xref: /dragonfly/bin/sh/var.c (revision 0d5aaed6) 
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 1.13 2007/01/07 01:14:53 pavalos 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 	const char *text;
76 	void (*func)(const char *);
77 };
78 
79 
80 #ifndef NO_HISTORY
81 struct var vhistsize;
82 #endif
83 struct var vifs;
84 struct var vmail;
85 struct var vmpath;
86 struct var vpath;
87 struct var vppid;
88 struct var vps1;
89 struct var vps2;
90 struct var vps4;
91 struct var vvers;
92 STATIC struct var voptind;
93 
94 STATIC const struct varinit varinit[] = {
95 #ifndef NO_HISTORY
96 	{ &vhistsize,	VSTRFIXED|VTEXTFIXED|VUNSET,	"HISTSIZE=",
97 	  sethistsize },
98 #endif
99 	{ &vifs,	VSTRFIXED|VTEXTFIXED,		"IFS= \t\n",
100 	  NULL },
101 	{ &vmail,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAIL=",
102 	  NULL },
103 	{ &vmpath,	VSTRFIXED|VTEXTFIXED|VUNSET,	"MAILPATH=",
104 	  NULL },
105 	{ &vpath,	VSTRFIXED|VTEXTFIXED,		"PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/pkg/bin:/usr/pkg/sbin",
106 	  changepath },
107 	{ &vppid,	VSTRFIXED|VTEXTFIXED|VUNSET,	"PPID=",
108 	  NULL },
109 	/*
110 	 * vps1 depends on uid
111 	 */
112 	{ &vps2,	VSTRFIXED|VTEXTFIXED,		"PS2=> ",
113 	  NULL },
114 	{ &vps4,	VSTRFIXED|VTEXTFIXED,		"PS4=+ ",
115 	  NULL },
116 	{ &voptind,	VSTRFIXED|VTEXTFIXED,		"OPTIND=1",
117 	  getoptsreset },
118 	{ NULL,	0,				NULL,
119 	  NULL }
120 };
121 
122 STATIC struct var *vartab[VTABSIZE];
123 
124 STATIC struct var **hashvar(const char *);
125 STATIC int varequal(const char *, const char *);
126 STATIC int localevar(const char *);
127 
128 /*
129  * Initialize the variable symbol tables and import the environment.
130  */
131 
132 #ifdef mkinit
133 INCLUDE "var.h"
134 MKINIT char **environ;
135 INIT {
136 	char **envp;
137 
138 	initvar();
139 	for (envp = environ ; *envp ; envp++) {
140 		if (strchr(*envp, '=')) {
141 			setvareq(*envp, VEXPORT|VTEXTFIXED);
142 		}
143 	}
144 }
145 #endif
146 
147 
148 /*
149  * This routine initializes the builtin variables.  It is called when the
150  * shell is initialized and again when a shell procedure is spawned.
151  */
152 
153 void
154 initvar(void)
155 {
156 	char ppid[20];
157 	const struct varinit *ip;
158 	struct var *vp;
159 	struct var **vpp;
160 
161 	for (ip = varinit ; (vp = ip->var) != NULL ; ip++) {
162 		if ((vp->flags & VEXPORT) == 0) {
163 			vpp = hashvar(ip->text);
164 			vp->next = *vpp;
165 			*vpp = vp;
166 			vp->text = strdup(ip->text);
167 			vp->flags = ip->flags;
168 			vp->func = ip->func;
169 		}
170 	}
171 	/*
172 	 * PS1 depends on uid
173 	 */
174 	if ((vps1.flags & VEXPORT) == 0) {
175 		vpp = hashvar("PS1=");
176 		vps1.next = *vpp;
177 		*vpp = &vps1;
178 		vps1.text = strdup(geteuid() ? "PS1=$ " : "PS1=# ");
179 		vps1.flags = VSTRFIXED|VTEXTFIXED;
180 	}
181 	if ((vppid.flags & VEXPORT) == 0) {
182 		fmtstr(ppid, sizeof(ppid), "%d", (int)getppid());
183 		setvarsafe("PPID", ppid, 0);
184 	}
185 }
186 
187 /*
188  * Safe version of setvar, returns 1 on success 0 on failure.
189  */
190 
191 int
192 setvarsafe(const char *name, const char *val, int flags)
193 {
194 	struct jmploc jmploc;
195 	struct jmploc *volatile savehandler = handler;
196 	int err = 0;
197 #if __GNUC__
198 	/* Avoid longjmp clobbering */
199 	(void) &err;
200 #endif
201 
202 	if (setjmp(jmploc.loc))
203 		err = 1;
204 	else {
205 		handler = &jmploc;
206 		setvar(name, val, flags);
207 	}
208 	handler = savehandler;
209 	return err;
210 }
211 
212 /*
213  * Set the value of a variable.  The flags argument is tored with the
214  * flags of the variable.  If val is NULL, the variable is unset.
215  */
216 
217 void
218 setvar(const char *name, const char *val, int flags)
219 {
220 	const char *cp;
221 	char *p;
222 	int len;
223 	int namelen;
224 	char *nameeq;
225 	int isbad;
226 
227 	isbad = 0;
228 	cp = name;
229 	if (!is_name(*cp))
230 		isbad = 1;
231 	cp++;
232 	for (;;) {
233 		if (!is_in_name(*cp)) {
234 			if (*cp == '\0' || *cp == '=')
235 				break;
236 			isbad = 1;
237 		}
238 		cp++;
239 	}
240 	namelen = cp - name;
241 	if (isbad)
242 		error("%.*s: bad variable name", namelen, name);
243 	len = namelen + 2;		/* 2 is space for '=' and '\0' */
244 	if (val == NULL) {
245 		flags |= VUNSET;
246 	} else {
247 		len += strlen(val);
248 	}
249 	p = nameeq = ckmalloc(len);
250 	cp = name;
251 	while (--namelen >= 0)
252 		*p++ = *cp++;
253 	*p++ = '=';
254 	*p = '\0';
255 	if (val)
256 		scopy(val, p);
257 	setvareq(nameeq, flags);
258 }
259 
260 STATIC int
261 localevar(const char *s)
262 {
263 	static const char * const lnames[7] = {
264 		"ALL", "COLLATE", "CTYPE", "MONETARY",
265 		"NUMERIC", "TIME", NULL
266 	};
267 	const char * const *ss;
268 
269 	if (*s != 'L')
270 		return 0;
271 	if (varequal(s + 1, "ANG"))
272 		return 1;
273 	if (strncmp(s + 1, "C_", 2) != 0)
274 		return 0;
275 	for (ss = lnames; *ss ; ss++)
276 		if (varequal(s + 3, *ss))
277 			return 1;
278 	return 0;
279 }
280 
281 /*
282  * Same as setvar except that the variable and value are passed in
283  * the first argument as name=value.  Since the first argument will
284  * be actually stored in the table, it should not be a string that
285  * will go away.
286  */
287 
288 void
289 setvareq(char *s, int flags)
290 {
291 	struct var *vp, **vpp;
292 	int len;
293 
294 	if (aflag)
295 		flags |= VEXPORT;
296 	vpp = hashvar(s);
297 	for (vp = *vpp ; vp ; vp = vp->next) {
298 		if (varequal(s, vp->text)) {
299 			if (vp->flags & VREADONLY) {
300 				len = strchr(s, '=') - s;
301 				error("%.*s: is read only", len, s);
302 			}
303 			INTOFF;
304 
305 			if (vp->func && (flags & VNOFUNC) == 0)
306 				(*vp->func)(strchr(s, '=') + 1);
307 
308 			if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
309 				ckfree(vp->text);
310 
311 			vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
312 			vp->flags |= flags;
313 			vp->text = s;
314 
315 			/*
316 			 * We could roll this to a function, to handle it as
317 			 * a regular variable function callback, but why bother?
318 			 */
319 			if (vp == &vmpath || (vp == &vmail && ! mpathset()))
320 				chkmail(1);
321 			if ((vp->flags & VEXPORT) && localevar(s)) {
322 				if (putenv(s) != 0)
323 					error("putenv: cannot set %s", s);
324 				setlocale(LC_ALL, "");
325 			}
326 			INTON;
327 			return;
328 		}
329 	}
330 	/* not found */
331 	vp = ckmalloc(sizeof (*vp));
332 	vp->flags = flags;
333 	vp->text = s;
334 	vp->next = *vpp;
335 	vp->func = NULL;
336 	INTOFF;
337 	*vpp = vp;
338 	if ((vp->flags & VEXPORT) && localevar(s)) {
339 		if (putenv(s) != 0)
340 			error("putenv: cannot set %s", s);
341 		setlocale(LC_ALL, "");
342 	}
343 	INTON;
344 }
345 
346 
347 
348 /*
349  * Process a linked list of variable assignments.
350  */
351 
352 void
353 listsetvar(struct strlist *list)
354 {
355 	struct strlist *lp;
356 
357 	INTOFF;
358 	for (lp = list ; lp ; lp = lp->next) {
359 		setvareq(savestr(lp->text), 0);
360 	}
361 	INTON;
362 }
363 
364 
365 
366 /*
367  * Find the value of a variable.  Returns NULL if not set.
368  */
369 
370 char *
371 lookupvar(const char *name)
372 {
373 	struct var *v;
374 
375 	for (v = *hashvar(name) ; v ; v = v->next) {
376 		if (varequal(v->text, name)) {
377 			if (v->flags & VUNSET)
378 				return NULL;
379 			return strchr(v->text, '=') + 1;
380 		}
381 	}
382 	return NULL;
383 }
384 
385 
386 
387 /*
388  * Search the environment of a builtin command.  If the second argument
389  * is nonzero, return the value of a variable even if it hasn't been
390  * exported.
391  */
392 
393 char *
394 bltinlookup(const char *name, int doall)
395 {
396 	struct strlist *sp;
397 	struct var *v;
398 
399 	for (sp = cmdenviron ; sp ; sp = sp->next) {
400 		if (varequal(sp->text, name))
401 			return strchr(sp->text, '=') + 1;
402 	}
403 	for (v = *hashvar(name) ; v ; v = v->next) {
404 		if (varequal(v->text, name)) {
405 			if ((v->flags & VUNSET)
406 			 || (!doall && (v->flags & VEXPORT) == 0))
407 				return NULL;
408 			return strchr(v->text, '=') + 1;
409 		}
410 	}
411 	return NULL;
412 }
413 
414 
415 
416 /*
417  * Generate a list of exported variables.  This routine is used to construct
418  * the third argument to execve when executing a program.
419  */
420 
421 char **
422 environment(void)
423 {
424 	int nenv;
425 	struct var **vpp;
426 	struct var *vp;
427 	char **env, **ep;
428 
429 	nenv = 0;
430 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
431 		for (vp = *vpp ; vp ; vp = vp->next)
432 			if (vp->flags & VEXPORT)
433 				nenv++;
434 	}
435 	ep = env = stalloc((nenv + 1) * sizeof *env);
436 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
437 		for (vp = *vpp ; vp ; vp = vp->next)
438 			if (vp->flags & VEXPORT)
439 				*ep++ = vp->text;
440 	}
441 	*ep = NULL;
442 	return env;
443 }
444 
445 
446 /*
447  * Called when a shell procedure is invoked to clear out nonexported
448  * variables.  It is also necessary to reallocate variables of with
449  * VSTACK set since these are currently allocated on the stack.
450  */
451 
452 #ifdef mkinit
453 void shprocvar(void);
454 
455 SHELLPROC {
456 	shprocvar();
457 }
458 #endif
459 
460 void
461 shprocvar(void)
462 {
463 	struct var **vpp;
464 	struct var *vp, **prev;
465 
466 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
467 		for (prev = vpp ; (vp = *prev) != NULL ; ) {
468 			if ((vp->flags & VEXPORT) == 0) {
469 				*prev = vp->next;
470 				if ((vp->flags & VTEXTFIXED) == 0)
471 					ckfree(vp->text);
472 				if ((vp->flags & VSTRFIXED) == 0)
473 					ckfree(vp);
474 			} else {
475 				if (vp->flags & VSTACK) {
476 					vp->text = savestr(vp->text);
477 					vp->flags &=~ VSTACK;
478 				}
479 				prev = &vp->next;
480 			}
481 		}
482 	}
483 	initvar();
484 }
485 
486 
487 
488 /*
489  * Command to list all variables which are set.  Currently this command
490  * is invoked from the set command when the set command is called without
491  * any variables.
492  */
493 
494 int
495 showvarscmd(int argc __unused, char **argv __unused)
496 {
497 	struct var **vpp;
498 	struct var *vp;
499 	const char *s;
500 
501 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
502 		for (vp = *vpp ; vp ; vp = vp->next) {
503 			if (vp->flags & VUNSET)
504 				continue;
505 			for (s = vp->text; *s != '='; s++)
506 				out1c(*s);
507 			out1c('=');
508 			out1qstr(s + 1);
509 			out1c('\n');
510 		}
511 	}
512 	return 0;
513 }
514 
515 
516 
517 /*
518  * The export and readonly commands.
519  */
520 
521 int
522 exportcmd(int argc, char **argv)
523 {
524 	struct var **vpp;
525 	struct var *vp;
526 	char *name;
527 	char *p;
528 	char *cmdname;
529 	int ch, values;
530 	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
531 
532 	cmdname = argv[0];
533 	optreset = optind = 1;
534 	opterr = 0;
535 	values = 0;
536 	while ((ch = getopt(argc, argv, "p")) != -1) {
537 		switch (ch) {
538 		case 'p':
539 			values = 1;
540 			break;
541 		case '?':
542 		default:
543 			error("unknown option: -%c", optopt);
544 		}
545 	}
546 	argc -= optind;
547 	argv += optind;
548 
549 	listsetvar(cmdenviron);
550 	if (argc != 0) {
551 		while ((name = *argptr++) != NULL) {
552 			if ((p = strchr(name, '=')) != NULL) {
553 				p++;
554 			} else {
555 				vpp = hashvar(name);
556 				for (vp = *vpp ; vp ; vp = vp->next) {
557 					if (varequal(vp->text, name)) {
558 
559 						vp->flags |= flag;
560 						if ((vp->flags & VEXPORT) && localevar(vp->text)) {
561 							if (putenv(vp->text) != 0)
562 								error("putenv: cannot set %s", vp->text);
563 							setlocale(LC_ALL, "");
564 						}
565 						goto found;
566 					}
567 				}
568 			}
569 			setvar(name, p, flag);
570 found:;
571 		}
572 	} else {
573 		for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
574 			for (vp = *vpp ; vp ; vp = vp->next) {
575 				if (vp->flags & flag) {
576 					if (values) {
577 						out1str(cmdname);
578 						out1c(' ');
579 					}
580 					for (p = vp->text ; *p != '=' ; p++)
581 						out1c(*p);
582 					if (values && !(vp->flags & VUNSET)) {
583 						out1c('=');
584 						out1qstr(p + 1);
585 					}
586 					out1c('\n');
587 				}
588 			}
589 		}
590 	}
591 	return 0;
592 }
593 
594 
595 /*
596  * The "local" command.
597  */
598 
599 int
600 localcmd(int argc __unused, char **argv __unused)
601 {
602 	char *name;
603 
604 	if (! in_function())
605 		error("Not in a function");
606 	while ((name = *argptr++) != NULL) {
607 		mklocal(name);
608 	}
609 	return 0;
610 }
611 
612 
613 /*
614  * Make a variable a local variable.  When a variable is made local, it's
615  * value and flags are saved in a localvar structure.  The saved values
616  * will be restored when the shell function returns.  We handle the name
617  * "-" as a special case.
618  */
619 
620 void
621 mklocal(char *name)
622 {
623 	struct localvar *lvp;
624 	struct var **vpp;
625 	struct var *vp;
626 
627 	INTOFF;
628 	lvp = ckmalloc(sizeof (struct localvar));
629 	if (name[0] == '-' && name[1] == '\0') {
630 		lvp->text = ckmalloc(sizeof optlist);
631 		memcpy(lvp->text, optlist, sizeof optlist);
632 		vp = NULL;
633 	} else {
634 		vpp = hashvar(name);
635 		for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
636 		if (vp == NULL) {
637 			if (strchr(name, '='))
638 				setvareq(savestr(name), VSTRFIXED);
639 			else
640 				setvar(name, NULL, VSTRFIXED);
641 			vp = *vpp;	/* the new variable */
642 			lvp->text = NULL;
643 			lvp->flags = VUNSET;
644 		} else {
645 			lvp->text = vp->text;
646 			lvp->flags = vp->flags;
647 			vp->flags |= VSTRFIXED|VTEXTFIXED;
648 			if (strchr(name, '='))
649 				setvareq(savestr(name), 0);
650 		}
651 	}
652 	lvp->vp = vp;
653 	lvp->next = localvars;
654 	localvars = lvp;
655 	INTON;
656 }
657 
658 
659 /*
660  * Called after a function returns.
661  */
662 
663 void
664 poplocalvars(void)
665 {
666 	struct localvar *lvp;
667 	struct var *vp;
668 
669 	while ((lvp = localvars) != NULL) {
670 		localvars = lvp->next;
671 		vp = lvp->vp;
672 		if (vp == NULL) {	/* $- saved */
673 			memcpy(optlist, lvp->text, sizeof optlist);
674 			ckfree(lvp->text);
675 		} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
676 			unsetvar(vp->text);
677 		} else {
678 			if ((vp->flags & VTEXTFIXED) == 0)
679 				ckfree(vp->text);
680 			vp->flags = lvp->flags;
681 			vp->text = lvp->text;
682 		}
683 		ckfree(lvp);
684 	}
685 }
686 
687 
688 int
689 setvarcmd(int argc, char **argv)
690 {
691 	if (argc <= 2)
692 		return unsetcmd(argc, argv);
693 	else if (argc == 3)
694 		setvar(argv[1], argv[2], 0);
695 	else
696 		error("List assignment not implemented");
697 	return 0;
698 }
699 
700 
701 /*
702  * The unset builtin command.  We unset the function before we unset the
703  * variable to allow a function to be unset when there is a readonly variable
704  * with the same name.
705  */
706 
707 int
708 unsetcmd(int argc __unused, char **argv __unused)
709 {
710 	char **ap;
711 	int i;
712 	int flg_func = 0;
713 	int flg_var = 0;
714 	int ret = 0;
715 
716 	while ((i = nextopt("vf")) != '\0') {
717 		if (i == 'f')
718 			flg_func = 1;
719 		else
720 			flg_var = 1;
721 	}
722 	if (flg_func == 0 && flg_var == 0)
723 		flg_var = 1;
724 
725 	for (ap = argptr; *ap ; ap++) {
726 		if (flg_func)
727 			ret |= unsetfunc(*ap);
728 		if (flg_var)
729 			ret |= unsetvar(*ap);
730 	}
731 	return ret;
732 }
733 
734 
735 /*
736  * Unset the specified variable.
737  */
738 
739 int
740 unsetvar(const char *s)
741 {
742 	struct var **vpp;
743 	struct var *vp;
744 
745 	vpp = hashvar(s);
746 	for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
747 		if (varequal(vp->text, s)) {
748 			if (vp->flags & VREADONLY)
749 				return (1);
750 			INTOFF;
751 			if (*(strchr(vp->text, '=') + 1) != '\0')
752 				setvar(s, nullstr, 0);
753 			if ((vp->flags & VEXPORT) && localevar(vp->text)) {
754 				unsetenv(s);
755 				setlocale(LC_ALL, "");
756 			}
757 			vp->flags &= ~VEXPORT;
758 			vp->flags |= VUNSET;
759 			if ((vp->flags & VSTRFIXED) == 0) {
760 				if ((vp->flags & VTEXTFIXED) == 0)
761 					ckfree(vp->text);
762 				*vpp = vp->next;
763 				ckfree(vp);
764 			}
765 			INTON;
766 			return (0);
767 		}
768 	}
769 	return (0);
770 }
771 
772 
773 
774 /*
775  * Find the appropriate entry in the hash table from the name.
776  */
777 
778 STATIC struct var **
779 hashvar(const char *p)
780 {
781 	unsigned int hashval;
782 
783 	hashval = ((unsigned char) *p) << 4;
784 	while (*p && *p != '=')
785 		hashval += (unsigned char) *p++;
786 	return &vartab[hashval % VTABSIZE];
787 }
788 
789 
790 
791 /*
792  * Returns true if the two strings specify the same varable.  The first
793  * variable name is terminated by '='; the second may be terminated by
794  * either '=' or '\0'.
795  */
796 
797 STATIC int
798 varequal(const char *p, const char *q)
799 {
800 	while (*p == *q++) {
801 		if (*p++ == '=')
802 			return 1;
803 	}
804 	if (*p == '=' && *(q - 1) == '\0')
805 		return 1;
806 	return 0;
807 }
808