curl_memrchr.c (1808B)
1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl 22 * 23 ***************************************************************************/ 24 25 #include "curl_setup.h" 26 27 #include <curl/curl.h> 28 29 #include "curl_memrchr.h" 30 #include "curl_memory.h" 31 32 /* The last #include file should be: */ 33 #include "memdebug.h" 34 35 #ifndef HAVE_MEMRCHR 36 /* 37 * Curl_memrchr() 38 * 39 * Our memrchr() function clone for systems which lack this function. The 40 * memrchr() function is like the memchr() function, except that it searches 41 * backwards from the end of the n bytes pointed to by s instead of forward 42 * from the beginning. 43 */ 44 45 void * 46 Curl_memrchr(const void *s, int c, size_t n) 47 { 48 if(n > 0) { 49 const unsigned char *p = s; 50 const unsigned char *q = s; 51 52 p += n - 1; 53 54 while(p >= q) { 55 if(*p == (unsigned char)c) 56 return CURL_UNCONST(p); 57 p--; 58 } 59 } 60 return NULL; 61 } 62 #endif /* HAVE_MEMRCHR */