//credit bobobobo.wordpress.com/2008/02/23/how-to-use-zlib/

 int z_result = compress(

        dataCompressed,         // destination buffer,
                                // must be at least
                                // (1.01X + 12) bytes as large
                                // as source.. we made it 1.1X + 12bytes

        &sizeDataCompressed,    // pointer to var containing
                                // the current size of the
                                // destination buffer.
                                // WHEN this function completes,
                                // this var will be updated to
                                // contain the NEW size of the
                                // compressed data in bytes.

        dataOriginal,           // source data for compression

        sizeDataOriginal ) ;    // size of source data in bytes

    switch( z_result )
    {
    case Z_OK:
        printf("***** SUCCESS! *****\n");
        break;

    case Z_MEM_ERROR:
        printf("out of memory\n");
        exit(1);    // quit.
        break;

    case Z_BUF_ERROR:
        printf("output buffer wasn't large enough!\n");
        exit(1);    // quit.
        break;
    }