lib/strcspn.c

/* Copyright (C) 1991, 1994, 1996-1997, 2002-2003, 2005-2006, 2009-2026 Free
 * Software Foundation, Inc.

   NOTE: The canonical source of this file is maintained with the GNU C Library.
   Bugs can be reported to bug-glibc@gnu.org.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation, either version 3 of the
   License, or (at your option) any later version.

   This file is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#include <stddef.h>
#include <string.h>

#if _LIBC
# undef strcspn
#endif

/* Return the length of the maximum initial segment of S
   which contains no characters from REJECT.  */
size_t
strcspn (const char *s, const char *reject)
{
  size_t count = 0;

  while (*s != '\0')
    if (strchr (reject, *s++) == NULL)
      ++count;
    else
      return count;

  return count;
}