php获取本地ip-针对linux

public static function getLocalIp() {
$preg = "/\A((([0-9]?[0-9])|(1[0-9]{2})|(2[0-4][0-9])|(25[0-5]))\.){3}(([0-9]?[0-9])|(1[0-9]{2})|(2[0-4][0-9])|(25[0-5]))\Z/";
exec("ifconfig", $out, $stats);
if (!empty($out)) {
if (isset($out[1]) && strstr($out[1], 'addr:')) {
$tmpArray = explode(":", $out[1]);
$tmpIp = explode(" ", $tmpArray[1]);
if (preg_match($preg, trim($tmpIp[0]))) {
return trim($tmpIp[0]);
}
}
}
return '127.0.0.1';
}