xref: /dragonfly/bin/sh/var.c (revision 17b61719) 
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 1.4 2004/03/19 18:39:41 cpressey 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 #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(const char *);
136 STATIC int varequal(const char *, const char *);
137 STATIC int localevar(const char *);
138 
139 /*
140  * Initialize the variable 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(const char *name, const 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(const char *name, const char *val, int flags)
230 {
231 	const char *cp;
232 	char *p;
233 	int len;
234 	int namelen;
235 	char *nameeq;
236 	int isbad;
237 
238 	isbad = 0;
239 	cp = name;
240 	if (!is_name(*cp))
241 		isbad = 1;
242 	cp++;
243 	for (;;) {
244 		if (!is_in_name(*cp)) {
245 			if (*cp == '\0' || *cp == '=')
246 				break;
247 			isbad = 1;
248 		}
249 		cp++;
250 	}
251 	namelen = cp - name;
252 	if (isbad)
253 		error("%.*s: bad variable name", namelen, name);
254 	len = namelen + 2;		/* 2 is space for '=' and '\0' */
255 	if (val == NULL) {
256 		flags |= VUNSET;
257 	} else {
258 		len += strlen(val);
259 	}
260 	p = nameeq = ckmalloc(len);
261 	cp = name;
262 	while (--namelen >= 0)
263 		*p++ = *cp++;
264 	*p++ = '=';
265 	*p = '\0';
266 	if (val)
267 		scopy(val, p);
268 	setvareq(nameeq, flags);
269 }
270 
271 STATIC int
272 localevar(const char *s)
273 {
274 	static const char * const lnames[7] = {
275 		"ALL", "COLLATE", "CTYPE", "MONETARY",
276 		"NUMERIC", "TIME", NULL
277 	};
278 	const char * const *ss;
279 
280 	if (*s != 'L')
281 		return 0;
282 	if (varequal(s + 1, "ANG"))
283 		return 1;
284 	if (strncmp(s + 1, "C_", 2) != 0)
285 		return 0;
286 	for (ss = lnames; *ss ; ss++)
287 		if (varequal(s + 3, *ss))
288 			return 1;
289 	return 0;
290 }
291 
292 /*
293  * Same as setvar except that the variable and value are passed in
294  * the first argument as name=value.  Since the first argument will
295  * be actually stored in the table, it should not be a string that
296  * will go away.
297  */
298 
299 void
300 setvareq(char *s, int flags)
301 {
302 	struct var *vp, **vpp;
303 	int len;
304 
305 	if (aflag)
306 		flags |= VEXPORT;
307 	vpp = hashvar(s);
308 	for (vp = *vpp ; vp ; vp = vp->next) {
309 		if (varequal(s, vp->text)) {
310 			if (vp->flags & VREADONLY) {
311 				len = strchr(s, '=') - s;
312 				error("%.*s: is read only", len, s);
313 			}
314 			INTOFF;
315 
316 			if (vp->func && (flags & VNOFUNC) == 0)
317 				(*vp->func)(strchr(s, '=') + 1);
318 
319 			if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
320 				ckfree(vp->text);
321 
322 			vp->flags &= ~(VTEXTFIXED|VSTACK|VUNSET);
323 			vp->flags |= flags;
324 			vp->text = s;
325 
326 			/*
327 			 * We could roll this to a function, to handle it as
328 			 * a regular variable function callback, but why bother?
329 			 */
330 			if (vp == &vmpath || (vp == &vmail && ! mpathset()))
331 				chkmail(1);
332 			if ((vp->flags & VEXPORT) && localevar(s)) {
333 				putenv(s);
334 				(void) setlocale(LC_ALL, "");
335 			}
336 			INTON;
337 			return;
338 		}
339 	}
340 	/* not found */
341 	vp = ckmalloc(sizeof (*vp));
342 	vp->flags = flags;
343 	vp->text = s;
344 	vp->next = *vpp;
345 	vp->func = NULL;
346 	INTOFF;
347 	*vpp = vp;
348 	if ((vp->flags & VEXPORT) && localevar(s)) {
349 		putenv(s);
350 		(void) setlocale(LC_ALL, "");
351 	}
352 	INTON;
353 }
354 
355 
356 
357 /*
358  * Process a linked list of variable assignments.
359  */
360 
361 void
362 listsetvar(struct strlist *list)
363 {
364 	struct strlist *lp;
365 
366 	INTOFF;
367 	for (lp = list ; lp ; lp = lp->next) {
368 		setvareq(savestr(lp->text), 0);
369 	}
370 	INTON;
371 }
372 
373 
374 
375 /*
376  * Find the value of a variable.  Returns NULL if not set.
377  */
378 
379 char *
380 lookupvar(const char *name)
381 {
382 	struct var *v;
383 
384 	for (v = *hashvar(name) ; v ; v = v->next) {
385 		if (varequal(v->text, name)) {
386 			if (v->flags & VUNSET)
387 				return NULL;
388 			return strchr(v->text, '=') + 1;
389 		}
390 	}
391 	return NULL;
392 }
393 
394 
395 
396 /*
397  * Search the environment of a builtin command.  If the second argument
398  * is nonzero, return the value of a variable even if it hasn't been
399  * exported.
400  */
401 
402 char *
403 bltinlookup(const char *name, int doall)
404 {
405 	struct strlist *sp;
406 	struct var *v;
407 
408 	for (sp = cmdenviron ; sp ; sp = sp->next) {
409 		if (varequal(sp->text, name))
410 			return strchr(sp->text, '=') + 1;
411 	}
412 	for (v = *hashvar(name) ; v ; v = v->next) {
413 		if (varequal(v->text, name)) {
414 			if ((v->flags & VUNSET)
415 			 || (!doall && (v->flags & VEXPORT) == 0))
416 				return NULL;
417 			return strchr(v->text, '=') + 1;
418 		}
419 	}
420 	return NULL;
421 }
422 
423 
424 
425 /*
426  * Generate a list of exported variables.  This routine is used to construct
427  * the third argument to execve when executing a program.
428  */
429 
430 char **
431 environment(void)
432 {
433 	int nenv;
434 	struct var **vpp;
435 	struct var *vp;
436 	char **env, **ep;
437 
438 	nenv = 0;
439 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
440 		for (vp = *vpp ; vp ; vp = vp->next)
441 			if (vp->flags & VEXPORT)
442 				nenv++;
443 	}
444 	ep = env = stalloc((nenv + 1) * sizeof *env);
445 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
446 		for (vp = *vpp ; vp ; vp = vp->next)
447 			if (vp->flags & VEXPORT)
448 				*ep++ = vp->text;
449 	}
450 	*ep = NULL;
451 	return env;
452 }
453 
454 
455 /*
456  * Called when a shell procedure is invoked to clear out nonexported
457  * variables.  It is also necessary to reallocate variables of with
458  * VSTACK set since these are currently allocated on the stack.
459  */
460 
461 #ifdef mkinit
462 MKINIT void shprocvar(void);
463 
464 SHELLPROC {
465 	shprocvar();
466 }
467 #endif
468 
469 void
470 shprocvar(void)
471 {
472 	struct var **vpp;
473 	struct var *vp, **prev;
474 
475 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
476 		for (prev = vpp ; (vp = *prev) != NULL ; ) {
477 			if ((vp->flags & VEXPORT) == 0) {
478 				*prev = vp->next;
479 				if ((vp->flags & VTEXTFIXED) == 0)
480 					ckfree(vp->text);
481 				if ((vp->flags & VSTRFIXED) == 0)
482 					ckfree(vp);
483 			} else {
484 				if (vp->flags & VSTACK) {
485 					vp->text = savestr(vp->text);
486 					vp->flags &=~ VSTACK;
487 				}
488 				prev = &vp->next;
489 			}
490 		}
491 	}
492 	initvar();
493 }
494 
495 
496 
497 /*
498  * Command to list all variables which are set.  Currently this command
499  * is invoked from the set command when the set command is called without
500  * any variables.
501  */
502 
503 int
504 showvarscmd(int argc __unused, char **argv __unused)
505 {
506 	struct var **vpp;
507 	struct var *vp;
508 	const char *s;
509 
510 	for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
511 		for (vp = *vpp ; vp ; vp = vp->next) {
512 			if (vp->flags & VUNSET)
513 				continue;
514 			for (s = vp->text; *s != '='; s++)
515 				out1c(*s);
516 			out1c('=');
517 			out1qstr(s + 1);
518 			out1c('\n');
519 		}
520 	}
521 	return 0;
522 }
523 
524 
525 
526 /*
527  * The export and readonly commands.
528  */
529 
530 int
531 exportcmd(int argc, char **argv)
532 {
533 	struct var **vpp;
534 	struct var *vp;
535 	char *name;
536 	char *p;
537 	char *cmdname;
538 	int ch, values;
539 	int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
540 
541 	cmdname = argv[0];
542 	optreset = optind = 1;
543 	opterr = 0;
544 	values = 0;
545 	while ((ch = getopt(argc, argv, "p")) != -1) {
546 		switch (ch) {
547 		case 'p':
548 			values = 1;
549 			break;
550 		case '?':
551 		default:
552 			error("unknown option: -%c", optopt);
553 		}
554 	}
555 	argc -= optind;
556 	argv += optind;
557 
558 	listsetvar(cmdenviron);
559 	if (argc != 0) {
560 		while ((name = *argptr++) != NULL) {
561 			if ((p = strchr(name, '=')) != NULL) {
562 				p++;
563 			} else {
564 				vpp = hashvar(name);
565 				for (vp = *vpp ; vp ; vp = vp->next) {
566 					if (varequal(vp->text, name)) {
567 
568 						vp->flags |= flag;
569 						if ((vp->flags & VEXPORT) && localevar(vp->text)) {
570 							putenv(vp->text);
571 							(void) setlocale(LC_ALL, "");
572 						}
573 						goto found;
574 					}
575 				}
576 			}
577 			setvar(name, p, flag);
578 found:;
579 		}
580 	} else {
581 		for (vpp = vartab ; vpp < vartab + VTABSIZE ; vpp++) {
582 			for (vp = *vpp ; vp ; vp = vp->next) {
583 				if (vp->flags & flag) {
584 					if (values) {
585 						out1str(cmdname);
586 						out1c(' ');
587 					}
588 					for (p = vp->text ; *p != '=' ; p++)
589 						out1c(*p);
590 					if (values && !(vp->flags & VUNSET)) {
591 						out1c('=');
592 						out1qstr(p + 1);
593 					}
594 					out1c('\n');
595 				}
596 			}
597 		}
598 	}
599 	return 0;
600 }
601 
602 
603 /*
604  * The "local" command.
605  */
606 
607 int
608 localcmd(int argc __unused, char **argv __unused)
609 {
610 	char *name;
611 
612 	if (! in_function())
613 		error("Not in a function");
614 	while ((name = *argptr++) != NULL) {
615 		mklocal(name);
616 	}
617 	return 0;
618 }
619 
620 
621 /*
622  * Make a variable a local variable.  When a variable is made local, it's
623  * value and flags are saved in a localvar structure.  The saved values
624  * will be restored when the shell function returns.  We handle the name
625  * "-" as a special case.
626  */
627 
628 void
629 mklocal(char *name)
630 {
631 	struct localvar *lvp;
632 	struct var **vpp;
633 	struct var *vp;
634 
635 	INTOFF;
636 	lvp = ckmalloc(sizeof (struct localvar));
637 	if (name[0] == '-' && name[1] == '\0') {
638 		lvp->text = ckmalloc(sizeof optlist);
639 		memcpy(lvp->text, optlist, sizeof optlist);
640 		vp = NULL;
641 	} else {
642 		vpp = hashvar(name);
643 		for (vp = *vpp ; vp && ! varequal(vp->text, name) ; vp = vp->next);
644 		if (vp == NULL) {
645 			if (strchr(name, '='))
646 				setvareq(savestr(name), VSTRFIXED);
647 			else
648 				setvar(name, NULL, VSTRFIXED);
649 			vp = *vpp;	/* the new variable */
650 			lvp->text = NULL;
651 			lvp->flags = VUNSET;
652 		} else {
653 			lvp->text = vp->text;
654 			lvp->flags = vp->flags;
655 			vp->flags |= VSTRFIXED|VTEXTFIXED;
656 			if (strchr(name, '='))
657 				setvareq(savestr(name), 0);
658 		}
659 	}
660 	lvp->vp = vp;
661 	lvp->next = localvars;
662 	localvars = lvp;
663 	INTON;
664 }
665 
666 
667 /*
668  * Called after a function returns.
669  */
670 
671 void
672 poplocalvars(void)
673 {
674 	struct localvar *lvp;
675 	struct var *vp;
676 
677 	while ((lvp = localvars) != NULL) {
678 		localvars = lvp->next;
679 		vp = lvp->vp;
680 		if (vp == NULL) {	/* $- saved */
681 			memcpy(optlist, lvp->text, sizeof optlist);
682 			ckfree(lvp->text);
683 		} else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
684 			(void)unsetvar(vp->text);
685 		} else {
686 			if ((vp->flags & VTEXTFIXED) == 0)
687 				ckfree(vp->text);
688 			vp->flags = lvp->flags;
689 			vp->text = lvp->text;
690 		}
691 		ckfree(lvp);
692 	}
693 }
694 
695 
696 int
697 setvarcmd(int argc, char **argv)
698 {
699 	if (argc <= 2)
700 		return unsetcmd(argc, argv);
701 	else if (argc == 3)
702 		setvar(argv[1], argv[2], 0);
703 	else
704 		error("List assignment not implemented");
705 	return 0;
706 }
707 
708 
709 /*
710  * The unset builtin command.  We unset the function before we unset the
711  * variable to allow a function to be unset when there is a readonly variable
712  * with the same name.
713  */
714 
715 int
716 unsetcmd(int argc __unused, char **argv __unused)
717 {
718 	char **ap;
719 	int i;
720 	int flg_func = 0;
721 	int flg_var = 0;
722 	int ret = 0;
723 
724 	while ((i = nextopt("vf")) != '\0') {
725 		if (i == 'f')
726 			flg_func = 1;
727 		else
728 			flg_var = 1;
729 	}
730 	if (flg_func == 0 && flg_var == 0)
731 		flg_var = 1;
732 
733 	for (ap = argptr; *ap ; ap++) {
734 		if (flg_func)
735 			ret |= unsetfunc(*ap);
736 		if (flg_var)
737 			ret |= unsetvar(*ap);
738 	}
739 	return ret;
740 }
741 
742 
743 /*
744  * Unset the specified variable.
745  */
746 
747 int
748 unsetvar(const char *s)
749 {
750 	struct var **vpp;
751 	struct var *vp;
752 
753 	vpp = hashvar(s);
754 	for (vp = *vpp ; vp ; vpp = &vp->next, vp = *vpp) {
755 		if (varequal(vp->text, s)) {
756 			if (vp->flags & VREADONLY)
757 				return (1);
758 			INTOFF;
759 			if (*(strchr(vp->text, '=') + 1) != '\0')
760 				setvar(s, nullstr, 0);
761 			if ((vp->flags & VEXPORT) && localevar(vp->text)) {
762 				unsetenv(s);
763 				setlocale(LC_ALL, "");
764 			}
765 			vp->flags &= ~VEXPORT;
766 			vp->flags |= VUNSET;
767 			if ((vp->flags & VSTRFIXED) == 0) {
768 				if ((vp->flags & VTEXTFIXED) == 0)
769 					ckfree(vp->text);
770 				*vpp = vp->next;
771 				ckfree(vp);
772 			}
773 			INTON;
774 			return (0);
775 		}
776 	}
777 
778 	return (1);
779 }
780 
781 
782 
783 /*
784  * Find the appropriate entry in the hash table from the name.
785  */
786 
787 STATIC struct var **
788 hashvar(const char *p)
789 {
790 	unsigned int hashval;
791 
792 	hashval = ((unsigned char) *p) << 4;
793 	while (*p && *p != '=')
794 		hashval += (unsigned char) *p++;
795 	return &vartab[hashval % VTABSIZE];
796 }
797 
798 
799 
800 /*
801  * Returns true if the two strings specify the same varable.  The first
802  * variable name is terminated by '='; the second may be terminated by
803  * either '=' or '\0'.
804  */
805 
806 STATIC int
807 varequal(const char *p, const char *q)
808 {
809 	while (*p == *q++) {
810 		if (*p++ == '=')
811 			return 1;
812 	}
813 	if (*p == '=' && *(q - 1) == '\0')
814 		return 1;
815 	return 0;
816 }
817