1  char _hex_value[256];
       2  
       3  void
       4  hex_init ()
       5  {
       6    int i;
       7    for (i = 0; i < 256; i++)
       8      _hex_value[i] = 99;
       9    for (i = 0; i < 10; i++)
      10      _hex_value['0' + i] = i;
      11  }