string/strnlen.c

   1 /* Find the length of STRING, but scan at most MAXLEN characters.
   2    Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <string.h>
  21
  22 /* Find the length of STRING, but scan at most MAXLEN characters.
  23    If no '\0' terminator is found in that many characters, return MAXLEN.  */
  24
  25 size_t
  26 strnlen (const char *string, size_t maxlen)
  27 {
  28   const char *end = memchr (string, '\0', maxlen);
  29   return end ? end - string : maxlen;
  30 }