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getsubopt.c revision 1.6 
      1 /*	$NetBSD: getsubopt.c,v 1.6 1999/09/20 04:39:37 lukem 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 #if 0
     39 static char sccsid[] = "@(#)getsubopt.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 __RCSID("$NetBSD: getsubopt.c,v 1.6 1999/09/20 04:39:37 lukem Exp $");
     42 #endif
     43 #endif /* LIBC_SCCS and not lint */
     44 
     45 #include <assert.h>
     46 #include <stdlib.h>
     47 #include <string.h>
     48 #include <unistd.h>
     49 
     50 /*
     51  * The SVID interface to getsubopt provides no way of figuring out which
     52  * part of the suboptions list wasn't matched.  This makes error messages
     53  * tricky...  The extern variable suboptarg is a pointer to the token
     54  * which didn't match.
     55  */
     56 char *suboptarg;
     57 
     58 int
     59 getsubopt(optionp, tokens, valuep)
     60 	char **optionp, **valuep;
     61 	char * const *tokens;
     62 {
     63 	int cnt;
     64 	char *p;
     65 
     66 	_DIAGASSERT(valuep != NULL);
     67 	_DIAGASSERT(tokens != NULL);
     68 	/* optionp is tested below */
     69 
     70 	suboptarg = *valuep = NULL;
     71 
     72 	if (!optionp || !*optionp)
     73 		return(-1);
     74 
     75 	/* skip leading white-space, commas */
     76 	for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
     77 
     78 	if (!*p) {
     79 		*optionp = p;
     80 		return(-1);
     81 	}
     82 
     83 	/* save the start of the token, and skip the rest of the token. */
     84 	for (suboptarg = p;
     85 	    *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
     86 
     87 	if (*p) {
     88 		/*
     89 		 * If there's an equals sign, set the value pointer, and
     90 		 * skip over the value part of the token.  Terminate the
     91 		 * token.
     92 		 */
     93 		if (*p == '=') {
     94 			*p = '\0';
     95 			for (*valuep = ++p;
     96 			    *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
     97 			if (*p)
     98 				*p++ = '\0';
     99 		} else
    100 			*p++ = '\0';
    101 		/* Skip any whitespace or commas after this token. */
    102 		for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
    103 	}
    104 
    105 	/* set optionp for next round. */
    106 	*optionp = p;
    107 
    108 	for (cnt = 0; *tokens; ++tokens, ++cnt)
    109 		if (!strcmp(suboptarg, *tokens))
    110 			return(cnt);
    111 	return(-1);
    112 }
    113