lib/libc/stdlib/getsubopt.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)getsubopt.c      8.1 (Berkeley) 6/4/93
  30  * $FreeBSD: src/lib/libc/stdlib/getsubopt.c,v 1.7 2007/01/09 00:28:10 imp Exp $
  31  * $DragonFly: src/lib/libc/stdlib/getsubopt.c,v 1.4 2005/11/20 12:37:48 swildner Exp $
  32  */
  33
  34 #include <stdlib.h>
  35 #include <string.h>
  36
  37 /*
  38  * The SVID interface to getsubopt provides no way of figuring out which
  39  * part of the suboptions list wasn't matched.  This makes error messages
  40  * tricky...  The extern variable suboptarg is a pointer to the token
  41  * which didn't match.
  42  */
  43 char *suboptarg;
  44
  45 int
  46 getsubopt(char **optionp, char * const *tokens, char **valuep)
  47 {
  48         int cnt;
  49         char *p;
  50
  51         suboptarg = *valuep = NULL;
  52
  53         if (!optionp || !*optionp)
  54                 return(-1);
  55
  56         /* skip leading white-space, commas */
  57         for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
  58
  59         if (!*p) {
  60                 *optionp = p;
  61                 return(-1);
  62         }
  63
  64         /* save the start of the token, and skip the rest of the token. */
  65         for (suboptarg = p;
  66             *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
  67
  68         if (*p) {
  69                 /*
  70                  * If there's an equals sign, set the value pointer, and
  71                  * skip over the value part of the token.  Terminate the
  72                  * token.
  73                  */
  74                 if (*p == '=') {
  75                         *p = '\0';
  76                         for (*valuep = ++p;
  77                             *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
  78                         if (*p)
  79                                 *p++ = '\0';
  80                 } else
  81                         *p++ = '\0';
  82                 /* Skip any whitespace or commas after this token. */
  83                 for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
  84         }
  85
  86         /* set optionp for next round. */
  87         *optionp = p;
  88
  89         for (cnt = 0; *tokens; ++tokens, ++cnt)
  90                 if (!strcmp(suboptarg, *tokens))
  91                         return(cnt);
  92         return(-1);
  93 }