A Linux terminal on a laptop with other terminal sessions superimposed behind it.
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With the Linux screen command, you can push running terminal applications to the background and pull them forward when you want to see them. It also supports split-screen displays and works over SSH connections, even after you disconnect and reconnect!

What Is the screen Command?

The screen command is a terminal multiplexer, and it’s absolutely packed with options. To say it can do a lot is the granddaddy of understatements. The man page runs to over 4,100 lines.

The following are the most common cases in which you would use the screen command, and we’ll cover these further in this article:

  • The standard operation is to create a new window with a shell in it, run a command, and then push the window to the background (called “detaching”). When you want to see how your process is doing, you can pull the window to the foreground again (“reattach”) and use it again. This is great for long processes you don’t want to accidentally terminate by closing the terminal window.
  • Once you’ve got a screen session running, you can create new windows and run other processes in them. You can easily hop between windows to monitor their progress. You can also split your terminal window into vertical or horizontal regions, and display your various screen windows in one window.
  • You can connect to a remote machine, start a screen session, and launch a process. You can disconnect from the remote host, reconnect, and your process will still be running.
  • You can share a screen session between two different SSH connections so two people can see the same thing, in real-time.

Installing screen

To install screen on ubuntu, use this command:

sudo apt-get install screen

The "sudo apt-get install screen" command in a terminal window.

To install screen on Manjaro, use the following command:

sudo pacman -Sy screen

The "sudo pacman -Sy screen" command in a terminal window.

On Fedora, you type the following:

sudo dnf install screen

The "sudo dnf install screen" command in a terminal window.

Getting Started with screen

To start screen, simply type it as shown below and hit Enter:

screen

The "screen" command in a terminal window.

You’ll see a page of license information. You can press the Space bar to read the second page or Enter to return to the command prompt.

The "screen" command license information in a terminal window.

You’re left at the command prompt, and nothing much seems to have happened. However, you’re now running a shell inside a multiplexed terminal emulator. Why is this a good thing? Well, let’s start a process that’s going to take a long time to complete. We’ll download the source code for the latest Linux kernel and redirect it into a file called latest_kernel.zip.

To do so, we type the following:

curl https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.5.9.tar.xz > latest_kernel.zip

The "curl https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.5.9.tar.xz > latest_kernel.zip" command in a terminal window.

Our download begins, and the curl output shows us the progress.

The output from the "curl https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.5.9.tar.xz > latest_kernel.zip" command in a terminal window.

We can’t show you an image of the next bit, because it’s a keystroke sequence. You type Ctrl+A, release those keys, and then press d to detach the screen.

The download process is still running but the window showing the download is removed. You’re returned to the terminal window from which you launched the screen session. A message tells you that a screen window labeled 23167.pts-0.howtogeek has been detached.

You need the number from the start of the window name to reattach it. If you forget it, you can always use the -ls (list) option, as shown below, to get a list of the detached windows:

screen -ls

The "screen -ls" command in a terminal window.

When you’re ready, you can use the -r (reattach) option and the number of the session to reattach it, like so:

screen -r 23167

The "screen -3 23167" command in a terminal window.

The window that’s been working away in the background is now brought back to your terminal window as if it had never left.

A reattached screen session restored to the terminal window.

If it’s a process that’s going to run through to its conclusion it will eventually complete. If it’s a continual process, you’ll eventually want to terminate it. Either way, when the process ends, you can type exit to exit from the screen. Alternatively, you can press Ctrl+A, and then K to forcibly kill a window.

Type the following command:

exit

The "exit" command in a terminal window.

You’re returned to your previous terminal window, which will still show the command you used to reattach the window. Because we closed our one and only detached window, we get a message that screen is terminating.

The "screen" command terminating message in a terminal window.

RELATED: How to Use curl to Download Files From the Linux Command Line

Using Named screen Sessions

You can use the -S (session name) option to name your screen session. If you use a memorable name rather than the numerical identity of the session, it’s more convenient to reconnect to a session. We type the following to name our session “bigfile”:

screen -S bigfile

The "screen -S bigfile" command in a terminal window.

When screen launches our session, we see a blank window with a command prompt. We’re going to download a big file, so we can use a long-running process as an example.

We type the following:

curl http://ipv4.download.thinkbroadband.com/1GB.zip > bigfile.zip

The "curl http://ipv4.download.thinkbroadband.com/1GB.zip > bigfile.zip" command in a terminal window.

When the download starts, we press Ctrl+A, and then press D to detach the session. We type the following to use the -ls (list) option with screen to see the details of our detached session:

screen -ls

The "screen -ls" command in a terminal window.

Behind the numeric identifier (23266), we see the name of our session (bigfile). We type the following, including the session’s name, to reattach it:

screen -r bigfile

The "screen -r bigfile" command in a terminal window.

We’re reconnected to our download window and see the long download is still in progress.

Curl download output in a reattached screen session in a terminal window.

When the download is complete, we type exit to close the session window.

Using screen with Multiple Windows

So far, we’ve used screen to place a single process in the background in a detached window. However, screen is capable of doing much more than that. Next, we’ll run a few processes that allow us to monitor some aspects of our computer.

We type the following to start a screen session called “monitor”:

screen -S monitor

The "screen -S monitor" command in a terminal window.

At the command prompt in our new window session, we’ll launch dmesg and use the -H (human-readable) and -w (wait for new messages) options. This will display the kernel buffer messages; new messages will appear as they occur.

We type the following:

dmesg -H -w

The "dmesg -H -w" command in a terminal window.

The existing messages appear. We’re not returned to the command prompt because dmseg is waiting for new messages, and will display them as they arrive.

The "dmsesg" output in a terminal window.

RELATED: How to Use the dmesg Command on Linux

We want to run another application, so we need a new screen window. We press Ctrl+A, and then C to create a fresh window. We’re going to use watch to repeatedly run vmstat, so we get a frequently updated display of the virtual memory usage on our computer.

At the new command prompt, we type the following:

watch vmstat

The "watch vmstat" command in a terminal window.

The vmstat output appears and updates every two seconds.

The "vmstat" output in a terminal window.

Our two processes are now running. To hop between the screen windows, you press Ctrl+A, and the number of the window. The first one we created is window zero (0), the next is window 1, and so on. To hop to the first window (the dmesg one), we press Ctrl+A and 0.

Returning to the "dmesg" screen in a terminal window.

If we press Ctrl+A and 1, it takes us back to the vmstat window.

Returning to the "vmstat" screen in a terminal window.

That’s pretty nifty! We can press Ctrl+A, and then D to detach from this session; we can reattach later. Both sessions will still be running. Again, to switch between the windows, we press Ctrl+A and the number (0 or 1) of the window we want to switch to.

Let’s go to the next step and view both screens in one window. When you do this, you’ll stretch your terminal window to a size that makes this step useful. Our examples are constrained to the size of our screenshots, so our windows will look a little cramped.

To do this, we press Ctrl+A, and then Shift+S (a capital “S” is required).

The window splits into two “regions.”

A "screen" window session split into two horizontal regions in a terminal window.

The top region still displays vmstat, and the bottom region is blank. The cursor is highlighted in the screenshot below. To move it to the lower region, we press Ctrl+A, and then Tab.

A "screen" window session split into two horizontal regions with cursor in the bottom region in a terminal window.

The cursor moves to the lower region, which really is just an empty space. It isn’t a shell, so we can’t type anything in it. To get a useful display, we press Ctrl+A, and then press “0” to display the dmesg window in this region.

The "screen" session with a horizontal split pane showing a different process in each region in a terminal window.

This gives us both live outputs in one split window. If we press Ctrl+A and D to detach the window, and then reattach it, we’ll lose the split-pane view. However, we can restore it with the following keyboard shortcuts:

  • Ctrl+A, S: Split the window horizontally.
  • Ctrl+A, Tab: Move to the lower region.
  • Ctrl+A, 0: Display window zero in the lower region.

We can take things even a step further. We’ll now split the lower pane vertically, and add a third process to the display. With the cursor in the lower region, we press Ctrl+A and C to create a new window with a shell in it. The lower region displays the new window and gives us a command prompt.

A "screen" session with a horizontal split pane showing a new window in the lower region in a terminal window.

Next, we run the df command to check file system usage:

df

A "screen" session with a horizontal split pane, and "df" typed in the lower region in a terminal window.

When we see df running, we hit Ctrl+A and the pipe character (|). This splits the lower region vertically. We press Ctrl+A and Tab to move to the new region. Next, we press Ctrl+A and 0 to display the dmesg window.

A "screen" session showing three panes in a terminal window.

You can also move from region to region, and add more vertical or horizontal splits. Here are some more useful key combinations:

  • Ctrl+A: Hop back and forth between the current and previous regions.
  • Ctrl+A, Q: Close all regions except the current one.
  • Ctrl+A, X: Close the current region.

Using screen Over SSH

With screen, you can start a window session, detach it so it’s still running in the background, log off or back in, and reattach the session.

Let’s make an SSH connection to our computer from a different one with the ssh command. We have to provide the name of the account with which we’re going to connect and the address of the remote computer.

For our example, we type the following:

ssh dave@192.168.4.30

The "ssh dave@192.168.4.30" command in a terminal window.

After we authenticate on the remote computer and log in, we type the following to start a screen session called “ssh-geek”:

screen -S ssh-geek

The "screen -S ssh-geek" command in a terminal window.

For demonstration purposes, we’ll run top in the screen window, but you could start any long-running or endless process.

We type the following:

top

The "top" command in a terminal window.

Once top is running in the window, we hit Ctrl+A, and then D to detach the window.

The "top" process running in a "screen" window in a terminal window.

We’re returned to the original, remote terminal window.

User returned to their original terminal window

If we type exit, as shown below, it disconnects the SSH session and we’re back on our local computer:

exit

The "exit" command in a terminal window.

We type the following to reconnect:

ssh dave@192.168.4.30

The "ssh dave@192.168.4.30" command in a terminal window.

After we’re reconnected and logged in, we can type the following to reattach the screen session:

screen -r ssh-geek

The "screen -r ssh-geek" command in a terminal window.

We’re now reconnected to our still-running instance of top.

The "top" process running in a terminal window.

This is great if you want to start a process on one machine, and then pick up wherever you left off on another.

RELATED: How to Create and Install SSH Keys From the Linux Shell

Sharing a screen Session

You can also use a screen session to allow two people to see and interact with the same window. Let’s say someone running Fedora on his computer wants to connect to our Ubuntu server.

He would type the following:

ssh dave@192.168.4.30

The "ssh dave@192.168.4.30" command in a terminal window.

After he’s connected, he starts a screen session called “ssh-geek” using the -S (session name) option. He also uses the -d (detach) and -m (enforced creation) options to create a new screen session that’s already detached.

He types the following:

screen -d -m -S ssh-geek

The "screen -d -m -S ssh-geek" command in a terminal window.

He types the following, using the -X (multiscreen mode) option to attach the session:

screen -X ssh-geek

The "screen -X ssh-geek" command in a terminal window.

On a Manjaro computer, another person connects to the Ubuntu computer with the same account credentials, as shown below:

ssh dave@192.168.4.1

The "ssh dave@192.168.4.1" command in a terminal window.

Once she’s connected, she types the screen command and uses the -X (multiscreen mode) option to join the same window session, like so:

screen -X ssh-geek

The "screen -X ssh-geek" command in a terminal window.

Now, anything either person types, the other will see. For example, when one person issues the date command, they both see it as it’s typed, as well as its output.

The "date" command in a terminal window.

Output from the "date" command in a terminal window.

Both people are now sharing a screen session that’s running on a remote Ubuntu computer.


For a piece of software that first saw the light of day in 1987, screen still packs a good productivity wallop. Familiarizing yourself with it will be time well spent!

RELATED: 37 Important Linux Commands You Should Know

Dave McKay Dave McKay
Dave McKay first used computers when punched paper tape was in vogue, and he has been programming ever since. After over 30 years in the IT industry, he is now a full-time technology journalist. During his career, he has worked as a freelance programmer, manager of an international software development team, an IT services project manager, and, most recently, as a Data Protection Officer. Dave is a Linux evangelist and open source advocate.
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