crc8.cc

#include <stdio.h>

const int crc8_Table[] = {
    0,   94,  188, 226, 97,  63,  221, 131, 194, 156, 126, 32,  163, 253, 31,
    65,  157, 195, 33,  127, 252, 162, 64,  30,  95,  1,   227, 189, 62,  96,
    130, 220, 35,  125, 159, 193, 66,  28,  254, 160, 225, 191, 93,  3,   128,
    222, 60,  98,  190, 224, 2,   92,  223, 129, 99,  61,  124, 34,  192, 158,
    29,  67,  161, 255, 70,  24,  250, 164, 39,  121, 155, 197, 132, 218, 56,
    102, 229, 187, 89,  7,   219, 133, 103, 57,  186, 228, 6,   88,  25,  71,
    165, 251, 120, 38,  196, 154, 101, 59,  217, 135, 4,   90,  184, 230, 167,
    249, 27,  69,  198, 152, 122, 36,  248, 166, 68,  26,  153, 199, 37,  123,
    58,  100, 134, 216, 91,  5,   231, 185, 140, 210, 48,  110, 237, 179, 81,
    15,  78,  16,  242, 172, 47,  113, 147, 205, 17,  79,  173, 243, 112, 46,
    204, 146, 211, 141, 111, 49,  178, 236, 14,  80,  175, 241, 19,  77,  206,
    144, 114, 44,  109, 51,  209, 143, 12,  82,  176, 238, 50,  108, 142, 208,
    83,  13,  239, 177, 240, 174, 76,  18,  145, 207, 45,  115, 202, 148, 118,
    40,  171, 245, 23,  73,  8,   86,  180, 234, 105, 55,  213, 139, 87,  9,
    235, 181, 54,  104, 138, 212, 149, 203, 41,  119, 244, 170, 72,  22,  233,
    183, 85,  11,  136, 214, 52,  106, 43,  117, 151, 201, 74,  20,  246, 168,
    116, 42,  200, 150, 21,  75,  169, 247, 182, 232, 10,  84,  215, 137, 107,
    53
};

unsigned int
crc8( const char* s )
{
    int crc = 0;
    for ( ; *s; s++ )
    {
        crc = crc8_Table[ crc ^ *s ];
    }
    return crc;
}

char*
crc8_str( const char* s )
{
    static char buf[ 3 ];
    sprintf( buf, "%x", crc8( s ) );
    return buf;
}

#ifdef USE_MAIN

int
main( int argc, char* argv[] )
{
    if ( argc > 1 )
        puts( crc8_str( argv[ 1 ] ) );
    else
        puts( "Usage: crc8 file_name" );
}
#endif