切换桌面：

update-alternatives --config x-session-manager

回显如下：

root@kali:~# update-alternatives --config x-session-manager
There are 3 choices for the alternative x-session-manager (providing /usr/bin/x-session-manager).
 
  Selection    Path                    Priority   Status
------------------------------------------------------------
* 0            /usr/bin/gnome-session   50        auto mode
  1            /usr/bin/gnome-session   50        manual mode
  2            /usr/bin/startxfce4      50        manual mode
  3            /usr/bin/xfce4-session   40        manual mode
 
Press <enter> to keep the current choice[*], or type selection number: