/* Parse comma separate list into words.

   Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <stdlib.h>

#include <string.h>

#if !_LIBC

/* This code is written for inclusion in gnu-libc, and uses names in

   the namespace reserved for libc.  If we're compiling in gnulib,

   define those names to be the normal ones instead.  */

# include "strchrnul.h"

# undef __strchrnul

# define __strchrnul strchrnul

#endif

/* Parse comma separated suboption from *OPTIONP and match against

   strings in TOKENS.  If found return index and set *VALUEP to

   optional value introduced by an equal sign.  If the suboption is

   not part of TOKENS return in *VALUEP beginning of unknown

   suboption.  On exit *OPTIONP is set to the beginning of the next

   token or at the terminating NUL character.  */

int

getsubopt (char **optionp, char *const *tokens, char **valuep)

{

  char *endp, *vstart;

  int cnt;

  if (**optionp == '\0')

    return -1;

  /* Find end of next token.  */

  endp = __strchrnul (*optionp, ',');

  /* Find start of value.  */

  vstart = memchr (*optionp, '=', endp - *optionp);

  if (vstart == NULL)

    vstart = endp;

  /* Try to match the characters between *OPTIONP and VSTART against

     one of the TOKENS.  */

  for (cnt = 0; tokens[cnt] != NULL; ++cnt)

    if (strncmp (*optionp, tokens[cnt], vstart - *optionp) == 0

	&& tokens[cnt][vstart - *optionp] == '\0')

      {

	/* We found the current option in TOKENS.  */

	*valuep = vstart != endp ? vstart + 1 : NULL;

	if (*endp != '\0')

	  *endp++ = '\0';

	*optionp = endp;

	return cnt;

      }

  /* The current suboption does not match any option.  */

  *valuep = *optionp;

  if (*endp != '\0')

    *endp++ = '\0';

  *optionp = endp;

  return -1;

}