gethostbyaddr — Gets the human-readable name for an
string IP_address: IP
address of the Internet host
Internet hostname; IP_address argument on error
gethostbyaddr() performs a DNS lookup of an
Internet IP address and returns the corresponding domain
name. If no name exists, the function returns the IP_address argument.
PHP Version: 3+, 4+
Example 834. Find the
hostname for an IP address
$ip = '220.127.116.11';
$host = gethostbyaddr ($ip);
if ($ip != $host)
echo "The hostname for <i>$ip</i> is <i>$host</i>.";
echo "I could not successfully look up <i>$ip</i>.";
PHP Functions Essential Reference. Copyright © 2002 by New Riders Publishing
(Authors: Zak Greant, Graeme Merrall, Torben Wilson, Brett Michlitsch).
This material may be distributed only subject to the terms and conditions set forth
in the Open Publication License, v1.0 or later (the latest version is presently available at
The authors of this book have elected not to choose any options under the OPL. This online book was obtained
and is designed to provide information about the PHP programming language, focusing on PHP version 4.0.4
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