Some Fedora users spend most or all their time at a command line terminal. The terminal gives you access to your whole system, as well as thousands of powerful utilities. However, it only shows you one command line session at a time by default. Even with a large terminal window, the entire window only shows one session. This wastes space, especially on large monitors and high resolution laptop screens. But what if you could break up that terminal into multiple sessions? This is precisely where tmux is handy — some say indispensable.
Install and start tmux
The tmux utility gets its name from being a terminal muxer, or multiplexer. In other words, it can break your single terminal session into multiple sessions. It manages both windows and panes:
- A window is a single view — that is, an assortment of things shown in your terminal.
- A pane is one part of that view, often a terminal session.
To get started, install the tmux utility on your system. You’ll need to have sudo setup for your user account (check out this article for instructions if needed).
sudo dnf -y install tmux
Run the utility to get started:
The status bar
At first, it might seem like nothing happens, other than a status bar that appears at the bottom of the terminal:
The bottom bar shows you:
-  – You’re in the first session that was created by the tmux server. Numbering starts with 0. The server tracks all sessions whether they’re still alive or not.
- 0:username@host:~ – Information about the first window of that session. Numbering starts with 0. The terminal in the active pane of the window is owned by username at hostname host. The current directory is ~ (the home directory).
- * – Shows that you’re currently in this window.
- “hostname” – the hostname of the tmux server you’re using.
- Also, the date and time on that particular host is shown.
The information bar will change as you add more windows and panes to the session.
Basics of tmux
Stretch your terminal window to make it much larger. Now let’s experiment with a few simple commands to create additional panes. All commands by default start with Ctrl+b.
- Hit Ctrl+b, “ to split the current single pane horizontally. Now you have two command line panes in the window, one on top and one on bottom. Notice that the new bottom pane is your active pane.
- Hit Ctrl+b, % to split the current pane vertically. Now you have three command line panes in the window. The new bottom right pane is your active pane.
Notice the highlighted border around your current pane. To navigate around panes, do any of the following:
- Hit Ctrl+b and then an arrow key.
- Hit Ctrl+b, q. Numbers appear on the panes briefly. During this time, you can hit the number for the pane you want.
Now, try using the panes to run different commands. For instance, try this:
- Use ls to show directory contents in the top pane.
- Start vi in the bottom left pane to edit a text file.
- Run top in the bottom right pane to monitor processes on your system.
The display will look something like this:
So far, this example has only used one window with multiple panes. You can also run multiple windows in your session.
- To create a new window, hit Ctrl+b, c. Notice that the status bar now shows two windows running. (Keen readers will see this in the screenshot above.)
- To move to the previous window, hit Ctrl+b, p.
- If you want to move to the next window, hit Ctrl+b, n.
- To immediately move to a specific window (0-9), hit Ctrl+b followed by the window number.
If you’re wondering how to close a pane, simply quit that specific command line shell using exit, logout, or Ctrl+d. Once you close all panes in a window, that window disappears as well.
Detaching and attaching
One of the most powerful features of tmux is the ability to detach and reattach to a session. You can leave your windows and panes running when you detach. Moreover, you can even logout of the system entirely. Then later you can login to the same system, reattach to the tmux session, and see all your windows and panes where you left them. The commands you were running stay running while you’re detached.
To detach from a session, hit Ctrl+b, d. The session disappears and you’ll be back at the standard single shell. To reattach to the session, use this command:
This function is also a lifesaver when your network connection to a host is shaky. If your connection fails, all the processes in the session will stay running. Once your connection is back up, you can resume your work as if nothing happened.
And if that weren’t enough, on top of multiple windows and panes per session, you can also run multiple sessions. You can list these and then attach to the correct one by number or name:
This article only scratches the surface of tmux’s capabilities. You can manipulate your sessions in many other ways:
- Swap one pane with another
- Move a pane to another window (in the same or a different session!)
- Set keybindings that perform your favorite commands automatically
- Configure a ~/.tmux.conf file with your favorite settings by default so each new session looks the way you like
For a full explanation of all commands, check out these references:
- The official manual page
- This eBook all about tmux
Cool information! I had never run across
before. I can think of several situations in the past where it would have saved a lot of time and frustration. Thanks!
I use tmux and powerline together as my terminal choice. It makes for an efficient terminal experience.
Also try out byobu package for better defaults.
Can i run specific panes or even windows as root, while others not?
Due to scripts running under root.
If you start a session under a certain user, then new windows and panes will, by default, be under that user, but yes you can run a process as root using sudo or su in a window or pane with the others staying unaffected.
Yes, that’s definitely possible.
Yes you can! They are all independent TTY sessions!
Kind of. You run tmux as root, and su to your other user in the panes you want. Or the other way around. Think about the security implications though,
Nothing stops you to switch to whatever user you need in any pane. Or use sudo. Whatever you can do in a shell.
You can start tmux as a “normal” user and run “su -” in a specific pane / window. So you can run scripts under root in the pane ( sorry for my english ). I use tmux for years to connect to multiple servers ( each pane has it own ssh connection ), which is very cool.
Kyle R. Conway
Yes you can. Different panels within tmux can be root and non-root (or even ssh’d into other machines as other users). Very powerful tool.
One of the features that I rely on is the fact that tmux is scriptable. Just typing a key combination will setup the dev & test environment within appropriate panes.
I tried it and like it. I’m always looking for new ways to increase efficiency while at the term. Currently use ansi-term from within emacs where I too can split windows, create multiple sessions and more. But tmux is something I can also use and recommend to others. Thanks!
I don’t know why but the Ctrl+b is not working for me . Thanks
Linux samurai 4.8.13-100.fc23.x86_64 #1 SMP Fri Dec 9 14:51:40 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
Each pane is a new shell instance, so this an absolute yes.
You can also create preconfigured sessions with panes in the size you need them.
Thanks for article! Always want to know what is the difference between tmux and screen. Still doesn’t know, but at least I’ve tried tmux 😉
Very useful (for myself at least) Ctrl-b,z: zoom-in/out the pane (make pane fullscreen and then back to previous size)
I think a Window manager like i3 does this better
André Luís de Andrade Mendes
Which is better, tmux or screen ?
Paul W. Frields
@André: It’s not really a matter of better/worse, although I think tmux may have the edge on features. But tmux is also actively maintained, and I believe screen, although stable, is not really updated regularly these days. On that basis I would recommend tmux.
I just use screen all the day, it does what i need, e.x. create a new named detached session with a script.
But what I`m really missing is to capture a terminal started with a ssh login into a session, which a can detach.
Can tmux do this, and most important, reliable?
Why not using Terminator instead? What are the pros about Tmux? Thanks!
Since you can detach and reattach to a tmux session, it works incredibly well for remote terminal access. If your network connection drops or you need to reboot your local machine, you can pickup where you left off just by reconnecting and typing “tmux attach”. Terminator is amazing, but to me, this is tmux’s killer feature.
my keybindings don’t work
The only thing that works for me is:
And it doesnt behave as expected. It asks me for a index value for the window to switch to and since I have only one window it fails unless I add 0
I tried adding a local conf file and rebinding to Ctl+C but same result.
I even went through systematically using keys with the bind key and most didn’t work and none mapped to the documentation.
I am running F25 with Wayland
Paul W. Frields
@Peeved: I’m also running on F25 Workstation with Wayland so I can testify that tmux works fine. Try duplicating the issue on a brand new user account, and/or a fresh installation. It’s possible certain keyboard models or configurations could interfere with proper operation. Also, some non-standard desktop environments may have keybindings that interfere with tmux. Please use community help channels for more support, as this is not a support forum: https://fedoraproject.org/wiki/Communicating_and_getting_help
For those who said i3 Window Manager or Terminator does a better job, you’re missing an important point. tmux works in within your terminal session, can continue running in the background, and was primarily made for remote sessions. You can start a tmux session, start a long running process in it, “disconnect” and then come back to it later. This works great if your connected via ssh to a server. You can run tmux, do your work, and if the connection drops you can re-establish your ssh session and then reconnect to the tmux session you dropped from. Whatever you were doing is still sitting there waiting for you to return.
Another program called “screen” does pretty much the same thing.
Reminds me of Glenda. I like it!
How can I get tmux to automatically start when I start my terminal.
Paul W. Frields
@Kevin: You can usually set a command to run for each terminal in the settings for your terminal app. In the Fedora Workstation’s Terminal app, you can find this by editing the Profile (right click the Terminal or choose it from the app menu on the GNOME Shell menu bar). Edit the profile, choose Command, and use a custom command ‘tmux’.
This is what I use. Then I use tmux windows instead of tabs or different terminals.
I have this in my bashrc
if [ -z “$TMUX” ]
tmux new-session -As default