Never Lose Long‑Running Linux Tasks Again: Master the Screen Command

Installation

Many Linux distributions ship screen by default. Verify the installation with:

$ screen --version
Screen version 4.06.02 (GNU) 23-Oct-17

If it is missing, install it using the package manager:

$ sudo apt install screen

Starting a Screen Session

Launch a new session simply by running: $ screen The initial screen shows copyright information; press Enter or Space to continue to a regular terminal.

You can give the session a name for easier identification:

$ screen -S alvin

Detaching and Re‑attaching

While a long‑running command (e.g., a system update) is executing, detach the session with Ctrl‑a d. The process continues in the background.

Re‑attach to the most recent session with: $ screen -r If multiple sessions exist, list them: $ screen -ls Then re‑attach by specifying the session ID or name, e.g.:

$ screen -r 4352
$ screen -r alvin

Nested Sessions

Start a screen inside an existing screen to run parallel tasks. Use the same screen command or the shortcut Ctrl‑a c: $ screen Switch between nested sessions with Ctrl‑a n (next) or Ctrl‑a p (previous).

Closing a Session

Terminate a screen session as you would a normal shell: press Ctrl‑d or type exit:

$ exit

Best Practices

Using screen prevents data loss when network connections drop and allows multiple concurrent tasks within a single terminal window. Naming sessions ( -S) simplifies re‑attachment, and detaching ( Ctrl‑a d) keeps long‑running jobs alive without keeping the SSH connection open.