1 /* Parse comma separate list into words.
2    Copyright (C) 1996, 1997, 1999, 2004 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
5 
6    The GNU C Library is free software; you can redistribute it and/or
7    modify it under the terms of the GNU Lesser General Public
8    License as published by the Free Software Foundation; either
9    version 2.1 of the License, or (at your option) any later version.
10 
11    The GNU C Library is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14    Lesser General Public License for more details.
15 
16    You should have received a copy of the GNU Lesser General Public
17    License along with the GNU C Library; if not, see
18    <http://www.gnu.org/licenses/>.  */
19 
20 #include <stdlib.h>
21 #include <string.h>
22 
23 
24 /* Parse comma separated suboption from *OPTIONP and match against
25    strings in TOKENS.  If found return index and set *VALUEP to
26    optional value introduced by an equal sign.  If the suboption is
27    not part of TOKENS return in *VALUEP beginning of unknown
28    suboption.  On exit *OPTIONP is set to the beginning of the next
29    token or at the terminating NUL character.  */
30 int
getsubopt(char ** optionp,char * const * tokens,char ** valuep)31 getsubopt (char **optionp, char *const *tokens, char **valuep)
32 {
33   char *endp, *vstart;
34   int cnt;
35 
36   if (**optionp == '\0')
37     return -1;
38 
39   /* Find end of next token.  */
40   endp = strchrnul (*optionp, ',');
41 
42   /* Find start of value.  */
43   vstart = memchr (*optionp, '=', endp - *optionp);
44   if (vstart == NULL)
45     vstart = endp;
46 
47   /* Try to match the characters between *OPTIONP and VSTART against
48      one of the TOKENS.  */
49   for (cnt = 0; tokens[cnt] != NULL; ++cnt)
50     if (strncmp (*optionp, tokens[cnt], vstart - *optionp) == 0
51 	&& tokens[cnt][vstart - *optionp] == '\0')
52       {
53 	/* We found the current option in TOKENS.  */
54 	*valuep = vstart != endp ? vstart + 1 : NULL;
55 
56 	if (*endp != '\0')
57 	  *endp++ = '\0';
58 	*optionp = endp;
59 
60 	return cnt;
61       }
62 
63   /* The current suboption does not match any option.  */
64   *valuep = *optionp;
65 
66   if (*endp != '\0')
67     *endp++ = '\0';
68   *optionp = endp;
69 
70   return -1;
71 }
72