php获取本地IP

function get_local_ip() {
        $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/";
        //获取操作系统为win2000/xp、win7的本机IP真实地址
        exec("ipconfig", $out, $stats);
        if (!empty($out)) {
                foreach ($out AS $row) {
                        if (strstr($row, "IP") && strstr($row, ":") && !strstr($row, "IPv6")) {
                                $tmpIp = explode(":", $row);
                                if (preg_match($preg, trim($tmpIp[1]))) {
                                        return trim($tmpIp[1]);
                                }
                        }
                }
        }
        //获取操作系统为linux类型的本机IP真实地址
        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';
}