lib/libc/stdlib/getsubopt.c

   1 /*      $NetBSD: getsubopt.c,v 1.9 2012/06/25 22:32:45 abs 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 1.9 2012/06/25 22:32:45 abs 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(char **optionp, char * const *tokens, char **valuep)
  62 {
  63         int cnt;
  64         char *p;
  65
  66         _DIAGASSERT(tokens != NULL);
  67         _DIAGASSERT(valuep != 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 }