string/strcspn.c

   1 /* Copyright (C) 1991-2013 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 #if HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21
  22 #if defined _LIBC || HAVE_STRING_H
  23 # include <string.h>
  24 #else
  25 # include <strings.h>
  26 # ifndef strchr
  27 #  define strchr index
  28 # endif
  29 #endif
  30
  31 #undef strcspn
  32
  33 /* Return the length of the maximum initial segment of S
  34    which contains no characters from REJECT.  */
  35 size_t
  36 strcspn (s, reject)
  37      const char *s;
  38      const char *reject;
  39 {
  40   size_t count = 0;
  41
  42   while (*s != '\0')
  43     if (strchr (reject, *s++) == NULL)
  44       ++count;
  45     else
  46       return count;
  47
  48   return count;
  49 }
  50 libc_hidden_builtin_def (strcspn)