How to use screen

When to use Linux screen

Have you ever experienced a connection loss while using the command line over SSH? As an alternative, have you ever wished to use the command line to launch several programs without having to establish a new SSH connection for each command?

These and other scenarios can be handled by the screen software. Even if the connection drops, you can still utilize screen to keep your terminal open. Similarly, you can execute several commands and open multiple text windows from within one SSH session.

How to use screen

To start screen, log in to your Hostvento Hosting account using SSH, and then type the following command:

Copyscreen

If you receive an error message, please see the Troubleshooting section below.

You can obtain a list of active screen sessions by typing the following command:

Copyscreen -ls

You should see output similar to the following text:

There is a screen on:
        231102.pts-2.sr10       (Attached)
1 Socket in /home/username/.screen.

This output shows that you currently have one attached screen session. You can type commands and work in the shell as you normally would.

• To open a new text window, press Ctrl-a and then type c. A new window opens where you can type commands.
• To move between windows, press Ctrl-a and then type n. This command takes you to the next window.
• To close a window or screen session, type exit.
• You can view online help for the screen application by pressing Ctrl-a and then ?. You can also use the following command:Copyman screen

You may also want to create a customized status bar to make it easier to see which window you are currently using. To do this, create a ~/.screenrc file. For example, to display the server hostname and window name at the bottom of the screen, add the following line to the ~/.screenrc file:

hardstatus alwayslastline "[%H] %w "

Please do not leave idle screen sessions open for long periods of time. Also, make sure you do not violate the Hostvento Hosting Terms of Service. For example, do not leave CPU-intensive processes running for a long time. For more information, please see the Hostvento Hosting Terms of Service.

Troubleshooting Linux screen

Certain account types (such shared hosting accounts) might not be able to use the screen software by default. Your account needs to have the bash shell enabled in order for screen to function. Enter the following command into your account after logging in via SSH to find out your current shell environment:

Copyecho $SHELL

If your shell is set to jailshell, the screen program will not work. If you want to use screen, open a ticket with the Hostvento Hosting Guru Crew at http://hostvento.com and request that the bash shell be enabled for your account.

However, even if the bash shell is enabled for your account, you may receive an error similar to the following message when you try to start screen:

Directory '/var/run/screen' must have mode 775.

If you receive this error message, type the following command:

Copymkdir ~/.screen && chmod 700 ~/.screen

Then add the following line to your ~/.bashrc file:

export SCREENDIR=$HOME/.screen

Log out of SSH, and then log back in. Screen should now work.