save a pdf to my machine

I have a code on a server that, when running, I want it to download a file to the client machine. In this case, by running this, it just copies the file to the server.

$local_file = 'output.rar';
$server_file = '/somedir/1/bar/foo/somearchive.rar';
$ftp_user_name='anonymous';
$ftp_user_pass='[email protected]';
$ftp_server='server.host';
// set up basic connection
$conn_id = ftp_connect($ftp_server);

// login with username and password
$login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);

/* uncomment if you need to change directories
if (ftp_chdir($conn_id, "<directory>")) {
    echo "Current directory is now: " . ftp_pwd($conn_id) . "\n";
} else { 
    echo "Couldn't change directory\n";
}
*/

// try to download $server_file and save to $local_file
if (ftp_get($conn_id, $local_file, $server_file, FTP_BINARY)) {
    echo "Successfully written to $local_file\n";
} else {
    echo "There was a problem\n";
}

// close the connection
ftp_close($conn_id);

        ?>