1/* Parse comma separate list into words.
2 Copyright (C) 1996-2022 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 <https://www.gnu.org/licenses/>. */
19
20#include <stdlib.h>
21#include <string.h>
22
23#if !_LIBC
24/* This code is written for inclusion in gnu-libc, and uses names in
25 the namespace reserved for libc. If we're compiling in gnulib,
26 define those names to be the normal ones instead. */
27# include "strchrnul.h"
28# undef __strchrnul
29# define __strchrnul strchrnul
30#endif
31
32/* Parse comma separated suboption from *OPTIONP and match against
33 strings in TOKENS. If found return index and set *VALUEP to
34 optional value introduced by an equal sign. If the suboption is
35 not part of TOKENS return in *VALUEP beginning of unknown
36 suboption. On exit *OPTIONP is set to the beginning of the next
37 token or at the terminating NUL character. */
38int
39getsubopt (char **optionp, char *const *tokens, char **valuep)
40{
41 char *endp, *vstart;
42 int cnt;
43
44 if (**optionp == '\0')
45 return -1;
46
47 /* Find end of next token. */
48 endp = __strchrnul (*optionp, ',');
49
50 /* Find start of value. */
51 vstart = memchr (*optionp, '=', endp - *optionp);
52 if (vstart == NULL)
53 vstart = endp;
54
55 /* Try to match the characters between *OPTIONP and VSTART against
56 one of the TOKENS. */
57 for (cnt = 0; tokens[cnt] != NULL; ++cnt)
58 if (strncmp (*optionp, tokens[cnt], vstart - *optionp) == 0
59 && tokens[cnt][vstart - *optionp] == '\0')
60 {
61 /* We found the current option in TOKENS. */
62 *valuep = vstart != endp ? vstart + 1 : NULL;
63
64 if (*endp != '\0')
65 *endp++ = '\0';
66 *optionp = endp;
67
68 return cnt;
69 }
70
71 /* The current suboption does not match any option. */
72 *valuep = *optionp;
73
74 if (*endp != '\0')
75 *endp++ = '\0';
76 *optionp = endp;
77
78 return -1;
79}
80