xref: /freebsd/bin/sh/expand.c (revision 83d9fd40d5cb67ff1e805523a6fae48c3389f396)
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 void subevalvar_trim(const char *, struct nodelist *, int, int, int);
100 static int subevalvar_misc(const char *, struct nodelist *, const char *, int,
101     int, int);
102 static const char *evalvar(const char *, struct nodelist **restrict, int,
103     struct worddest *);
104 static int varisset(const char *, int);
105 static void strtodest(const char *, int, int, int, struct worddest *);
106 static void reprocess(int, int, int, int, struct worddest *);
107 static void varvalue(const char *, int, int, int, struct worddest *);
108 static void expandmeta(char *, struct arglist *);
109 static void expmeta(char *, char *, struct arglist *);
110 static int expsortcmp(const void *, const void *);
111 static int patmatch(const char *, const char *);
112 static void cvtnum(int, char *);
113 static int collate_range_cmp(wchar_t, wchar_t);
114 
115 void
116 emptyarglist(struct arglist *list)
117 {
118 
119 	list->args = list->smallarg;
120 	list->count = 0;
121 	list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
122 }
123 
124 void
125 appendarglist(struct arglist *list, char *str)
126 {
127 	char **newargs;
128 	int newcapacity;
129 
130 	if (list->count >= list->capacity) {
131 		newcapacity = list->capacity * 2;
132 		if (newcapacity < 16)
133 			newcapacity = 16;
134 		if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
135 			error("Too many entries in arglist");
136 		newargs = stalloc(newcapacity * sizeof(newargs[0]));
137 		memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
138 		list->args = newargs;
139 		list->capacity = newcapacity;
140 	}
141 	list->args[list->count++] = str;
142 }
143 
144 static int
145 collate_range_cmp(wchar_t c1, wchar_t c2)
146 {
147 	static wchar_t s1[2], s2[2];
148 
149 	s1[0] = c1;
150 	s2[0] = c2;
151 	return (wcscoll(s1, s2));
152 }
153 
154 static char *
155 stputs_quotes(const char *data, const char *syntax, char *p)
156 {
157 	while (*data) {
158 		CHECKSTRSPACE(2, p);
159 		if (syntax[(int)*data] == CCTL)
160 			USTPUTC(CTLESC, p);
161 		USTPUTC(*data++, p);
162 	}
163 	return (p);
164 }
165 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
166 
167 static char *
168 nextword(char c, int flag, char *p, struct worddest *dst)
169 {
170 	int is_ws;
171 
172 	is_ws = c == '\t' || c == '\n' || c == ' ';
173 	if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
174 	    dst->state != WORD_WS_DELIMITED) || c == '\0') {
175 		STPUTC('\0', p);
176 		if (flag & EXP_GLOB)
177 			expandmeta(grabstackstr(p), dst->list);
178 		else
179 			appendarglist(dst->list, grabstackstr(p));
180 		dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
181 	} else if (!is_ws && dst->state == WORD_WS_DELIMITED)
182 		dst->state = WORD_IDLE;
183 	/* Reserve space while the stack string is empty. */
184 	appendarglist(dst->list, NULL);
185 	dst->list->count--;
186 	STARTSTACKSTR(p);
187 	return p;
188 }
189 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
190 
191 static char *
192 stputs_split(const char *data, const char *syntax, int flag, char *p,
193     struct worddest *dst)
194 {
195 	const char *ifs;
196 	char c;
197 
198 	ifs = ifsset() ? ifsval() : " \t\n";
199 	while (*data) {
200 		CHECKSTRSPACE(2, p);
201 		c = *data++;
202 		if (strchr(ifs, c) != NULL) {
203 			NEXTWORD(c, flag, p, dst);
204 			continue;
205 		}
206 		if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
207 			USTPUTC(CTLESC, p);
208 		USTPUTC(c, p);
209 	}
210 	return (p);
211 }
212 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
213 
214 /*
215  * Perform expansions on an argument, placing the resulting list of arguments
216  * in arglist.  Parameter expansion, command substitution and arithmetic
217  * expansion are always performed; additional expansions can be requested
218  * via flag (EXP_*).
219  * The result is left in the stack string.
220  * When arglist is NULL, perform here document expansion.
221  *
222  * Caution: this function uses global state and is not reentrant.
223  * However, a new invocation after an interrupted invocation is safe
224  * and will reset the global state for the new call.
225  */
226 void
227 expandarg(union node *arg, struct arglist *arglist, int flag)
228 {
229 	struct worddest exparg;
230 	struct nodelist *argbackq;
231 
232 	if (fflag)
233 		flag &= ~EXP_GLOB;
234 	argbackq = arg->narg.backquote;
235 	exparg.list = arglist;
236 	exparg.state = WORD_IDLE;
237 	STARTSTACKSTR(expdest);
238 	argstr(arg->narg.text, &argbackq, flag, &exparg);
239 	if (arglist == NULL) {
240 		STACKSTRNUL(expdest);
241 		return;			/* here document expanded */
242 	}
243 	if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
244 	    exparg.state == WORD_QUOTEMARK) {
245 		STPUTC('\0', expdest);
246 		if (flag & EXP_SPLIT) {
247 			if (flag & EXP_GLOB)
248 				expandmeta(grabstackstr(expdest), exparg.list);
249 			else
250 				appendarglist(exparg.list, grabstackstr(expdest));
251 		}
252 	}
253 	if ((flag & EXP_SPLIT) == 0)
254 		appendarglist(arglist, grabstackstr(expdest));
255 }
256 
257 
258 
259 /*
260  * Perform parameter expansion, command substitution and arithmetic
261  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
262  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
263  * This is used to expand word in ${var+word} etc.
264  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
265  * characters to allow for further processing.
266  *
267  * If EXP_SPLIT is set, dst receives any complete words produced.
268  */
269 static const char *
270 argstr(const char *p, struct nodelist **restrict argbackq, int flag,
271     struct worddest *dst)
272 {
273 	char c;
274 	int quotes = flag & (EXP_GLOB | EXP_CASE);	/* do CTLESC */
275 	int firsteq = 1;
276 	int split_lit;
277 	int lit_quoted;
278 
279 	split_lit = flag & EXP_SPLIT_LIT;
280 	lit_quoted = flag & EXP_LIT_QUOTED;
281 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
282 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
283 		p = exptilde(p, flag);
284 	for (;;) {
285 		CHECKSTRSPACE(2, expdest);
286 		switch (c = *p++) {
287 		case '\0':
288 			return (p - 1);
289 		case CTLENDVAR:
290 		case CTLENDARI:
291 			return (p);
292 		case CTLQUOTEMARK:
293 			lit_quoted = 1;
294 			/* "$@" syntax adherence hack */
295 			if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
296 			    p[2] == '@' && p[3] == '=')
297 				break;
298 			if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
299 				dst->state = WORD_QUOTEMARK;
300 			break;
301 		case CTLQUOTEEND:
302 			lit_quoted = 0;
303 			break;
304 		case CTLESC:
305 			c = *p++;
306 			if (split_lit && !lit_quoted &&
307 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
308 				NEXTWORD(c, flag, expdest, dst);
309 				break;
310 			}
311 			if (quotes)
312 				USTPUTC(CTLESC, expdest);
313 			USTPUTC(c, expdest);
314 			break;
315 		case CTLVAR:
316 			p = evalvar(p, argbackq, flag, dst);
317 			break;
318 		case CTLBACKQ:
319 		case CTLBACKQ|CTLQUOTE:
320 			expbackq((*argbackq)->n, c & CTLQUOTE, flag, dst);
321 			*argbackq = (*argbackq)->next;
322 			break;
323 		case CTLARI:
324 			p = expari(p, argbackq, flag, dst);
325 			break;
326 		case ':':
327 		case '=':
328 			/*
329 			 * sort of a hack - expand tildes in variable
330 			 * assignments (after the first '=' and after ':'s).
331 			 */
332 			if (split_lit && !lit_quoted &&
333 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
334 				NEXTWORD(c, flag, expdest, dst);
335 				break;
336 			}
337 			USTPUTC(c, expdest);
338 			if (flag & EXP_VARTILDE && *p == '~' &&
339 			    (c != '=' || firsteq)) {
340 				if (c == '=')
341 					firsteq = 0;
342 				p = exptilde(p, flag);
343 			}
344 			break;
345 		default:
346 			if (split_lit && !lit_quoted &&
347 			    strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
348 				NEXTWORD(c, flag, expdest, dst);
349 				break;
350 			}
351 			USTPUTC(c, expdest);
352 		}
353 	}
354 }
355 
356 /*
357  * Perform tilde expansion, placing the result in the stack string and
358  * returning the next position in the input string to process.
359  */
360 static const char *
361 exptilde(const char *p, int flag)
362 {
363 	char c;
364 	const char *startp = p;
365 	const char *user;
366 	struct passwd *pw;
367 	char *home;
368 	int len;
369 
370 	for (;;) {
371 		c = *p;
372 		switch(c) {
373 		case CTLESC: /* This means CTL* are always considered quoted. */
374 		case CTLVAR:
375 		case CTLBACKQ:
376 		case CTLBACKQ | CTLQUOTE:
377 		case CTLARI:
378 		case CTLENDARI:
379 		case CTLQUOTEMARK:
380 			return (startp);
381 		case ':':
382 			if ((flag & EXP_VARTILDE) == 0)
383 				break;
384 			/* FALLTHROUGH */
385 		case '\0':
386 		case '/':
387 		case CTLENDVAR:
388 			len = p - startp - 1;
389 			STPUTBIN(startp + 1, len, expdest);
390 			STACKSTRNUL(expdest);
391 			user = expdest - len;
392 			if (*user == '\0') {
393 				home = lookupvar("HOME");
394 			} else {
395 				pw = getpwnam(user);
396 				home = pw != NULL ? pw->pw_dir : NULL;
397 			}
398 			STADJUST(-len, expdest);
399 			if (home == NULL || *home == '\0')
400 				return (startp);
401 			strtodest(home, flag, VSNORMAL, 1, NULL);
402 			return (p);
403 		}
404 		p++;
405 	}
406 }
407 
408 
409 /*
410  * Expand arithmetic expression.
411  */
412 static const char *
413 expari(const char *p, struct nodelist **restrict argbackq, int flag,
414     struct worddest *dst)
415 {
416 	char *q, *start;
417 	arith_t result;
418 	int begoff;
419 	int quoted;
420 	int adj;
421 
422 	quoted = *p++ == '"';
423 	begoff = expdest - stackblock();
424 	p = argstr(p, argbackq, 0, NULL);
425 	STPUTC('\0', expdest);
426 	start = stackblock() + begoff;
427 
428 	q = grabstackstr(expdest);
429 	result = arith(start);
430 	ungrabstackstr(q, expdest);
431 
432 	start = stackblock() + begoff;
433 	adj = start - expdest;
434 	STADJUST(adj, expdest);
435 
436 	CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
437 	fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
438 	adj = strlen(expdest);
439 	STADJUST(adj, expdest);
440 	if (!quoted)
441 		reprocess(expdest - adj - stackblock(), flag, VSNORMAL, 0, dst);
442 	return p;
443 }
444 
445 
446 /*
447  * Perform command substitution.
448  */
449 static void
450 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
451 {
452 	struct backcmd in;
453 	int i;
454 	char buf[128];
455 	char *p;
456 	char *dest = expdest;
457 	char lastc;
458 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
459 	int quotes = flag & (EXP_GLOB | EXP_CASE);
460 	size_t nnl;
461 	const char *ifs;
462 
463 	INTOFF;
464 	p = grabstackstr(dest);
465 	evalbackcmd(cmd, &in);
466 	ungrabstackstr(p, dest);
467 
468 	p = in.buf;
469 	nnl = 0;
470 	if (!quoted && flag & EXP_SPLIT)
471 		ifs = ifsset() ? ifsval() : " \t\n";
472 	else
473 		ifs = "";
474 	/* Don't copy trailing newlines */
475 	for (;;) {
476 		if (--in.nleft < 0) {
477 			if (in.fd < 0)
478 				break;
479 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
480 				;
481 			TRACE(("expbackq: read returns %d\n", i));
482 			if (i <= 0)
483 				break;
484 			p = buf;
485 			in.nleft = i - 1;
486 		}
487 		lastc = *p++;
488 		if (lastc == '\0')
489 			continue;
490 		if (lastc == '\n') {
491 			nnl++;
492 		} else {
493 			if (nnl > 0) {
494 				if (strchr(ifs, '\n') != NULL) {
495 					NEXTWORD('\n', flag, dest, dst);
496 					nnl = 0;
497 				} else {
498 					CHECKSTRSPACE(nnl + 2, dest);
499 					while (nnl > 0) {
500 						nnl--;
501 						USTPUTC('\n', dest);
502 					}
503 				}
504 			}
505 			if (strchr(ifs, lastc) != NULL)
506 				NEXTWORD(lastc, flag, dest, dst);
507 			else {
508 				CHECKSTRSPACE(2, dest);
509 				if (quotes && syntax[(int)lastc] == CCTL)
510 					USTPUTC(CTLESC, dest);
511 				USTPUTC(lastc, dest);
512 			}
513 		}
514 	}
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: size=%td: \"%.*s\"\n",
526 		((dest - stackblock()) - startloc),
527 		(int)((dest - stackblock()) - startloc),
528 		stackblock() + startloc));
529 	expdest = dest;
530 	INTON;
531 }
532 
533 
534 
535 static void
536 recordleft(const char *str, const char *loc, char *startp)
537 {
538 	int amount;
539 
540 	amount = ((str - 1) - (loc - startp)) - expdest;
541 	STADJUST(amount, expdest);
542 	while (loc != str - 1)
543 		*startp++ = *loc++;
544 }
545 
546 static void
547 subevalvar_trim(const char *p, struct nodelist *argbackq, int strloc,
548     int subtype, int startloc)
549 {
550 	char *startp;
551 	char *loc = NULL;
552 	char *str;
553 	int c = 0;
554 	struct nodelist *argbackqcopy = argbackq;
555 	int amount;
556 
557 	argstr(p, &argbackqcopy, EXP_CASE | EXP_TILDE, NULL);
558 	STACKSTRNUL(expdest);
559 	startp = stackblock() + startloc;
560 	str = stackblock() + strloc;
561 
562 	switch (subtype) {
563 	case VSTRIMLEFT:
564 		for (loc = startp; loc < str; loc++) {
565 			c = *loc;
566 			*loc = '\0';
567 			if (patmatch(str, startp)) {
568 				*loc = c;
569 				recordleft(str, loc, startp);
570 				return;
571 			}
572 			*loc = c;
573 		}
574 		break;
575 
576 	case VSTRIMLEFTMAX:
577 		for (loc = str - 1; loc >= startp;) {
578 			c = *loc;
579 			*loc = '\0';
580 			if (patmatch(str, startp)) {
581 				*loc = c;
582 				recordleft(str, loc, startp);
583 				return;
584 			}
585 			*loc = c;
586 			loc--;
587 		}
588 		break;
589 
590 	case VSTRIMRIGHT:
591 		for (loc = str - 1; loc >= startp;) {
592 			if (patmatch(str, loc)) {
593 				amount = loc - expdest;
594 				STADJUST(amount, expdest);
595 				return;
596 			}
597 			loc--;
598 		}
599 		break;
600 
601 	case VSTRIMRIGHTMAX:
602 		for (loc = startp; loc < str - 1; loc++) {
603 			if (patmatch(str, loc)) {
604 				amount = loc - expdest;
605 				STADJUST(amount, expdest);
606 				return;
607 			}
608 		}
609 		break;
610 
611 
612 	default:
613 		abort();
614 	}
615 	amount = (expdest - stackblock() - strloc) + 1;
616 	STADJUST(-amount, expdest);
617 }
618 
619 
620 static int
621 subevalvar_misc(const char *p, struct nodelist *argbackq, const char *var, int subtype, int startloc,
622   int varflags)
623 {
624 	char *startp;
625 	struct nodelist *argbackqcopy = argbackq;
626 	int amount;
627 
628 	argstr(p, &argbackqcopy, EXP_TILDE, NULL);
629 	STACKSTRNUL(expdest);
630 	startp = stackblock() + startloc;
631 
632 	switch (subtype) {
633 	case VSASSIGN:
634 		setvar(var, startp, 0);
635 		amount = startp - expdest;
636 		STADJUST(amount, expdest);
637 		return 1;
638 
639 	case VSQUESTION:
640 		if (*p != CTLENDVAR) {
641 			outfmt(out2, "%s\n", startp);
642 			error((char *)NULL);
643 		}
644 		error("%.*s: parameter %snot set", (int)(p - var - 1),
645 		      var, (varflags & VSNUL) ? "null or " : "");
646 		return 0;
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 again: /* jump here after setting a variable with ${var=text} */
684 	if (varflags & VSLINENO) {
685 		set = 1;
686 		special = 1;
687 		val = NULL;
688 	} else if (special) {
689 		set = varisset(var, varflags & VSNUL);
690 		val = NULL;
691 	} else {
692 		val = bltinlookup(var, 1);
693 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
694 			val = NULL;
695 			set = 0;
696 		} else
697 			set = 1;
698 	}
699 	varlen = 0;
700 	startloc = expdest - stackblock();
701 	if (!set && uflag && *var != '@' && *var != '*') {
702 		switch (subtype) {
703 		case VSNORMAL:
704 		case VSTRIMLEFT:
705 		case VSTRIMLEFTMAX:
706 		case VSTRIMRIGHT:
707 		case VSTRIMRIGHTMAX:
708 		case VSLENGTH:
709 			error("%.*s: parameter not set", (int)(p - var - 1),
710 			    var);
711 		}
712 	}
713 	if (set && subtype != VSPLUS) {
714 		/* insert the value of the variable */
715 		if (special) {
716 			if (varflags & VSLINENO) {
717 				if (p - var > (ptrdiff_t)sizeof(buf))
718 					abort();
719 				memcpy(buf, var, p - var - 1);
720 				buf[p - var - 1] = '\0';
721 				strtodest(buf, flag, subtype,
722 				    varflags & VSQUOTE, dst);
723 			} else
724 				varvalue(var, varflags & VSQUOTE, subtype, flag,
725 				    dst);
726 			if (subtype == VSLENGTH) {
727 				varlenb = expdest - stackblock() - startloc;
728 				varlen = varlenb;
729 				if (localeisutf8) {
730 					val = stackblock() + startloc;
731 					for (;val != expdest; val++)
732 						if ((*val & 0xC0) == 0x80)
733 							varlen--;
734 				}
735 				STADJUST(-varlenb, expdest);
736 			}
737 		} else {
738 			if (subtype == VSLENGTH) {
739 				for (;*val; val++)
740 					if (!localeisutf8 ||
741 					    (*val & 0xC0) != 0x80)
742 						varlen++;
743 			}
744 			else
745 				strtodest(val, flag, subtype,
746 				    varflags & VSQUOTE, dst);
747 		}
748 	}
749 
750 	if (subtype == VSPLUS)
751 		set = ! set;
752 
753 	switch (subtype) {
754 	case VSLENGTH:
755 		cvtnum(varlen, buf);
756 		strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
757 		break;
758 
759 	case VSNORMAL:
760 		break;
761 
762 	case VSPLUS:
763 	case VSMINUS:
764 		if (!set) {
765 			argstr(p, argbackq,
766 			    flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
767 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
768 			break;
769 		}
770 		break;
771 
772 	case VSTRIMLEFT:
773 	case VSTRIMLEFTMAX:
774 	case VSTRIMRIGHT:
775 	case VSTRIMRIGHTMAX:
776 		if (!set) {
777 			set = 1;
778 			break;
779 		}
780 		/*
781 		 * Terminate the string and start recording the pattern
782 		 * right after it
783 		 */
784 		STPUTC('\0', expdest);
785 		patloc = expdest - stackblock();
786 		subevalvar_trim(p, *argbackq, patloc, subtype, startloc);
787 		reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
788 		if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
789 			dst->state = WORD_QUOTEMARK;
790 		break;
791 
792 	case VSASSIGN:
793 	case VSQUESTION:
794 		if (!set) {
795 			if (subevalvar_misc(p, *argbackq, var, subtype,
796 			    startloc, varflags)) {
797 				varflags &= ~VSNUL;
798 				goto again;
799 			}
800 			break;
801 		}
802 		break;
803 
804 	case VSERROR:
805 		c = p - var - 1;
806 		error("${%.*s%s}: Bad substitution", c, var,
807 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
808 
809 	default:
810 		abort();
811 	}
812 
813 	if (subtype != VSNORMAL) {	/* skip to end of alternative */
814 		int nesting = 1;
815 		for (;;) {
816 			if ((c = *p++) == CTLESC)
817 				p++;
818 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
819 				if (set)
820 					*argbackq = (*argbackq)->next;
821 			} else if (c == CTLVAR) {
822 				if ((*p++ & VSTYPE) != VSNORMAL)
823 					nesting++;
824 			} else if (c == CTLENDVAR) {
825 				if (--nesting == 0)
826 					break;
827 			}
828 		}
829 	}
830 	return p;
831 }
832 
833 
834 
835 /*
836  * Test whether a specialized variable is set.
837  */
838 
839 static int
840 varisset(const char *name, int nulok)
841 {
842 
843 	if (*name == '!')
844 		return backgndpidset();
845 	else if (*name == '@' || *name == '*') {
846 		if (*shellparam.p == NULL)
847 			return 0;
848 
849 		if (nulok) {
850 			char **av;
851 
852 			for (av = shellparam.p; *av; av++)
853 				if (**av != '\0')
854 					return 1;
855 			return 0;
856 		}
857 	} else if (is_digit(*name)) {
858 		char *ap;
859 		long num;
860 
861 		errno = 0;
862 		num = strtol(name, NULL, 10);
863 		if (errno != 0 || num > shellparam.nparam)
864 			return 0;
865 
866 		if (num == 0)
867 			ap = arg0;
868 		else
869 			ap = shellparam.p[num - 1];
870 
871 		if (nulok && (ap == NULL || *ap == '\0'))
872 			return 0;
873 	}
874 	return 1;
875 }
876 
877 static void
878 strtodest(const char *p, int flag, int subtype, int quoted,
879     struct worddest *dst)
880 {
881 	if (subtype == VSLENGTH || subtype == VSTRIMLEFT ||
882 	    subtype == VSTRIMLEFTMAX || subtype == VSTRIMRIGHT ||
883 	    subtype == VSTRIMRIGHTMAX)
884 		STPUTS(p, expdest);
885 	else if (flag & EXP_SPLIT && !quoted && dst != NULL)
886 		STPUTS_SPLIT(p, BASESYNTAX, flag, expdest, dst);
887 	else if (flag & (EXP_GLOB | EXP_CASE))
888 		STPUTS_QUOTES(p, quoted ? DQSYNTAX : BASESYNTAX, expdest);
889 	else
890 		STPUTS(p, expdest);
891 }
892 
893 static void
894 reprocess(int startloc, int flag, int subtype, int quoted,
895     struct worddest *dst)
896 {
897 	static char *buf = NULL;
898 	static size_t buflen = 0;
899 	char *startp;
900 	size_t len, zpos, zlen;
901 
902 	startp = stackblock() + startloc;
903 	len = expdest - startp;
904 	if (len >= SIZE_MAX / 2)
905 		abort();
906 	INTOFF;
907 	if (len >= buflen) {
908 		ckfree(buf);
909 		buf = NULL;
910 	}
911 	if (buflen < 128)
912 		buflen = 128;
913 	while (len >= buflen)
914 		buflen <<= 1;
915 	if (buf == NULL)
916 		buf = ckmalloc(buflen);
917 	INTON;
918 	memcpy(buf, startp, len);
919 	buf[len] = '\0';
920 	STADJUST(-len, expdest);
921 	for (zpos = 0;;) {
922 		zlen = strlen(buf + zpos);
923 		strtodest(buf + zpos, flag, subtype, quoted, dst);
924 		zpos += zlen + 1;
925 		if (zpos == len + 1)
926 			break;
927 		if (flag & EXP_SPLIT && (quoted || (zlen > 0 && zpos < len)))
928 			NEXTWORD('\0', flag, expdest, dst);
929 	}
930 }
931 
932 /*
933  * Add the value of a specialized variable to the stack string.
934  */
935 
936 static void
937 varvalue(const char *name, int quoted, int subtype, int flag,
938     struct worddest *dst)
939 {
940 	int num;
941 	char *p;
942 	int i;
943 	int splitlater;
944 	char sep[2];
945 	char **ap;
946 	char buf[(NSHORTOPTS > 10 ? NSHORTOPTS : 10) + 1];
947 
948 	if (subtype == VSLENGTH)
949 		flag &= ~EXP_FULL;
950 	splitlater = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX ||
951 		subtype == VSTRIMRIGHT || subtype == VSTRIMRIGHTMAX;
952 
953 	switch (*name) {
954 	case '$':
955 		num = rootpid;
956 		break;
957 	case '?':
958 		num = oexitstatus;
959 		break;
960 	case '#':
961 		num = shellparam.nparam;
962 		break;
963 	case '!':
964 		num = backgndpidval();
965 		break;
966 	case '-':
967 		p = buf;
968 		for (i = 0 ; i < NSHORTOPTS ; i++) {
969 			if (optval[i])
970 				*p++ = optletter[i];
971 		}
972 		*p = '\0';
973 		strtodest(buf, flag, subtype, quoted, dst);
974 		return;
975 	case '@':
976 		if (flag & EXP_SPLIT && quoted) {
977 			for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
978 				strtodest(p, flag, subtype, quoted, dst);
979 				if (*ap) {
980 					if (splitlater)
981 						STPUTC('\0', expdest);
982 					else
983 						NEXTWORD('\0', flag, expdest,
984 						    dst);
985 				}
986 			}
987 			if (shellparam.nparam > 0)
988 				dst->state = WORD_QUOTEMARK;
989 			return;
990 		}
991 		/* FALLTHROUGH */
992 	case '*':
993 		if (ifsset())
994 			sep[0] = ifsval()[0];
995 		else
996 			sep[0] = ' ';
997 		sep[1] = '\0';
998 		for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
999 			strtodest(p, flag, subtype, quoted, dst);
1000 			if (!*ap)
1001 				break;
1002 			if (sep[0])
1003 				strtodest(sep, flag, subtype, quoted, dst);
1004 			else if (flag & EXP_SPLIT && !quoted && **ap != '\0') {
1005 				if (splitlater)
1006 					STPUTC('\0', expdest);
1007 				else
1008 					NEXTWORD('\0', flag, expdest, dst);
1009 			}
1010 		}
1011 		return;
1012 	default:
1013 		if (is_digit(*name)) {
1014 			num = atoi(name);
1015 			if (num == 0)
1016 				p = arg0;
1017 			else if (num > 0 && num <= shellparam.nparam)
1018 				p = shellparam.p[num - 1];
1019 			else
1020 				return;
1021 			strtodest(p, flag, subtype, quoted, dst);
1022 		}
1023 		return;
1024 	}
1025 	cvtnum(num, buf);
1026 	strtodest(buf, flag, subtype, quoted, dst);
1027 }
1028 
1029 
1030 
1031 static char expdir[PATH_MAX];
1032 #define expdir_end (expdir + sizeof(expdir))
1033 
1034 /*
1035  * Perform pathname generation and remove control characters.
1036  * At this point, the only control characters should be CTLESC.
1037  * The results are stored in the list dstlist.
1038  */
1039 static void
1040 expandmeta(char *pattern, struct arglist *dstlist)
1041 {
1042 	char *p;
1043 	int firstmatch;
1044 	char c;
1045 
1046 	firstmatch = dstlist->count;
1047 	p = pattern;
1048 	for (; (c = *p) != '\0'; p++) {
1049 		/* fast check for meta chars */
1050 		if (c == '*' || c == '?' || c == '[') {
1051 			INTOFF;
1052 			expmeta(expdir, pattern, dstlist);
1053 			INTON;
1054 			break;
1055 		}
1056 	}
1057 	if (dstlist->count == firstmatch) {
1058 		/*
1059 		 * no matches
1060 		 */
1061 		rmescapes(pattern);
1062 		appendarglist(dstlist, pattern);
1063 	} else {
1064 		qsort(&dstlist->args[firstmatch],
1065 		    dstlist->count - firstmatch,
1066 		    sizeof(dstlist->args[0]), expsortcmp);
1067 	}
1068 }
1069 
1070 
1071 /*
1072  * Do metacharacter (i.e. *, ?, [...]) expansion.
1073  */
1074 
1075 static void
1076 expmeta(char *enddir, char *name, struct arglist *arglist)
1077 {
1078 	const char *p;
1079 	const char *q;
1080 	const char *start;
1081 	char *endname;
1082 	int metaflag;
1083 	struct stat statb;
1084 	DIR *dirp;
1085 	struct dirent *dp;
1086 	int atend;
1087 	int matchdot;
1088 	int esc;
1089 	int namlen;
1090 
1091 	metaflag = 0;
1092 	start = name;
1093 	for (p = name; esc = 0, *p; p += esc + 1) {
1094 		if (*p == '*' || *p == '?')
1095 			metaflag = 1;
1096 		else if (*p == '[') {
1097 			q = p + 1;
1098 			if (*q == '!' || *q == '^')
1099 				q++;
1100 			for (;;) {
1101 				if (*q == CTLESC)
1102 					q++;
1103 				if (*q == '/' || *q == '\0')
1104 					break;
1105 				if (*++q == ']') {
1106 					metaflag = 1;
1107 					break;
1108 				}
1109 			}
1110 		} else if (*p == '\0')
1111 			break;
1112 		else {
1113 			if (*p == CTLESC)
1114 				esc++;
1115 			if (p[esc] == '/') {
1116 				if (metaflag)
1117 					break;
1118 				start = p + esc + 1;
1119 			}
1120 		}
1121 	}
1122 	if (metaflag == 0) {	/* we've reached the end of the file name */
1123 		if (enddir != expdir)
1124 			metaflag++;
1125 		for (p = name ; ; p++) {
1126 			if (*p == CTLESC)
1127 				p++;
1128 			*enddir++ = *p;
1129 			if (*p == '\0')
1130 				break;
1131 			if (enddir == expdir_end)
1132 				return;
1133 		}
1134 		if (metaflag == 0 || lstat(expdir, &statb) >= 0)
1135 			appendarglist(arglist, stsavestr(expdir));
1136 		return;
1137 	}
1138 	endname = name + (p - name);
1139 	if (start != name) {
1140 		p = name;
1141 		while (p < start) {
1142 			if (*p == CTLESC)
1143 				p++;
1144 			*enddir++ = *p++;
1145 			if (enddir == expdir_end)
1146 				return;
1147 		}
1148 	}
1149 	if (enddir == expdir) {
1150 		p = ".";
1151 	} else if (enddir == expdir + 1 && *expdir == '/') {
1152 		p = "/";
1153 	} else {
1154 		p = expdir;
1155 		enddir[-1] = '\0';
1156 	}
1157 	if ((dirp = opendir(p)) == NULL)
1158 		return;
1159 	if (enddir != expdir)
1160 		enddir[-1] = '/';
1161 	if (*endname == 0) {
1162 		atend = 1;
1163 	} else {
1164 		atend = 0;
1165 		*endname = '\0';
1166 		endname += esc + 1;
1167 	}
1168 	matchdot = 0;
1169 	p = start;
1170 	if (*p == CTLESC)
1171 		p++;
1172 	if (*p == '.')
1173 		matchdot++;
1174 	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1175 		if (dp->d_name[0] == '.' && ! matchdot)
1176 			continue;
1177 		if (patmatch(start, dp->d_name)) {
1178 			namlen = dp->d_namlen;
1179 			if (enddir + namlen + 1 > expdir_end)
1180 				continue;
1181 			memcpy(enddir, dp->d_name, namlen + 1);
1182 			if (atend)
1183 				appendarglist(arglist, stsavestr(expdir));
1184 			else {
1185 				if (dp->d_type != DT_UNKNOWN &&
1186 				    dp->d_type != DT_DIR &&
1187 				    dp->d_type != DT_LNK)
1188 					continue;
1189 				if (enddir + namlen + 2 > expdir_end)
1190 					continue;
1191 				enddir[namlen] = '/';
1192 				enddir[namlen + 1] = '\0';
1193 				expmeta(enddir + namlen + 1, endname, arglist);
1194 			}
1195 		}
1196 	}
1197 	closedir(dirp);
1198 	if (! atend)
1199 		endname[-esc - 1] = esc ? CTLESC : '/';
1200 }
1201 
1202 
1203 static int
1204 expsortcmp(const void *p1, const void *p2)
1205 {
1206 	const char *s1 = *(const char * const *)p1;
1207 	const char *s2 = *(const char * const *)p2;
1208 
1209 	return (strcoll(s1, s2));
1210 }
1211 
1212 
1213 
1214 static wchar_t
1215 get_wc(const char **p)
1216 {
1217 	wchar_t c;
1218 	int chrlen;
1219 
1220 	chrlen = mbtowc(&c, *p, 4);
1221 	if (chrlen == 0)
1222 		return 0;
1223 	else if (chrlen == -1)
1224 		c = 0;
1225 	else
1226 		*p += chrlen;
1227 	return c;
1228 }
1229 
1230 
1231 /*
1232  * See if a character matches a character class, starting at the first colon
1233  * of "[:class:]".
1234  * If a valid character class is recognized, a pointer to the next character
1235  * after the final closing bracket is stored into *end, otherwise a null
1236  * pointer is stored into *end.
1237  */
1238 static int
1239 match_charclass(const char *p, wchar_t chr, const char **end)
1240 {
1241 	char name[20];
1242 	const char *nameend;
1243 	wctype_t cclass;
1244 
1245 	*end = NULL;
1246 	p++;
1247 	nameend = strstr(p, ":]");
1248 	if (nameend == NULL || (size_t)(nameend - p) >= sizeof(name) ||
1249 	    nameend == p)
1250 		return 0;
1251 	memcpy(name, p, nameend - p);
1252 	name[nameend - p] = '\0';
1253 	*end = nameend + 2;
1254 	cclass = wctype(name);
1255 	/* An unknown class matches nothing but is valid nevertheless. */
1256 	if (cclass == 0)
1257 		return 0;
1258 	return iswctype(chr, cclass);
1259 }
1260 
1261 
1262 /*
1263  * Returns true if the pattern matches the string.
1264  */
1265 
1266 static int
1267 patmatch(const char *pattern, const char *string)
1268 {
1269 	const char *p, *q, *end;
1270 	const char *bt_p, *bt_q;
1271 	char c;
1272 	wchar_t wc, wc2;
1273 
1274 	p = pattern;
1275 	q = string;
1276 	bt_p = NULL;
1277 	bt_q = NULL;
1278 	for (;;) {
1279 		switch (c = *p++) {
1280 		case '\0':
1281 			if (*q != '\0')
1282 				goto backtrack;
1283 			return 1;
1284 		case CTLESC:
1285 			if (*q++ != *p++)
1286 				goto backtrack;
1287 			break;
1288 		case '?':
1289 			if (*q == '\0')
1290 				return 0;
1291 			if (localeisutf8) {
1292 				wc = get_wc(&q);
1293 				/*
1294 				 * A '?' does not match invalid UTF-8 but a
1295 				 * '*' does, so backtrack.
1296 				 */
1297 				if (wc == 0)
1298 					goto backtrack;
1299 			} else
1300 				q++;
1301 			break;
1302 		case '*':
1303 			c = *p;
1304 			while (c == '*')
1305 				c = *++p;
1306 			/*
1307 			 * If the pattern ends here, we know the string
1308 			 * matches without needing to look at the rest of it.
1309 			 */
1310 			if (c == '\0')
1311 				return 1;
1312 			/*
1313 			 * First try the shortest match for the '*' that
1314 			 * could work. We can forget any earlier '*' since
1315 			 * there is no way having it match more characters
1316 			 * can help us, given that we are already here.
1317 			 */
1318 			bt_p = p;
1319 			bt_q = q;
1320 			break;
1321 		case '[': {
1322 			const char *savep, *saveq;
1323 			int invert, found;
1324 			wchar_t chr;
1325 
1326 			savep = p, saveq = q;
1327 			invert = 0;
1328 			if (*p == '!' || *p == '^') {
1329 				invert++;
1330 				p++;
1331 			}
1332 			found = 0;
1333 			if (*q == '\0')
1334 				return 0;
1335 			if (localeisutf8) {
1336 				chr = get_wc(&q);
1337 				if (chr == 0)
1338 					goto backtrack;
1339 			} else
1340 				chr = (unsigned char)*q++;
1341 			c = *p++;
1342 			do {
1343 				if (c == '\0') {
1344 					p = savep, q = saveq;
1345 					c = '[';
1346 					goto dft;
1347 				}
1348 				if (c == '[' && *p == ':') {
1349 					found |= match_charclass(p, chr, &end);
1350 					if (end != NULL)
1351 						p = end;
1352 				}
1353 				if (c == CTLESC)
1354 					c = *p++;
1355 				if (localeisutf8 && c & 0x80) {
1356 					p--;
1357 					wc = get_wc(&p);
1358 					if (wc == 0) /* bad utf-8 */
1359 						return 0;
1360 				} else
1361 					wc = (unsigned char)c;
1362 				if (*p == '-' && p[1] != ']') {
1363 					p++;
1364 					if (*p == CTLESC)
1365 						p++;
1366 					if (localeisutf8) {
1367 						wc2 = get_wc(&p);
1368 						if (wc2 == 0) /* bad utf-8 */
1369 							return 0;
1370 					} else
1371 						wc2 = (unsigned char)*p++;
1372 					if (   collate_range_cmp(chr, wc) >= 0
1373 					    && collate_range_cmp(chr, wc2) <= 0
1374 					   )
1375 						found = 1;
1376 				} else {
1377 					if (chr == wc)
1378 						found = 1;
1379 				}
1380 			} while ((c = *p++) != ']');
1381 			if (found == invert)
1382 				goto backtrack;
1383 			break;
1384 		}
1385 dft:	        default:
1386 			if (*q == '\0')
1387 				return 0;
1388 			if (*q++ == c)
1389 				break;
1390 backtrack:
1391 			/*
1392 			 * If we have a mismatch (other than hitting the end
1393 			 * of the string), go back to the last '*' seen and
1394 			 * have it match one additional character.
1395 			 */
1396 			if (bt_p == NULL)
1397 				return 0;
1398 			if (*bt_q == '\0')
1399 				return 0;
1400 			bt_q++;
1401 			p = bt_p;
1402 			q = bt_q;
1403 			break;
1404 		}
1405 	}
1406 }
1407 
1408 
1409 
1410 /*
1411  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1412  */
1413 
1414 void
1415 rmescapes(char *str)
1416 {
1417 	char *p, *q;
1418 
1419 	p = str;
1420 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1421 		if (*p++ == '\0')
1422 			return;
1423 	}
1424 	q = p;
1425 	while (*p) {
1426 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1427 			p++;
1428 			continue;
1429 		}
1430 		if (*p == CTLESC)
1431 			p++;
1432 		*q++ = *p++;
1433 	}
1434 	*q = '\0';
1435 }
1436 
1437 
1438 
1439 /*
1440  * See if a pattern matches in a case statement.
1441  */
1442 
1443 int
1444 casematch(union node *pattern, const char *val)
1445 {
1446 	struct stackmark smark;
1447 	struct nodelist *argbackq;
1448 	int result;
1449 	char *p;
1450 
1451 	setstackmark(&smark);
1452 	argbackq = pattern->narg.backquote;
1453 	STARTSTACKSTR(expdest);
1454 	argstr(pattern->narg.text, &argbackq, EXP_TILDE | EXP_CASE, NULL);
1455 	STPUTC('\0', expdest);
1456 	p = grabstackstr(expdest);
1457 	result = patmatch(p, val);
1458 	popstackmark(&smark);
1459 	return result;
1460 }
1461 
1462 /*
1463  * Our own itoa().
1464  */
1465 
1466 static void
1467 cvtnum(int num, char *buf)
1468 {
1469 	char temp[32];
1470 	int neg = num < 0;
1471 	char *p = temp + 31;
1472 
1473 	temp[31] = '\0';
1474 
1475 	do {
1476 		*--p = num % 10 + '0';
1477 	} while ((num /= 10) != 0);
1478 
1479 	if (neg)
1480 		*--p = '-';
1481 
1482 	memcpy(buf, p, temp + 32 - p);
1483 }
1484 
1485 /*
1486  * Do most of the work for wordexp(3).
1487  */
1488 
1489 int
1490 wordexpcmd(int argc, char **argv)
1491 {
1492 	size_t len;
1493 	int i;
1494 
1495 	out1fmt("%08x", argc - 1);
1496 	for (i = 1, len = 0; i < argc; i++)
1497 		len += strlen(argv[i]);
1498 	out1fmt("%08x", (int)len);
1499 	for (i = 1; i < argc; i++)
1500 		outbin(argv[i], strlen(argv[i]) + 1, out1);
1501         return (0);
1502 }
1503 
1504 /*
1505  * Do most of the work for wordexp(3), new version.
1506  */
1507 
1508 int
1509 freebsd_wordexpcmd(int argc __unused, char **argv __unused)
1510 {
1511 	struct arglist arglist;
1512 	union node *args, *n;
1513 	size_t len;
1514 	int ch;
1515 	int protected = 0;
1516 	int fd = -1;
1517 	int i;
1518 
1519 	while ((ch = nextopt("f:p")) != '\0') {
1520 		switch (ch) {
1521 		case 'f':
1522 			fd = number(shoptarg);
1523 			break;
1524 		case 'p':
1525 			protected = 1;
1526 			break;
1527 		}
1528 	}
1529 	if (*argptr != NULL)
1530 		error("wrong number of arguments");
1531 	if (fd < 0)
1532 		error("missing fd");
1533 	INTOFF;
1534 	setinputfd(fd, 1);
1535 	INTON;
1536 	args = parsewordexp();
1537 	popfile(); /* will also close fd */
1538 	if (protected)
1539 		for (n = args; n != NULL; n = n->narg.next) {
1540 			if (n->narg.backquote != NULL) {
1541 				outcslow('C', out1);
1542 				error("command substitution disabled");
1543 			}
1544 		}
1545 	outcslow(' ', out1);
1546 	emptyarglist(&arglist);
1547 	for (n = args; n != NULL; n = n->narg.next)
1548 		expandarg(n, &arglist, EXP_FULL | EXP_TILDE);
1549 	for (i = 0, len = 0; i < arglist.count; i++)
1550 		len += strlen(arglist.args[i]);
1551 	out1fmt("%016x %016zx", arglist.count, len);
1552 	for (i = 0; i < arglist.count; i++)
1553 		outbin(arglist.args[i], strlen(arglist.args[i]) + 1, out1);
1554 	return (0);
1555 }
1556