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