Linux Screen Tutorial
Screen is a shell layer that allows you to use one shell session, detach from it, and then reattach from a different computer where you left off. It’s useful for long jobs, recording what commands were run, and bad connections that might drop your SSH shell in the middle of a work session.
$ which screen
For Debian-Based Linux, the command is:
$ sudo apt-get install screen
Start screen with the simple “screen” command and hit enter to begin using it.
Here is the TLDR version that you probably are looking for:
- screen -S something
- screen -ls
- screen -r xxxx.something -D
Everything Else besides TLDR:
Linux Screen uses ctrl + a to start commands and then a character to do a specific command. You can see all of the commands using ctrl-a ?
|Ctrl-a ?||Show Help File|
|Ctrl-a H||Create or Stop Log of Session|
A pwd will tell you what your working directory is, and you will have a screenlog.0 file in it with whatever commands you typed. If you Ctrl-a H again it will stop logging.
|Ctrl-a M||Monitor for output|
|Ctrl-a _||Monitor for silence|
|Ctrl-a x||Lock Screen|
|Ctrl-a d||Detach Screen|
|Ctrl-a c||Create new screen|
|screen -ls||List all Screens|
|screen -r xxxx||Reattach to existing Screen xxxx|
|Ctrl-a n||Cycle to Next Screen|
|Ctrl-a p||Cycle to Previous Screen|
|Ctrl-a k||Stop Screen|
When you finally type “exit” or ctrl-a k to kill a session you will see the [screen is terminating] message.
Check if Screen is Running
If screen isn’t running, you can verify using the pgrep utilitiy
$ pgrep screen
If screen is running, you will get 2 process IDs:
$ pgrep screen
Example of Using Screen
|ctrl a, H||Turn on logging|
|ctrl a, c||Make a New Screen|
|start some command||long boring output|
|ctrl a, c||Makes a new screen|
|do other commands||bleh bleh whatever|
|ctrl a, n||Cycle to the next screen|
|exit||Type exit, it will scroll through screens shutting them down each time.|
Now you can review screenlog.0 file