</pre><pre name="code" class="php">function hex2bin($str){
$len = strlen($str)/2;
$re = '';
for($i=0;$i<$len;$i++){
$pos = $i*2;
$re .= chr(hexdec(substr($str,$pos,1))<<4) | chr(hexdec(substr($str,$pos+1,1)));
}
return $re;
}
</pre><pre name="code" class="php">function hex2bin($str){
$len = strlen($str)/2;
$re = '';
for($i=0;$i<$len;$i++){
$pos = $i*2;
$re .= chr(hexdec(substr($str,$pos,1))<<4) | chr(hexdec(substr($str,$pos+1,1)));
}
return $re;
}