xref: /freebsd/bin/sh/expand.c (revision dc36d6f9bb1753f3808552f3afd30eda9a7b206a)
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 #endif /* not lint */
39 #include <sys/cdefs.h>
40 #include <sys/types.h>
41 #include <sys/time.h>
42 #include <sys/stat.h>
43 #include <dirent.h>
44 #include <errno.h>
45 #include <inttypes.h>
46 #include <limits.h>
47 #include <pwd.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <wchar.h>
53 #include <wctype.h>
54 
55 /*
56  * Routines to expand arguments to commands.  We have to deal with
57  * backquotes, shell variables, and file metacharacters.
58  */
59 
60 #include "shell.h"
61 #include "main.h"
62 #include "nodes.h"
63 #include "eval.h"
64 #include "expand.h"
65 #include "syntax.h"
66 #include "parser.h"
67 #include "jobs.h"
68 #include "options.h"
69 #include "var.h"
70 #include "input.h"
71 #include "output.h"
72 #include "memalloc.h"
73 #include "error.h"
74 #include "mystring.h"
75 #include "arith.h"
76 #include "show.h"
77 #include "builtins.h"
78 
79 enum wordstate { WORD_IDLE, WORD_WS_DELIMITED, WORD_QUOTEMARK };
80 
81 struct worddest {
82 	struct arglist *list;
83 	enum wordstate state;
84 };
85 
86 static char *expdest;			/* output of current string */
87 
88 static const char *argstr(const char *, struct nodelist **restrict, int,
89     struct worddest *);
90 static const char *exptilde(const char *, int);
91 static const char *expari(const char *, struct nodelist **restrict, int,
92     struct worddest *);
93 static void expbackq(union node *, int, int, struct worddest *);
94 static const char *subevalvar_trim(const char *, struct nodelist **restrict,
95     int, int, int);
96 static const char *subevalvar_misc(const char *, struct nodelist **restrict,
97     const char *, int, int, int);
98 static const char *evalvar(const char *, struct nodelist **restrict, int,
99     struct worddest *);
100 static int varisset(const char *, int);
101 static void strtodest(const char *, int, int, int, struct worddest *);
102 static void reprocess(int, int, int, int, struct worddest *);
103 static void varvalue(const char *, int, int, int, struct worddest *);
104 static void expandmeta(char *, struct arglist *);
105 static void expmeta(char *, char *, struct arglist *);
106 static int expsortcmp(const void *, const void *);
107 static int patmatch(const char *, const char *);
108 static void cvtnum(int, char *);
109 static int collate_range_cmp(wchar_t, wchar_t);
110 
111 void
112 emptyarglist(struct arglist *list)
113 {
114 
115 	list->args = list->smallarg;
116 	list->count = 0;
117 	list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
118 }
119 
120 void
121 appendarglist(struct arglist *list, char *str)
122 {
123 	char **newargs;
124 	int newcapacity;
125 
126 	if (list->count >= list->capacity) {
127 		newcapacity = list->capacity * 2;
128 		if (newcapacity < 16)
129 			newcapacity = 16;
130 		if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
131 			error("Too many entries in arglist");
132 		newargs = stalloc(newcapacity * sizeof(newargs[0]));
133 		memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
134 		list->args = newargs;
135 		list->capacity = newcapacity;
136 	}
137 	list->args[list->count++] = str;
138 }
139 
140 static int
141 collate_range_cmp(wchar_t c1, wchar_t c2)
142 {
143 	wchar_t s1[2], s2[2];
144 
145 	s1[0] = c1;
146 	s1[1] = L'\0';
147 	s2[0] = c2;
148 	s2[1] = L'\0';
149 	return (wcscoll(s1, s2));
150 }
151 
152 static char *
153 stputs_quotes(const char *data, const char *syntax, char *p)
154 {
155 	while (*data) {
156 		CHECKSTRSPACE(2, p);
157 		if (syntax[(int)*data] == CCTL)
158 			USTPUTC(CTLESC, p);
159 		USTPUTC(*data++, p);
160 	}
161 	return (p);
162 }
163 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
164 
165 static char *
166 nextword(char c, int flag, char *p, struct worddest *dst)
167 {
168 	int is_ws;
169 
170 	is_ws = c == '\t' || c == '\n' || c == ' ';
171 	if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
172 	    dst->state != WORD_WS_DELIMITED) || c == '\0') {
173 		STPUTC('\0', p);
174 		if (flag & EXP_GLOB)
175 			expandmeta(grabstackstr(p), dst->list);
176 		else
177 			appendarglist(dst->list, grabstackstr(p));
178 		dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
179 	} else if (!is_ws && dst->state == WORD_WS_DELIMITED)
180 		dst->state = WORD_IDLE;
181 	/* Reserve space while the stack string is empty. */
182 	appendarglist(dst->list, NULL);
183 	dst->list->count--;
184 	STARTSTACKSTR(p);
185 	return p;
186 }
187 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
188 
189 static char *
190 stputs_split(const char *data, const char *syntax, int flag, char *p,
191     struct worddest *dst)
192 {
193 	const char *ifs;
194 	char c;
195 
196 	ifs = ifsset() ? ifsval() : " \t\n";
197 	while (*data) {
198 		CHECKSTRSPACE(2, p);
199 		c = *data++;
200 		if (strchr(ifs, c) != NULL) {
201 			NEXTWORD(c, flag, p, dst);
202 			continue;
203 		}
204 		if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
205 			USTPUTC(CTLESC, p);
206 		USTPUTC(c, p);
207 	}
208 	return (p);
209 }
210 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
211 
212 /*
213  * Perform expansions on an argument, placing the resulting list of arguments
214  * in arglist.  Parameter expansion, command substitution and arithmetic
215  * expansion are always performed; additional expansions can be requested
216  * via flag (EXP_*).
217  * The result is left in the stack string.
218  * When arglist is NULL, perform here document expansion.
219  *
220  * When doing something that may cause this to be re-entered, make sure
221  * the stack string is empty via grabstackstr() and do not assume expdest
222  * remains valid.
223  */
224 void
225 expandarg(union node *arg, struct arglist *arglist, int flag)
226 {
227 	struct worddest exparg;
228 	struct nodelist *argbackq;
229 
230 	if (fflag)
231 		flag &= ~EXP_GLOB;
232 	argbackq = arg->narg.backquote;
233 	exparg.list = arglist;
234 	exparg.state = WORD_IDLE;
235 	STARTSTACKSTR(expdest);
236 	argstr(arg->narg.text, &argbackq, flag, &exparg);
237 	if (arglist == NULL) {
238 		STACKSTRNUL(expdest);
239 		return;			/* here document expanded */
240 	}
241 	if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
242 	    exparg.state == WORD_QUOTEMARK) {
243 		STPUTC('\0', expdest);
244 		if (flag & EXP_SPLIT) {
245 			if (flag & EXP_GLOB)
246 				expandmeta(grabstackstr(expdest), exparg.list);
247 			else
248 				appendarglist(exparg.list, grabstackstr(expdest));
249 		}
250 	}
251 	if ((flag & EXP_SPLIT) == 0)
252 		appendarglist(arglist, grabstackstr(expdest));
253 }
254 
255 
256 
257 /*
258  * Perform parameter expansion, command substitution and arithmetic
259  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
260  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
261  * This is used to expand word in ${var+word} etc.
262  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
263  * characters to allow for further processing.
264  *
265  * If EXP_SPLIT is set, dst receives any complete words produced.
266  */
267 static const char *
268 argstr(const char *p, struct nodelist **restrict argbackq, int flag,
269     struct worddest *dst)
270 {
271 	char c;
272 	int quotes = flag & (EXP_GLOB | EXP_CASE);	/* do CTLESC */
273 	int firsteq = 1;
274 	int split_lit;
275 	int lit_quoted;
276 
277 	split_lit = flag & EXP_SPLIT_LIT;
278 	lit_quoted = flag & EXP_LIT_QUOTED;
279 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
280 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
281 		p = exptilde(p, flag);
282 	for (;;) {
283 		CHECKSTRSPACE(2, expdest);
284 		switch (c = *p++) {
285 		case '\0':
286 			return (p - 1);
287 		case CTLENDVAR:
288 		case CTLENDARI:
289 			return (p);
290 		case CTLQUOTEMARK:
291 			lit_quoted = 1;
292 			/* "$@" syntax adherence hack */
293 			if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
294 			    p[2] == '@' && p[3] == '=')
295 				break;
296 			if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
297 				dst->state = WORD_QUOTEMARK;
298 			break;
299 		case CTLQUOTEEND:
300 			lit_quoted = 0;
301 			break;
302 		case CTLESC:
303 			c = *p++;
304 			if (split_lit && !lit_quoted &&
305 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
306 				NEXTWORD(c, flag, expdest, dst);
307 				break;
308 			}
309 			if (quotes)
310 				USTPUTC(CTLESC, expdest);
311 			USTPUTC(c, expdest);
312 			break;
313 		case CTLVAR:
314 			p = evalvar(p, argbackq, flag, dst);
315 			break;
316 		case CTLBACKQ:
317 		case CTLBACKQ|CTLQUOTE:
318 			expbackq((*argbackq)->n, c & CTLQUOTE, flag, dst);
319 			*argbackq = (*argbackq)->next;
320 			break;
321 		case CTLARI:
322 			p = expari(p, argbackq, flag, dst);
323 			break;
324 		case ':':
325 		case '=':
326 			/*
327 			 * sort of a hack - expand tildes in variable
328 			 * assignments (after the first '=' and after ':'s).
329 			 */
330 			if (split_lit && !lit_quoted &&
331 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
332 				NEXTWORD(c, flag, expdest, dst);
333 				break;
334 			}
335 			USTPUTC(c, expdest);
336 			if (flag & EXP_VARTILDE && *p == '~' &&
337 			    (c != '=' || firsteq)) {
338 				if (c == '=')
339 					firsteq = 0;
340 				p = exptilde(p, flag);
341 			}
342 			break;
343 		default:
344 			if (split_lit && !lit_quoted &&
345 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
346 				NEXTWORD(c, flag, expdest, dst);
347 				break;
348 			}
349 			USTPUTC(c, expdest);
350 		}
351 	}
352 }
353 
354 /*
355  * Perform tilde expansion, placing the result in the stack string and
356  * returning the next position in the input string to process.
357  */
358 static const char *
359 exptilde(const char *p, int flag)
360 {
361 	char c;
362 	const char *startp = p;
363 	const char *user;
364 	struct passwd *pw;
365 	char *home;
366 	int len;
367 
368 	for (;;) {
369 		c = *p;
370 		switch(c) {
371 		case CTLESC: /* This means CTL* are always considered quoted. */
372 		case CTLVAR:
373 		case CTLBACKQ:
374 		case CTLBACKQ | CTLQUOTE:
375 		case CTLARI:
376 		case CTLENDARI:
377 		case CTLQUOTEMARK:
378 			return (startp);
379 		case ':':
380 			if ((flag & EXP_VARTILDE) == 0)
381 				break;
382 			/* FALLTHROUGH */
383 		case '\0':
384 		case '/':
385 		case CTLENDVAR:
386 			len = p - startp - 1;
387 			STPUTBIN(startp + 1, len, expdest);
388 			STACKSTRNUL(expdest);
389 			user = expdest - len;
390 			if (*user == '\0') {
391 				home = lookupvar("HOME");
392 			} else {
393 				pw = getpwnam(user);
394 				home = pw != NULL ? pw->pw_dir : NULL;
395 			}
396 			STADJUST(-len, expdest);
397 			if (home == NULL || *home == '\0')
398 				return (startp);
399 			strtodest(home, flag, VSNORMAL, 1, NULL);
400 			return (p);
401 		}
402 		p++;
403 	}
404 }
405 
406 
407 /*
408  * Expand arithmetic expression.
409  */
410 static const char *
411 expari(const char *p, struct nodelist **restrict argbackq, int flag,
412     struct worddest *dst)
413 {
414 	char *q, *start;
415 	arith_t result;
416 	int begoff;
417 	int quoted;
418 	int adj;
419 
420 	quoted = *p++ == '"';
421 	begoff = expdest - stackblock();
422 	p = argstr(p, argbackq, 0, NULL);
423 	STPUTC('\0', expdest);
424 	start = stackblock() + begoff;
425 
426 	q = grabstackstr(expdest);
427 	result = arith(start);
428 	ungrabstackstr(q, expdest);
429 
430 	start = stackblock() + begoff;
431 	adj = start - expdest;
432 	STADJUST(adj, expdest);
433 
434 	CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
435 	fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
436 	adj = strlen(expdest);
437 	STADJUST(adj, expdest);
438 	/*
439 	 * If this is quoted, a '-' must not indicate a range in [...].
440 	 * If this is not quoted, splitting may occur.
441 	 */
442 	if (quoted ?
443 	    result < 0 && begoff > 1 && flag & (EXP_GLOB | EXP_CASE) :
444 	    flag & EXP_SPLIT)
445 		reprocess(expdest - adj - stackblock(), flag, VSNORMAL, quoted,
446 		    dst);
447 	return p;
448 }
449 
450 
451 /*
452  * Perform command substitution.
453  */
454 static void
455 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
456 {
457 	struct backcmd in;
458 	int i;
459 	char buf[128];
460 	char *p;
461 	char *dest = expdest;
462 	char lastc;
463 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
464 	int quotes = flag & (EXP_GLOB | EXP_CASE);
465 	size_t nnl;
466 	const char *ifs;
467 	int startloc;
468 
469 	INTOFF;
470 	p = grabstackstr(dest);
471 	evalbackcmd(cmd, &in);
472 	ungrabstackstr(p, dest);
473 
474 	p = in.buf;
475 	startloc = dest - stackblock();
476 	nnl = 0;
477 	if (!quoted && flag & EXP_SPLIT)
478 		ifs = ifsset() ? ifsval() : " \t\n";
479 	else
480 		ifs = "";
481 	/* Remove trailing newlines */
482 	for (;;) {
483 		if (--in.nleft < 0) {
484 			if (in.fd < 0)
485 				break;
486 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
487 				;
488 			TRACE(("expbackq: read returns %d\n", i));
489 			if (i <= 0)
490 				break;
491 			p = buf;
492 			in.nleft = i - 1;
493 		}
494 		lastc = *p++;
495 		if (lastc == '\0')
496 			continue;
497 		if (nnl > 0 && lastc != '\n') {
498 			NEXTWORD('\n', flag, dest, dst);
499 			nnl = 0;
500 		}
501 		if (strchr(ifs, lastc) != NULL) {
502 			if (lastc == '\n')
503 				nnl++;
504 			else
505 				NEXTWORD(lastc, flag, dest, dst);
506 		} else {
507 			CHECKSTRSPACE(2, dest);
508 			if (quotes && syntax[(int)lastc] == CCTL)
509 				USTPUTC(CTLESC, dest);
510 			USTPUTC(lastc, dest);
511 		}
512 	}
513 	while (dest > stackblock() + startloc && STTOPC(dest) == '\n')
514 		STUNPUTC(dest);
515 
516 	if (in.fd >= 0)
517 		close(in.fd);
518 	if (in.buf)
519 		ckfree(in.buf);
520 	if (in.jp) {
521 		p = grabstackstr(dest);
522 		exitstatus = waitforjob(in.jp, (int *)NULL);
523 		ungrabstackstr(p, dest);
524 	}
525 	TRACE(("expbackq: done\n"));
526 	expdest = dest;
527 	INTON;
528 }
529 
530 
531 
532 static void
533 recordleft(const char *str, const char *loc, char *startp)
534 {
535 	int amount;
536 
537 	amount = ((str - 1) - (loc - startp)) - expdest;
538 	STADJUST(amount, expdest);
539 	while (loc != str - 1)
540 		*startp++ = *loc++;
541 }
542 
543 static const char *
544 subevalvar_trim(const char *p, struct nodelist **restrict argbackq, int strloc,
545     int subtype, int startloc)
546 {
547 	char *startp;
548 	char *loc = NULL;
549 	char *str;
550 	int c = 0;
551 	int amount;
552 
553 	p = argstr(p, argbackq, EXP_CASE | EXP_TILDE, NULL);
554 	STACKSTRNUL(expdest);
555 	startp = stackblock() + startloc;
556 	str = stackblock() + strloc;
557 
558 	switch (subtype) {
559 	case VSTRIMLEFT:
560 		for (loc = startp; loc < str; loc++) {
561 			c = *loc;
562 			*loc = '\0';
563 			if (patmatch(str, startp)) {
564 				*loc = c;
565 				recordleft(str, loc, startp);
566 				return p;
567 			}
568 			*loc = c;
569 		}
570 		break;
571 
572 	case VSTRIMLEFTMAX:
573 		for (loc = str - 1; loc >= startp;) {
574 			c = *loc;
575 			*loc = '\0';
576 			if (patmatch(str, startp)) {
577 				*loc = c;
578 				recordleft(str, loc, startp);
579 				return p;
580 			}
581 			*loc = c;
582 			loc--;
583 		}
584 		break;
585 
586 	case VSTRIMRIGHT:
587 		for (loc = str - 1; loc >= startp;) {
588 			if (patmatch(str, loc)) {
589 				amount = loc - expdest;
590 				STADJUST(amount, expdest);
591 				return p;
592 			}
593 			loc--;
594 		}
595 		break;
596 
597 	case VSTRIMRIGHTMAX:
598 		for (loc = startp; loc < str - 1; loc++) {
599 			if (patmatch(str, loc)) {
600 				amount = loc - expdest;
601 				STADJUST(amount, expdest);
602 				return p;
603 			}
604 		}
605 		break;
606 
607 
608 	default:
609 		abort();
610 	}
611 	amount = (expdest - stackblock() - strloc) + 1;
612 	STADJUST(-amount, expdest);
613 	return p;
614 }
615 
616 
617 static const char *
618 subevalvar_misc(const char *p, struct nodelist **restrict argbackq,
619     const char *var, int subtype, int startloc, int varflags)
620 {
621 	const char *end;
622 	char *startp;
623 	int amount;
624 
625 	end = argstr(p, argbackq, EXP_TILDE, NULL);
626 	STACKSTRNUL(expdest);
627 	startp = stackblock() + startloc;
628 
629 	switch (subtype) {
630 	case VSASSIGN:
631 		setvar(var, startp, 0);
632 		amount = startp - expdest;
633 		STADJUST(amount, expdest);
634 		return end;
635 
636 	case VSQUESTION:
637 		if (*p != CTLENDVAR) {
638 			outfmt(out2, "%s\n", startp);
639 			error((char *)NULL);
640 		}
641 		error("%.*s: parameter %snot set", (int)(p - var - 1),
642 		      var, (varflags & VSNUL) ? "null or " : "");
643 
644 	default:
645 		abort();
646 	}
647 }
648 
649 
650 /*
651  * Expand a variable, and return a pointer to the next character in the
652  * input string.
653  */
654 
655 static const char *
656 evalvar(const char *p, struct nodelist **restrict argbackq, int flag,
657     struct worddest *dst)
658 {
659 	int subtype;
660 	int varflags;
661 	const char *var;
662 	const char *val;
663 	int patloc;
664 	int c;
665 	int set;
666 	int special;
667 	int startloc;
668 	int varlen;
669 	int varlenb;
670 	char buf[21];
671 
672 	varflags = (unsigned char)*p++;
673 	subtype = varflags & VSTYPE;
674 	var = p;
675 	special = 0;
676 	if (! is_name(*p))
677 		special = 1;
678 	p = strchr(p, '=') + 1;
679 	if (varflags & VSLINENO) {
680 		set = 1;
681 		special = 1;
682 		val = NULL;
683 	} else if (special) {
684 		set = varisset(var, varflags & VSNUL);
685 		val = NULL;
686 	} else {
687 		val = bltinlookup(var, 1);
688 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
689 			val = NULL;
690 			set = 0;
691 		} else
692 			set = 1;
693 	}
694 	varlen = 0;
695 	startloc = expdest - stackblock();
696 	if (!set && uflag && *var != '@' && *var != '*') {
697 		switch (subtype) {
698 		case VSNORMAL:
699 		case VSTRIMLEFT:
700 		case VSTRIMLEFTMAX:
701 		case VSTRIMRIGHT:
702 		case VSTRIMRIGHTMAX:
703 		case VSLENGTH:
704 			error("%.*s: parameter not set", (int)(p - var - 1),
705 			    var);
706 		}
707 	}
708 	if (set && subtype != VSPLUS) {
709 		/* insert the value of the variable */
710 		if (special) {
711 			if (varflags & VSLINENO) {
712 				if (p - var > (ptrdiff_t)sizeof(buf))
713 					abort();
714 				memcpy(buf, var, p - var - 1);
715 				buf[p - var - 1] = '\0';
716 				strtodest(buf, flag, subtype,
717 				    varflags & VSQUOTE, dst);
718 			} else
719 				varvalue(var, varflags & VSQUOTE, subtype, flag,
720 				    dst);
721 			if (subtype == VSLENGTH) {
722 				varlenb = expdest - stackblock() - startloc;
723 				varlen = varlenb;
724 				if (localeisutf8) {
725 					val = stackblock() + startloc;
726 					for (;val != expdest; val++)
727 						if ((*val & 0xC0) == 0x80)
728 							varlen--;
729 				}
730 				STADJUST(-varlenb, expdest);
731 			}
732 		} else {
733 			if (subtype == VSLENGTH) {
734 				for (;*val; val++)
735 					if (!localeisutf8 ||
736 					    (*val & 0xC0) != 0x80)
737 						varlen++;
738 			}
739 			else
740 				strtodest(val, flag, subtype,
741 				    varflags & VSQUOTE, dst);
742 		}
743 	}
744 
745 	if (subtype == VSPLUS)
746 		set = ! set;
747 
748 	switch (subtype) {
749 	case VSLENGTH:
750 		cvtnum(varlen, buf);
751 		strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
752 		break;
753 
754 	case VSNORMAL:
755 		return p;
756 
757 	case VSPLUS:
758 	case VSMINUS:
759 		if (!set) {
760 			return argstr(p, argbackq,
761 			    flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
762 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
763 		}
764 		break;
765 
766 	case VSTRIMLEFT:
767 	case VSTRIMLEFTMAX:
768 	case VSTRIMRIGHT:
769 	case VSTRIMRIGHTMAX:
770 		if (!set)
771 			break;
772 		/*
773 		 * Terminate the string and start recording the pattern
774 		 * right after it
775 		 */
776 		STPUTC('\0', expdest);
777 		patloc = expdest - stackblock();
778 		p = subevalvar_trim(p, argbackq, patloc, subtype, startloc);
779 		reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
780 		if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
781 			dst->state = WORD_QUOTEMARK;
782 		return p;
783 
784 	case VSASSIGN:
785 	case VSQUESTION:
786 		if (!set) {
787 			p = subevalvar_misc(p, argbackq, var, subtype,
788 			    startloc, varflags);
789 			/* assert(subtype == VSASSIGN); */
790 			val = lookupvar(var);
791 			strtodest(val, flag, subtype, varflags & VSQUOTE, dst);
792 			return p;
793 		}
794 		break;
795 
796 	case VSERROR:
797 		c = p - var - 1;
798 		error("${%.*s%s}: Bad substitution", c, var,
799 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
800 
801 	default:
802 		abort();
803 	}
804 
805 	{	/* skip to end of alternative */
806 		int nesting = 1;
807 		for (;;) {
808 			if ((c = *p++) == CTLESC)
809 				p++;
810 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE))
811 				*argbackq = (*argbackq)->next;
812 			else if (c == CTLVAR) {
813 				if ((*p++ & VSTYPE) != VSNORMAL)
814 					nesting++;
815 			} else if (c == CTLENDVAR) {
816 				if (--nesting == 0)
817 					break;
818 			}
819 		}
820 	}
821 	return p;
822 }
823 
824 
825 
826 /*
827  * Test whether a special or positional parameter is set.
828  */
829 
830 static int
831 varisset(const char *name, int nulok)
832 {
833 
834 	if (*name == '!')
835 		return backgndpidset();
836 	else if (*name == '@' || *name == '*') {
837 		if (*shellparam.p == NULL)
838 			return 0;
839 
840 		if (nulok) {
841 			char **av;
842 
843 			for (av = shellparam.p; *av; av++)
844 				if (**av != '\0')
845 					return 1;
846 			return 0;
847 		}
848 	} else if (is_digit(*name)) {
849 		char *ap;
850 		long num;
851 
852 		errno = 0;
853 		num = strtol(name, NULL, 10);
854 		if (errno != 0 || num > shellparam.nparam)
855 			return 0;
856 
857 		if (num == 0)
858 			ap = arg0;
859 		else
860 			ap = shellparam.p[num - 1];
861 
862 		if (nulok && (ap == NULL || *ap == '\0'))
863 			return 0;
864 	}
865 	return 1;
866 }
867 
868 static void
869 strtodest(const char *p, int flag, int subtype, int quoted,
870     struct worddest *dst)
871 {
872 	if (subtype == VSLENGTH || subtype == VSTRIMLEFT ||
873 	    subtype == VSTRIMLEFTMAX || subtype == VSTRIMRIGHT ||
874 	    subtype == VSTRIMRIGHTMAX)
875 		STPUTS(p, expdest);
876 	else if (flag & EXP_SPLIT && !quoted && dst != NULL)
877 		STPUTS_SPLIT(p, BASESYNTAX, flag, expdest, dst);
878 	else if (flag & (EXP_GLOB | EXP_CASE))
879 		STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
880 	else
881 		STPUTS(p, expdest);
882 }
883 
884 static void
885 reprocess(int startloc, int flag, int subtype, int quoted,
886     struct worddest *dst)
887 {
888 	static char *buf = NULL;
889 	static size_t buflen = 0;
890 	char *startp;
891 	size_t len, zpos, zlen;
892 
893 	startp = stackblock() + startloc;
894 	len = expdest - startp;
895 	if (len >= SIZE_MAX / 2 || len > PTRDIFF_MAX)
896 		abort();
897 	INTOFF;
898 	if (len >= buflen) {
899 		ckfree(buf);
900 		buf = NULL;
901 	}
902 	if (buflen < 128)
903 		buflen = 128;
904 	while (len >= buflen)
905 		buflen <<= 1;
906 	if (buf == NULL)
907 		buf = ckmalloc(buflen);
908 	INTON;
909 	memcpy(buf, startp, len);
910 	buf[len] = '\0';
911 	STADJUST(-(ptrdiff_t)len, expdest);
912 	for (zpos = 0;;) {
913 		zlen = strlen(buf + zpos);
914 		strtodest(buf + zpos, flag, subtype, quoted, dst);
915 		zpos += zlen + 1;
916 		if (zpos == len + 1)
917 			break;
918 		if (flag & EXP_SPLIT && (quoted || (zlen > 0 && zpos < len)))
919 			NEXTWORD('\0', flag, expdest, dst);
920 	}
921 }
922 
923 /*
924  * Add the value of a special or positional parameter to the stack string.
925  */
926 
927 static void
928 varvalue(const char *name, int quoted, int subtype, int flag,
929     struct worddest *dst)
930 {
931 	int num;
932 	char *p;
933 	int i;
934 	int splitlater;
935 	char sep[2];
936 	char **ap;
937 	char buf[(NSHORTOPTS > 10 ? NSHORTOPTS : 10) + 1];
938 
939 	if (subtype == VSLENGTH)
940 		flag &= ~EXP_FULL;
941 	splitlater = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
942 		subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX;
943 
944 	switch (*name) {
945 	case '$':
946 		num = rootpid;
947 		break;
948 	case '?':
949 		num = oexitstatus;
950 		break;
951 	case '#':
952 		num = shellparam.nparam;
953 		break;
954 	case '!':
955 		num = backgndpidval();
956 		break;
957 	case '-':
958 		p = buf;
959 		for (i = 0 ; i < NSHORTOPTS ; i++) {
960 			if (optval[i])
961 				*p++ = optletter[i];
962 		}
963 		*p = '\0';
964 		strtodest(buf, flag, subtype, quoted, dst);
965 		return;
966 	case '@':
967 		if (flag & EXP_SPLIT && quoted) {
968 			for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
969 				strtodest(p, flag, subtype, quoted, dst);
970 				if (*ap) {
971 					if (splitlater)
972 						STPUTC('\0', expdest);
973 					else
974 						NEXTWORD('\0', flag, expdest,
975 						    dst);
976 				}
977 			}
978 			if (shellparam.nparam > 0)
979 				dst->state = WORD_QUOTEMARK;
980 			return;
981 		}
982 		/* FALLTHROUGH */
983 	case '*':
984 		if (ifsset())
985 			sep[0] = ifsval()[0];
986 		else
987 			sep[0] = ' ';
988 		sep[1] = '\0';
989 		for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
990 			strtodest(p, flag, subtype, quoted, dst);
991 			if (!*ap)
992 				break;
993 			if (sep[0])
994 				strtodest(sep, flag, subtype, quoted, dst);
995 			else if (flag & EXP_SPLIT && !quoted && **ap != '\0') {
996 				if (splitlater)
997 					STPUTC('\0', expdest);
998 				else
999 					NEXTWORD('\0', flag, expdest, dst);
1000 			}
1001 		}
1002 		return;
1003 	default:
1004 		if (is_digit(*name)) {
1005 			num = atoi(name);
1006 			if (num == 0)
1007 				p = arg0;
1008 			else if (num > 0 && num <= shellparam.nparam)
1009 				p = shellparam.p[num - 1];
1010 			else
1011 				return;
1012 			strtodest(p, flag, subtype, quoted, dst);
1013 		}
1014 		return;
1015 	}
1016 	cvtnum(num, buf);
1017 	strtodest(buf, flag, subtype, quoted, dst);
1018 }
1019 
1020 
1021 
1022 static char expdir[PATH_MAX];
1023 #define expdir_end (expdir + sizeof(expdir))
1024 
1025 /*
1026  * Perform pathname generation and remove control characters.
1027  * At this point, the only control characters should be CTLESC.
1028  * The results are stored in the list dstlist.
1029  */
1030 static void
1031 expandmeta(char *pattern, struct arglist *dstlist)
1032 {
1033 	char *p;
1034 	int firstmatch;
1035 	char c;
1036 
1037 	firstmatch = dstlist->count;
1038 	p = pattern;
1039 	for (; (c = *p) != '\0'; p++) {
1040 		/* fast check for meta chars */
1041 		if (c == '*' || c == '?' || c == '[') {
1042 			INTOFF;
1043 			expmeta(expdir, pattern, dstlist);
1044 			INTON;
1045 			break;
1046 		}
1047 	}
1048 	if (dstlist->count == firstmatch) {
1049 		/*
1050 		 * no matches
1051 		 */
1052 		rmescapes(pattern);
1053 		appendarglist(dstlist, pattern);
1054 	} else {
1055 		qsort(&dstlist->args[firstmatch],
1056 		    dstlist->count - firstmatch,
1057 		    sizeof(dstlist->args[0]), expsortcmp);
1058 	}
1059 }
1060 
1061 
1062 /*
1063  * Do metacharacter (i.e. *, ?, [...]) expansion.
1064  */
1065 
1066 static void
1067 expmeta(char *enddir, char *name, struct arglist *arglist)
1068 {
1069 	const char *p;
1070 	const char *q;
1071 	const char *start;
1072 	char *endname;
1073 	int metaflag;
1074 	struct stat statb;
1075 	DIR *dirp;
1076 	struct dirent *dp;
1077 	int atend;
1078 	int matchdot;
1079 	int esc;
1080 	int namlen;
1081 
1082 	metaflag = 0;
1083 	start = name;
1084 	for (p = name; esc = 0, *p; p += esc + 1) {
1085 		if (*p == '*' || *p == '?')
1086 			metaflag = 1;
1087 		else if (*p == '[') {
1088 			q = p + 1;
1089 			if (*q == '!' || *q == '^')
1090 				q++;
1091 			for (;;) {
1092 				if (*q == CTLESC)
1093 					q++;
1094 				if (*q == '/' || *q == '\0')
1095 					break;
1096 				if (*++q == ']') {
1097 					metaflag = 1;
1098 					break;
1099 				}
1100 			}
1101 		} else if (*p == '\0')
1102 			break;
1103 		else {
1104 			if (*p == CTLESC)
1105 				esc++;
1106 			if (p[esc] == '/') {
1107 				if (metaflag)
1108 					break;
1109 				start = p + esc + 1;
1110 			}
1111 		}
1112 	}
1113 	if (metaflag == 0) {	/* we've reached the end of the file name */
1114 		if (enddir != expdir)
1115 			metaflag++;
1116 		for (p = name ; ; p++) {
1117 			if (*p == CTLESC)
1118 				p++;
1119 			*enddir++ = *p;
1120 			if (*p == '\0')
1121 				break;
1122 			if (enddir == expdir_end)
1123 				return;
1124 		}
1125 		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1126 			appendarglist(arglist, stsavestr(expdir));
1127 		return;
1128 	}
1129 	endname = name + (p - name);
1130 	if (start != name) {
1131 		p = name;
1132 		while (p < start) {
1133 			if (*p == CTLESC)
1134 				p++;
1135 			*enddir++ = *p++;
1136 			if (enddir == expdir_end)
1137 				return;
1138 		}
1139 	}
1140 	if (enddir == expdir) {
1141 		p = ".";
1142 	} else if (enddir == expdir + 1 && *expdir == '/') {
1143 		p = "/";
1144 	} else {
1145 		p = expdir;
1146 		enddir[-1] = '\0';
1147 	}
1148 	if ((dirp = opendir(p)) == NULL)
1149 		return;
1150 	if (enddir != expdir)
1151 		enddir[-1] = '/';
1152 	if (*endname == 0) {
1153 		atend = 1;
1154 	} else {
1155 		atend = 0;
1156 		*endname = '\0';
1157 		endname += esc + 1;
1158 	}
1159 	matchdot = 0;
1160 	p = start;
1161 	if (*p == CTLESC)
1162 		p++;
1163 	if (*p == '.')
1164 		matchdot++;
1165 	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1166 		if (dp->d_name[0] == '.' && ! matchdot)
1167 			continue;
1168 		if (patmatch(start, dp->d_name)) {
1169 			namlen = dp->d_namlen;
1170 			if (enddir + namlen + 1 > expdir_end)
1171 				continue;
1172 			memcpy(enddir, dp->d_name, namlen + 1);
1173 			if (atend)
1174 				appendarglist(arglist, stsavestr(expdir));
1175 			else {
1176 				if (dp->d_type != DT_UNKNOWN &&
1177 				    dp->d_type != DT_DIR &&
1178 				    dp->d_type != DT_LNK)
1179 					continue;
1180 				if (enddir + namlen + 2 > expdir_end)
1181 					continue;
1182 				enddir[namlen] = '/';
1183 				enddir[namlen + 1] = '\0';
1184 				expmeta(enddir + namlen + 1, endname, arglist);
1185 			}
1186 		}
1187 	}
1188 	closedir(dirp);
1189 	if (! atend)
1190 		endname[-esc - 1] = esc ? CTLESC : '/';
1191 }
1192 
1193 
1194 static int
1195 expsortcmp(const void *p1, const void *p2)
1196 {
1197 	const char *s1 = *(const char * const *)p1;
1198 	const char *s2 = *(const char * const *)p2;
1199 
1200 	return (strcoll(s1, s2));
1201 }
1202 
1203 
1204 
1205 static wchar_t
1206 get_wc(const char **p)
1207 {
1208 	wchar_t c;
1209 	int chrlen;
1210 
1211 	chrlen = mbtowc(&c, *p, 4);
1212 	if (chrlen == 0)
1213 		return 0;
1214 	else if (chrlen == -1)
1215 		c = 0;
1216 	else
1217 		*p += chrlen;
1218 	return c;
1219 }
1220 
1221 
1222 /*
1223  * See if a character matches a character class, starting at the first colon
1224  * of "[:class:]".
1225  * If a valid character class is recognized, a pointer to the next character
1226  * after the final closing bracket is stored into *end, otherwise a null
1227  * pointer is stored into *end.
1228  */
1229 static int
1230 match_charclass(const char *p, wchar_t chr, const char **end)
1231 {
1232 	char name[20];
1233 	const char *nameend;
1234 	wctype_t cclass;
1235 
1236 	*end = NULL;
1237 	p++;
1238 	nameend = strstr(p, ":]");
1239 	if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1240 	    nameend == p)
1241 		return 0;
1242 	memcpy(name, p, nameend - p);
1243 	name[nameend - p] = '\0';
1244 	*end = nameend + 2;
1245 	cclass = wctype(name);
1246 	/* An unknown class matches nothing but is valid nevertheless. */
1247 	if (cclass == 0)
1248 		return 0;
1249 	return iswctype(chr, cclass);
1250 }
1251 
1252 
1253 /*
1254  * Returns true if the pattern matches the string.
1255  */
1256 
1257 static int
1258 patmatch(const char *pattern, const char *string)
1259 {
1260 	const char *p, *q, *end;
1261 	const char *bt_p, *bt_q;
1262 	char c;
1263 	wchar_t wc, wc2;
1264 
1265 	p = pattern;
1266 	q = string;
1267 	bt_p = NULL;
1268 	bt_q = NULL;
1269 	for (;;) {
1270 		switch (c = *p++) {
1271 		case '\0':
1272 			if (*q != '\0')
1273 				goto backtrack;
1274 			return 1;
1275 		case CTLESC:
1276 			if (*q++ != *p++)
1277 				goto backtrack;
1278 			break;
1279 		case '?':
1280 			if (*q == '\0')
1281 				return 0;
1282 			if (localeisutf8) {
1283 				wc = get_wc(&q);
1284 				/*
1285 				 * A '?' does not match invalid UTF-8 but a
1286 				 * '*' does, so backtrack.
1287 				 */
1288 				if (wc == 0)
1289 					goto backtrack;
1290 			} else
1291 				q++;
1292 			break;
1293 		case '*':
1294 			c = *p;
1295 			while (c == '*')
1296 				c = *++p;
1297 			/*
1298 			 * If the pattern ends here, we know the string
1299 			 * matches without needing to look at the rest of it.
1300 			 */
1301 			if (c == '\0')
1302 				return 1;
1303 			/*
1304 			 * First try the shortest match for the '*' that
1305 			 * could work. We can forget any earlier '*' since
1306 			 * there is no way having it match more characters
1307 			 * can help us, given that we are already here.
1308 			 */
1309 			bt_p = p;
1310 			bt_q = q;
1311 			break;
1312 		case '[': {
1313 			const char *savep, *saveq;
1314 			int invert, found;
1315 			wchar_t chr;
1316 
1317 			savep = p, saveq = q;
1318 			invert = 0;
1319 			if (*p == '!' || *p == '^') {
1320 				invert++;
1321 				p++;
1322 			}
1323 			found = 0;
1324 			if (*q == '\0')
1325 				return 0;
1326 			if (localeisutf8) {
1327 				chr = get_wc(&q);
1328 				if (chr == 0)
1329 					goto backtrack;
1330 			} else
1331 				chr = (unsigned char)*q++;
1332 			c = *p++;
1333 			do {
1334 				if (c == '\0') {
1335 					p = savep, q = saveq;
1336 					c = '[';
1337 					goto dft;
1338 				}
1339 				if (c == '[' && *p == ':') {
1340 					found |= match_charclass(p, chr, &end);
1341 					if (end != NULL) {
1342 						p = end;
1343 						continue;
1344 					}
1345 				}
1346 				if (c == CTLESC)
1347 					c = *p++;
1348 				if (localeisutf8 && c & 0x80) {
1349 					p--;
1350 					wc = get_wc(&p);
1351 					if (wc == 0) /* bad utf-8 */
1352 						return 0;
1353 				} else
1354 					wc = (unsigned char)c;
1355 				if (*p == '-' && p[1] != ']') {
1356 					p++;
1357 					if (*p == CTLESC)
1358 						p++;
1359 					if (localeisutf8) {
1360 						wc2 = get_wc(&p);
1361 						if (wc2 == 0) /* bad utf-8 */
1362 							return 0;
1363 					} else
1364 						wc2 = (unsigned char)*p++;
1365 					if (   collate_range_cmp(chr, wc) >= 0
1366 					    && collate_range_cmp(chr, wc2) <= 0
1367 					   )
1368 						found = 1;
1369 				} else {
1370 					if (chr == wc)
1371 						found = 1;
1372 				}
1373 			} while ((c = *p++) != ']');
1374 			if (found == invert)
1375 				goto backtrack;
1376 			break;
1377 		}
1378 dft:	        default:
1379 			if (*q == '\0')
1380 				return 0;
1381 			if (*q++ == c)
1382 				break;
1383 backtrack:
1384 			/*
1385 			 * If we have a mismatch (other than hitting the end
1386 			 * of the string), go back to the last '*' seen and
1387 			 * have it match one additional character.
1388 			 */
1389 			if (bt_p == NULL)
1390 				return 0;
1391 			if (*bt_q == '\0')
1392 				return 0;
1393 			bt_q++;
1394 			p = bt_p;
1395 			q = bt_q;
1396 			break;
1397 		}
1398 	}
1399 }
1400 
1401 
1402 
1403 /*
1404  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1405  */
1406 
1407 void
1408 rmescapes(char *str)
1409 {
1410 	char *p, *q;
1411 
1412 	p = str;
1413 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1414 		if (*p++ == '\0')
1415 			return;
1416 	}
1417 	q = p;
1418 	while (*p) {
1419 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1420 			p++;
1421 			continue;
1422 		}
1423 		if (*p == CTLESC)
1424 			p++;
1425 		*q++ = *p++;
1426 	}
1427 	*q = '\0';
1428 }
1429 
1430 
1431 
1432 /*
1433  * See if a pattern matches in a case statement.
1434  */
1435 
1436 int
1437 casematch(union node *pattern, const char *val)
1438 {
1439 	struct stackmark smark;
1440 	struct nodelist *argbackq;
1441 	int result;
1442 	char *p;
1443 
1444 	setstackmark(&smark);
1445 	argbackq = pattern->narg.backquote;
1446 	STARTSTACKSTR(expdest);
1447 	argstr(pattern->narg.text, &argbackq, EXP_TILDE | EXP_CASE, NULL);
1448 	STPUTC('\0', expdest);
1449 	p = grabstackstr(expdest);
1450 	result = patmatch(p, val);
1451 	popstackmark(&smark);
1452 	return result;
1453 }
1454 
1455 /*
1456  * Our own itoa().
1457  */
1458 
1459 static void
1460 cvtnum(int num, char *buf)
1461 {
1462 	char temp[32];
1463 	int neg = num < 0;
1464 	char *p = temp + 31;
1465 
1466 	temp[31] = '\0';
1467 
1468 	do {
1469 		*--p = num % 10 + '0';
1470 	} while ((num /= 10) != 0);
1471 
1472 	if (neg)
1473 		*--p = '-';
1474 
1475 	memcpy(buf, p, temp + 32 - p);
1476 }
1477 
1478 /*
1479  * Do most of the work for wordexp(3).
1480  */
1481 
1482 int
1483 wordexpcmd(int argc, char **argv)
1484 {
1485 	size_t len;
1486 	int i;
1487 
1488 	out1fmt("%08x", argc - 1);
1489 	for (i = 1, len = 0; i < argc; i++)
1490 		len += strlen(argv[i]);
1491 	out1fmt("%08x", (int)len);
1492 	for (i = 1; i < argc; i++)
1493 		outbin(argv[i], strlen(argv[i]) + 1, out1);
1494         return (0);
1495 }
1496 
1497 /*
1498  * Do most of the work for wordexp(3), new version.
1499  */
1500 
1501 int
1502 freebsd_wordexpcmd(int argc __unused, char **argv __unused)
1503 {
1504 	struct arglist arglist;
1505 	union node *args, *n;
1506 	size_t len;
1507 	int ch;
1508 	int protected = 0;
1509 	int fd = -1;
1510 	int i;
1511 
1512 	while ((ch = nextopt("f:p")) != '\0') {
1513 		switch (ch) {
1514 		case 'f':
1515 			fd = number(shoptarg);
1516 			break;
1517 		case 'p':
1518 			protected = 1;
1519 			break;
1520 		}
1521 	}
1522 	if (*argptr != NULL)
1523 		error("wrong number of arguments");
1524 	if (fd < 0)
1525 		error("missing fd");
1526 	INTOFF;
1527 	setinputfd(fd, 1);
1528 	INTON;
1529 	args = parsewordexp();
1530 	popfile(); /* will also close fd */
1531 	if (protected)
1532 		for (n = args; n != NULL; n = n->narg.next) {
1533 			if (n->narg.backquote != NULL) {
1534 				outcslow('C', out1);
1535 				error("command substitution disabled");
1536 			}
1537 		}
1538 	outcslow(' ', out1);
1539 	emptyarglist(&arglist);
1540 	for (n = args; n != NULL; n = n->narg.next)
1541 		expandarg(n, &arglist, EXP_FULL | EXP_TILDE);
1542 	for (i = 0, len = 0; i < arglist.count; i++)
1543 		len += strlen(arglist.args[i]);
1544 	out1fmt("%016x %016zx", arglist.count, len);
1545 	for (i = 0; i < arglist.count; i++)
1546 		outbin(arglist.args[i], strlen(arglist.args[i]) + 1, out1);
1547 	return (0);
1548 }
1549