About the screen program in Unix
The screen
program allows you to use multiple windows (virtual VT100 terminals) in Unix.
Note: UITS does not support screen
.
Features
- If your local computer crashes or you lose the connection, the processes or login sessions you establish through
screen
don't go away. You can resume yourscreen
sessions with the following command:screen -r
In some cases you may have to manually "detach" yourscreen
session before resuming it. For more information, see the Knowledge Base document When you can't re-attach to your screen session after a lost connection. - The
screen
program creates multiple processes instead of multiple Unix login sessions, which means that it is resource-efficient. - You can cut and paste between different screens without using a mouse. Thus, you don't need to be on a computer with a windowing environment such as macOS, Windows, or the X Window System.
- It has a block copy feature which is similar to the kill rectangle feature of Emacs.
- You can copy and paste more than one page at a time, which you cannot do with some clients. You can scroll up more than one page, depending on how many scrolling lines you have set with the
-h
option. - Using the detach feature, you can save
screen
processes when logging out and resume where you left off, saving the trouble of restarting them.
Starting screen
To start screen
, enter the following command:
screen
General commands
Note: Every screen
command begins with Ctrl-a
.
Ctrl-a c |
Create new window (shell) |
Ctrl-a k |
Kill the current window |
Ctrl-a w |
List all windows (the current window is marked with "*") |
Ctrl-a 0-9 |
Go to a window numbered 0-9 |
Ctrl-a n |
Go to the next window |
Ctrl-a Ctrl-a |
Toggle between the current and previous window |
Ctrl-a [ |
Start copy mode |
Ctrl-a ] |
Paste copied text |
Ctrl-a ? |
Help (display a list of commands) |
Ctrl-a Ctrl-\ |
Quit screen |
Ctrl-a D (Shift-d) |
Power detach and logout |
Ctrl-a d |
Detach but keep shell window open |
Press the Spacebar or Enter
to end a command.
To copy a block
To get into copy mode, press Ctrl-a [
.
To move the cursor, press the h
, j
, k
, and l
(the letter l) keys. The 0
(the number 0) or ^
(the caret) moves to the start of the line and $
(the dollar sign) moves to the end of the line. Ctrl-b
scrolls the cursor back one page and Ctrl-f
scrolls forward one page. To set the left and right margins of copy, press c
and C
(Shift-c). The Spacebar starts selecting the text and ends selecting the text. To abort copy mode, press Ctrl-g
.
To paste a block
To paste the copied text to the current window (as many times as you want), press Ctrl-a ]
.
Other commands
To run a program or execute any Unix command in a new window, at the Unix prompt, enter:
screen unixcommand
Above, replace unixcommand
with the appropriate command name.
To automatically start several windows when you run screen
, create a .screenrc
file in your home directory and put screen
commands in it.
To quit screen
(kill all windows in the current session), press Ctrl-a
Ctrl-\
.
The man pages for screen
are quite readable and make a good tutorial. At the Unix prompt, enter:
man screen
At Indiana University, for personal or departmental Linux or Unix systems support, see Get help for Linux or Unix at IU.
Related documents
This is document acuy in the Knowledge Base.
Last modified on 2019-06-18 14:45:39.