Redirects a variety of shorthand URLs to the admin.

If a user visits example.com/admin, they’ll be redirected to /wp-admin.
Visiting /login redirects to /wp-login.php, and so on.

function wp_redirect_admin_locations() {
	global $wp_rewrite;

	if ( ! ( is_404() && $wp_rewrite->using_permalinks() ) ) {
		return;
	}

	$admins = array(
		home_url( 'wp-admin', 'relative' ),
		home_url( 'dashboard', 'relative' ),
		home_url( 'admin', 'relative' ),
		site_url( 'dashboard', 'relative' ),
		site_url( 'admin', 'relative' ),
	);

	if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $admins, true ) ) {
		wp_redirect( admin_url() );
		exit;
	}

	$logins = array(
		home_url( 'wp-login.php', 'relative' ),
		home_url( 'login', 'relative' ),
		site_url( 'login', 'relative' ),
	);

	if ( in_array( untrailingslashit( $_SERVER['REQUEST_URI'] ), $logins, true ) ) {
		wp_redirect( wp_login_url() );
		exit;
	}
}