1/* Searching a string for a character.
2   Copyright (C) 2007-2012 Free Software Foundation, Inc.
3   Written by Bruno Haible <bruno@clisp.org>, 2007.
4
5   This program is free software: you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 3 of the License, or
8   (at your option) any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18#include <config.h>
19
20/* Specification.  */
21#include <string.h>
22
23#include "mbuiter.h"
24
25/* Locate the first single-byte character C in the character string STRING,
26   and return a pointer to it.  Return NULL if C is not found in STRING.  */
27char *
28mbschr (const char *string, int c)
29{
30  if (MB_CUR_MAX > 1
31      /* Optimization: We know that ASCII characters < 0x30 don't occur as
32         part of multibyte characters longer than 1 byte.  Hence, if c < 0x30,
33         the faster unibyte loop can be used.  */
34      && (unsigned char) c >= 0x30)
35    {
36      mbui_iterator_t iter;
37
38      for (mbui_init (iter, string);; mbui_advance (iter))
39        {
40          if (!mbui_avail (iter))
41            goto notfound;
42          if (mb_len (mbui_cur (iter)) == 1
43              && (unsigned char) * mbui_cur_ptr (iter) == (unsigned char) c)
44            break;
45        }
46      return (char *) mbui_cur_ptr (iter);
47     notfound:
48      return NULL;
49    }
50  else
51    return strchr (string, c);
52}
53