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getsubopt.c revision 1.7 
      1 /*	$NetBSD: getsubopt.c,v 1.7 2003/08/07 16:43:40 agc 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 1.7 2003/08/07 16:43:40 agc Exp $");
     38 #endif
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include <assert.h>
     42 #include <stdlib.h>
     43 #include <string.h>
     44 #include <unistd.h>
     45 
     46 /*
     47  * The SVID interface to getsubopt provides no way of figuring out which
     48  * part of the suboptions list wasn't matched.  This makes error messages
     49  * tricky...  The extern variable suboptarg is a pointer to the token
     50  * which didn't match.
     51  */
     52 char *suboptarg;
     53 
     54 int
     55 getsubopt(optionp, tokens, valuep)
     56 	char **optionp, **valuep;
     57 	char * const *tokens;
     58 {
     59 	int cnt;
     60 	char *p;
     61 
     62 	_DIAGASSERT(valuep != NULL);
     63 	_DIAGASSERT(tokens != NULL);
     64 	/* optionp is tested below */
     65 
     66 	suboptarg = *valuep = NULL;
     67 
     68 	if (!optionp || !*optionp)
     69 		return(-1);
     70 
     71 	/* skip leading white-space, commas */
     72 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
     73 
     74 	if (!*p) {
     75 		*optionp = p;
     76 		return(-1);
     77 	}
     78 
     79 	/* save the start of the token, and skip the rest of the token. */
     80 	for (suboptarg = p;
     81 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
     82 
     83 	if (*p) {
     84 		/*
     85 		 * If there's an equals sign, set the value pointer, and
     86 		 * skip over the value part of the token.  Terminate the
     87 		 * token.
     88 		 */
     89 		if (*p == '=') {
     90 			*p = '\0';
     91 			for (*valuep = ++p;
     92 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
     93 			if (*p)
     94 				*p++ = '\0';
     95 		} else
     96 			*p++ = '\0';
     97 		/* Skip any whitespace or commas after this token. */
     98 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
     99 	}
    100 
    101 	/* set optionp for next round. */
    102 	*optionp = p;
    103 
    104 	for (cnt = 0; *tokens; ++tokens, ++cnt)
    105 		if (!strcmp(suboptarg, *tokens))
    106 			return(cnt);
    107 	return(-1);
    108 }
    109