xref: /dragonfly/bin/sh/var.c (revision af79c6e5) 
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Kenneth Almquist.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  * @(#)var.c	8.3 (Berkeley) 5/4/95
37  * $FreeBSD: src/bin/sh/var.c,v 1.15.2.2 2002/08/27 01:36:28 tjr Exp $
38  * $DragonFly: src/bin/sh/var.c,v 1.3 2003/08/24 16:26:00 drhodus Exp $
39  */
40 
41 #include <unistd.h>
42 #include <stdlib.h>
43 
44 /*
45  * Shell variables.
46  */
47 
48 #include <locale.h>
49 
50 #include "shell.h"
51 #include "output.h"
52 #include "expand.h"
53 #include "nodes.h"	/* for other headers */
54 #include "eval.h"	/* defines cmdenviron */
55 #include "exec.h"
56 #include "syntax.h"
57 #include "options.h"
58 #include "mail.h"
59 #include "var.h"
60 #include "memalloc.h"
61 #include "error.h"
62 #include "mystring.h"
63 #include "parser.h"
64 #ifndef NO_HISTORY
65 #include "myhistedit.h"
66 #endif
67 
68 
69 #define VTABSIZE 39
70 
71 
72 struct varinit {
73 	struct var *var;
74 	int flags;
75 	char *text;
76 	void (*func)(const char *);
77 };
78 
79 
80 #if ATTY
81 struct var vatty;
82 #endif
83 #ifndef NO_HISTORY
84 struct var vhistsize;
85 #endif
86 struct var vifs;
87 struct var vmail;
88 struct var vmpath;
89 struct var vpath;
90 struct var vppid;
91 struct var vps1;
92 struct var vps2;
93 struct var vvers;
94 #if ATTY
95 STATIC struct var vterm;
96 #endif
97 STATIC struct var voptind;
98 
99 STATIC const struct varinit varinit[] = {
100 #if ATTY
101 	{ &vatty,	VSTRFIXED|VTEXTFIXED|VUNSET,	"ATTY=",
102 	  NULL },
103 #endif
104 #ifndef NO_HISTORY
105 	{ &vhistsize,	VSTRFIXED|VTEXTFIXED|VUNSET,	"HISTSIZE=",
106 	  sethistsize },
107 #endif
108 	{ &vifs,	VSTRFIXED|VTEXTFIXED,		"IFS= \t\n",
109 	  NULL },
110 	{ &vmail,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAIL=",
111 	  NULL },
112 	{ &vmpath,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAILPATH=",
113 	  NULL },
114 	{ &vpath,	VSTRFIXED|VTEXTFIXED,		"PATH=/bin:/usr/bin",
115 	  changepath },
116 	{ &vppid,	VSTRFIXED|VTEXTFIXED|VUNSET,	"PPID=",
117 	  NULL },
118 	/*
119 	 * vps1 depends on uid
120 	 */
121 	{ &vps2,	VSTRFIXED|VTEXTFIXED,		"PS2=> ",
122 	  NULL },
123 #if ATTY
124 	{ &vterm,	VSTRFIXED|VTEXTFIXED|VUNSET,	"TERM=",
125 	  NULL },
126 #endif
127 	{ &voptind,	VSTRFIXED|VTEXTFIXED,		"OPTIND=1",
128 	  getoptsreset },
129 	{ NULL,	0,				NULL,
130 	  NULL }
131 };
132 
133 STATIC struct var *vartab[VTABSIZE];
134 
135 STATIC struct var **hashvar(char *);
136 STATIC int varequal(char *, char *);
137 STATIC int localevar(char *);
138 
139 /*
140  * Initialize the varable symbol tables and import the environment
141  */
142 
143 #ifdef mkinit
144 INCLUDE "var.h"
145 INIT {
146 	char **envp;
147 	extern char **environ;
148 
149 	initvar();
150 	for (envp = environ ; *envp ; envp++) {
151 		if (strchr(*envp, '=')) {
152 			setvareq(*envp, VEXPORT|VTEXTFIXED);
153 		}
154 	}
155 }
156 #endif
157 
158 
159 /*
160  * This routine initializes the builtin variables.  It is called when the
161  * shell is initialized and again when a shell procedure is spawned.
162  */
163 
164 void
165 initvar(void)
166 {
167 	char ppid[20];
168 	const struct varinit *ip;
169 	struct var *vp;
170 	struct var **vpp;
171 
172 	for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
173 		if ((vp->flags & VEXPORT) == 0) {
174 			vpp = hashvar(ip->text);
175 			vp->next = *vpp;
176 			*vpp = vp;
177 			vp->text = ip->text;
178 			vp->flags = ip->flags;
179 			vp->func = ip->func;
180 		}
181 	}
182 	/*
183 	 * PS1 depends on uid
184 	 */
185 	if ((vps1.flags & VEXPORT) == 0) {
186 		vpp = hashvar("PS1=");
187 		vps1.next = *vpp;
188 		*vpp = &vps1;
189 		vps1.text = geteuid() ? "PS1=$ " : "PS1=# ";
190 		vps1.flags = VSTRFIXED|VTEXTFIXED;
191 	}
192 	if ((vppid.flags & VEXPORT) == 0) {
193 		fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
194 		setvarsafe("PPID", ppid, 0);
195 	}
196 }
197 
198 /*
199  * Safe version of setvar, returns 1 on success 0 on failure.
200  */
201 
202 int
203 setvarsafe(char *name, char *val, int flags)
204 {
205 	struct jmploc jmploc;
206 	struct jmploc *volatile savehandler = handler;
207 	int err = 0;
208 #if __GNUC__
209 	/* Avoid longjmp clobbering */
210 	(void) &err;
211 #endif
212 
213 	if (setjmp(jmploc.loc))
214 		err = 1;
215 	else {
216 		handler = &jmploc;
217 		setvar(name, val, flags);
218 	}
219 	handler = savehandler;
220 	return err;
221 }
222 
223 /*
224  * Set the value of a variable.  The flags argument is tored with the
225  * flags of the variable.  If val is NULL, the variable is unset.
226  */
227 
228 void
229 setvar(char *name, char *val, int flags)
230 {
231 	char *p, *q;
232 	int len;
233 	int namelen;
234 	char *nameeq;
235 	int isbad;
236 
237 	isbad = 0;
238 	p = name;
239 	if (! is_name(*p))
240 		isbad = 1;
241 	p++;
242 	for (;;) {
243 		if (! is_in_name(*p)) {
244 			if (*p == '\0' || *p == '=')
245 				break;
246 			isbad = 1;
247 		}
248 		p++;
249 	}
250 	namelen = p - name;
251 	if (isbad)
252 		error("%.*s: bad variable name", namelen, name);
253 	len = namelen + 2;		/* 2 is space for '=' and '\0' */
254 	if (val == NULL) {
255 		flags |= VUNSET;
256 	} else {
257 		len += strlen(val);
258 	}
259 	p = nameeq = ckmalloc(len);
260 	q = name;
261 	while (--namelen >= 0)
262 		*p++ = *q++;
263 	*p++ = '=';
264 	*p = '\0';
265 	if (val)
266 		scopy(val, p);
267 	setvareq(nameeq, flags);
268 }
269 
270 STATIC int
271 localevar(char *s)
272 {
273 	static char *lnames[7] = {
274 		"ALL", "COLLATE", "CTYPE", "MONETARY",
275 		"NUMERIC", "TIME", NULL
276 	};
277 	char **ss;
278 
279 	if (*s != 'L')
280 		return 0;
281 	if (varequal(s + 1, "ANG"))
282 		return 1;
283 	if (strncmp(s + 1, "C_", 2) != 0)
284 		return 0;
285 	for (ss = lnames; *ss ; ss++)
286 		if (varequal(s + 3, *ss))
287 			return 1;
288 	return 0;
289 }
290 
291 /*
292  * Same as setvar except that the variable and value are passed in
293  * the first argument as name=value.  Since the first argument will
294  * be actually stored in the table, it should not be a string that
295  * will go away.
296  */
297 
298 void
299 setvareq(char *s, int flags)
300 {
301 	struct var *vp, **vpp;
302 	int len;
303 
304 	if (aflag)
305 		flags |= VEXPORT;
306 	vpp = hashvar(s);
307 	for (vp = *vpp ; vp ; vp = vp->next) {
308 		if (varequal(s, vp->text)) {
309 			if (vp->flags & VREADONLY) {
310 				len = strchr(s, '=') - s;
311 				error("%.*s: is read only", len, s);
312 			}
313 			INTOFF;
314 
315 			if (vp->func && (flags & VNOFUNC) == 0)
316 				(*vp->func)(strchr(s, '=') + 1);
317 
318 			if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
319 				ckfree(vp->text);
320 
321 			vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
322 			vp->flags |= flags;
323 			vp->text = s;
324 
325 			/*
326 			 * We could roll this to a function, to handle it as
327 			 * a regular variable function callback, but why bother?
328 			 */
329 			if (vp == &vmpath || (vp == &vmail && ! mpathset()))
330 				chkmail(1);
331 			if ((vp->flags & VEXPORT) && localevar(s)) {
332 				putenv(s);
333 				(void) setlocale(LC_ALL, "");
334 			}
335 			INTON;
336 			return;
337 		}
338 	}
339 	/* not found */
340 	vp = ckmalloc(sizeof (*vp));
341 	vp->flags = flags;
342 	vp->text = s;
343 	vp->next = *vpp;
344 	vp->func = NULL;
345 	INTOFF;
346 	*vpp = vp;
347 	if ((vp->flags & VEXPORT) && localevar(s)) {
348 		putenv(s);
349 		(void) setlocale(LC_ALL, "");
350 	}
351 	INTON;
352 }
353 
354 
355 
356 /*
357  * Process a linked list of variable assignments.
358  */
359 
360 void
361 listsetvar(struct strlist *list)
362 {
363 	struct strlist *lp;
364 
365 	INTOFF;
366 	for (lp = list ; lp ; lp = lp->next) {
367 		setvareq(savestr(lp->text), 0);
368 	}
369 	INTON;
370 }
371 
372 
373 
374 /*
375  * Find the value of a variable.  Returns NULL if not set.
376  */
377 
378 char *
379 lookupvar(char *name)
380 {
381 	struct var *v;
382 
383 	for (v = *hashvar(name) ; v ; v = v->next) {
384 		if (varequal(v->text, name)) {
385 			if (v->flags & VUNSET)
386 				return NULL;
387 			return strchr(v->text, '=') + 1;
388 		}
389 	}
390 	return NULL;
391 }
392 
393 
394 
395 /*
396  * Search the environment of a builtin command.  If the second argument
397  * is nonzero, return the value of a variable even if it hasn't been
398  * exported.
399  */
400 
401 char *
402 bltinlookup(char *name, int doall)
403 {
404 	struct strlist *sp;
405 	struct var *v;
406 
407 	for (sp = cmdenviron ; sp ; sp = sp->next) {
408 		if (varequal(sp->text, name))
409 			return strchr(sp->text, '=') + 1;
410 	}
411 	for (v = *hashvar(name) ; v ; v = v->next) {
412 		if (varequal(v->text, name)) {
413 			if ((v->flags & VUNSET)
414 			 || (!doall && (v->flags & VEXPORT) == 0))
415 				return NULL;
416 			return strchr(v->text, '=') + 1;
417 		}
418 	}
419 	return NULL;
420 }
421 
422 
423 
424 /*
425  * Generate a list of exported variables.  This routine is used to construct
426  * the third argument to execve when executing a program.
427  */
428 
429 char **
430 environment(void)
431 {
432 	int nenv;
433 	struct var **vpp;
434 	struct var *vp;
435 	char **env, **ep;
436 
437 	nenv = 0;
438 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
439 		for (vp = *vpp ; vp ; vp = vp->next)
440 			if (vp->flags & VEXPORT)
441 				nenv++;
442 	}
443 	ep = env = stalloc((nenv + 1) * sizeof *env);
444 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
445 		for (vp = *vpp ; vp ; vp = vp->next)
446 			if (vp->flags & VEXPORT)
447 				*ep++ = vp->text;
448 	}
449 	*ep = NULL;
450 	return env;
451 }
452 
453 
454 /*
455  * Called when a shell procedure is invoked to clear out nonexported
456  * variables.  It is also necessary to reallocate variables of with
457  * VSTACK set since these are currently allocated on the stack.
458  */
459 
460 #ifdef mkinit
461 MKINIT void shprocvar();
462 
463 SHELLPROC {
464 	shprocvar();
465 }
466 #endif
467 
468 void
469 shprocvar(void)
470 {
471 	struct var **vpp;
472 	struct var *vp, **prev;
473 
474 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
475 		for (prev = vpp ; (vp = *prev) != NULL ; ) {
476 			if ((vp->flags & VEXPORT) == 0) {
477 				*prev = vp->next;
478 				if ((vp->flags & VTEXTFIXED) == 0)
479 					ckfree(vp->text);
480 				if ((vp->flags & VSTRFIXED) == 0)
481 					ckfree(vp);
482 			} else {
483 				if (vp->flags & VSTACK) {
484 					vp->text = savestr(vp->text);
485 					vp->flags &=~ VSTACK;
486 				}
487 				prev = &vp->next;
488 			}
489 		}
490 	}
491 	initvar();
492 }
493 
494 
495 
496 /*
497  * Command to list all variables which are set.  Currently this command
498  * is invoked from the set command when the set command is called without
499  * any variables.
500  */
501 
502 int
503 showvarscmd(int argc __unused, char **argv __unused)
504 {
505 	struct var **vpp;
506 	struct var *vp;
507 	const char *s;
508 
509 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
510 		for (vp = *vpp ; vp ; vp = vp->next) {
511 			if (vp->flags & VUNSET)
512 				continue;
513 			for (s = vp->text; *s != '='; s++)
514 				out1c(*s);
515 			out1c('=');
516 			out1qstr(s + 1);
517 			out1c('\n');
518 		}
519 	}
520 	return 0;
521 }
522 
523 
524 
525 /*
526  * The export and readonly commands.
527  */
528 
529 int
530 exportcmd(int argc, char **argv)
531 {
532 	struct var **vpp;
533 	struct var *vp;
534 	char *name;
535 	char *p;
536 	char *cmdname;
537 	int ch, values;
538 	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
539 
540 	cmdname = argv[0];
541 	optreset = optind = 1;
542 	opterr = 0;
543 	values = 0;
544 	while ((ch = getopt(argc, argv, "p")) != -1) {
545 		switch (ch) {
546 		case 'p':
547 			values = 1;
548 			break;
549 		case '?':
550 		default:
551 			error("unknown option: -%c", optopt);
552 		}
553 	}
554 	argc -= optind;
555 	argv += optind;
556 
557 	listsetvar(cmdenviron);
558 	if (argc != 0) {
559 		while ((name = *argptr++) != NULL) {
560 			if ((p = strchr(name, '=')) != NULL) {
561 				p++;
562 			} else {
563 				vpp = hashvar(name);
564 				for (vp = *vpp ; vp ; vp = vp->next) {
565 					if (varequal(vp->text, name)) {
566 
567 						vp->flags |= flag;
568 						if ((vp->flags & VEXPORT) && localevar(vp->text)) {
569 							putenv(vp->text);
570 							(void) setlocale(LC_ALL, "");
571 						}
572 						goto found;
573 					}
574 				}
575 			}
576 			setvar(name, p, flag);
577 found:;
578 		}
579 	} else {
580 		for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
581 			for (vp = *vpp ; vp ; vp = vp->next) {
582 				if (vp->flags & flag) {
583 					if (values) {
584 						out1str(cmdname);
585 						out1c(' ');
586 					}
587 					for (p = vp->text ; *p != '=' ; p++)
588 						out1c(*p);
589 					if (values && !(vp->flags & VUNSET)) {
590 						out1c('=');
591 						out1qstr(p + 1);
592 					}
593 					out1c('\n');
594 				}
595 			}
596 		}
597 	}
598 	return 0;
599 }
600 
601 
602 /*
603  * The "local" command.
604  */
605 
606 int
607 localcmd(int argc __unused, char **argv __unused)
608 {
609 	char *name;
610 
611 	if (! in_function())
612 		error("Not in a function");
613 	while ((name = *argptr++) != NULL) {
614 		mklocal(name);
615 	}
616 	return 0;
617 }
618 
619 
620 /*
621  * Make a variable a local variable.  When a variable is made local, it's
622  * value and flags are saved in a localvar structure.  The saved values
623  * will be restored when the shell function returns.  We handle the name
624  * "-" as a special case.
625  */
626 
627 void
628 mklocal(char *name)
629 {
630 	struct localvar *lvp;
631 	struct var **vpp;
632 	struct var *vp;
633 
634 	INTOFF;
635 	lvp = ckmalloc(sizeof (struct localvar));
636 	if (name[0] == '-' && name[1] == '\0') {
637 		lvp->text = ckmalloc(sizeof optlist);
638 		memcpy(lvp->text, optlist, sizeof optlist);
639 		vp = NULL;
640 	} else {
641 		vpp = hashvar(name);
642 		for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
643 		if (vp == NULL) {
644 			if (strchr(name, '='))
645 				setvareq(savestr(name), VSTRFIXED);
646 			else
647 				setvar(name, NULL, VSTRFIXED);
648 			vp = *vpp;	/* the new variable */
649 			lvp->text = NULL;
650 			lvp->flags = VUNSET;
651 		} else {
652 			lvp->text = vp->text;
653 			lvp->flags = vp->flags;
654 			vp->flags |= VSTRFIXED|VTEXTFIXED;
655 			if (strchr(name, '='))
656 				setvareq(savestr(name), 0);
657 		}
658 	}
659 	lvp->vp = vp;
660 	lvp->next = localvars;
661 	localvars = lvp;
662 	INTON;
663 }
664 
665 
666 /*
667  * Called after a function returns.
668  */
669 
670 void
671 poplocalvars(void)
672 {
673 	struct localvar *lvp;
674 	struct var *vp;
675 
676 	while ((lvp = localvars) != NULL) {
677 		localvars = lvp->next;
678 		vp = lvp->vp;
679 		if (vp == NULL) {	/* $- saved */
680 			memcpy(optlist, lvp->text, sizeof optlist);
681 			ckfree(lvp->text);
682 		} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
683 			(void)unsetvar(vp->text);
684 		} else {
685 			if ((vp->flags & VTEXTFIXED) == 0)
686 				ckfree(vp->text);
687 			vp->flags = lvp->flags;
688 			vp->text = lvp->text;
689 		}
690 		ckfree(lvp);
691 	}
692 }
693 
694 
695 int
696 setvarcmd(int argc, char **argv)
697 {
698 	if (argc <= 2)
699 		return unsetcmd(argc, argv);
700 	else if (argc == 3)
701 		setvar(argv[1], argv[2], 0);
702 	else
703 		error("List assignment not implemented");
704 	return 0;
705 }
706 
707 
708 /*
709  * The unset builtin command.  We unset the function before we unset the
710  * variable to allow a function to be unset when there is a readonly variable
711  * with the same name.
712  */
713 
714 int
715 unsetcmd(int argc __unused, char **argv __unused)
716 {
717 	char **ap;
718 	int i;
719 	int flg_func = 0;
720 	int flg_var = 0;
721 	int ret = 0;
722 
723 	while ((i = nextopt("vf")) != '\0') {
724 		if (i == 'f')
725 			flg_func = 1;
726 		else
727 			flg_var = 1;
728 	}
729 	if (flg_func == 0 && flg_var == 0)
730 		flg_var = 1;
731 
732 	for (ap = argptr; *ap ; ap++) {
733 		if (flg_func)
734 			ret |= unsetfunc(*ap);
735 		if (flg_var)
736 			ret |= unsetvar(*ap);
737 	}
738 	return ret;
739 }
740 
741 
742 /*
743  * Unset the specified variable.
744  */
745 
746 int
747 unsetvar(char *s)
748 {
749 	struct var **vpp;
750 	struct var *vp;
751 
752 	vpp = hashvar(s);
753 	for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
754 		if (varequal(vp->text, s)) {
755 			if (vp->flags & VREADONLY)
756 				return (1);
757 			INTOFF;
758 			if (*(strchr(vp->text, '=') + 1) != '\0')
759 				setvar(s, nullstr, 0);
760 			if ((vp->flags & VEXPORT) && localevar(vp->text)) {
761 				unsetenv(s);
762 				setlocale(LC_ALL, "");
763 			}
764 			vp->flags &= ~VEXPORT;
765 			vp->flags |= VUNSET;
766 			if ((vp->flags & VSTRFIXED) == 0) {
767 				if ((vp->flags & VTEXTFIXED) == 0)
768 					ckfree(vp->text);
769 				*vpp = vp->next;
770 				ckfree(vp);
771 			}
772 			INTON;
773 			return (0);
774 		}
775 	}
776 
777 	return (1);
778 }
779 
780 
781 
782 /*
783  * Find the appropriate entry in the hash table from the name.
784  */
785 
786 STATIC struct var **
787 hashvar(char *p)
788 {
789 	unsigned int hashval;
790 
791 	hashval = ((unsigned char) *p) << 4;
792 	while (*p && *p != '=')
793 		hashval += (unsigned char) *p++;
794 	return &vartab[hashval % VTABSIZE];
795 }
796 
797 
798 
799 /*
800  * Returns true if the two strings specify the same varable.  The first
801  * variable name is terminated by '='; the second may be terminated by
802  * either '=' or '\0'.
803  */
804 
805 STATIC int
806 varequal(char *p, char *q)
807 {
808 	while (*p == *q++) {
809 		if (*p++ == '=')
810 			return 1;
811 	}
812 	if (*p == '=' && *(q - 1) == '\0')
813 		return 1;
814 	return 0;
815 }
816