3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $hostname = gethostbyaddr($_SERVER['REMOTE_ADDR']); echo $hostname; ?>
Output for 5.3.0 - 5.6.28, 7.0.0 - 7.1.0
Notice: Undefined index: REMOTE_ADDR in /in/UrbE5 on line 2 Warning: gethostbyaddr(): Address is not a valid IPv4 or IPv6 address in /in/UrbE5 on line 2
Output for hhvm-3.12.0
Notice: Undefined index: REMOTE_ADDR in /in/UrbE5 on line 2 Warning: gethostbyaddr() expects parameter 1 to be string, null given in /in/UrbE5 on line 2
Output for hhvm-3.10.0
Notice: Undefined index: REMOTE_ADDR in /in/UrbE5 on line 2
Output for 4.3.2 - 5.2.17
Notice: Undefined index: REMOTE_ADDR in /in/UrbE5 on line 2 Warning: gethostbyaddr(): Address is not a valid IPv4 or IPv6 address in /in/UrbE5 on line 2
Output for 4.3.0 - 4.3.1
Notice: Undefined index: REMOTE_ADDR in /in/UrbE5 on line 2 Warning: gethostbyaddr() [http://www.php.net/function.gethostbyaddr]: Address is not a valid IPv4 or IPv6 address in /in/UrbE5 on line 2