(PHP 4, PHP 5, PHP 7, PHP 8)
gethostbyaddr — Get the Internet host name corresponding to a given IP address
Returns the host name of the Internet host specified by
ip.
ipThe host IP address.
Returns the host name on success, the unmodified ip
on failure, or false on malformed input.
Example #1 A simple gethostbyaddr() example
<?php
$hostname = gethostbyaddr($_SERVER['REMOTE_ADDR']);
echo $hostname;
?>