xref: /dragonfly/bin/sh/var.c (revision 984263bc) 
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 
37 #ifndef lint
38 #if 0
39 static char sccsid[] = "@(#)var.c	8.3 (Berkeley) 5/4/95";
40 #endif
41 #endif /* not lint */
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD: src/bin/sh/var.c,v 1.15.2.2 2002/08/27 01:36:28 tjr Exp $");
44 
45 #include <unistd.h>
46 #include <stdlib.h>
47 
48 /*
49  * Shell variables.
50  */
51 
52 #include <locale.h>
53 
54 #include "shell.h"
55 #include "output.h"
56 #include "expand.h"
57 #include "nodes.h"	/* for other headers */
58 #include "eval.h"	/* defines cmdenviron */
59 #include "exec.h"
60 #include "syntax.h"
61 #include "options.h"
62 #include "mail.h"
63 #include "var.h"
64 #include "memalloc.h"
65 #include "error.h"
66 #include "mystring.h"
67 #include "parser.h"
68 #ifndef NO_HISTORY
69 #include "myhistedit.h"
70 #endif
71 
72 
73 #define VTABSIZE 39
74 
75 
76 struct varinit {
77 	struct var *var;
78 	int flags;
79 	char *text;
80 	void (*func)(const char *);
81 };
82 
83 
84 #if ATTY
85 struct var vatty;
86 #endif
87 #ifndef NO_HISTORY
88 struct var vhistsize;
89 #endif
90 struct var vifs;
91 struct var vmail;
92 struct var vmpath;
93 struct var vpath;
94 struct var vppid;
95 struct var vps1;
96 struct var vps2;
97 struct var vvers;
98 #if ATTY
99 struct var vterm;
100 #endif
101 struct var voptind;
102 
103 const struct varinit varinit[] = {
104 #if ATTY
105 	{ &vatty,	VSTRFIXED|VTEXTFIXED|VUNSET,	"ATTY=",
106 	  NULL },
107 #endif
108 #ifndef NO_HISTORY
109 	{ &vhistsize,	VSTRFIXED|VTEXTFIXED|VUNSET,	"HISTSIZE=",
110 	  sethistsize },
111 #endif
112 	{ &vifs,	VSTRFIXED|VTEXTFIXED,		"IFS= \t\n",
113 	  NULL },
114 	{ &vmail,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAIL=",
115 	  NULL },
116 	{ &vmpath,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAILPATH=",
117 	  NULL },
118 	{ &vpath,	VSTRFIXED|VTEXTFIXED,		"PATH=/bin:/usr/bin",
119 	  changepath },
120 	{ &vppid,	VSTRFIXED|VTEXTFIXED|VUNSET,	"PPID=",
121 	  NULL },
122 	/*
123 	 * vps1 depends on uid
124 	 */
125 	{ &vps2,	VSTRFIXED|VTEXTFIXED,		"PS2=> ",
126 	  NULL },
127 #if ATTY
128 	{ &vterm,	VSTRFIXED|VTEXTFIXED|VUNSET,	"TERM=",
129 	  NULL },
130 #endif
131 	{ &voptind,	VSTRFIXED|VTEXTFIXED,		"OPTIND=1",
132 	  getoptsreset },
133 	{ NULL,	0,				NULL,
134 	  NULL }
135 };
136 
137 struct var *vartab[VTABSIZE];
138 
139 STATIC struct var **hashvar(char *);
140 STATIC int varequal(char *, char *);
141 STATIC int localevar(char *);
142 
143 /*
144  * Initialize the varable symbol tables and import the environment
145  */
146 
147 #ifdef mkinit
148 INCLUDE "var.h"
149 INIT {
150 	char **envp;
151 	extern char **environ;
152 
153 	initvar();
154 	for (envp = environ ; *envp ; envp++) {
155 		if (strchr(*envp, '=')) {
156 			setvareq(*envp, VEXPORT|VTEXTFIXED);
157 		}
158 	}
159 }
160 #endif
161 
162 
163 /*
164  * This routine initializes the builtin variables.  It is called when the
165  * shell is initialized and again when a shell procedure is spawned.
166  */
167 
168 void
169 initvar(void)
170 {
171 	char ppid[20];
172 	const struct varinit *ip;
173 	struct var *vp;
174 	struct var **vpp;
175 
176 	for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
177 		if ((vp->flags & VEXPORT) == 0) {
178 			vpp = hashvar(ip->text);
179 			vp->next = *vpp;
180 			*vpp = vp;
181 			vp->text = ip->text;
182 			vp->flags = ip->flags;
183 			vp->func = ip->func;
184 		}
185 	}
186 	/*
187 	 * PS1 depends on uid
188 	 */
189 	if ((vps1.flags & VEXPORT) == 0) {
190 		vpp = hashvar("PS1=");
191 		vps1.next = *vpp;
192 		*vpp = &vps1;
193 		vps1.text = geteuid() ? "PS1=$ " : "PS1=# ";
194 		vps1.flags = VSTRFIXED|VTEXTFIXED;
195 	}
196 	if ((vppid.flags & VEXPORT) == 0) {
197 		fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
198 		setvarsafe("PPID", ppid, 0);
199 	}
200 }
201 
202 /*
203  * Safe version of setvar, returns 1 on success 0 on failure.
204  */
205 
206 int
207 setvarsafe(char *name, char *val, int flags)
208 {
209 	struct jmploc jmploc;
210 	struct jmploc *volatile savehandler = handler;
211 	int err = 0;
212 #if __GNUC__
213 	/* Avoid longjmp clobbering */
214 	(void) &err;
215 #endif
216 
217 	if (setjmp(jmploc.loc))
218 		err = 1;
219 	else {
220 		handler = &jmploc;
221 		setvar(name, val, flags);
222 	}
223 	handler = savehandler;
224 	return err;
225 }
226 
227 /*
228  * Set the value of a variable.  The flags argument is tored with the
229  * flags of the variable.  If val is NULL, the variable is unset.
230  */
231 
232 void
233 setvar(char *name, char *val, int flags)
234 {
235 	char *p, *q;
236 	int len;
237 	int namelen;
238 	char *nameeq;
239 	int isbad;
240 
241 	isbad = 0;
242 	p = name;
243 	if (! is_name(*p))
244 		isbad = 1;
245 	p++;
246 	for (;;) {
247 		if (! is_in_name(*p)) {
248 			if (*p == '\0' || *p == '=')
249 				break;
250 			isbad = 1;
251 		}
252 		p++;
253 	}
254 	namelen = p - name;
255 	if (isbad)
256 		error("%.*s: bad variable name", namelen, name);
257 	len = namelen + 2;		/* 2 is space for '=' and '\0' */
258 	if (val == NULL) {
259 		flags |= VUNSET;
260 	} else {
261 		len += strlen(val);
262 	}
263 	p = nameeq = ckmalloc(len);
264 	q = name;
265 	while (--namelen >= 0)
266 		*p++ = *q++;
267 	*p++ = '=';
268 	*p = '\0';
269 	if (val)
270 		scopy(val, p);
271 	setvareq(nameeq, flags);
272 }
273 
274 STATIC int
275 localevar(char *s)
276 {
277 	static char *lnames[7] = {
278 		"ALL", "COLLATE", "CTYPE", "MONETARY",
279 		"NUMERIC", "TIME", NULL
280 	};
281 	char **ss;
282 
283 	if (*s != 'L')
284 		return 0;
285 	if (varequal(s + 1, "ANG"))
286 		return 1;
287 	if (strncmp(s + 1, "C_", 2) != 0)
288 		return 0;
289 	for (ss = lnames; *ss ; ss++)
290 		if (varequal(s + 3, *ss))
291 			return 1;
292 	return 0;
293 }
294 
295 /*
296  * Same as setvar except that the variable and value are passed in
297  * the first argument as name=value.  Since the first argument will
298  * be actually stored in the table, it should not be a string that
299  * will go away.
300  */
301 
302 void
303 setvareq(char *s, int flags)
304 {
305 	struct var *vp, **vpp;
306 	int len;
307 
308 	if (aflag)
309 		flags |= VEXPORT;
310 	vpp = hashvar(s);
311 	for (vp = *vpp ; vp ; vp = vp->next) {
312 		if (varequal(s, vp->text)) {
313 			if (vp->flags & VREADONLY) {
314 				len = strchr(s, '=') - s;
315 				error("%.*s: is read only", len, s);
316 			}
317 			INTOFF;
318 
319 			if (vp->func && (flags & VNOFUNC) == 0)
320 				(*vp->func)(strchr(s, '=') + 1);
321 
322 			if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
323 				ckfree(vp->text);
324 
325 			vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
326 			vp->flags |= flags;
327 			vp->text = s;
328 
329 			/*
330 			 * We could roll this to a function, to handle it as
331 			 * a regular variable function callback, but why bother?
332 			 */
333 			if (vp == &vmpath || (vp == &vmail && ! mpathset()))
334 				chkmail(1);
335 			if ((vp->flags & VEXPORT) && localevar(s)) {
336 				putenv(s);
337 				(void) setlocale(LC_ALL, "");
338 			}
339 			INTON;
340 			return;
341 		}
342 	}
343 	/* not found */
344 	vp = ckmalloc(sizeof (*vp));
345 	vp->flags = flags;
346 	vp->text = s;
347 	vp->next = *vpp;
348 	vp->func = NULL;
349 	INTOFF;
350 	*vpp = vp;
351 	if ((vp->flags & VEXPORT) && localevar(s)) {
352 		putenv(s);
353 		(void) setlocale(LC_ALL, "");
354 	}
355 	INTON;
356 }
357 
358 
359 
360 /*
361  * Process a linked list of variable assignments.
362  */
363 
364 void
365 listsetvar(struct strlist *list)
366 {
367 	struct strlist *lp;
368 
369 	INTOFF;
370 	for (lp = list ; lp ; lp = lp->next) {
371 		setvareq(savestr(lp->text), 0);
372 	}
373 	INTON;
374 }
375 
376 
377 
378 /*
379  * Find the value of a variable.  Returns NULL if not set.
380  */
381 
382 char *
383 lookupvar(char *name)
384 {
385 	struct var *v;
386 
387 	for (v = *hashvar(name) ; v ; v = v->next) {
388 		if (varequal(v->text, name)) {
389 			if (v->flags & VUNSET)
390 				return NULL;
391 			return strchr(v->text, '=') + 1;
392 		}
393 	}
394 	return NULL;
395 }
396 
397 
398 
399 /*
400  * Search the environment of a builtin command.  If the second argument
401  * is nonzero, return the value of a variable even if it hasn't been
402  * exported.
403  */
404 
405 char *
406 bltinlookup(char *name, int doall)
407 {
408 	struct strlist *sp;
409 	struct var *v;
410 
411 	for (sp = cmdenviron ; sp ; sp = sp->next) {
412 		if (varequal(sp->text, name))
413 			return strchr(sp->text, '=') + 1;
414 	}
415 	for (v = *hashvar(name) ; v ; v = v->next) {
416 		if (varequal(v->text, name)) {
417 			if ((v->flags & VUNSET)
418 			 || (!doall && (v->flags & VEXPORT) == 0))
419 				return NULL;
420 			return strchr(v->text, '=') + 1;
421 		}
422 	}
423 	return NULL;
424 }
425 
426 
427 
428 /*
429  * Generate a list of exported variables.  This routine is used to construct
430  * the third argument to execve when executing a program.
431  */
432 
433 char **
434 environment(void)
435 {
436 	int nenv;
437 	struct var **vpp;
438 	struct var *vp;
439 	char **env, **ep;
440 
441 	nenv = 0;
442 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
443 		for (vp = *vpp ; vp ; vp = vp->next)
444 			if (vp->flags & VEXPORT)
445 				nenv++;
446 	}
447 	ep = env = stalloc((nenv + 1) * sizeof *env);
448 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
449 		for (vp = *vpp ; vp ; vp = vp->next)
450 			if (vp->flags & VEXPORT)
451 				*ep++ = vp->text;
452 	}
453 	*ep = NULL;
454 	return env;
455 }
456 
457 
458 /*
459  * Called when a shell procedure is invoked to clear out nonexported
460  * variables.  It is also necessary to reallocate variables of with
461  * VSTACK set since these are currently allocated on the stack.
462  */
463 
464 #ifdef mkinit
465 MKINIT void shprocvar();
466 
467 SHELLPROC {
468 	shprocvar();
469 }
470 #endif
471 
472 void
473 shprocvar(void)
474 {
475 	struct var **vpp;
476 	struct var *vp, **prev;
477 
478 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
479 		for (prev = vpp ; (vp = *prev) != NULL ; ) {
480 			if ((vp->flags & VEXPORT) == 0) {
481 				*prev = vp->next;
482 				if ((vp->flags & VTEXTFIXED) == 0)
483 					ckfree(vp->text);
484 				if ((vp->flags & VSTRFIXED) == 0)
485 					ckfree(vp);
486 			} else {
487 				if (vp->flags & VSTACK) {
488 					vp->text = savestr(vp->text);
489 					vp->flags &=~ VSTACK;
490 				}
491 				prev = &vp->next;
492 			}
493 		}
494 	}
495 	initvar();
496 }
497 
498 
499 
500 /*
501  * Command to list all variables which are set.  Currently this command
502  * is invoked from the set command when the set command is called without
503  * any variables.
504  */
505 
506 int
507 showvarscmd(int argc __unused, char **argv __unused)
508 {
509 	struct var **vpp;
510 	struct var *vp;
511 	const char *s;
512 
513 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
514 		for (vp = *vpp ; vp ; vp = vp->next) {
515 			if (vp->flags & VUNSET)
516 				continue;
517 			for (s = vp->text; *s != '='; s++)
518 				out1c(*s);
519 			out1c('=');
520 			out1qstr(s + 1);
521 			out1c('\n');
522 		}
523 	}
524 	return 0;
525 }
526 
527 
528 
529 /*
530  * The export and readonly commands.
531  */
532 
533 int
534 exportcmd(int argc, char **argv)
535 {
536 	struct var **vpp;
537 	struct var *vp;
538 	char *name;
539 	char *p;
540 	char *cmdname;
541 	int ch, values;
542 	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
543 
544 	cmdname = argv[0];
545 	optreset = optind = 1;
546 	opterr = 0;
547 	values = 0;
548 	while ((ch = getopt(argc, argv, "p")) != -1) {
549 		switch (ch) {
550 		case 'p':
551 			values = 1;
552 			break;
553 		case '?':
554 		default:
555 			error("unknown option: -%c", optopt);
556 		}
557 	}
558 	argc -= optind;
559 	argv += optind;
560 
561 	listsetvar(cmdenviron);
562 	if (argc != 0) {
563 		while ((name = *argptr++) != NULL) {
564 			if ((p = strchr(name, '=')) != NULL) {
565 				p++;
566 			} else {
567 				vpp = hashvar(name);
568 				for (vp = *vpp ; vp ; vp = vp->next) {
569 					if (varequal(vp->text, name)) {
570 
571 						vp->flags |= flag;
572 						if ((vp->flags & VEXPORT) && localevar(vp->text)) {
573 							putenv(vp->text);
574 							(void) setlocale(LC_ALL, "");
575 						}
576 						goto found;
577 					}
578 				}
579 			}
580 			setvar(name, p, flag);
581 found:;
582 		}
583 	} else {
584 		for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
585 			for (vp = *vpp ; vp ; vp = vp->next) {
586 				if (vp->flags & flag) {
587 					if (values) {
588 						out1str(cmdname);
589 						out1c(' ');
590 					}
591 					for (p = vp->text ; *p != '=' ; p++)
592 						out1c(*p);
593 					if (values && !(vp->flags & VUNSET)) {
594 						out1c('=');
595 						out1qstr(p + 1);
596 					}
597 					out1c('\n');
598 				}
599 			}
600 		}
601 	}
602 	return 0;
603 }
604 
605 
606 /*
607  * The "local" command.
608  */
609 
610 int
611 localcmd(int argc __unused, char **argv __unused)
612 {
613 	char *name;
614 
615 	if (! in_function())
616 		error("Not in a function");
617 	while ((name = *argptr++) != NULL) {
618 		mklocal(name);
619 	}
620 	return 0;
621 }
622 
623 
624 /*
625  * Make a variable a local variable.  When a variable is made local, it's
626  * value and flags are saved in a localvar structure.  The saved values
627  * will be restored when the shell function returns.  We handle the name
628  * "-" as a special case.
629  */
630 
631 void
632 mklocal(char *name)
633 {
634 	struct localvar *lvp;
635 	struct var **vpp;
636 	struct var *vp;
637 
638 	INTOFF;
639 	lvp = ckmalloc(sizeof (struct localvar));
640 	if (name[0] == '-' && name[1] == '\0') {
641 		lvp->text = ckmalloc(sizeof optlist);
642 		memcpy(lvp->text, optlist, sizeof optlist);
643 		vp = NULL;
644 	} else {
645 		vpp = hashvar(name);
646 		for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
647 		if (vp == NULL) {
648 			if (strchr(name, '='))
649 				setvareq(savestr(name), VSTRFIXED);
650 			else
651 				setvar(name, NULL, VSTRFIXED);
652 			vp = *vpp;	/* the new variable */
653 			lvp->text = NULL;
654 			lvp->flags = VUNSET;
655 		} else {
656 			lvp->text = vp->text;
657 			lvp->flags = vp->flags;
658 			vp->flags |= VSTRFIXED|VTEXTFIXED;
659 			if (strchr(name, '='))
660 				setvareq(savestr(name), 0);
661 		}
662 	}
663 	lvp->vp = vp;
664 	lvp->next = localvars;
665 	localvars = lvp;
666 	INTON;
667 }
668 
669 
670 /*
671  * Called after a function returns.
672  */
673 
674 void
675 poplocalvars(void)
676 {
677 	struct localvar *lvp;
678 	struct var *vp;
679 
680 	while ((lvp = localvars) != NULL) {
681 		localvars = lvp->next;
682 		vp = lvp->vp;
683 		if (vp == NULL) {	/* $- saved */
684 			memcpy(optlist, lvp->text, sizeof optlist);
685 			ckfree(lvp->text);
686 		} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
687 			(void)unsetvar(vp->text);
688 		} else {
689 			if ((vp->flags & VTEXTFIXED) == 0)
690 				ckfree(vp->text);
691 			vp->flags = lvp->flags;
692 			vp->text = lvp->text;
693 		}
694 		ckfree(lvp);
695 	}
696 }
697 
698 
699 int
700 setvarcmd(int argc, char **argv)
701 {
702 	if (argc <= 2)
703 		return unsetcmd(argc, argv);
704 	else if (argc == 3)
705 		setvar(argv[1], argv[2], 0);
706 	else
707 		error("List assignment not implemented");
708 	return 0;
709 }
710 
711 
712 /*
713  * The unset builtin command.  We unset the function before we unset the
714  * variable to allow a function to be unset when there is a readonly variable
715  * with the same name.
716  */
717 
718 int
719 unsetcmd(int argc __unused, char **argv __unused)
720 {
721 	char **ap;
722 	int i;
723 	int flg_func = 0;
724 	int flg_var = 0;
725 	int ret = 0;
726 
727 	while ((i = nextopt("vf")) != '\0') {
728 		if (i == 'f')
729 			flg_func = 1;
730 		else
731 			flg_var = 1;
732 	}
733 	if (flg_func == 0 && flg_var == 0)
734 		flg_var = 1;
735 
736 	for (ap = argptr; *ap ; ap++) {
737 		if (flg_func)
738 			ret |= unsetfunc(*ap);
739 		if (flg_var)
740 			ret |= unsetvar(*ap);
741 	}
742 	return ret;
743 }
744 
745 
746 /*
747  * Unset the specified variable.
748  */
749 
750 int
751 unsetvar(char *s)
752 {
753 	struct var **vpp;
754 	struct var *vp;
755 
756 	vpp = hashvar(s);
757 	for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
758 		if (varequal(vp->text, s)) {
759 			if (vp->flags & VREADONLY)
760 				return (1);
761 			INTOFF;
762 			if (*(strchr(vp->text, '=') + 1) != '\0')
763 				setvar(s, nullstr, 0);
764 			if ((vp->flags & VEXPORT) && localevar(vp->text)) {
765 				unsetenv(s);
766 				setlocale(LC_ALL, "");
767 			}
768 			vp->flags &= ~VEXPORT;
769 			vp->flags |= VUNSET;
770 			if ((vp->flags & VSTRFIXED) == 0) {
771 				if ((vp->flags & VTEXTFIXED) == 0)
772 					ckfree(vp->text);
773 				*vpp = vp->next;
774 				ckfree(vp);
775 			}
776 			INTON;
777 			return (0);
778 		}
779 	}
780 
781 	return (1);
782 }
783 
784 
785 
786 /*
787  * Find the appropriate entry in the hash table from the name.
788  */
789 
790 STATIC struct var **
791 hashvar(char *p)
792 {
793 	unsigned int hashval;
794 
795 	hashval = ((unsigned char) *p) << 4;
796 	while (*p && *p != '=')
797 		hashval += (unsigned char) *p++;
798 	return &vartab[hashval % VTABSIZE];
799 }
800 
801 
802 
803 /*
804  * Returns true if the two strings specify the same varable.  The first
805  * variable name is terminated by '='; the second may be terminated by
806  * either '=' or '\0'.
807  */
808 
809 STATIC int
810 varequal(char *p, char *q)
811 {
812 	while (*p == *q++) {
813 		if (*p++ == '=')
814 			return 1;
815 	}
816 	if (*p == '=' && *(q - 1) == '\0')
817 		return 1;
818 	return 0;
819 }
820