var.c@ 2427

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

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source: kBuild/trunk/src/kash/var.c@ 2427

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