lib/strcspn.c

   1 /* Copyright (C) 1991, 1994, 1996-1997, 2002-2003, 2005-2006, 2009-2020 Free
   2  * Software Foundation, Inc.
   3
   4    NOTE: The canonical source of this file is maintained with the GNU C Library.
   5    Bugs can be reported to bug-glibc@gnu.org.
   6
   7    This program is free software: you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by the
   9    Free Software Foundation; either version 3 of the License, or any
  10    later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  19
  20 #include <config.h>
  21
  22 #include <stddef.h>
  23 #include <string.h>
  24
  25 #if _LIBC
  26 # undef strcspn
  27 #endif
  28
  29 /* Return the length of the maximum initial segment of S
  30    which contains no characters from REJECT.  */
  31 size_t
  32 strcspn (const char *s, const char *reject)
  33 {
  34   size_t count = 0;
  35
  36   while (*s != '\0')
  37     if (strchr (reject, *s++) == NULL)
  38       ++count;
  39     else
  40       return count;
  41
  42   return count;
  43 }