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getsubopt.c revision 1.8 
      1 /*	$NetBSD: getsubopt.c,v 1.8 2004/05/09 19:34:11 kleink Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1990, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 #if 0
     35 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
     36 #else
     37 __RCSID("$NetBSD: getsubopt.c,v 1.8 2004/05/09 19:34:11 kleink Exp $");
     38 #endif
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include "namespace.h"
     42 
     43 #include <assert.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 #include <unistd.h>
     47 
     48 #ifdef __weak_alias
     49 __weak_alias(getsubopt,_getsubopt)
     50 #endif
     51 
     52 /*
     53  * The SVID interface to getsubopt provides no way of figuring out which
     54  * part of the suboptions list wasn't matched.  This makes error messages
     55  * tricky...  The extern variable suboptarg is a pointer to the token
     56  * which didn't match.
     57  */
     58 char *suboptarg;
     59 
     60 int
     61 getsubopt(optionp, tokens, valuep)
     62 	char **optionp, **valuep;
     63 	char * const *tokens;
     64 {
     65 	int cnt;
     66 	char *p;
     67 
     68 	_DIAGASSERT(tokens != NULL);
     69 	_DIAGASSERT(valuep != NULL);
     70 	/* optionp is tested below */
     71 
     72 	suboptarg = *valuep = NULL;
     73 
     74 	if (!optionp || !*optionp)
     75 		return(-1);
     76 
     77 	/* skip leading white-space, commas */
     78 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
     79 
     80 	if (!*p) {
     81 		*optionp = p;
     82 		return(-1);
     83 	}
     84 
     85 	/* save the start of the token, and skip the rest of the token. */
     86 	for (suboptarg = p;
     87 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
     88 
     89 	if (*p) {
     90 		/*
     91 		 * If there's an equals sign, set the value pointer, and
     92 		 * skip over the value part of the token.  Terminate the
     93 		 * token.
     94 		 */
     95 		if (*p == '=') {
     96 			*p = '\0';
     97 			for (*valuep = ++p;
     98 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
     99 			if (*p)
    100 				*p++ = '\0';
    101 		} else
    102 			*p++ = '\0';
    103 		/* Skip any whitespace or commas after this token. */
    104 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
    105 	}
    106 
    107 	/* set optionp for next round. */
    108 	*optionp = p;
    109 
    110 	for (cnt = 0; *tokens; ++tokens, ++cnt)
    111 		if (!strcmp(suboptarg, *tokens))
    112 			return(cnt);
    113 	return(-1);
    114 }
    115