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source: trunk/src/kash/var.c@ 3487

Last change on this file since 3487 was 3477, checked in by bird, 5 years ago
kash: Use kHlpAssert instead of assert.h (debugger stops on the assertion rather than at exit process code).
Property svn:eol-style set to `LF` Property svn:keywords set to `Id`
File size: 21.9 KB

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

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