Use xhost + to tell this display that it’s okay for a process running on a remote host to write to my local display. Note that the first login did not work because suncs9 does not know my made-up hostname “greg-pc”. On the second attempt, it recognizes my DHCP assigned hostname “dhcp5132.procket”. Then, Enter “echo $DISPLAY” to check if my display environment variable is correct. Use this echo command to see if my display variable will propogate all on its own for when I enter the “rlogin” command. It’s supposed to propogate, but it does not always do it. If it didn’t propogate, we would either set the display environment variable or give a display parameter ourselves when we start it up, which is usually “-d”. If I don’t him a display name on his parameter line, then he’s supposed to read the environment variable. The environment variable gets derrived from the hostname that I inherit from the network.

greg-pc# xhost + suncs9
suncs9 being added to access control list
greg-pc# rlogin suncs9
...
Password:
Login incorrect
login: gmcmillan
Password:
Last login: Thu Sep 13 17:10:14 from dhcp5132.procket 
...
[gmcmillan@suncs9 ~]% echo $DISPLAYG
dhcp5132.procket.com:0
[gmcmillan@suncs9 ~]% maker &
[1] 10404
[gmcmillan@suncs9 ~]% starting maker ...

Note: I could enter just “xhost +”, but then everyone can write to my display. In most environments, that’s not very smart. However, some people do it.

greg-pc# xhost + suncs9 suncs9 being added to access control list greg-pc#