expand.c@ 881

Last change on this file since 881 was 809, checked in by bird, 18 years ago
Solaris + cleanup.
Property svn:eol-style set to `native`
File size: 30.6 KB

Line
1	/* $NetBSD: expand.c,v 1.71 2005/06/01 15:41:19 lukem Exp $ */
2
3	/*-
4	* Copyright (c) 1991, 1993
5	* The Regents of the University of California. All rights reserved.
6	*
7	* This code is derived from software contributed to Berkeley by
8	* Kenneth Almquist.
9	*
10	* Redistribution and use in source and binary forms, with or without
11	* modification, are permitted provided that the following conditions
12	* are met:
13	* 1. Redistributions of source code must retain the above copyright
14	* notice, this list of conditions and the following disclaimer.
15	* 2. Redistributions in binary form must reproduce the above copyright
16	* notice, this list of conditions and the following disclaimer in the
17	* documentation and/or other materials provided with the distribution.
18	* 3. Neither the name of the University nor the names of its contributors
19	* may be used to endorse or promote products derived from this software
20	* without specific prior written permission.
21	*
22	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32	* SUCH DAMAGE.
33	*/
34
35	#ifdef HAVE_SYS_CDEFS_H
36	#include <sys/cdefs.h>
37	#endif
38	#ifndef lint
39	#if 0
40	static char sccsid[] = "@(#)expand.c 8.5 (Berkeley) 5/15/95";
41	#else
42	__RCSID("$NetBSD: expand.c,v 1.71 2005/06/01 15:41:19 lukem Exp $");
43	#endif
44	#endif /* not lint */
45
46	#include <sys/types.h>
47	#include <sys/time.h>
48	#include <sys/stat.h>
49	#include <errno.h>
50	#include <dirent.h>
51	#include <unistd.h>
52	#include <pwd.h>
53	#include <stdlib.h>
54	#include <stdio.h>
55	#ifdef __sun__
56	#include <iso/limits_iso.h>
57	#endif
58
59	/*
60	* Routines to expand arguments to commands. We have to deal with
61	* backquotes, shell variables, and file metacharacters.
62	*/
63
64	#include "shell.h"
65	#include "main.h"
66	#include "nodes.h"
67	#include "eval.h"
68	#include "expand.h"
69	#include "syntax.h"
70	#include "parser.h"
71	#include "jobs.h"
72	#include "options.h"
73	#include "var.h"
74	#include "input.h"
75	#include "output.h"
76	#include "memalloc.h"
77	#include "error.h"
78	#include "mystring.h"
79	#include "show.h"
80
81	/*
82	* Structure specifying which parts of the string should be searched
83	* for IFS characters.
84	*/
85
86	struct ifsregion {
87	struct ifsregion next; / next region in list */
88	int begoff; /* offset of start of region */
89	int endoff; /* offset of end of region */
90	int inquotes; /* search for nul bytes only */
91	};
92
93
94	char expdest; / output of current string */
95	struct nodelist argbackq; / list of back quote expressions */
96	struct ifsregion ifsfirst; /* first struct in list of ifs regions */
97	struct ifsregion ifslastp; / last struct in list */
98	struct arglist exparg; /* holds expanded arg list */
99
100	STATIC void argstr(char *, int);
101	STATIC char exptilde(char , int);
102	STATIC void expbackq(union node *, int, int);
103	STATIC int subevalvar(char , char , int, int, int, int);
104	STATIC char evalvar(char , int);
105	STATIC int varisset(char *, int);
106	STATIC void varvalue(char *, int, int, int);
107	STATIC void recordregion(int, int, int);
108	STATIC void removerecordregions(int);
109	STATIC void ifsbreakup(char , struct arglist );
110	STATIC void ifsfree(void);
111	STATIC void expandmeta(struct strlist *, int);
112	STATIC void expmeta(char , char );
113	STATIC void addfname(char *);
114	STATIC struct strlist expsort(struct strlist );
115	STATIC struct strlist msort(struct strlist , int);
116	STATIC int pmatch(char , char , int);
117	STATIC char cvtnum(int, char );
118
119	/*
120	* Expand shell variables and backquotes inside a here document.
121	*/
122
123	void
124	expandhere(union node *arg, int fd)
125	{
126	herefd = fd;
127	expandarg(arg, (struct arglist *)NULL, 0);
128	xwrite(fd, stackblock(), expdest - stackblock());
129	}
130
131
132	/*
133	* Perform variable substitution and command substitution on an argument,
134	* placing the resulting list of arguments in arglist. If EXP_FULL is true,
135	* perform splitting and file name expansion. When arglist is NULL, perform
136	* here document expansion.
137	*/
138
139	void
140	expandarg(union node arg, struct arglist arglist, int flag)
141	{
142	struct strlist *sp;
143	char *p;
144
145	argbackq = arg->narg.backquote;
146	STARTSTACKSTR(expdest);
147	ifsfirst.next = NULL;
148	ifslastp = NULL;
149	argstr(arg->narg.text, flag);
150	if (arglist == NULL) {
151	return; /* here document expanded */
152	}
153	STPUTC('\0', expdest);
154	p = grabstackstr(expdest);
155	exparg.lastp = &exparg.list;
156	/*
157	* TODO - EXP_REDIR
158	*/
159	if (flag & EXP_FULL) {
160	ifsbreakup(p, &exparg);
161	*exparg.lastp = NULL;
162	exparg.lastp = &exparg.list;
163	expandmeta(exparg.list, flag);
164	} else {
165	if (flag & EXP_REDIR) /XXX - for now, just remove escapes /
166	rmescapes(p);
167	sp = (struct strlist *)stalloc(sizeof (struct strlist));
168	sp->text = p;
169	*exparg.lastp = sp;
170	exparg.lastp = &sp->next;
171	}
172	ifsfree();
173	*exparg.lastp = NULL;
174	if (exparg.list) {
175	*arglist->lastp = exparg.list;
176	arglist->lastp = exparg.lastp;
177	}
178	}
179
180
181
182	/*
183	* Perform variable and command substitution.
184	* If EXP_FULL is set, output CTLESC characters to allow for further processing.
185	* Otherwise treat $@ like $* since no splitting will be performed.
186	*/
187
188	STATIC void
189	argstr(char *p, int flag)
190	{
191	char c;
192	int quotes = flag & (EXP_FULL \| EXP_CASE); /* do CTLESC */
193	int firsteq = 1;
194	const char *ifs = NULL;
195	int ifs_split = EXP_IFS_SPLIT;
196
197	if (flag & EXP_IFS_SPLIT)
198	ifs = ifsset() ? ifsval() : " \t\n";
199
200	if (*p == '~' && (flag & (EXP_TILDE \| EXP_VARTILDE)))
201	p = exptilde(p, flag);
202	for (;;) {
203	switch (c = *p++) {
204	case '\0':
205	case CTLENDVAR: /* end of expanding yyy in ${xxx-yyy} */
206	return;
207	case CTLQUOTEMARK:
208	/* "$@" syntax adherence hack */
209	if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
210	break;
211	if ((flag & EXP_FULL) != 0)
212	STPUTC(c, expdest);
213	ifs_split = 0;
214	break;
215	case CTLQUOTEEND:
216	ifs_split = EXP_IFS_SPLIT;
217	break;
218	case CTLESC:
219	if (quotes)
220	STPUTC(c, expdest);
221	c = *p++;
222	STPUTC(c, expdest);
223	break;
224	case CTLVAR:
225	p = evalvar(p, (flag & ~EXP_IFS_SPLIT) \| (flag & ifs_split));
226	break;
227	case CTLBACKQ:
228	case CTLBACKQ\|CTLQUOTE:
229	expbackq(argbackq->n, c & CTLQUOTE, flag);
230	argbackq = argbackq->next;
231	break;
232	case CTLENDARI:
233	expari(flag);
234	break;
235	case ':':
236	case '=':
237	/*
238	* sort of a hack - expand tildes in variable
239	* assignments (after the first '=' and after ':'s).
240	*/
241	STPUTC(c, expdest);
242	if (flag & EXP_VARTILDE && *p == '~') {
243	if (c == '=') {
244	if (firsteq)
245	firsteq = 0;
246	else
247	break;
248	}
249	p = exptilde(p, flag);
250	}
251	break;
252	default:
253	STPUTC(c, expdest);
254	if (flag & EXP_IFS_SPLIT & ifs_split && strchr(ifs, c) != NULL) {
255	/* We need to get the output split here... */
256	recordregion(expdest - stackblock() - 1,
257	expdest - stackblock(), 0);
258	}
259	break;
260	}
261	}
262	}
263
264	STATIC char *
265	exptilde(char *p, int flag)
266	{
267	char c, *startp = p;
268	struct passwd *pw;
269	const char *home;
270	int quotes = flag & (EXP_FULL \| EXP_CASE);
271
272	while ((c = *p) != '\0') {
273	switch(c) {
274	case CTLESC:
275	return (startp);
276	case CTLQUOTEMARK:
277	return (startp);
278	case ':':
279	if (flag & EXP_VARTILDE)
280	goto done;
281	break;
282	case '/':
283	goto done;
284	}
285	p++;
286	}
287	done:
288	*p = '\0';
289	if (*(startp+1) == '\0') {
290	if ((home = lookupvar("HOME")) == NULL)
291	goto lose;
292	} else {
293	if ((pw = getpwnam(startp+1)) == NULL)
294	goto lose;
295	home = pw->pw_dir;
296	}
297	if (*home == '\0')
298	goto lose;
299	*p = c;
300	while ((c = *home++) != '\0') {
301	if (quotes && SQSYNTAX[(int)c] == CCTL)
302	STPUTC(CTLESC, expdest);
303	STPUTC(c, expdest);
304	}
305	return (p);
306	lose:
307	*p = c;
308	return (startp);
309	}
310
311
312	STATIC void
313	removerecordregions(int endoff)
314	{
315	if (ifslastp == NULL)
316	return;
317
318	if (ifsfirst.endoff > endoff) {
319	while (ifsfirst.next != NULL) {
320	struct ifsregion *ifsp;
321	INTOFF;
322	ifsp = ifsfirst.next->next;
323	ckfree(ifsfirst.next);
324	ifsfirst.next = ifsp;
325	INTON;
326	}
327	if (ifsfirst.begoff > endoff)
328	ifslastp = NULL;
329	else {
330	ifslastp = &ifsfirst;
331	ifsfirst.endoff = endoff;
332	}
333	return;
334	}
335
336	ifslastp = &ifsfirst;
337	while (ifslastp->next && ifslastp->next->begoff < endoff)
338	ifslastp=ifslastp->next;
339	while (ifslastp->next != NULL) {
340	struct ifsregion *ifsp;
341	INTOFF;
342	ifsp = ifslastp->next->next;
343	ckfree(ifslastp->next);
344	ifslastp->next = ifsp;
345	INTON;
346	}
347	if (ifslastp->endoff > endoff)
348	ifslastp->endoff = endoff;
349	}
350
351
352	/*
353	* Expand arithmetic expression. Backup to start of expression,
354	* evaluate, place result in (backed up) result, adjust string position.
355	*/
356	void
357	expari(int flag)
358	{
359	char p, start;
360	int result;
361	int begoff;
362	int quotes = flag & (EXP_FULL \| EXP_CASE);
363	int quoted;
364
365	/* ifsfree(); */
366
367	/*
368	* This routine is slightly over-complicated for
369	* efficiency. First we make sure there is
370	* enough space for the result, which may be bigger
371	* than the expression if we add exponentation. Next we
372	* scan backwards looking for the start of arithmetic. If the
373	* next previous character is a CTLESC character, then we
374	* have to rescan starting from the beginning since CTLESC
375	* characters have to be processed left to right.
376	*/
377	#if INT_MAX / 1000000000 >= 10 \|\| INT_MIN / 1000000000 <= -10
378	#error "integers with more than 10 digits are not supported"
379	#endif
380	CHECKSTRSPACE(12 - 2, expdest);
381	USTPUTC('\0', expdest);
382	start = stackblock();
383	p = expdest - 1;
384	while (*p != CTLARI && p >= start)
385	--p;
386	if (*p != CTLARI)
387	error("missing CTLARI (shouldn't happen)");
388	if (p > start && *(p-1) == CTLESC)
389	for (p = start; *p != CTLARI; p++)
390	if (*p == CTLESC)
391	p++;
392
393	if (p[1] == '"')
394	quoted=1;
395	else
396	quoted=0;
397	begoff = p - start;
398	removerecordregions(begoff);
399	if (quotes)
400	rmescapes(p+2);
401	result = arith(p+2);
402	fmtstr(p, 12, "%d", result);
403
404	while (*p++)
405	;
406
407	if (quoted == 0)
408	recordregion(begoff, p - 1 - start, 0);
409	result = expdest - p + 1;
410	STADJUST(-result, expdest);
411	}
412
413
414	/*
415	* Expand stuff in backwards quotes.
416	*/
417
418	STATIC void
419	expbackq(union node *cmd, int quoted, int flag)
420	{
421	struct backcmd in;
422	int i;
423	char buf[128];
424	char *p;
425	char *dest = expdest;
426	struct ifsregion saveifs, *savelastp;
427	struct nodelist *saveargbackq;
428	char lastc;
429	int startloc = dest - stackblock();
430	char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
431	int saveherefd;
432	int quotes = flag & (EXP_FULL \| EXP_CASE);
433
434	INTOFF;
435	saveifs = ifsfirst;
436	savelastp = ifslastp;
437	saveargbackq = argbackq;
438	saveherefd = herefd;
439	herefd = -1;
440	p = grabstackstr(dest);
441	evalbackcmd(cmd, &in);
442	ungrabstackstr(p, dest);
443	ifsfirst = saveifs;
444	ifslastp = savelastp;
445	argbackq = saveargbackq;
446	herefd = saveherefd;
447
448	p = in.buf;
449	lastc = '\0';
450	for (;;) {
451	if (--in.nleft < 0) {
452	if (in.fd < 0)
453	break;
454	while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
455	TRACE(("expbackq: read returns %d\n", i));
456	if (i <= 0)
457	break;
458	p = buf;
459	in.nleft = i - 1;
460	}
461	lastc = *p++;
462	if (lastc != '\0') {
463	if (quotes && syntax[(int)lastc] == CCTL)
464	STPUTC(CTLESC, dest);
465	STPUTC(lastc, dest);
466	}
467	}
468
469	/* Eat all trailing newlines */
470	p = stackblock() + startloc;
471	while (dest > p && dest[-1] == '\n')
472	STUNPUTC(dest);
473
474	if (in.fd >= 0)
475	close(in.fd);
476	if (in.buf)
477	ckfree(in.buf);
478	if (in.jp)
479	back_exitstatus = waitforjob(in.jp);
480	if (quoted == 0)
481	recordregion(startloc, dest - stackblock(), 0);
482	TRACE(("evalbackq: size=%d: \"%.*s\"\n",
483	(dest - stackblock()) - startloc,
484	(dest - stackblock()) - startloc,
485	stackblock() + startloc));
486	expdest = dest;
487	INTON;
488	}
489
490
491
492	STATIC int
493	subevalvar(char p, char str, int strloc, int subtype, int startloc, int varflags)
494	{
495	char *startp;
496	char *loc = NULL;
497	char *q;
498	int c = 0;
499	int saveherefd = herefd;
500	struct nodelist *saveargbackq = argbackq;
501	int amount;
502
503	herefd = -1;
504	argstr(p, 0);
505	STACKSTRNUL(expdest);
506	herefd = saveherefd;
507	argbackq = saveargbackq;
508	startp = stackblock() + startloc;
509	if (str == NULL)
510	str = stackblock() + strloc;
511
512	switch (subtype) {
513	case VSASSIGN:
514	setvar(str, startp, 0);
515	amount = startp - expdest;
516	STADJUST(amount, expdest);
517	varflags &= ~VSNUL;
518	if (c != 0)
519	*loc = c;
520	return 1;
521
522	case VSQUESTION:
523	if (*p != CTLENDVAR) {
524	outfmt(&errout, "%s\n", startp);
525	error((char *)NULL);
526	}
527	error("%.*s: parameter %snot set", p - str - 1,
528	str, (varflags & VSNUL) ? "null or "
529	: nullstr);
530	/* NOTREACHED */
531
532	case VSTRIMLEFT:
533	for (loc = startp; loc < str; loc++) {
534	c = *loc;
535	*loc = '\0';
536	if (patmatch(str, startp, varflags & VSQUOTE))
537	goto recordleft;
538	*loc = c;
539	if ((varflags & VSQUOTE) && *loc == CTLESC)
540	loc++;
541	}
542	return 0;
543
544	case VSTRIMLEFTMAX:
545	for (loc = str - 1; loc >= startp;) {
546	c = *loc;
547	*loc = '\0';
548	if (patmatch(str, startp, varflags & VSQUOTE))
549	goto recordleft;
550	*loc = c;
551	loc--;
552	if ((varflags & VSQUOTE) && loc > startp &&
553	*(loc - 1) == CTLESC) {
554	for (q = startp; q < loc; q++)
555	if (*q == CTLESC)
556	q++;
557	if (q > loc)
558	loc--;
559	}
560	}
561	return 0;
562
563	case VSTRIMRIGHT:
564	for (loc = str - 1; loc >= startp;) {
565	if (patmatch(str, loc, varflags & VSQUOTE))
566	goto recordright;
567	loc--;
568	if ((varflags & VSQUOTE) && loc > startp &&
569	*(loc - 1) == CTLESC) {
570	for (q = startp; q < loc; q++)
571	if (*q == CTLESC)
572	q++;
573	if (q > loc)
574	loc--;
575	}
576	}
577	return 0;
578
579	case VSTRIMRIGHTMAX:
580	for (loc = startp; loc < str - 1; loc++) {
581	if (patmatch(str, loc, varflags & VSQUOTE))
582	goto recordright;
583	if ((varflags & VSQUOTE) && *loc == CTLESC)
584	loc++;
585	}
586	return 0;
587
588	default:
589	abort();
590	}
591
592	recordleft:
593	*loc = c;
594	amount = ((str - 1) - (loc - startp)) - expdest;
595	STADJUST(amount, expdest);
596	while (loc != str - 1)
597	startp++ = loc++;
598	return 1;
599
600	recordright:
601	amount = loc - expdest;
602	STADJUST(amount, expdest);
603	STPUTC('\0', expdest);
604	STADJUST(-1, expdest);
605	return 1;
606	}
607
608
609	/*
610	* Expand a variable, and return a pointer to the next character in the
611	* input string.
612	*/
613
614	STATIC char *
615	evalvar(char *p, int flag)
616	{
617	int subtype;
618	int varflags;
619	char *var;
620	char *val;
621	int patloc;
622	int c;
623	int set;
624	int special;
625	int startloc;
626	int varlen;
627	int apply_ifs;
628	int quotes = flag & (EXP_FULL \| EXP_CASE);
629
630	varflags = (unsigned char)*p++;
631	subtype = varflags & VSTYPE;
632	var = p;
633	special = !is_name(*p);
634	p = strchr(p, '=') + 1;
635
636	again: /* jump here after setting a variable with ${var=text} */
637	if (special) {
638	set = varisset(var, varflags & VSNUL);
639	val = NULL;
640	} else {
641	val = lookupvar(var);
642	if (val == NULL \|\| ((varflags & VSNUL) && val[0] == '\0')) {
643	val = NULL;
644	set = 0;
645	} else
646	set = 1;
647	}
648
649	varlen = 0;
650	startloc = expdest - stackblock();
651
652	if (!set && uflag) {
653	switch (subtype) {
654	case VSNORMAL:
655	case VSTRIMLEFT:
656	case VSTRIMLEFTMAX:
657	case VSTRIMRIGHT:
658	case VSTRIMRIGHTMAX:
659	case VSLENGTH:
660	error("%.*s: parameter not set", p - var - 1, var);
661	/* NOTREACHED */
662	}
663	}
664
665	if (set && subtype != VSPLUS) {
666	/* insert the value of the variable */
667	if (special) {
668	varvalue(var, varflags & VSQUOTE, subtype, flag);
669	if (subtype == VSLENGTH) {
670	varlen = expdest - stackblock() - startloc;
671	STADJUST(-varlen, expdest);
672	}
673	} else {
674	char const *syntax = (varflags & VSQUOTE) ? DQSYNTAX
675	: BASESYNTAX;
676
677	if (subtype == VSLENGTH) {
678	for (;*val; val++)
679	varlen++;
680	} else {
681	while (*val) {
682	if (quotes && syntax[(int)*val] == CCTL)
683	STPUTC(CTLESC, expdest);
684	STPUTC(*val++, expdest);
685	}
686
687	}
688	}
689	}
690
691
692	apply_ifs = ((varflags & VSQUOTE) == 0 \|\|
693	(*var == '@' && shellparam.nparam != 1));
694
695	switch (subtype) {
696	case VSLENGTH:
697	expdest = cvtnum(varlen, expdest);
698	break;
699
700	case VSNORMAL:
701	break;
702
703	case VSPLUS:
704	set = !set;
705	/* FALLTHROUGH */
706	case VSMINUS:
707	if (!set) {
708	argstr(p, flag \| (apply_ifs ? EXP_IFS_SPLIT : 0));
709	/*
710	* ${x-a b c} doesn't get split, but removing the
711	* 'apply_ifs = 0' apparantly breaks ${1+"$@"}..
712	* ${x-'a b' c} should generate 2 args.
713	*/
714	/* We should have marked stuff already */
715	apply_ifs = 0;
716	}
717	break;
718
719	case VSTRIMLEFT:
720	case VSTRIMLEFTMAX:
721	case VSTRIMRIGHT:
722	case VSTRIMRIGHTMAX:
723	if (!set)
724	break;
725	/*
726	* Terminate the string and start recording the pattern
727	* right after it
728	*/
729	STPUTC('\0', expdest);
730	patloc = expdest - stackblock();
731	if (subevalvar(p, NULL, patloc, subtype,
732	startloc, varflags) == 0) {
733	int amount = (expdest - stackblock() - patloc) + 1;
734	STADJUST(-amount, expdest);
735	}
736	/* Remove any recorded regions beyond start of variable */
737	removerecordregions(startloc);
738	apply_ifs = 1;
739	break;
740
741	case VSASSIGN:
742	case VSQUESTION:
743	if (set)
744	break;
745	if (subevalvar(p, var, 0, subtype, startloc, varflags)) {
746	varflags &= ~VSNUL;
747	/*
748	* Remove any recorded regions beyond
749	* start of variable
750	*/
751	removerecordregions(startloc);
752	goto again;
753	}
754	apply_ifs = 0;
755	break;
756
757	default:
758	abort();
759	}
760
761	if (apply_ifs)
762	recordregion(startloc, expdest - stackblock(),
763	varflags & VSQUOTE);
764
765	if (subtype != VSNORMAL) { /* skip to end of alternative */
766	int nesting = 1;
767	for (;;) {
768	if ((c = *p++) == CTLESC)
769	p++;
770	else if (c == CTLBACKQ \|\| c == (CTLBACKQ\|CTLQUOTE)) {
771	if (set)
772	argbackq = argbackq->next;
773	} else if (c == CTLVAR) {
774	if ((*p++ & VSTYPE) != VSNORMAL)
775	nesting++;
776	} else if (c == CTLENDVAR) {
777	if (--nesting == 0)
778	break;
779	}
780	}
781	}
782	return p;
783	}
784
785
786
787	/*
788	* Test whether a specialized variable is set.
789	*/
790
791	STATIC int
792	varisset(char *name, int nulok)
793	{
794	if (*name == '!')
795	return backgndpid != -1;
796	else if (name == '@' \|\| name == '*') {
797	if (*shellparam.p == NULL)
798	return 0;
799
800	if (nulok) {
801	char **av;
802
803	for (av = shellparam.p; *av; av++)
804	if (**av != '\0')
805	return 1;
806	return 0;
807	}
808	} else if (is_digit(*name)) {
809	char *ap;
810	int num = atoi(name);
811
812	if (num > shellparam.nparam)
813	return 0;
814
815	if (num == 0)
816	ap = arg0;
817	else
818	ap = shellparam.p[num - 1];
819
820	if (nulok && (ap == NULL \|\| *ap == '\0'))
821	return 0;
822	}
823	return 1;
824	}
825
826
827
828	/*
829	* Add the value of a specialized variable to the stack string.
830	*/
831
832	STATIC void
833	varvalue(char *name, int quoted, int subtype, int flag)
834	{
835	int num;
836	char *p;
837	int i;
838	char sep;
839	char **ap;
840	char const *syntax;
841
842	#define STRTODEST(p) \
843	do {\
844	if (flag & (EXP_FULL \| EXP_CASE) && subtype != VSLENGTH) { \
845	syntax = quoted? DQSYNTAX : BASESYNTAX; \
846	while (*p) { \
847	if (syntax[(int)*p] == CCTL) \
848	STPUTC(CTLESC, expdest); \
849	STPUTC(*p++, expdest); \
850	} \
851	} else \
852	while (*p) \
853	STPUTC(*p++, expdest); \
854	} while (0)
855
856
857	switch (*name) {
858	case '$':
859	num = rootpid;
860	goto numvar;
861	case '?':
862	num = exitstatus;
863	goto numvar;
864	case '#':
865	num = shellparam.nparam;
866	goto numvar;
867	case '!':
868	num = backgndpid;
869	numvar:
870	expdest = cvtnum(num, expdest);
871	break;
872	case '-':
873	for (i = 0; optlist[i].name; i++) {
874	if (optlist[i].val)
875	STPUTC(optlist[i].letter, expdest);
876	}
877	break;
878	case '@':
879	if (flag & EXP_FULL && quoted) {
880	for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
881	STRTODEST(p);
882	if (*ap)
883	STPUTC('\0', expdest);
884	}
885	break;
886	}
887	/* fall through */
888	case '*':
889	if (ifsset() != 0)
890	sep = ifsval()[0];
891	else
892	sep = ' ';
893	for (ap = shellparam.p ; (p = *ap++) != NULL ; ) {
894	STRTODEST(p);
895	if (*ap && sep)
896	STPUTC(sep, expdest);
897	}
898	break;
899	case '0':
900	p = arg0;
901	STRTODEST(p);
902	break;
903	default:
904	if (is_digit(*name)) {
905	num = atoi(name);
906	if (num > 0 && num <= shellparam.nparam) {
907	p = shellparam.p[num - 1];
908	STRTODEST(p);
909	}
910	}
911	break;
912	}
913	}
914
915
916
917	/*
918	* Record the fact that we have to scan this region of the
919	* string for IFS characters.
920	*/
921
922	STATIC void
923	recordregion(int start, int end, int inquotes)
924	{
925	struct ifsregion *ifsp;
926
927	if (ifslastp == NULL) {
928	ifsp = &ifsfirst;
929	} else {
930	if (ifslastp->endoff == start
931	&& ifslastp->inquotes == inquotes) {
932	/* extend previous area */
933	ifslastp->endoff = end;
934	return;
935	}
936	ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
937	ifslastp->next = ifsp;
938	}
939	ifslastp = ifsp;
940	ifslastp->next = NULL;
941	ifslastp->begoff = start;
942	ifslastp->endoff = end;
943	ifslastp->inquotes = inquotes;
944	}
945
946
947
948	/*
949	* Break the argument string into pieces based upon IFS and add the
950	* strings to the argument list. The regions of the string to be
951	* searched for IFS characters have been stored by recordregion.
952	*/
953	STATIC void
954	ifsbreakup(char string, struct arglist arglist)
955	{
956	struct ifsregion *ifsp;
957	struct strlist *sp;
958	char *start;
959	char *p;
960	char *q;
961	const char *ifs;
962	const char *ifsspc;
963	int inquotes;
964
965	start = string;
966	ifsspc = NULL;
967	inquotes = 0;
968
969	if (ifslastp == NULL) {
970	/* Return entire argument, IFS doesn't apply to any of it */
971	sp = (struct strlist )stalloc(sizeof sp);
972	sp->text = start;
973	*arglist->lastp = sp;
974	arglist->lastp = &sp->next;
975	return;
976	}
977
978	ifs = ifsset() ? ifsval() : " \t\n";
979
980	for (ifsp = &ifsfirst; ifsp != NULL; ifsp = ifsp->next) {
981	p = string + ifsp->begoff;
982	inquotes = ifsp->inquotes;
983	ifsspc = NULL;
984	while (p < string + ifsp->endoff) {
985	q = p;
986	if (*p == CTLESC)
987	p++;
988	if (inquotes) {
989	/* Only NULs (probably from "$@") end args */
990	if (*p != 0) {
991	p++;
992	continue;
993	}
994	} else {
995	if (!strchr(ifs, *p)) {
996	p++;
997	continue;
998	}
999	ifsspc = strchr(" \t\n", *p);
1000
1001	/* Ignore IFS whitespace at start */
1002	if (q == start && ifsspc != NULL) {
1003	p++;
1004	start = p;
1005	continue;
1006	}
1007	}
1008
1009	/* Save this argument... */
1010	*q = '\0';
1011	sp = (struct strlist )stalloc(sizeof sp);
1012	sp->text = start;
1013	*arglist->lastp = sp;
1014	arglist->lastp = &sp->next;
1015	p++;
1016
1017	if (ifsspc != NULL) {
1018	/* Ignore further trailing IFS whitespace */
1019	for (; p < string + ifsp->endoff; p++) {
1020	q = p;
1021	if (*p == CTLESC)
1022	p++;
1023	if (strchr(ifs, *p) == NULL) {
1024	p = q;
1025	break;
1026	}
1027	if (strchr(" \t\n", *p) == NULL) {
1028	p++;
1029	break;
1030	}
1031	}
1032	}
1033	start = p;
1034	}
1035	}
1036
1037	/*
1038	* Save anything left as an argument.
1039	* Traditionally we have treated 'IFS=':'; set -- x$IFS' as
1040	* generating 2 arguments, the second of which is empty.
1041	* Some recent clarification of the Posix spec say that it
1042	* should only generate one....
1043	*/
1044	if (start / \|\| (!ifsspc && start > string) */) {
1045	sp = (struct strlist )stalloc(sizeof sp);
1046	sp->text = start;
1047	*arglist->lastp = sp;
1048	arglist->lastp = &sp->next;
1049	}
1050	}
1051
1052	STATIC void
1053	ifsfree(void)
1054	{
1055	while (ifsfirst.next != NULL) {
1056	struct ifsregion *ifsp;
1057	INTOFF;
1058	ifsp = ifsfirst.next->next;
1059	ckfree(ifsfirst.next);
1060	ifsfirst.next = ifsp;
1061	INTON;
1062	}
1063	ifslastp = NULL;
1064	ifsfirst.next = NULL;
1065	}
1066
1067
1068
1069	/*
1070	* Expand shell metacharacters. At this point, the only control characters
1071	* should be escapes. The results are stored in the list exparg.
1072	*/
1073
1074	char *expdir;
1075
1076
1077	STATIC void
1078	expandmeta(struct strlist *str, int flag)
1079	{
1080	char *p;
1081	struct strlist **savelastp;
1082	struct strlist *sp;
1083	char c;
1084	/* TODO - EXP_REDIR */
1085
1086	while (str) {
1087	if (fflag)
1088	goto nometa;
1089	p = str->text;
1090	for (;;) { /* fast check for meta chars */
1091	if ((c = *p++) == '\0')
1092	goto nometa;
1093	if (c == '*' \|\| c == '?' \|\| c == '[' \|\| c == '!')
1094	break;
1095	}
1096	savelastp = exparg.lastp;
1097	INTOFF;
1098	if (expdir == NULL) {
1099	int i = strlen(str->text);
1100	expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
1101	}
1102
1103	expmeta(expdir, str->text);
1104	ckfree(expdir);
1105	expdir = NULL;
1106	INTON;
1107	if (exparg.lastp == savelastp) {
1108	/*
1109	* no matches
1110	*/
1111	nometa:
1112	*exparg.lastp = str;
1113	rmescapes(str->text);
1114	exparg.lastp = &str->next;
1115	} else {
1116	*exparg.lastp = NULL;
1117	savelastp = sp = expsort(savelastp);
1118	while (sp->next != NULL)
1119	sp = sp->next;
1120	exparg.lastp = &sp->next;
1121	}
1122	str = str->next;
1123	}
1124	}
1125
1126
1127	/*
1128	* Do metacharacter (i.e. *, ?, [...]) expansion.
1129	*/
1130
1131	STATIC void
1132	expmeta(char enddir, char name)
1133	{
1134	char *p;
1135	const char *cp;
1136	char *q;
1137	char *start;
1138	char *endname;
1139	int metaflag;
1140	struct stat statb;
1141	DIR *dirp;
1142	struct dirent *dp;
1143	int atend;
1144	int matchdot;
1145
1146	metaflag = 0;
1147	start = name;
1148	for (p = name ; ; p++) {
1149	if (p == '' \|\| *p == '?')
1150	metaflag = 1;
1151	else if (*p == '[') {
1152	q = p + 1;
1153	if (*q == '!')
1154	q++;
1155	for (;;) {
1156	while (*q == CTLQUOTEMARK)
1157	q++;
1158	if (*q == CTLESC)
1159	q++;
1160	if (q == '/' \|\| q == '\0')
1161	break;
1162	if (*++q == ']') {
1163	metaflag = 1;
1164	break;
1165	}
1166	}
1167	} else if (*p == '!' && p[1] == '!' && (p == name \|\| p[-1] == '/')) {
1168	metaflag = 1;
1169	} else if (*p == '\0')
1170	break;
1171	else if (*p == CTLQUOTEMARK)
1172	continue;
1173	else if (*p == CTLESC)
1174	p++;
1175	if (*p == '/') {
1176	if (metaflag)
1177	break;
1178	start = p + 1;
1179	}
1180	}
1181	if (metaflag == 0) { /* we've reached the end of the file name */
1182	if (enddir != expdir)
1183	metaflag++;
1184	for (p = name ; ; p++) {
1185	if (*p == CTLQUOTEMARK)
1186	continue;
1187	if (*p == CTLESC)
1188	p++;
1189	enddir++ = p;
1190	if (*p == '\0')
1191	break;
1192	}
1193	if (metaflag == 0 \|\| lstat(expdir, &statb) >= 0)
1194	addfname(expdir);
1195	return;
1196	}
1197	endname = p;
1198	if (start != name) {
1199	p = name;
1200	while (p < start) {
1201	while (*p == CTLQUOTEMARK)
1202	p++;
1203	if (*p == CTLESC)
1204	p++;
1205	enddir++ = p++;
1206	}
1207	}
1208	if (enddir == expdir) {
1209	cp = ".";
1210	} else if (enddir == expdir + 1 && *expdir == '/') {
1211	cp = "/";
1212	} else {
1213	cp = expdir;
1214	enddir[-1] = '\0';
1215	}
1216	if ((dirp = opendir(cp)) == NULL)
1217	return;
1218	if (enddir != expdir)
1219	enddir[-1] = '/';
1220	if (*endname == 0) {
1221	atend = 1;
1222	} else {
1223	atend = 0;
1224	*endname++ = '\0';
1225	}
1226	matchdot = 0;
1227	p = start;
1228	while (*p == CTLQUOTEMARK)
1229	p++;
1230	if (*p == CTLESC)
1231	p++;
1232	if (*p == '.')
1233	matchdot++;
1234	while (! int_pending() && (dp = readdir(dirp)) != NULL) {
1235	if (dp->d_name[0] == '.' && ! matchdot)
1236	continue;
1237	if (patmatch(start, dp->d_name, 0)) {
1238	if (atend) {
1239	scopy(dp->d_name, enddir);
1240	addfname(expdir);
1241	} else {
1242	for (p = enddir, cp = dp->d_name;
1243	(p++ = cp++) != '\0';)
1244	continue;
1245	p[-1] = '/';
1246	expmeta(p, endname);
1247	}
1248	}
1249	}
1250	closedir(dirp);
1251	if (! atend)
1252	endname[-1] = '/';
1253	}
1254
1255
1256	/*
1257	* Add a file name to the list.
1258	*/
1259
1260	STATIC void
1261	addfname(char *name)
1262	{
1263	char *p;
1264	struct strlist *sp;
1265
1266	p = stalloc(strlen(name) + 1);
1267	scopy(name, p);
1268	sp = (struct strlist )stalloc(sizeof sp);
1269	sp->text = p;
1270	*exparg.lastp = sp;
1271	exparg.lastp = &sp->next;
1272	}
1273
1274
1275	/*
1276	* Sort the results of file name expansion. It calculates the number of
1277	* strings to sort and then calls msort (short for merge sort) to do the
1278	* work.
1279	*/
1280
1281	STATIC struct strlist *
1282	expsort(struct strlist *str)
1283	{
1284	int len;
1285	struct strlist *sp;
1286
1287	len = 0;
1288	for (sp = str ; sp ; sp = sp->next)
1289	len++;
1290	return msort(str, len);
1291	}
1292
1293
1294	STATIC struct strlist *
1295	msort(struct strlist *list, int len)
1296	{
1297	struct strlist p, q = NULL;
1298	struct strlist **lpp;
1299	int half;
1300	int n;
1301
1302	if (len <= 1)
1303	return list;
1304	half = len >> 1;
1305	p = list;
1306	for (n = half ; --n >= 0 ; ) {
1307	q = p;
1308	p = p->next;
1309	}
1310	q->next = NULL; /* terminate first half of list */
1311	q = msort(list, half); /* sort first half of list */
1312	p = msort(p, len - half); /* sort second half */
1313	lpp = &list;
1314	for (;;) {
1315	if (strcmp(p->text, q->text) < 0) {
1316	*lpp = p;
1317	lpp = &p->next;
1318	if ((p = *lpp) == NULL) {
1319	*lpp = q;
1320	break;
1321	}
1322	} else {
1323	*lpp = q;
1324	lpp = &q->next;
1325	if ((q = *lpp) == NULL) {
1326	*lpp = p;
1327	break;
1328	}
1329	}
1330	}
1331	return list;
1332	}
1333
1334
1335
1336	/*
1337	* Returns true if the pattern matches the string.
1338	*/
1339
1340	int
1341	patmatch(char pattern, char string, int squoted)
1342	{
1343	#ifdef notdef
1344	if (pattern[0] == '!' && pattern[1] == '!')
1345	return 1 - pmatch(pattern + 2, string);
1346	else
1347	#endif
1348	return pmatch(pattern, string, squoted);
1349	}
1350
1351
1352	STATIC int
1353	pmatch(char pattern, char string, int squoted)
1354	{
1355	char p, q;
1356	char c;
1357
1358	p = pattern;
1359	q = string;
1360	for (;;) {
1361	switch (c = *p++) {
1362	case '\0':
1363	goto breakloop;
1364	case CTLESC:
1365	if (squoted && *q == CTLESC)
1366	q++;
1367	if (q++ != p++)
1368	return 0;
1369	break;
1370	case CTLQUOTEMARK:
1371	continue;
1372	case '?':
1373	if (squoted && *q == CTLESC)
1374	q++;
1375	if (*q++ == '\0')
1376	return 0;
1377	break;
1378	case '*':
1379	c = *p;
1380	while (c == CTLQUOTEMARK \|\| c == '*')
1381	c = *++p;
1382	if (c != CTLESC && c != CTLQUOTEMARK &&
1383	c != '?' && c != '*' && c != '[') {
1384	while (*q != c) {
1385	if (squoted && *q == CTLESC &&
1386	q[1] == c)
1387	break;
1388	if (*q == '\0')
1389	return 0;
1390	if (squoted && *q == CTLESC)
1391	q++;
1392	q++;
1393	}
1394	}
1395	do {
1396	if (pmatch(p, q, squoted))
1397	return 1;
1398	if (squoted && *q == CTLESC)
1399	q++;
1400	} while (*q++ != '\0');
1401	return 0;
1402	case '[': {
1403	char *endp;
1404	int invert, found;
1405	char chr;
1406
1407	endp = p;
1408	if (*endp == '!')
1409	endp++;
1410	for (;;) {
1411	while (*endp == CTLQUOTEMARK)
1412	endp++;
1413	if (*endp == '\0')
1414	goto dft; /* no matching ] */
1415	if (*endp == CTLESC)
1416	endp++;
1417	if (*++endp == ']')
1418	break;
1419	}
1420	invert = 0;
1421	if (*p == '!') {
1422	invert++;
1423	p++;
1424	}
1425	found = 0;
1426	chr = *q++;
1427	if (squoted && chr == CTLESC)
1428	chr = *q++;
1429	if (chr == '\0')
1430	return 0;
1431	c = *p++;
1432	do {
1433	if (c == CTLQUOTEMARK)
1434	continue;
1435	if (c == CTLESC)
1436	c = *p++;
1437	if (*p == '-' && p[1] != ']') {
1438	p++;
1439	while (*p == CTLQUOTEMARK)
1440	p++;
1441	if (*p == CTLESC)
1442	p++;
1443	if (chr >= c && chr <= *p)
1444	found = 1;
1445	p++;
1446	} else {
1447	if (chr == c)
1448	found = 1;
1449	}
1450	} while ((c = *p++) != ']');
1451	if (found == invert)
1452	return 0;
1453	break;
1454	}
1455	dft: default:
1456	if (squoted && *q == CTLESC)
1457	q++;
1458	if (*q++ != c)
1459	return 0;
1460	break;
1461	}
1462	}
1463	breakloop:
1464	if (*q != '\0')
1465	return 0;
1466	return 1;
1467	}
1468
1469
1470
1471	/*
1472	* Remove any CTLESC characters from a string.
1473	*/
1474
1475	void
1476	rmescapes(char *str)
1477	{
1478	char p, q;
1479
1480	p = str;
1481	while (p != CTLESC && p != CTLQUOTEMARK) {
1482	if (*p++ == '\0')
1483	return;
1484	}
1485	q = p;
1486	while (*p) {
1487	if (*p == CTLQUOTEMARK) {
1488	p++;
1489	continue;
1490	}
1491	if (*p == CTLESC)
1492	p++;
1493	q++ = p++;
1494	}
1495	*q = '\0';
1496	}
1497
1498
1499
1500	/*
1501	* See if a pattern matches in a case statement.
1502	*/
1503
1504	int
1505	casematch(union node pattern, char val)
1506	{
1507	struct stackmark smark;
1508	int result;
1509	char *p;
1510
1511	setstackmark(&smark);
1512	argbackq = pattern->narg.backquote;
1513	STARTSTACKSTR(expdest);
1514	ifslastp = NULL;
1515	argstr(pattern->narg.text, EXP_TILDE \| EXP_CASE);
1516	STPUTC('\0', expdest);
1517	p = grabstackstr(expdest);
1518	result = patmatch(p, val, 0);
1519	popstackmark(&smark);
1520	return result;
1521	}
1522
1523	/*
1524	* Our own itoa().
1525	*/
1526
1527	STATIC char *
1528	cvtnum(int num, char *buf)
1529	{
1530	char temp[32];
1531	int neg = num < 0;
1532	char *p = temp + 31;
1533
1534	temp[31] = '\0';
1535
1536	do {
1537	*--p = num % 10 + '0';
1538	} while ((num /= 10) != 0);
1539
1540	if (neg)
1541	*--p = '-';
1542
1543	while (*p)
1544	STPUTC(*p++, buf);
1545	return buf;
1546	}
1547
1548	/*
1549	* Do most of the work for wordexp(3).
1550	*/
1551
1552	int
1553	wordexpcmd(int argc, char **argv)
1554	{
1555	size_t len;
1556	int i;
1557
1558	out1fmt("%d", argc - 1);
1559	out1c('\0');
1560	for (i = 1, len = 0; i < argc; i++)
1561	len += strlen(argv[i]);
1562	out1fmt("%zd", len);
1563	out1c('\0');
1564	for (i = 1; i < argc; i++) {
1565	out1str(argv[i]);
1566	out1c('\0');
1567	}
1568	return (0);
1569	}

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source: kBuild/trunk/src/ash-messup/expand.c@ 881

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