1 /* Searching a string for the last occurrence of a character.
2 Copyright (C) 2007-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2007.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 3 of the
8 License, or (at your option) any later version.
9
10 This file 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 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://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 last 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 *
mbsrchr(const char * string,int c)28 mbsrchr (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 const char *result = NULL;
37 mbui_iterator_t iter;
38
39 for (mbui_init (iter, string); mbui_avail (iter); mbui_advance (iter))
40 {
41 if (mb_len (mbui_cur (iter)) == 1
42 && (unsigned char) * mbui_cur_ptr (iter) == (unsigned char) c)
43 result = mbui_cur_ptr (iter);
44 }
45 return (char *) result;
46 }
47 else
48 return strrchr (string, c);
49 }
50