curl_memrchr.c 1.7 KB

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  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. #include "curl_setup.h"
  23. #include <curl/curl.h>
  24. #include "curl_memrchr.h"
  25. #include "curl_memory.h"
  26. /* The last #include file should be: */
  27. #include "memdebug.h"
  28. #ifndef HAVE_MEMRCHR
  29. /*
  30. * Curl_memrchr()
  31. *
  32. * Our memrchr() function clone for systems which lack this function. The
  33. * memrchr() function is like the memchr() function, except that it searches
  34. * backwards from the end of the n bytes pointed to by s instead of forward
  35. * from the beginning.
  36. */
  37. void *
  38. Curl_memrchr(const void *s, int c, size_t n)
  39. {
  40. if(n > 0) {
  41. const unsigned char *p = s;
  42. const unsigned char *q = s;
  43. p += n - 1;
  44. while(p >= q) {
  45. if(*p == (unsigned char)c)
  46. return (void *)p;
  47. p--;
  48. }
  49. }
  50. return NULL;
  51. }
  52. #endif /* HAVE_MEMRCHR */