--TEST-- hex2bin(); function test --CREDITS-- edgarsandi - <edgar.r.sandi@gmail.com> --FILE-- <?php var_dump(hex2bin('AH')); var_dump(hex2bin('HA')); ?> --EXPECTF-- Warning: hex2bin(): Input string must be hexadecimal string in %s on line %d bool(false) Warning: hex2bin(): Input string must be hexadecimal string in %s on line %d bool(false)