1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
9  *
10  * This software is licensed as described in the file COPYING, which
11  * you should have received as part of this distribution. The terms
12  * are also available at https://curl.haxx.se/docs/copyright.html.
13  *
14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15  * copies of the Software, and permit persons to whom the Software is
16  * furnished to do so, under the terms of the COPYING file.
17  *
18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19  * KIND, either express or implied.
20  *
21  ***************************************************************************/
22 
23 #include "curl_setup.h"
24 
25 #include <curl/curl.h>
26 
27 #include "curl_memrchr.h"
28 #include "curl_memory.h"
29 
30 /* The last #include file should be: */
31 #include "memdebug.h"
32 
33 #ifndef HAVE_MEMRCHR
34 
35 /*
36  * Curl_memrchr()
37  *
38  * Our memrchr() function clone for systems which lack this function. The
39  * memrchr() function is like the memchr() function, except that it searches
40  * backwards from the end of the n bytes pointed to by s instead of forward
41  * from the beginning.
42  */
43 
44 void *
Curl_memrchr(const void * s,int c,size_t n)45 Curl_memrchr(const void *s, int c, size_t n)
46 {
47   if(n > 0) {
48     const unsigned char *p = s;
49     const unsigned char *q = s;
50 
51     p += n - 1;
52 
53     while(p >= q) {
54       if(*p == (unsigned char)c)
55         return (void *)p;
56       p--;
57     }
58   }
59   return NULL;
60 }
61 
62 #endif /* HAVE_MEMRCHR */
63