1498 int
1499 freebsd_wordexpcmd(int argc __unused, char **argv __unused)
1500 {
1501 	struct arglist arglist;
1502 	union node *args, *n;
1503 	size_t len;
1504 	int ch;
1505 	int protected = 0;
1506 	int fd = -1;
1507 	int i;
1508 
1509 	while ((ch = nextopt("f:p")) != '\0') {
1510 		switch (ch) {
1511 		case 'f':
1512 			fd = number(shoptarg);
1513 			break;
1514 		case 'p':
1515 			protected = 1;
1516 			break;
1517 		}
1518 	}
1519 	if (*argptr != NULL)
1520 		error("wrong number of arguments");
1521 	if (fd < 0)
1522 		error("missing fd");
1523 	INTOFF;
1524 	setinputfd(fd, 1);
1525 	INTON;
1526 	args = parsewordexp();
1527 	popfile(); /* will also close fd */
1528 	if (protected)
1529 		for (n = args; n != NULL; n = n->narg.next) {
1530 			if (n->narg.backquote != NULL) {
1531 				outcslow('C', out1);
1532 				error("command substitution disabled");
1533 			}
1534 		}
1535 	outcslow(' ', out1);
1536 	emptyarglist(&arglist);
1537 	for (n = args; n != NULL; n = n->narg.next)
1538 		expandarg(n, &arglist, EXP_FULL | EXP_TILDE);
1539 	for (i = 0, len = 0; i < arglist.count; i++)
1540 		len += strlen(arglist.args[i]);
1541 	out1fmt("%016x %016zx", arglist.count, len);
1542 	for (i = 0; i < arglist.count; i++)
1543 		outbin(arglist.args[i], strlen(arglist.args[i]) + 1, out1);
1544 	return (0);
1545 }
1546