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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.  */
27 char *
mbschr(const char * string,int c)28 mbschr (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