Question

PHP does not support unsigned ints. Is there a way to convert a string representation of an unsigned integer into a signed integer with overflow?

Example:
On a 32 bit system, PHP can store int values <= 2147483647. I want a way to convert the string “2147483648” to integer, causing it to overflow to -2147483648 instead of being reduced to 2147483647.

Why do I want to do this?
I store IPv4 addresses in a database as unsigned int (32 bits). I want to do binary operations on the addresses in PHP to check for subnets. This needs to be done on every request, so it needs to be quick. Therefore it seems better to store the IP address as an unsigned int rather than storing a string which will have to be converted back and forth.

Answer 1

here is the workaround.

<?php
    $unsignedString = "3000000000";
    echo "unsigned string: ".$unsignedString."<br />";
    $signedInt = intval(doubleval($unsignedString));
    echo "signed int: ".$signedInt."<br />";
?>