Posted by on July 2, 2006

A quick overview of the key combinations you’ll use 99% of the time in screen

Screen is a really really handy little bit of software I leave running on all the Linux boxes I run.

From the man page:

Screen is a full-screen window manager that multiplexes a physical ter-
minal between several processes (typically interactive shells). Each
virtual terminal provides the functions of a DEC VT100 terminal and, in
addition, several control functions from the ISO 6429 (ECMA 48, ANSI
X3.64) and ISO 2022 standards (e.g. insert/delete line and support for
multiple character sets). There is a scrollback history buffer for
each virtual terminal and a copy-and-paste mechanism that allows moving
text regions between windows.

It goes on a bit more at length. Anyway, the important thing is that it allows you to have more than one terminal session running in a single terminal and swap between them. You can also disconnect from screen and reconnect at a later date, maybe even from a different location (console as opposed to a remote putty session for example) and all the sessions will still be there, as will any programs running within them!

Brief overview:

Function Keystroke
Attatch to/start screen Type “screen -RD”
Detatch from screen and leave it running in the background “ctrl+a d”
New Terminal within screen “ctrl+a c” (created under the privs of the initial user, not the current one.)
Swap to a different session “ctrl+a [0-9]”
Swap to previous session “ctrl+a a”
Next session in sequence “ctrl+a n”
Previous session in sequence “ctrl+a p”
Enter Copy mode “ctrl+a [“ Then move about and highlight with the cursor keys, and hit enter to copy to screen’s clipboard
Paste Clipboard “ctrl+a ]”

Now if you have a screen session running under a screen (eg, ssh from within screen on host a to host b where you’re also running screen) and you want to perform a screen command on the remote screen you have to type ctrl+a ctrl+a . Thats an extra ctrl+a for every level of screen down you need to go.

Thats the important commands to remember.

If you use screen -RD to attatch to screen, and someone else is already attatched, then their connection is killed. You can do wierd stuff like shared sessions, but then it gets a bit messy and I’m not going to cover it here.

Tags: ,

Comments (1)

  • This is a great summary of the screen command. I just wanted to point out one error. The Enter Copy mode is actually “ctrl+a [“. You have it listed as the same as the paste command.

    Thanks for the abridged version of the man page. It’s been tagged and will be referenced.

Do you have anything to say?

Powered by Wordpress and Stripes Theme Entries (RSS) | Comments (RSS)