- base_convert: documentation ( source)
- pack: documentation ( source)
<?php
$bin = '011000110110100001100101011001010111101001100010011101010111001001100111011001010111001000101110011011010110010101000000011001110110110101100001011010010110110000101110011000110110111101101101';
echo pack('H*', base_convert($bin, 2, strlen($bin)));