/*** XOR_STR.  Exclusive-or an unsigned 4 byte number with a string.
/
/    num = xor_str (num, str);
/   
/    Parameters:
/
/    Purpose:
/
/    How it works:
/
/    Returns:
/
/    Error Conditions:
/  
/    Home:  xorstr.c
/ */

/*** Copyleft 1999 Caucus Systems Inc.  CPW2 is "Open Source". */

/*: CR 10/15/97 17:40 New function. */
/*: CR  5/27/99 12:24 Updated to copyleft license. */

#define  FUNCTION
typedef  unsigned int   uint4;    /* 4 byte unsigned integer on this platform */

FUNCTION  uint4 xor_str (uint4 num, char *str)
{
   union { uint4 num;   char str[4]; } map;
   char  *p;
   int    i;

   map.num = 0;
   for (i=0, p=str;   *p  &&  i<4;   ++i, ++p)  map.str[i] = *p;

   return (num ^ map.num);
}