1  /* Copyright (C) 1991-2023 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     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <string.h>
      19  
      20  #undef strchr
      21  #undef index
      22  
      23  #ifdef STRCHR
      24  # define strchr STRCHR
      25  #endif
      26  
      27  /* Find the first occurrence of C in S.  */
      28  char *
      29  strchr (const char *s, int c_in)
      30  {
      31    char *r = __strchrnul (s, c_in);
      32    return (*(unsigned char *)r == (unsigned char)c_in) ? r : NULL;
      33  }
      34  #ifndef STRCHR
      35  weak_alias (strchr, index)
      36  libc_hidden_builtin_def (strchr)
      37  #endif