- substr: documentation ( source)
- ctype_digit: documentation ( source)
- md5: documentation ( source)
<?php
function significant_number($string){
$offset=9;
$string=substr($string, $offset);
$count=strlen($string);
$i=0;
while($i < $count){
if(ctype_digit($string[$i])) {
break;
}
$i++;
}
return $string[$i];
}
$udid="086786dc4ae78dbf6a6a9b621b5ae4";
$md5udid=md5($udid);
$sigNo=significant_number($udid);
$testudid=substr($md5udid, 4, sigNo).substr($udid, sigNo, 6);
echo $testudid;
?>