php man page for gethostbyaddr

GETHOSTBYADDR(3)							 1							  GETHOSTBYADDR(3)

gethostbyaddr - Get the Internet host name corresponding to a given IP address

SYNOPSIS
       string gethostbyaddr (string  $ip_address)

DESCRIPTION
	Returns the host name of the Internet host specified by $ip_address.

PARAMETERS
	      o $ip_address
		- The host IP address.

RETURN VALUES
	Returns the host name on success, the unmodified $ip_address on failure, or FALSE on malformed input.

EXAMPLES
       Example #1

	      A simple gethostbyaddr(3) example

	      <?php
	      $hostname = gethostbyaddr($_SERVER['REMOTE_ADDR']);

	      echo $hostname;
	      ?>

SEE ALSO
       gethostbyname(3), gethostbynamel(3).

PHP Documentation Group 													  GETHOSTBYADDR(3)