Here we will show most frequent usage of screen command in Linux and that is…how to start a screen, how to give a name for a screen session, how to attach a terminal to “disconnected” screen session, how to list screen sessions and similar things.

Screen is very useful for admins if they are working from home from an unstable network where network outage can be expected and they doing sensitive operations which need time to be executed. In case you have started the screen session and network breaks – everything which is started from that session still work…and you can re-login to a server and do a reattach to that screen session.

Also, the screen is a good solution if you need to run multiple terminal sessions, for example – from one screen to edit a bash script – and from another one to run the same script (ok, it is a little bit stupid example but you know what I want to say)

How to start а screen with some generic name

screen

How to start a screen session with some normal descriptive name, like a “Pinging Google”

screen -S "Pinging Google"
# -S: "Session name"

How to list all active sessions of а screen

screen -ls
# -ls: list sessions

By default, you will see only your own sessions with this command, so if user Draza started own screen session, even if you are root – you will not be able to see him. If you want to list all screen sessions – you can do that by listing a /var/run/screen folder as a root (non-root user will see only own sessions)

ls -l /var/run/screen/*

How to reattach a screen session

screen -r "Pinging Google"
# -r: resumes a detached screen session

If you need to attach your session to already attached screen with r (resume a detached screen session) use a “-d” switch which will first detach session elsewhere

screen -r -d 1365
# -r: resumes a detached screen session
# -d: detach session elsewhere

How to kill а screen session

If you want to kill screen session you can do it while you are logged in a screen with simple “exit” command, like when you exiting from normal terminal windows. If you want to kill screen session without login to session – you can do that with a command:

screen -X -S "Pinging Google" quit # or
screen -X -S 1379 quit
# -X: Send the specified command to a running screen session
# -S: Session name
# quit: kill all and terminate screen session

Also, when you are in screen session – you can exit from her with a simple “exit” command.

Hotkeys

Most used hotkeys for me are:
CTRL+a+d which will detach screen session,
CTRL+a+n for next screen session, and
CTRL+a+c for a new screen session.

For more details about the screen, please use man page or go to screen homepage here.