string/strrchr.c

   1 /* Copyright (C) 1991-2019 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <string.h>
  19
  20 #undef strrchr
  21
  22 #ifndef STRRCHR
  23 # define STRRCHR strrchr
  24 #endif
  25
  26 /* Find the last occurrence of C in S.  */
  27 char *
  28 STRRCHR (const char *s, int c)
  29 {
  30   const char *found, *p;
  31
  32   c = (unsigned char) c;
  33
  34   /* Since strchr is fast, we use it rather than the obvious loop.  */
  35
  36   if (c == '\0')
  37     return strchr (s, '\0');
  38
  39   found = NULL;
  40   while ((p = strchr (s, c)) != NULL)
  41     {
  42       found = p;
  43       s = p + 1;
  44     }
  45
  46   return (char *) found;
  47 }
  48
  49 #ifdef weak_alias
  50 #undef rindex
  51 weak_alias (strrchr, rindex)
  52 #endif
  53 libc_hidden_builtin_def (strrchr)