newlib/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  * 3. 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
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)getsubopt.c 8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34
  35 #include <unistd.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 /*
  40  * The SVID interface to getsubopt provides no way of figuring out which
  41  * part of the suboptions list wasn't matched.  This makes error messages
  42  * tricky...  The extern variable suboptarg is a pointer to the token
  43  * which didn't match.
  44  */
  45 char *suboptarg;
  46
  47 int
  48 getsubopt(optionp, tokens, valuep)
  49         char **optionp, **valuep;
  50         char * const *tokens;
  51 {
  52         int cnt;
  53         char *p;
  54
  55         suboptarg = *valuep = NULL;
  56
  57         if (!optionp || !*optionp)
  58                 return(-1);
  59
  60         /* skip leading white-space, commas */
  61         for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
  62
  63         if (!*p) {
  64                 *optionp = p;
  65                 return(-1);
  66         }
  67
  68         /* save the start of the token, and skip the rest of the token. */
  69         for (suboptarg = p;
  70             *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);
  71
  72         if (*p) {
  73                 /*
  74                  * If there's an equals sign, set the value pointer, and
  75                  * skip over the value part of the token.  Terminate the
  76                  * token.
  77                  */
  78                 if (*p == '=') {
  79                         *p = '\0';
  80                         for (*valuep = ++p;
  81                             *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
  82                         if (*p)
  83                                 *p++ = '\0';
  84                 } else
  85                         *p++ = '\0';
  86                 /* Skip any whitespace or commas after this token. */
  87                 for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
  88         }
  89
  90         /* set optionp for next round. */
  91         *optionp = p;
  92
  93         for (cnt = 0; *tokens; ++tokens, ++cnt)
  94                 if (!strcmp(suboptarg, *tokens))
  95                         return(cnt);
  96         return(-1);
  97 }