uclibc-ng/libc/string/strspn.c

/* Copyright (C) 1992, 1993 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <string.h>

/* Return the length of the maximum initial segment
   of S which contains only characters in ACCEPT.  */
size_t
strspn(s, accept)
char *s;
char *accept;
{
  register char *p;
  register char *a;
  register size_t count = 0;

  for (p = s; *p != '\0'; ++p)
    {
      for (a = accept; *a != '\0'; ++a)
	if (*p == *a)
	  break;
      if (*a == '\0')
	return count;
      else
	++count;
    }

  return count;
}