Change IPv4 to IPv6 string

Question

Sander Steffann mentioned in a previous question of mine:

Addresses like 0000:0000:0000:0000:0000:0000:192.168.0.1 are written as 0000:0000:0000:00

Answer 1

Your best bet is to not do this manually, but instead call inet_pton to get a binary representation, and then convert that to the format you wish to have.

$foo = inet_pton("::1");
for ($i = 0 ; $i < 8 ; $i++)
    $arr[$i] = sprintf("%02x%02x", ord($foo[$i * 2]), ord($foo[$i * 2 + 1]));
$addr = implode(":", $arr);