ms_not_installed example

$path = stripslashes( $_SERVER['REQUEST_URI'] );
    if ( is_admin() ) {
        $path = preg_replace( '#(.*)/wp-admin/.*#', '$1/', $path );
    }
    list( $path ) = explode( '?', $path );

    $bootstrap_result = ms_load_current_site_and_network( $domain, $path, is_subdomain_install() );

    if ( true === $bootstrap_result ) {
        // `$current_blog` and `$current_site are now populated.     } elseif ( false === $bootstrap_result ) {
        ms_not_installed( $domain, $path );
    } else {
        header( 'Location: ' . $bootstrap_result );
        exit;
    }
    unset( $bootstrap_result );

    $blog_id = $current_blog->blog_id;
    $public  = $current_blog->public;

    if ( empty( $current_blog->site_id ) ) {
        // This dates to [MU134] and shouldn't be relevant anymore,