I know this is a fairly old question, but there doesn't seem to be a definitive answer (in as much as one is possible.) I've had a need to determine this value, both on *NIX boxes and on Win X boxes. Also from a CLI executed script as well as a non-CLI script. The following function is the best I've come up with, which borrows on different concepts people have spoke of over the years. Maybe it can be of some use:
function getServerAddress() {
if(isset($_SERVER["SERVER_ADDR"]))
return $_SERVER["SERVER_ADDR"];
else {
// Running CLI
if(stristr(PHP_OS, 'WIN')) {
// Rather hacky way to handle windows servers
exec('ipconfig /all', $catch);
foreach($catch as $line) {
if(eregi('IP Address', $line)) {
// Have seen exec return "multi-line" content, so another hack.
if(count($lineCount = split(':', $line)) == 1) {
list($t, $ip) = split(':', $line);
$ip = trim($ip);
} else {
$parts = explode('IP Address', $line);
$parts = explode('Subnet Mask', $parts[1]);
$parts = explode(': ', $parts[0]);
$ip = trim($parts[1]);
}
if(ip2long($ip > 0)) {
echo 'IP is '.$ip."\n";
return $ip;
} else
; // TODO: Handle this failure condition.
}
}
} else {
$ifconfig = shell_exec('/sbin/ifconfig eth0');
preg_match('/addr:([\d\.]+)/', $ifconfig, $match);
return $match[1];
}
}
}