Settings of DISPLAY in Linux

Linux DISPLAY settings-Linux Enterprise Application-Linux server application information. For more information, see. X11Forwarding yes

If this is enabled, the first user who logs on via ssh will obtain:

[Sky @ smsgw ~] $ Echo $ DISPLAY

Localhost: 12.0

Localhost: 12 in 12.0 is automatically allocated by the system, similar to DHCP.

So if you want to switch between users and use X11, You need to export DISPLAY = localhost: 12.0

Or write the export DISPLAY = localhost: 12.0 to the profile file.

[Sky @ smsgw ~] $ Su-oracle

Password:

[Oracle @ smsgw ~] $ Export DISPLAY = localhost: 12.0

At the same time
Ssh -- à edit -- à setting -- à tunneling

Check Tunnel X11 connect.