<?php
function readInterfaces($was){
/*
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
 
# The loopback network interface
auto lo
iface lo inet loopback
 
# The primary network interface
auto eth1
iface eth1 inet static
        address 192.168.1.245
        netmask 255.255.255.0
        network 192.168.1.0
        broadcast 192.168.1.255
        gateway 192.168.1.253
        dns-nameservers 192.168.1.253
        dns-search elektrohauffe.intern
*/
$fileArray = file("/etc/network/interfaces");
 
 
foreach($fileArray as $key => $val){
	if(preg_match("/".$was."/",$val)){
		$splitter = preg_split("/ /",trim($val));
		return $splitter[1];
	}
}
return false;
}
 
 
//Beispiel
readInterfaces('address');
readInterfaces('gateway');
 
?>