/*
FUNCTION
	<<strcspn>>---count characters not in string
INDEX
	strcspn
ANSI_SYNOPSIS
	size_t strcspn(const char *<[s1]>, const char *<[s2]>);
TRAD_SYNOPSIS
	size_t strcspn(<[s1]>, <[s2]>)
	char *<[s1]>;
	char *<[s2]>;
DESCRIPTION
	This function computes the length of the initial part of
	the string pointed to by <[s1]> which consists entirely of
	characters <[NOT]> from the string pointed to by <[s2]>
	(excluding the terminating null character).
RETURNS
	<<strcspn>> returns the length of the substring found.
PORTABILITY
<<strcspn>> is ANSI C.
<<strcspn>> requires no supporting OS subroutines.
 */
#include <string.h>
#include "_ansi.h" /* for _DEFUN */

size_t
_DEFUN (strcspn, (s1, s2),
        _CONST char *s1 _AND
        _CONST char *s2)
{
  _CONST char *s = s1;
  _CONST char *c;
  while (*s1)
    {
        for (c = s2; *c; c++)
        {
            if (*s1 == *c)
                break;
        }
        if (*c)
            break;
        s1++;
    }
    return s1 - s;
}