var.c@ 3438

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1	/* $NetBSD: var.c,v 1.36 2004/10/06 10:23:43 enami 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	#if 0
36	#ifndef lint
37	static char sccsid[] = "@(#)var.c 8.3 (Berkeley) 5/4/95";
38	#else
39	__RCSID("$NetBSD: var.c,v 1.36 2004/10/06 10:23:43 enami Exp $");
40	#endif /* not lint */
41	#endif
42
43	#include <assert.h>
44	#include <stddef.h>
45	#include <stdlib.h>
46	#include <string.h>
47
48	#ifdef PC_OS2_LIBPATHS
49	#define INCL_BASE
50	#include <os2.h>
51
52	#ifndef LIBPATHSTRICT
53	#define LIBPATHSTRICT 3
54	#endif
55
56	extern APIRET
57	#ifdef APIENTRY
58	APIENTRY
59	#endif
60	DosQueryHeaderInfo(HMODULE hmod, ULONG ulIndex, PVOID pvBuffer, ULONG cbBuffer, ULONG ulSubFunction);
61	#define QHINF_EXEINFO 1 /* NE exeinfo. */
62	#define QHINF_READRSRCTBL 2 /* Reads from the resource table. */
63	#define QHINF_READFILE 3 /* Reads from the executable file. */
64	#define QHINF_LIBPATHLENGTH 4 /* Gets the libpath length. */
65	#define QHINF_LIBPATH 5 /* Gets the entire libpath. */
66	#define QHINF_FIXENTRY 6 /* NE only */
67	#define QHINF_STE 7 /* NE only */
68	#define QHINF_MAPSEL 8 /* NE only */
69
70	#endif
71
72
73
74	/*
75	* Shell variables.
76	*/
77
78	#include "shell.h"
79	#include "output.h"
80	#include "expand.h"
81	#include "nodes.h" /* for other headers */
82	#include "eval.h" /* defines cmdenviron */
83	#include "exec.h"
84	#include "syntax.h"
85	#include "options.h"
86	#include "mail.h"
87	#include "var.h"
88	#include "memalloc.h"
89	#include "error.h"
90	#include "mystring.h"
91	#include "parser.h"
92	#include "show.h"
93	#ifndef SMALL
94	# include "myhistedit.h"
95	#endif
96	#include "shinstance.h"
97
98	//#ifdef SMALL
99	//#define VTABSIZE 39
100	//#else
101	//#define VTABSIZE 517
102	//#endif
103
104
105	struct varinit {
106	unsigned var_off;
107	int flags;
108	const char *text;
109	void (func)(shinstance , const char *);
110	};
111
112
113	//#if ATTY
114	//struct var vatty;
115	//#endif
116	//#ifndef SMALL
117	//struct var vhistsize;
118	//struct var vterm;
119	//#endif
120	//struct var vifs;
121	//struct var vmail;
122	//struct var vmpath;
123	//struct var vpath;
124	//#ifdef _MSC_VER
125	//struct var vpath2;
126	//#endif
127	//struct var vps1;
128	//struct var vps2;
129	//struct var vps4;
130	//struct var vvers; - unused
131	//struct var voptind;
132
133	#ifdef PC_OS2_LIBPATHS
134	//static struct var libpath_vars[4];
135	static const char * const libpath_envs[4] = {"LIBPATH=", "BEGINLIBPATH=", "ENDLIBPATH=", "LIBPATHSTRICT="};
136	#endif
137
138	const struct varinit varinit[] = {
139	#if ATTY
140	{ offsetof(shinstance, vatty), VSTRFIXED\|VTEXTFIXED\|VUNSET, "ATTY=",
141	NULL },
142	#endif
143	#ifndef SMALL
144	{ offsetof(shinstance, vhistsize), VSTRFIXED\|VTEXTFIXED\|VUNSET, "HISTSIZE=",
145	sethistsize },
146	#endif
147	{ offsetof(shinstance, vifs), VSTRFIXED\|VTEXTFIXED, "IFS= \t\n",
148	NULL },
149	{ offsetof(shinstance, vmail), VSTRFIXED\|VTEXTFIXED\|VUNSET, "MAIL=",
150	NULL },
151	{ offsetof(shinstance, vmpath), VSTRFIXED\|VTEXTFIXED\|VUNSET, "MAILPATH=",
152	NULL },
153	{ offsetof(shinstance, vpath), VSTRFIXED\|VTEXTFIXED, "PATH=" _PATH_DEFPATH,
154	changepath },
155	/*
156	* vps1 depends on uid
157	*/
158	{ offsetof(shinstance, vps2), VSTRFIXED\|VTEXTFIXED, "PS2=> ",
159	NULL },
160	{ offsetof(shinstance, vps4), VSTRFIXED\|VTEXTFIXED, "PS4=+ ",
161	NULL },
162	#ifndef SMALL
163	{ offsetof(shinstance, vterm), VSTRFIXED\|VTEXTFIXED\|VUNSET, "TERM=",
164	setterm },
165	#endif
166	{ offsetof(shinstance, voptind), VSTRFIXED\|VTEXTFIXED\|VNOFUNC, "OPTIND=1",
167	getoptsreset },
168	{ 0, 0, NULL,
169	NULL }
170	};
171
172	//struct var *vartab[VTABSIZE];
173
174	STATIC int strequal(const char , const char );
175	STATIC struct var find_var(shinstance , const char , struct var *, int );
176
177	/*
178	* Initialize the varable symbol tables and import the environment
179	*/
180
181	#ifdef mkinit
182	INCLUDE "var.h"
183
184	INIT {
185	char **envp;
186
187	initvar(psh);
188	for (envp = sh_environ(psh) ; *envp ; envp++) {
189	if (strchr(*envp, '=')) {
190	setvareq(psh, *envp, VEXPORT\|VTEXTFIXED);
191	}
192	}
193	}
194	#endif
195
196
197	/*
198	* This routine initializes the builtin variables. It is called when the
199	* shell is initialized and again when a shell procedure is spawned.
200	*/
201
202	void
203	initvar(shinstance *psh)
204	{
205	const struct varinit *ip;
206	struct var *vp;
207	struct var **vpp;
208	#ifdef PC_OS2_LIBPATHS
209	char *psz = ckmalloc(psh, 2048);
210	int rc;
211	int i;
212
213	for (i = 0; i < 4; i++)
214	{
215	psh->libpath_vars[i].flags = VSTRFIXED \| VOS2LIBPATH;
216	psh->libpath_vars[i].func = NULL;
217
218	if (i > 0)
219	{
220	psz[0] = psz[1] = psz[2] = psz[3] = '\0';
221	rc = DosQueryExtLIBPATH(psz, i);
222	}
223	else
224	{
225	rc = DosQueryHeaderInfo(NULLHANDLE, 0, psz, 2048, QHINF_LIBPATH);
226	psh->libpath_vars[i].flags \|= VREADONLY;
227	}
228	if (!rc && *psz)
229	{
230	int cch1 = strlen(libpath_envs[i]);
231	int cch2 = strlen(psz) + 1;
232	psh->libpath_vars[i].text = ckmalloc(psh, cch1 + cch2);
233	memcpy(psh->libpath_vars[i].text, libpath_envs[i], cch1);
234	memcpy(psh->libpath_vars[i].text + cch1, psz, cch2);
235	}
236	else
237	{
238	psh->libpath_vars[i].flags \|= VUNSET \| VTEXTFIXED;
239	psh->libpath_vars[i].text = (char*)libpath_envs[i];
240	}
241	if (find_var(psh, psh->libpath_vars[i].text, &vpp, &psh->libpath_vars[i].name_len) != NULL)
242	continue;
243	psh->libpath_vars[i].next = *vpp;
244	*vpp = &psh->libpath_vars[i];
245	}
246	ckfree(psh, psz);
247	#endif
248
249	for (ip = varinit; ip->text; ip++) {
250	vp = (struct var )((char )psh + ip->var_off);
251	if (find_var(psh, ip->text, &vpp, &vp->name_len) != NULL)
252	continue;
253	vp->next = *vpp;
254	*vpp = vp;
255	vp->text = sh_strdup(psh, ip->text);
256	vp->flags = ip->flags;
257	vp->func = ip->func;
258	}
259	/*
260	* PS1 depends on uid
261	*/
262	if (find_var(psh, "PS1", &vpp, &psh->vps1.name_len) == NULL) {
263	psh->vps1.next = *vpp;
264	*vpp = &psh->vps1;
265	#ifdef KBUILD_VERSION_MAJOR
266	psh->vps1.text = sh_strdup(psh, sh_geteuid(psh) ? "PS1=kash$ " : "PS1=kash# ");
267	#else
268	psh->vps1.text = sh_strdup(psh, sh_geteuid(psh) ? "PS1=$ " : "PS1=# ");
269	#endif
270	psh->vps1.flags = VSTRFIXED\|VTEXTFIXED;
271	}
272	}
273
274
275	#ifndef SH_FORKED_MODE
276	/*
277	* This routine is called to copy variable state from parent to child shell.
278	*/
279	void
280	subshellinitvar(shinstance psh, shinstance inherit)
281	{
282	unsigned i;
283	for (i = 0; i < K_ELEMENTS(inherit->vartab); i++) {
284	struct var const *vsrc = inherit->vartab[i];
285	if (!vsrc) {
286	} else {
287	struct var **ppdst = &psh->vartab[i];
288	do
289	{
290	struct var *dst;
291	if (!(vsrc->flags & VSTRFIXED)) {
292	dst = (struct var )ckmalloc(psh, sizeof(dst));
293	} else {
294	/* VSTRFIXED is used when the structure is a fixed allocation in
295	the shinstance structure, so scan those to find which it is: */
296	size_t left = ((struct var *)&inherit->vartab[0] - &inherit->vatty);
297	struct var const *fixedsrc = &inherit->vatty;
298	dst = &psh->vatty;
299	while (left-- > 0)
300	if (vsrc != fixedsrc) {
301	fixedsrc++;
302	dst++;
303	} else
304	break;
305	assert(left < 256 /whatever, just no rollover/);
306	}
307	dst = vsrc;
308
309	if (!(vsrc->flags & VTEXTFIXED)) {
310	dst->text = savestr(psh, vsrc->text);
311	dst->flags &= ~VSTACK;
312	}
313
314	*ppdst = dst;
315	ppdst = &dst->next;
316
317	vsrc = vsrc->next;
318	} while (vsrc);
319	*ppdst = NULL;
320	}
321	}
322
323	/** @todo We don't always need to copy local variables. */
324	if (inherit->localvars) {
325	struct localvar const *vsrc = inherit->localvars;
326	struct localvar **ppdst = &psh->localvars;
327	do
328	{
329	struct localvar dst = ckmalloc(psh, sizeof(dst));
330
331	dst->flags = vsrc->flags & ~VSTACK;
332	if (vsrc->flags & VTEXTFIXED)
333	dst->text = savestr(psh, vsrc->text);
334	else
335	dst->text = vsrc->text;
336
337	dst->vp = find_var(psh, vsrc->vp->text, NULL, NULL);
338	assert(dst->vp);
339
340	*ppdst = dst;
341	ppdst = &dst->next;
342
343	vsrc = vsrc->next;
344	} while (vsrc);
345	}
346	}
347	#endif /* !SH_FORKED_MODE */
348
349	/*
350	* Safe version of setvar, returns 1 on success 0 on failure.
351	*/
352
353	int
354	setvarsafe(shinstance psh, const char name, const char *val, int flags)
355	{
356	struct jmploc jmploc;
357	struct jmploc *volatile savehandler = psh->handler;
358	int err = 0;
359	#ifdef __GNUC__
360	(void) &err;
361	#endif
362
363	if (setjmp(jmploc.loc))
364	err = 1;
365	else {
366	psh->handler = &jmploc;
367	setvar(psh, name, val, flags);
368	}
369	psh->handler = savehandler;
370	return err;
371	}
372
373	/*
374	* Set the value of a variable. The flags argument is ored with the
375	* flags of the variable. If val is NULL, the variable is unset.
376	*/
377
378	void
379	setvar(shinstance psh, const char name, const char *val, int flags)
380	{
381	const char *p;
382	const char *q;
383	char *d;
384	size_t len;
385	int namelen;
386	char *nameeq;
387	int isbad;
388
389	isbad = 0;
390	p = name;
391	if (! is_name(*p))
392	isbad = 1;
393	p++;
394	for (;;) {
395	if (! is_in_name(*p)) {
396	if (p == '\0' \|\| p == '=')
397	break;
398	isbad = 1;
399	}
400	p++;
401	}
402	namelen = (int)(p - name);
403	if (isbad)
404	error(psh, "%.*s: bad variable name", namelen, name);
405	len = namelen + 2; /* 2 is space for '=' and '\0' */
406	if (val == NULL) {
407	flags \|= VUNSET;
408	} else {
409	len += strlen(val);
410	}
411	d = nameeq = ckmalloc(psh, len);
412	q = name;
413	while (--namelen >= 0)
414	d++ = q++;
415	*d++ = '=';
416	*d = '\0';
417	if (val)
418	scopy(val, d);
419	setvareq(psh, nameeq, flags);
420	}
421
422
423
424	/*
425	* Same as setvar except that the variable and value are passed in
426	* the first argument as name=value. Since the first argument will
427	* be actually stored in the table, it should not be a string that
428	* will go away.
429	*/
430
431	void
432	setvareq(shinstance psh, char s, int flags)
433	{
434	struct var vp, *vpp;
435	int nlen;
436
437	#if defined(_MSC_VER) \|\| defined(_WIN32)
438	/* On Windows PATH is often spelled 'Path', correct this here. */
439	if ( s[0] == 'P'
440	&& s[1] == 'a'
441	&& s[2] == 't'
442	&& s[3] == 'h'
443	&& (s[4] == '\0' \|\| s[4] == '=') ) {
444	s[1] = 'A';
445	s[2] = 'T';
446	s[3] = 'H';
447	}
448	#endif
449
450	if (aflag(psh))
451	flags \|= VEXPORT;
452	vp = find_var(psh, s, &vpp, &nlen);
453	if (vp != NULL) {
454	if (vp->flags & VREADONLY)
455	error(psh, "%.*s: is read only", vp->name_len, s);
456	if (flags & VNOSET)
457	return;
458	INTOFF;
459
460	if (vp->func && (flags & VNOFUNC) == 0)
461	(*vp->func)(psh, s + vp->name_len + 1);
462
463	if ((vp->flags & (VTEXTFIXED\|VSTACK)) == 0)
464	ckfree(psh, vp->text);
465
466	vp->flags &= ~(VTEXTFIXED\|VSTACK\|VUNSET);
467	vp->flags \|= flags & ~VNOFUNC;
468	vp->text = s;
469	#ifdef PC_OS2_LIBPATHS
470	if ((vp->flags & VOS2LIBPATH) && (vp->flags & VEXPORT))
471	vp->flags &= ~VEXPORT;
472	#endif
473
474	/*
475	* We could roll this to a function, to handle it as
476	* a regular variable function callback, but why bother?
477	*/
478	if (vp == &psh->vmpath \|\| (vp == &psh->vmail && ! mpathset(psh)))
479	chkmail(psh, 1);
480	INTON;
481	return;
482	}
483	/* not found */
484	if (flags & VNOSET)
485	return;
486
487	vp = ckmalloc(psh, sizeof (*vp));
488	vp->flags = flags & ~VNOFUNC;
489	vp->text = s;
490	vp->name_len = nlen;
491	vp->next = *vpp;
492	vp->func = NULL;
493	*vpp = vp;
494	}
495
496
497
498	/*
499	* Process a linked list of variable assignments.
500	*/
501
502	void
503	listsetvar(shinstance psh, struct strlist list, int flags)
504	{
505	struct strlist *lp;
506
507	INTOFF;
508	for (lp = list ; lp ; lp = lp->next) {
509	setvareq(psh, savestr(psh, lp->text), flags);
510	}
511	INTON;
512	}
513
514	void
515	listmklocal(shinstance psh, struct strlist list, int flags)
516	{
517	struct strlist *lp;
518
519	for (lp = list ; lp ; lp = lp->next)
520	mklocal(psh, lp->text, flags);
521	}
522
523
524	/*
525	* Find the value of a variable. Returns NULL if not set.
526	*/
527
528	char *
529	lookupvar(shinstance psh, const char name)
530	{
531	struct var *v;
532
533	v = find_var(psh, name, NULL, NULL);
534	if (v == NULL \|\| v->flags & VUNSET)
535	return NULL;
536	return v->text + v->name_len + 1;
537	}
538
539
540
541	/*
542	* Search the environment of a builtin command. If the second argument
543	* is nonzero, return the value of a variable even if it hasn't been
544	* exported.
545	*/
546
547	char *
548	bltinlookup(shinstance psh, const char name, int doall)
549	{
550	struct strlist *sp;
551	struct var *v;
552
553	for (sp = psh->cmdenviron ; sp ; sp = sp->next) {
554	if (strequal(sp->text, name))
555	return strchr(sp->text, '=') + 1;
556	}
557
558	v = find_var(psh, name, NULL, NULL);
559
560	if (v == NULL \|\| v->flags & VUNSET \|\| (!doall && !(v->flags & VEXPORT)))
561	return NULL;
562	return v->text + v->name_len + 1;
563	}
564
565
566
567	/*
568	* Generate a list of exported variables. This routine is used to construct
569	* the third argument to execve when executing a program.
570	*/
571
572	char **
573	environment(shinstance *psh)
574	{
575	int nenv;
576	struct var **vpp;
577	struct var *vp;
578	char **env;
579	char **ep;
580
581	nenv = 0;
582	for (vpp = psh->vartab ; vpp < psh->vartab + VTABSIZE ; vpp++) {
583	for (vp = *vpp ; vp ; vp = vp->next)
584	if (vp->flags & VEXPORT)
585	nenv++;
586	}
587	ep = env = stalloc(psh, (nenv + 1) * sizeof *env);
588	for (vpp = psh->vartab ; vpp < psh->vartab + VTABSIZE ; vpp++) {
589	for (vp = *vpp ; vp ; vp = vp->next)
590	if (vp->flags & VEXPORT)
591	*ep++ = vp->text;
592	}
593	*ep = NULL;
594
595	#ifdef PC_OS2_LIBPATHS
596	/*
597	* Set the libpaths now as this is exec() time.
598	*/
599	for (nenv = 0; nenv < 3; nenv++)
600	DosSetExtLIBPATH(strchr(psh->libpath_vars[nenv].text, '=') + 1, nenv);
601	#endif
602
603	return env;
604	}
605
606
607	/*
608	* Called when a shell procedure is invoked to clear out nonexported
609	* variables. It is also necessary to reallocate variables of with
610	* VSTACK set since these are currently allocated on the stack.
611	*/
612
613	#ifdef mkinit
614	void shprocvar(shinstance *psh);
615
616	SHELLPROC {
617	shprocvar(psh);
618	}
619	#endif
620
621	void
622	shprocvar(shinstance *psh)
623	{
624	struct var **vpp;
625	struct var vp, *prev;
626
627	for (vpp = psh->vartab ; vpp < psh->vartab + VTABSIZE ; vpp++) {
628	for (prev = vpp ; (vp = *prev) != NULL ; ) {
629	if ((vp->flags & VEXPORT) == 0) {
630	*prev = vp->next;
631	if ((vp->flags & VTEXTFIXED) == 0)
632	ckfree(psh, vp->text);
633	if ((vp->flags & VSTRFIXED) == 0)
634	ckfree(psh, vp);
635	} else {
636	if (vp->flags & VSTACK) {
637	vp->text = savestr(psh, vp->text);
638	vp->flags &=~ VSTACK;
639	}
640	prev = &vp->next;
641	}
642	}
643	}
644	initvar(psh);
645	}
646
647
648
649	/*
650	* Command to list all variables which are set. Currently this command
651	* is invoked from the set command when the set command is called without
652	* any variables.
653	*/
654
655	void
656	print_quoted(shinstance psh, const char p)
657	{
658	const char *q;
659
660	if (strcspn(p, "\|&;<>()$`\\\"' \t\n*?[]#~=%") == strlen(p)) {
661	out1fmt(psh, "%s", p);
662	return;
663	}
664	while (*p) {
665	if (*p == '\'') {
666	out1fmt(psh, "\\'");
667	p++;
668	continue;
669	}
670	q = strchr(p, '\'');
671	if (!q) {
672	out1fmt(psh, "'%s'", p );
673	return;
674	}
675	out1fmt(psh, "'%.*s'", (int)(q - p), p );
676	p = q;
677	}
678	}
679
680	static int
681	sort_var(const void v_v1, const void v_v2)
682	{
683	const struct var * const *v1 = v_v1;
684	const struct var * const *v2 = v_v2;
685
686	/* XXX Will anyone notice we include the '=' of the shorter name? */
687	return strcoll((v1)->text, (v2)->text);
688	}
689
690	/*
691	* POSIX requires that 'set' (but not export or readonly) output the
692	* variables in lexicographic order - by the locale's collating order (sigh).
693	* Maybe we could keep them in an ordered balanced binary tree
694	* instead of hashed lists.
695	* For now just roll 'em through qsort for printing...
696	*/
697
698	int
699	showvars(shinstance psh, const char name, int flag, int show_value)
700	{
701	struct var **vpp;
702	struct var *vp;
703	const char *p;
704
705	static struct var *list; / static in case we are interrupted */
706	static int list_len;
707	int count = 0;
708
709	if (!list) {
710	list_len = 32;
711	list = ckmalloc(psh, list_len * sizeof(*list));
712	}
713
714	for (vpp = psh->vartab ; vpp < psh->vartab + VTABSIZE ; vpp++) {
715	for (vp = *vpp ; vp ; vp = vp->next) {
716	if (flag && !(vp->flags & flag))
717	continue;
718	if (vp->flags & VUNSET && !(show_value & 2))
719	continue;
720	if (count >= list_len) {
721	list = ckrealloc(psh, list,
722	(list_len << 1) * sizeof(*list));
723	list_len <<= 1;
724	}
725	list[count++] = vp;
726	}
727	}
728
729	qsort(list, count, sizeof(*list), sort_var);
730
731	for (vpp = list; count--; vpp++) {
732	vp = *vpp;
733	if (name)
734	out1fmt(psh, "%s ", name);
735	for (p = vp->text ; *p != '=' ; p++)
736	out1c(psh, *p);
737	if (!(vp->flags & VUNSET) && show_value) {
738	out1fmt(psh, "=");
739	print_quoted(psh, ++p);
740	}
741	out1c(psh, '\n');
742	}
743	return 0;
744	}
745
746
747
748	/*
749	* The export and readonly commands.
750	*/
751
752	int
753	exportcmd(shinstance psh, int argc, char *argv)
754	{
755	struct var *vp;
756	char *name;
757	const char *p;
758	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
759	int pflag;
760
761	pflag = nextopt(psh, "p") == 'p' ? 3 : 0;
762	if (argc <= 1 \|\| pflag) {
763	showvars(psh, pflag ? argv[0] : 0, flag, pflag );
764	return 0;
765	}
766
767	while ((name = *psh->argptr++) != NULL) {
768	if ((p = strchr(name, '=')) != NULL) {
769	p++;
770	} else {
771	vp = find_var(psh, name, NULL, NULL);
772	if (vp != NULL) {
773	vp->flags \|= flag;
774	continue;
775	}
776	}
777	setvar(psh, name, p, flag);
778	}
779	return 0;
780	}
781
782
783	/*
784	* The "local" command.
785	*/
786
787	int
788	localcmd(shinstance psh, int argc, char *argv)
789	{
790	char *name;
791
792	if (! in_function(psh))
793	error(psh, "Not in a function");
794	while ((name = *psh->argptr++) != NULL) {
795	mklocal(psh, name, 0);
796	}
797	return 0;
798	}
799
800
801	/*
802	* Make a variable a local variable. When a variable is made local, it's
803	* value and flags are saved in a localvar structure. The saved values
804	* will be restored when the shell function returns. We handle the name
805	* "-" as a special case.
806	*/
807
808	void
809	mklocal(shinstance psh, const char name, int flags)
810	{
811	struct localvar *lvp;
812	struct var **vpp;
813	struct var *vp;
814
815	INTOFF;
816	lvp = ckmalloc(psh, sizeof (struct localvar));
817	if (name[0] == '-' && name[1] == '\0') {
818	char *p;
819	p = ckmalloc(psh, sizeof_optlist);
820	lvp->text = memcpy(p, psh->optlist, sizeof_optlist);
821	vp = NULL;
822	} else {
823	vp = find_var(psh, name, &vpp, NULL);
824	if (vp == NULL) {
825	if (strchr(name, '='))
826	setvareq(psh, savestr(psh, name), VSTRFIXED\|flags);
827	else
828	setvar(psh, name, NULL, VSTRFIXED\|flags);
829	vp = vpp; / the new variable */
830	lvp->text = NULL;
831	lvp->flags = VUNSET;
832	} else {
833	lvp->text = vp->text;
834	lvp->flags = vp->flags;
835	vp->flags \|= VSTRFIXED\|VTEXTFIXED;
836	if (name[vp->name_len] == '=')
837	setvareq(psh, savestr(psh, name), flags);
838	}
839	}
840	lvp->vp = vp;
841	lvp->next = psh->localvars;
842	psh->localvars = lvp;
843	INTON;
844	}
845
846
847	/*
848	* Called after a function returns.
849	*/
850
851	void
852	poplocalvars(shinstance *psh)
853	{
854	struct localvar *lvp;
855	struct var *vp;
856
857	while ((lvp = psh->localvars) != NULL) {
858	psh->localvars = lvp->next;
859	vp = lvp->vp;
860	TRACE((psh, "poplocalvar %s", vp ? vp->text : "-"));
861	if (vp == NULL) { /* $- saved */
862	memcpy(psh->optlist, lvp->text, sizeof_optlist);
863	ckfree(psh, lvp->text);
864	} else if ((lvp->flags & (VUNSET\|VSTRFIXED)) == VUNSET) {
865	(void)unsetvar(psh, vp->text, 0);
866	} else {
867	if (vp->func && (vp->flags & VNOFUNC) == 0)
868	(*vp->func)(psh, lvp->text + vp->name_len + 1);
869	if ((vp->flags & VTEXTFIXED) == 0)
870	ckfree(psh, vp->text);
871	vp->flags = lvp->flags;
872	vp->text = lvp->text;
873	}
874	ckfree(psh, lvp);
875	}
876	}
877
878
879	int
880	setvarcmd(shinstance psh, int argc, char *argv)
881	{
882	if (argc <= 2)
883	return unsetcmd(psh, argc, argv);
884	else if (argc == 3)
885	setvar(psh, argv[1], argv[2], 0);
886	else
887	error(psh, "List assignment not implemented");
888	return 0;
889	}
890
891
892	/*
893	* The unset builtin command. We unset the function before we unset the
894	* variable to allow a function to be unset when there is a readonly variable
895	* with the same name.
896	*/
897
898	int
899	unsetcmd(shinstance psh, int argc, char *argv)
900	{
901	char **ap;
902	int i;
903	int flg_func = 0;
904	int flg_var = 0;
905	int ret = 0;
906
907	while ((i = nextopt(psh, "evf")) != '\0') {
908	if (i == 'f')
909	flg_func = 1;
910	else
911	flg_var = i;
912	}
913	if (flg_func == 0 && flg_var == 0)
914	flg_var = 1;
915
916	for (ap = psh->argptr; *ap ; ap++) {
917	if (flg_func)
918	ret \|= unsetfunc(psh, *ap);
919	if (flg_var)
920	ret \|= unsetvar(psh, *ap, flg_var == 'e');
921	}
922	return ret;
923	}
924
925
926	/*
927	* Unset the specified variable.
928	*/
929
930	int
931	unsetvar(shinstance psh, const char s, int unexport)
932	{
933	struct var **vpp;
934	struct var *vp;
935
936	vp = find_var(psh, s, &vpp, NULL);
937	if (vp == NULL)
938	return 1;
939
940	if (vp->flags & VREADONLY)
941	return (1);
942
943	INTOFF;
944	if (unexport) {
945	vp->flags &= ~VEXPORT;
946	} else {
947	if (vp->text[vp->name_len + 1] != '\0')
948	setvar(psh, s, nullstr, 0);
949	vp->flags &= ~VEXPORT;
950	vp->flags \|= VUNSET;
951	if ((vp->flags & VSTRFIXED) == 0) {
952	if ((vp->flags & VTEXTFIXED) == 0)
953	ckfree(psh, vp->text);
954	*vpp = vp->next;
955	ckfree(psh, vp);
956	}
957	}
958	INTON;
959	return 0;
960	}
961
962
963	/*
964	* Returns true if the two strings specify the same varable. The first
965	* variable name is terminated by '='; the second may be terminated by
966	* either '=' or '\0'.
967	*/
968
969	STATIC int
970	strequal(const char p, const char q)
971	{
972	while (p == q++) {
973	if (*p++ == '=')
974	return 1;
975	}
976	if (p == '=' && (q - 1) == '\0')
977	return 1;
978	return 0;
979	}
980
981	/*
982	* Search for a variable.
983	* 'name' may be terminated by '=' or a NUL.
984	* vppp is set to the pointer to vp, or the list head if vp isn't found
985	* lenp is set to the number of charactets in 'name'
986	*/
987
988	STATIC struct var *
989	find_var(shinstance psh, const char name, struct var **vppp, int lenp)
990	{
991	unsigned int hashval;
992	int len;
993	struct var vp, *vpp;
994	const char *p = name;
995
996	hashval = 0;
997	while (p && p != '=')
998	hashval = 2 * hashval + (unsigned char)*p++;
999	len = (int)(p - name);
1000
1001	if (lenp)
1002	*lenp = len;
1003	vpp = &psh->vartab[hashval % VTABSIZE];
1004	if (vppp)
1005	*vppp = vpp;
1006
1007	for (vp = vpp ; vp ; vpp = &vp->next, vp = vpp) {
1008	if (vp->name_len != len)
1009	continue;
1010	if (memcmp(vp->text, name, len) != 0)
1011	continue;
1012	if (vppp)
1013	*vppp = vpp;
1014	return vp;
1015	}
1016	return NULL;
1017	}

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