/***
*strspn.c - find length of initial substring of chars from a control string
*
*       Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines strspn() - finds the length of the initial substring of
*       a string consisting entirely of characters from a control string.
*
*       defines strcspn()- finds the length of the initial substring of
*       a string consisting entirely of characters not in a control string.
*
*       defines strpbrk()- finds the index of the first character in a string
*       that is not in a control string
*
*******************************************************************************/



/***
*char *strpbrk(string, control) - scans string for a character from control
*
*Purpose:
*       Finds the first occurence in string of any character from
*       the control string.
*
*Entry:
*       char *string - string to search in
*       char *control - string containing characters to search for
*
*Exit:
*       returns a pointer to the first character from control found
*       in string.
*       returns NULL if string and control have no characters in common.
*
*Exceptions:
*
*******************************************************************************/


char *strpbrk(const char * string, const char * control)
{
	const unsigned char *str = (unsigned char *)string;
	const unsigned char *ctrl = (unsigned char *)control;

	unsigned char map[32];
	int count;

	/* Clear out bit map */
	for(count=0; count<32; count++)
		map[count] = 0;

	/* Set bits in control map */
	while(*ctrl)
	{
	map[*ctrl >> 3] |= (1 << (*ctrl & 7));
	ctrl++;
	}

	/* 1st char in control map stops search */
	while(*str)
	{
		if(map[*str >> 3] & (1 << (*str & 7)))
			return((char *)str);
	
		str++;
	}
	
	return 0;
}
