xref: /freebsd/bin/sh/expand.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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  * 4. 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 static struct nodelist *argbackq;	/* list of back quote expressions */
93 
94 static const char *argstr(const char *, int, struct worddest *);
95 static const char *exptilde(const char *, int);
96 static const char *expari(const char *, int, struct worddest *);
97 static void expbackq(union node *, int, int, struct worddest *);
98 static void subevalvar_trim(const char *, int, int, int);
99 static int subevalvar_misc(const char *, const char *, int, int, int);
100 static const char *evalvar(const char *, int, struct worddest *);
101 static int varisset(const char *, int);
102 static void strtodest(const char *, int, int, int, struct worddest *);
103 static void reprocess(int, int, int, int, struct worddest *);
104 static void varvalue(const char *, int, int, int, struct worddest *);
105 static void expandmeta(char *, struct arglist *);
106 static void expmeta(char *, char *, struct arglist *);
107 static int expsortcmp(const void *, const void *);
108 static int patmatch(const char *, const char *);
109 static void cvtnum(int, char *);
110 static int collate_range_cmp(wchar_t, wchar_t);
111 
112 void
113 emptyarglist(struct arglist *list)
114 {
115 
116 	list->args = list->smallarg;
117 	list->count = 0;
118 	list->capacity = sizeof(list->smallarg) / sizeof(list->smallarg[0]);
119 }
120 
121 void
122 appendarglist(struct arglist *list, char *str)
123 {
124 	char **newargs;
125 	int newcapacity;
126 
127 	if (list->count >= list->capacity) {
128 		newcapacity = list->capacity * 2;
129 		if (newcapacity < 16)
130 			newcapacity = 16;
131 		if (newcapacity > INT_MAX / (int)sizeof(newargs[0]))
132 			error("Too many entries in arglist");
133 		newargs = stalloc(newcapacity * sizeof(newargs[0]));
134 		memcpy(newargs, list->args, list->count * sizeof(newargs[0]));
135 		list->args = newargs;
136 		list->capacity = newcapacity;
137 	}
138 	list->args[list->count++] = str;
139 }
140 
141 static int
142 collate_range_cmp(wchar_t c1, wchar_t c2)
143 {
144 	static wchar_t s1[2], s2[2];
145 
146 	s1[0] = c1;
147 	s2[0] = c2;
148 	return (wcscoll(s1, s2));
149 }
150 
151 static char *
152 stputs_quotes(const char *data, const char *syntax, char *p)
153 {
154 	while (*data) {
155 		CHECKSTRSPACE(2, p);
156 		if (syntax[(int)*data] == CCTL)
157 			USTPUTC(CTLESC, p);
158 		USTPUTC(*data++, p);
159 	}
160 	return (p);
161 }
162 #define STPUTS_QUOTES(data, syntax, p) p = stputs_quotes((data), syntax, p)
163 
164 static char *
165 nextword(char c, int flag, char *p, struct worddest *dst)
166 {
167 	int is_ws;
168 
169 	is_ws = c == '\t' || c == '\n' || c == ' ';
170 	if (p != stackblock() || (is_ws ? dst->state == WORD_QUOTEMARK :
171 	    dst->state != WORD_WS_DELIMITED) || c == '\0') {
172 		STPUTC('\0', p);
173 		if (flag & EXP_GLOB)
174 			expandmeta(grabstackstr(p), dst->list);
175 		else
176 			appendarglist(dst->list, grabstackstr(p));
177 		dst->state = is_ws ? WORD_WS_DELIMITED : WORD_IDLE;
178 	} else if (!is_ws && dst->state == WORD_WS_DELIMITED)
179 		dst->state = WORD_IDLE;
180 	/* Reserve space while the stack string is empty. */
181 	appendarglist(dst->list, NULL);
182 	dst->list->count--;
183 	STARTSTACKSTR(p);
184 	return p;
185 }
186 #define NEXTWORD(c, flag, p, dstlist) p = nextword(c, flag, p, dstlist)
187 
188 static char *
189 stputs_split(const char *data, const char *syntax, int flag, char *p,
190     struct worddest *dst)
191 {
192 	const char *ifs;
193 	char c;
194 
195 	ifs = ifsset() ? ifsval() : " \t\n";
196 	while (*data) {
197 		CHECKSTRSPACE(2, p);
198 		c = *data++;
199 		if (strchr(ifs, c) != NULL) {
200 			NEXTWORD(c, flag, p, dst);
201 			continue;
202 		}
203 		if (flag & EXP_GLOB && syntax[(int)c] == CCTL)
204 			USTPUTC(CTLESC, p);
205 		USTPUTC(c, p);
206 	}
207 	return (p);
208 }
209 #define STPUTS_SPLIT(data, syntax, flag, p, dst) p = stputs_split((data), syntax, flag, p, dst)
210 
211 /*
212  * Perform expansions on an argument, placing the resulting list of arguments
213  * in arglist.  Parameter expansion, command substitution and arithmetic
214  * expansion are always performed; additional expansions can be requested
215  * via flag (EXP_*).
216  * The result is left in the stack string.
217  * When arglist is NULL, perform here document expansion.
218  *
219  * Caution: this function uses global state and is not reentrant.
220  * However, a new invocation after an interrupted invocation is safe
221  * and will reset the global state for the new call.
222  */
223 void
224 expandarg(union node *arg, struct arglist *arglist, int flag)
225 {
226 	struct worddest exparg;
227 
228 	if (fflag)
229 		flag &= ~EXP_GLOB;
230 	argbackq = arg->narg.backquote;
231 	exparg.list = arglist;
232 	exparg.state = WORD_IDLE;
233 	STARTSTACKSTR(expdest);
234 	argstr(arg->narg.text, flag, &exparg);
235 	if (arglist == NULL) {
236 		STACKSTRNUL(expdest);
237 		return;			/* here document expanded */
238 	}
239 	if ((flag & EXP_SPLIT) == 0 || expdest != stackblock() ||
240 	    exparg.state == WORD_QUOTEMARK) {
241 		STPUTC('\0', expdest);
242 		if (flag & EXP_SPLIT) {
243 			if (flag & EXP_GLOB)
244 				expandmeta(grabstackstr(expdest), exparg.list);
245 			else
246 				appendarglist(exparg.list, grabstackstr(expdest));
247 		}
248 	}
249 	if ((flag & EXP_SPLIT) == 0)
250 		appendarglist(arglist, grabstackstr(expdest));
251 }
252 
253 
254 
255 /*
256  * Perform parameter expansion, command substitution and arithmetic
257  * expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
258  * Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
259  * This is used to expand word in ${var+word} etc.
260  * If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
261  * characters to allow for further processing.
262  *
263  * If EXP_SPLIT is set, dst receives any complete words produced.
264  */
265 static const char *
266 argstr(const char *p, int flag, struct worddest *dst)
267 {
268 	char c;
269 	int quotes = flag & (EXP_GLOB | EXP_CASE);	/* do CTLESC */
270 	int firsteq = 1;
271 	int split_lit;
272 	int lit_quoted;
273 
274 	split_lit = flag & EXP_SPLIT_LIT;
275 	lit_quoted = flag & EXP_LIT_QUOTED;
276 	flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
277 	if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
278 		p = exptilde(p, flag);
279 	for (;;) {
280 		CHECKSTRSPACE(2, expdest);
281 		switch (c = *p++) {
282 		case '\0':
283 			return (p - 1);
284 		case CTLENDVAR:
285 		case CTLENDARI:
286 			return (p);
287 		case CTLQUOTEMARK:
288 			lit_quoted = 1;
289 			/* "$@" 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, 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, 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, int flag, struct worddest *dst)
409 {
410 	char *q, *start;
411 	arith_t result;
412 	int begoff;
413 	int quoted;
414 	int adj;
415 
416 	quoted = *p++ == '"';
417 	begoff = expdest - stackblock();
418 	p = argstr(p, 0, NULL);
419 	STPUTC('\0', expdest);
420 	start = stackblock() + begoff;
421 
422 	q = grabstackstr(expdest);
423 	result = arith(start);
424 	ungrabstackstr(q, expdest);
425 
426 	start = stackblock() + begoff;
427 	adj = start - expdest;
428 	STADJUST(adj, expdest);
429 
430 	CHECKSTRSPACE((int)(DIGITS(result) + 1), expdest);
431 	fmtstr(expdest, DIGITS(result), ARITH_FORMAT_STR, result);
432 	adj = strlen(expdest);
433 	STADJUST(adj, expdest);
434 	if (!quoted)
435 		reprocess(expdest - adj - stackblock(), flag, VSNORMAL, 0, dst);
436 	return p;
437 }
438 
439 
440 /*
441  * Perform command substitution.
442  */
443 static void
444 expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
445 {
446 	struct backcmd in;
447 	int i;
448 	char buf[128];
449 	char *p;
450 	char *dest = expdest;
451 	struct nodelist *saveargbackq;
452 	char lastc;
453 	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
454 	int quotes = flag & (EXP_GLOB | EXP_CASE);
455 	size_t nnl;
456 	const char *ifs;
457 
458 	INTOFF;
459 	saveargbackq = argbackq;
460 	p = grabstackstr(dest);
461 	evalbackcmd(cmd, &in);
462 	ungrabstackstr(p, dest);
463 	argbackq = saveargbackq;
464 
465 	p = in.buf;
466 	nnl = 0;
467 	if (!quoted && flag & EXP_SPLIT)
468 		ifs = ifsset() ? ifsval() : " \t\n";
469 	else
470 		ifs = "";
471 	/* Don't copy trailing newlines */
472 	for (;;) {
473 		if (--in.nleft < 0) {
474 			if (in.fd < 0)
475 				break;
476 			while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR)
477 				;
478 			TRACE(("expbackq: read returns %d\n", i));
479 			if (i <= 0)
480 				break;
481 			p = buf;
482 			in.nleft = i - 1;
483 		}
484 		lastc = *p++;
485 		if (lastc == '\0')
486 			continue;
487 		if (lastc == '\n') {
488 			nnl++;
489 		} else {
490 			if (nnl > 0) {
491 				if (strchr(ifs, '\n') != NULL) {
492 					NEXTWORD('\n', flag, dest, dst);
493 					nnl = 0;
494 				} else {
495 					CHECKSTRSPACE(nnl + 2, dest);
496 					while (nnl > 0) {
497 						nnl--;
498 						USTPUTC('\n', dest);
499 					}
500 				}
501 			}
502 			if (strchr(ifs, lastc) != NULL)
503 				NEXTWORD(lastc, flag, dest, dst);
504 			else {
505 				CHECKSTRSPACE(2, dest);
506 				if (quotes && syntax[(int)lastc] == CCTL)
507 					USTPUTC(CTLESC, dest);
508 				USTPUTC(lastc, dest);
509 			}
510 		}
511 	}
512 
513 	if (in.fd >= 0)
514 		close(in.fd);
515 	if (in.buf)
516 		ckfree(in.buf);
517 	if (in.jp)
518 		exitstatus = waitforjob(in.jp, (int *)NULL);
519 	TRACE(("expbackq: size=%td: \"%.*s\"\n",
520 		((dest - stackblock()) - startloc),
521 		(int)((dest - stackblock()) - startloc),
522 		stackblock() + startloc));
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 void
541 subevalvar_trim(const char *p, int strloc, int subtype, int startloc)
542 {
543 	char *startp;
544 	char *loc = NULL;
545 	char *str;
546 	int c = 0;
547 	struct nodelist *saveargbackq = argbackq;
548 	int amount;
549 
550 	argstr(p, EXP_CASE | EXP_TILDE, NULL);
551 	STACKSTRNUL(expdest);
552 	argbackq = saveargbackq;
553 	startp = stackblock() + startloc;
554 	str = stackblock() + strloc;
555 
556 	switch (subtype) {
557 	case VSTRIMLEFT:
558 		for (loc = startp; loc < str; loc++) {
559 			c = *loc;
560 			*loc = '\0';
561 			if (patmatch(str, startp)) {
562 				*loc = c;
563 				recordleft(str, loc, startp);
564 				return;
565 			}
566 			*loc = c;
567 		}
568 		break;
569 
570 	case VSTRIMLEFTMAX:
571 		for (loc = str - 1; loc >= startp;) {
572 			c = *loc;
573 			*loc = '\0';
574 			if (patmatch(str, startp)) {
575 				*loc = c;
576 				recordleft(str, loc, startp);
577 				return;
578 			}
579 			*loc = c;
580 			loc--;
581 		}
582 		break;
583 
584 	case VSTRIMRIGHT:
585 		for (loc = str - 1; loc >= startp;) {
586 			if (patmatch(str, loc)) {
587 				amount = loc - expdest;
588 				STADJUST(amount, expdest);
589 				return;
590 			}
591 			loc--;
592 		}
593 		break;
594 
595 	case VSTRIMRIGHTMAX:
596 		for (loc = startp; loc < str - 1; loc++) {
597 			if (patmatch(str, loc)) {
598 				amount = loc - expdest;
599 				STADJUST(amount, expdest);
600 				return;
601 			}
602 		}
603 		break;
604 
605 
606 	default:
607 		abort();
608 	}
609 	amount = (expdest - stackblock() - strloc) + 1;
610 	STADJUST(-amount, expdest);
611 }
612 
613 
614 static int
615 subevalvar_misc(const char *p, const char *var, int subtype, int startloc,
616   int varflags)
617 {
618 	char *startp;
619 	struct nodelist *saveargbackq = argbackq;
620 	int amount;
621 
622 	argstr(p, EXP_TILDE, NULL);
623 	STACKSTRNUL(expdest);
624 	argbackq = saveargbackq;
625 	startp = stackblock() + startloc;
626 
627 	switch (subtype) {
628 	case VSASSIGN:
629 		setvar(var, startp, 0);
630 		amount = startp - expdest;
631 		STADJUST(amount, expdest);
632 		return 1;
633 
634 	case VSQUESTION:
635 		if (*p != CTLENDVAR) {
636 			outfmt(out2, "%s\n", startp);
637 			error((char *)NULL);
638 		}
639 		error("%.*s: parameter %snot set", (int)(p - var - 1),
640 		      var, (varflags & VSNUL) ? "null or " : "");
641 		return 0;
642 
643 	default:
644 		abort();
645 	}
646 }
647 
648 
649 /*
650  * Expand a variable, and return a pointer to the next character in the
651  * input string.
652  */
653 
654 static const char *
655 evalvar(const char *p, int flag, struct worddest *dst)
656 {
657 	int subtype;
658 	int varflags;
659 	const char *var;
660 	const char *val;
661 	int patloc;
662 	int c;
663 	int set;
664 	int special;
665 	int startloc;
666 	int varlen;
667 	int varlenb;
668 	char buf[21];
669 
670 	varflags = (unsigned char)*p++;
671 	subtype = varflags & VSTYPE;
672 	var = p;
673 	special = 0;
674 	if (! is_name(*p))
675 		special = 1;
676 	p = strchr(p, '=') + 1;
677 again: /* jump here after setting a variable with ${var=text} */
678 	if (varflags & VSLINENO) {
679 		set = 1;
680 		special = 1;
681 		val = NULL;
682 	} else if (special) {
683 		set = varisset(var, varflags & VSNUL);
684 		val = NULL;
685 	} else {
686 		val = bltinlookup(var, 1);
687 		if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
688 			val = NULL;
689 			set = 0;
690 		} else
691 			set = 1;
692 	}
693 	varlen = 0;
694 	startloc = expdest - stackblock();
695 	if (!set && uflag && *var != '@' && *var != '*') {
696 		switch (subtype) {
697 		case VSNORMAL:
698 		case VSTRIMLEFT:
699 		case VSTRIMLEFTMAX:
700 		case VSTRIMRIGHT:
701 		case VSTRIMRIGHTMAX:
702 		case VSLENGTH:
703 			error("%.*s: parameter not set", (int)(p - var - 1),
704 			    var);
705 		}
706 	}
707 	if (set && subtype != VSPLUS) {
708 		/* insert the value of the variable */
709 		if (special) {
710 			if (varflags & VSLINENO) {
711 				if (p - var > (ptrdiff_t)sizeof(buf))
712 					abort();
713 				memcpy(buf, var, p - var - 1);
714 				buf[p - var - 1] = '\0';
715 				strtodest(buf, flag, subtype,
716 				    varflags & VSQUOTE, dst);
717 			} else
718 				varvalue(var, varflags & VSQUOTE, subtype, flag,
719 				    dst);
720 			if (subtype == VSLENGTH) {
721 				varlenb = expdest - stackblock() - startloc;
722 				varlen = varlenb;
723 				if (localeisutf8) {
724 					val = stackblock() + startloc;
725 					for (;val != expdest; val++)
726 						if ((*val & 0xC0) == 0x80)
727 							varlen--;
728 				}
729 				STADJUST(-varlenb, expdest);
730 			}
731 		} else {
732 			if (subtype == VSLENGTH) {
733 				for (;*val; val++)
734 					if (!localeisutf8 ||
735 					    (*val & 0xC0) != 0x80)
736 						varlen++;
737 			}
738 			else
739 				strtodest(val, flag, subtype,
740 				    varflags & VSQUOTE, dst);
741 		}
742 	}
743 
744 	if (subtype == VSPLUS)
745 		set = ! set;
746 
747 	switch (subtype) {
748 	case VSLENGTH:
749 		cvtnum(varlen, buf);
750 		strtodest(buf, flag, VSNORMAL, varflags & VSQUOTE, dst);
751 		break;
752 
753 	case VSNORMAL:
754 		break;
755 
756 	case VSPLUS:
757 	case VSMINUS:
758 		if (!set) {
759 			argstr(p, flag | (flag & EXP_SPLIT ? EXP_SPLIT_LIT : 0) |
760 			    (varflags & VSQUOTE ? EXP_LIT_QUOTED : 0), dst);
761 			break;
762 		}
763 		break;
764 
765 	case VSTRIMLEFT:
766 	case VSTRIMLEFTMAX:
767 	case VSTRIMRIGHT:
768 	case VSTRIMRIGHTMAX:
769 		if (!set)
770 			break;
771 		/*
772 		 * Terminate the string and start recording the pattern
773 		 * right after it
774 		 */
775 		STPUTC('\0', expdest);
776 		patloc = expdest - stackblock();
777 		subevalvar_trim(p, patloc, subtype, startloc);
778 		reprocess(startloc, flag, VSNORMAL, varflags & VSQUOTE, dst);
779 		if (flag & EXP_SPLIT && *var == '@' && varflags & VSQUOTE)
780 			dst->state = WORD_QUOTEMARK;
781 		break;
782 
783 	case VSASSIGN:
784 	case VSQUESTION:
785 		if (!set) {
786 			if (subevalvar_misc(p, var, subtype, startloc,
787 			    varflags)) {
788 				varflags &= ~VSNUL;
789 				goto again;
790 			}
791 			break;
792 		}
793 		break;
794 
795 	case VSERROR:
796 		c = p - var - 1;
797 		error("${%.*s%s}: Bad substitution", c, var,
798 		    (c > 0 && *p != CTLENDVAR) ? "..." : "");
799 
800 	default:
801 		abort();
802 	}
803 
804 	if (subtype != VSNORMAL) {	/* skip to end of alternative */
805 		int nesting = 1;
806 		for (;;) {
807 			if ((c = *p++) == CTLESC)
808 				p++;
809 			else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
810 				if (set)
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 specialized variable 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)
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(-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 specialized variable 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 				}
1344 				if (c == CTLESC)
1345 					c = *p++;
1346 				if (localeisutf8 && c & 0x80) {
1347 					p--;
1348 					wc = get_wc(&p);
1349 					if (wc == 0) /* bad utf-8 */
1350 						return 0;
1351 				} else
1352 					wc = (unsigned char)c;
1353 				if (*p == '-' && p[1] != ']') {
1354 					p++;
1355 					if (*p == CTLESC)
1356 						p++;
1357 					if (localeisutf8) {
1358 						wc2 = get_wc(&p);
1359 						if (wc2 == 0) /* bad utf-8 */
1360 							return 0;
1361 					} else
1362 						wc2 = (unsigned char)*p++;
1363 					if (   collate_range_cmp(chr, wc) >= 0
1364 					    && collate_range_cmp(chr, wc2) <= 0
1365 					   )
1366 						found = 1;
1367 				} else {
1368 					if (chr == wc)
1369 						found = 1;
1370 				}
1371 			} while ((c = *p++) != ']');
1372 			if (found == invert)
1373 				goto backtrack;
1374 			break;
1375 		}
1376 dft:	        default:
1377 			if (*q == '\0')
1378 				return 0;
1379 			if (*q++ == c)
1380 				break;
1381 backtrack:
1382 			/*
1383 			 * If we have a mismatch (other than hitting the end
1384 			 * of the string), go back to the last '*' seen and
1385 			 * have it match one additional character.
1386 			 */
1387 			if (bt_p == NULL)
1388 				return 0;
1389 			if (*bt_q == '\0')
1390 				return 0;
1391 			bt_q++;
1392 			p = bt_p;
1393 			q = bt_q;
1394 			break;
1395 		}
1396 	}
1397 }
1398 
1399 
1400 
1401 /*
1402  * Remove any CTLESC and CTLQUOTEMARK characters from a string.
1403  */
1404 
1405 void
1406 rmescapes(char *str)
1407 {
1408 	char *p, *q;
1409 
1410 	p = str;
1411 	while (*p != CTLESC && *p != CTLQUOTEMARK && *p != CTLQUOTEEND) {
1412 		if (*p++ == '\0')
1413 			return;
1414 	}
1415 	q = p;
1416 	while (*p) {
1417 		if (*p == CTLQUOTEMARK || *p == CTLQUOTEEND) {
1418 			p++;
1419 			continue;
1420 		}
1421 		if (*p == CTLESC)
1422 			p++;
1423 		*q++ = *p++;
1424 	}
1425 	*q = '\0';
1426 }
1427 
1428 
1429 
1430 /*
1431  * See if a pattern matches in a case statement.
1432  */
1433 
1434 int
1435 casematch(union node *pattern, const char *val)
1436 {
1437 	struct stackmark smark;
1438 	int result;
1439 	char *p;
1440 
1441 	setstackmark(&smark);
1442 	argbackq = pattern->narg.backquote;
1443 	STARTSTACKSTR(expdest);
1444 	argstr(pattern->narg.text, 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