How To Use And Understand Linux Screen.

Install Linux GNU Screen

The screen package is pre-installed on most Linux distros nowadays. You can check if it is installed on your system by typing:

screen --version

Screen version 4.01.00devel (GNU) 2-May-06

How to install screen.

sudo apt updatesudo apt install screen

Install Linux Screen on CentOS and Fedora

sudo yum install screen

Starting Linux Screen

To start a screen session, simply type screen in your console:

screen

This will open a screen session, create a new window, and start a shell in that window.

Now that you have opened a screen session, you can get a list of commands by typing:

Ctrl+a ?

Starting Named Session

Named sessions are useful when you run multiple screen sessions. To create a named session, run the screen command with the following arguments:

screen -S session_name

It’s always a good idea to choose a descriptive session name.

Working with Linux Screen Windows

When you start a new screen session, it creates a single window with a shell in it.

You can have multiple windows inside a Screen session.

To create a new window with shell type Ctrl+a c, the first available number from the range 0…9 will be assigned to it.

Below are some most common commands for managing Linux Screen Windows:

• Ctrl+a c Create a new window (with shell).

• Ctrl+a “ List all windows.

• Ctrl+a 0 Switch to window 0 (by number).

• Ctrl+a A Rename the current window.

• Ctrl+a S Split current region horizontally into two regions.

• Ctrl+a | Split current region vertically into two regions.

• Ctrl+a tab Switch the input focus to the next region.

• Ctrl+a Ctrl+a Toggle between the current and previous windows

• Ctrl+a Q Close all regions but the current one.

• Ctrl+a X Close the current region.

Detach from Linux Screen Session

You can detach from the screen session at any time by typing:

Ctrl+a d

The program running in the screen session will continue to run after you detach from the session.

Reattach to a Linux Screen

To resume your screen session use the following command:

screen -r

In case you have multiple screen sessions running on your machine, you will need to append the screen session ID after the r switch.

To find the session ID list the current running screen sessions with:

screen -ls

There are screens on:
    10835.pts-0.liviu-test-desktop   (Detached)
    10366.pts-0.liviu-test-desktop   (Detached)
2 Sockets in /run/screens/S-liviu-test.

If you want to restore screen 10835.pts-0, then type the following command:

screen -r 10835

Customize Linux Screen

When screen is started, it reads its configuration parameters from /etc/screenrc and ~/.screenrc if the file is present. We can modify the default Screen settings according to our preferences using the .screenrc file.

Here is a sample ~/.screenrc configuration with customized status line and few additional options:

~/.screenrc

# Turn off the welcome message
startup_message off

# Disable visual bell
vbell off

# Set scrollback buffer to 10000
defscrollback 10000

# Customize the status line
hardstatus alwayslastline
hardstatus string '%{= kG}[ %{G}%H %{g}][%= %{= kw}%?%-Lw%?%{r}(%{W}%n*%f%t%?(%u)%?%{r})%{w}%?%+Lw%?%?%= %{g}][%{B} %m-%d %{W}%c %{g}]'

Basic Linux Screen Usage

Below are the most basic steps for getting started with screen:

1. On the command prompt, type screen.

2. Run the desired program.

3. Use the key sequence Ctrl-a + Ctrl-d to detach from the screen session.

4. Reattach to the screen session by typing screen -r.

Conclusion

In this tutorial, you learned how to use Gnu Screen. Now you can start using the Screen utility and create multiple screen windows from a single session, navigate between windows, detach and resume screen sessions and personalize your screen terminal using the .screenrc file.