/*      $NetBSD: getsubopt.c,v 1.10 2018/08/30 12:06:06 christos Exp $  */

/*-
* Copyright (c) 1990, 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)getsubopt.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: getsubopt.c,v 1.10 2018/08/30 12:06:06 christos Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include "namespace.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#ifdef __weak_alias
__weak_alias(getsubopt,_getsubopt)
#endif

/*
* The SVID interface to getsubopt provides no way of figuring out which
* part of the suboptions list wasn't matched.  This makes error messages
* tricky...  The extern variable suboptarg is a pointer to the token
* which didn't match.
*/
char *suboptarg;

int
getsubopt(char **optionp, char * const *tokens, char **valuep)
{
       int cnt;
       char *p;

       _DIAGASSERT(tokens != NULL);
       _DIAGASSERT(valuep != NULL);
       /* optionp is tested below */

       suboptarg = *valuep = NULL;

       if (!optionp || !*optionp)
               return(-1);

       /* skip leading white-space, commas */
       for (p = *optionp; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);

       if (!*p) {
               *optionp = p;
               return(-1);
       }

       /* save the start of the token, and skip the rest of the token. */
       for (suboptarg = p;
           *++p && *p != ',' && *p != '=' && *p != ' ' && *p != '\t';);

       if (*p) {
               /*
                * If there's an equals sign, set the value pointer, and
                * skip over the value part of the token.  Terminate the
                * token.
                */
               if (*p == '=') {
                       *p = '\0';
                       for (*valuep = ++p;
                           *p && *p != ',' && *p != ' ' && *p != '\t'; ++p);
                       if (*p)
                               *p++ = '\0';
               } else
                       *p++ = '\0';
               /* Skip any whitespace or commas after this token. */
               for (; *p && (*p == ',' || *p == ' ' || *p == '\t'); ++p);
       }

       /* set optionp for next round. */
       *optionp = p;

       for (cnt = 0; *tokens; ++tokens, ++cnt)
               if (!strcmp(suboptarg, *tokens))
                       return(cnt);
       return(-1);
}