Tmux
The tmux tool is a terminal application that allows you to split your terminal
into panes in a single window. It can also be used to detach from sessions and
keep them running in the background. This allows you to keep processes or
scripts running in the background without being visible and allow you to still
use the terminal or to disconnect from the remote host and check back in
later. Additionally tmux can also allow multiple users to attach to the same
session of tmux. This can be very usefully when collaborating with others or
when having someone else review your work.
By simply type tmux after installing it you can open your first tmux
session. You will notice that it looks quite similar to your normal terminal
however now we will cover some of the basics of tmux like splitting our screen.
All tmux commands are triggered with a prefix key and a command key and
tmux uses Emacs notation for its key bindings. By default tmux uses C-b
for its prefix key binding. If you are unfamiliar with Emacs notation, this
simply means Ctrl and b. To split panes vertically in your tmux session the
command key is % meaning your fully sequence of keys would be C-b % (Ctrl
and b, then release and press Shift and 5). Similarly to split panes
horizontally the key sequence is C-b ".
Before we go to much further I want to point out that everything about tmux is customizable. Not only can you customize the prefix key or any of the command keys but you can also customize how the green status bar at the bottom of your session works like adding a calendar, battery icon, or upcoming events. Customization will not be covered in this guide at the current moment.
Now as useful as this is you also need to learn how to navigate the panes you
created to get any use out of them. To switch to a different pane you can simply
type C-b <arrow keys> or C-b o to switch panes in a clockwise rotation. Once
you are done with a pane and wish to close it out simply type exit or C-d to
kill it.
We can also create new windows with tmux. You can think of this like virtual
desktops in a modern operating system. Simply type C-b c to create a new
window where you can split up panes like before and do work with a clean
slate. To switch between your windows type C-b p to go to your previous window
or C-b n to go to your next window. You can also type C-b <number> to switch
to a specific window.
Now that you have knowledge of the basics of tmux usage let's dive into session
management with tmux. To detach from your current session of tmux and keep it
running in the background simply type C-b d or C-b D to have tmux prompt you
asking which session you want to detach. A detached session of tmux will
continue to run in the background which can be very handy if you are running
something that you want to keep running but need to get back to your terminal
for something else or you need to check back in for the results later.
To see the current running detached sessions simply run tmux ls at the command
line. This will print out the list of the current detached sessions, each with a
unique id. To attach to one of these detached sessions simply run
tmux attach -t <id> and you will be dropped right back into that session. It
is important to note that if you wanted to give your session a custom id to make
it more memorable you can run tmux new -s <name> to give it a unique name or
id. You can also rename existing session by running
tmux rename-session -t <id> <name>.
With all of that covered you have now mastered the basics of tmux! Going forward
if you want to learn more tmux key bindings there is a built in help menu that
can be accessed with C-b ?. I also find the tmux cheat sheet to be a great
online resource: tmux cheat sheet. I will also point out some of the neat key
bindings I have started using:
C-b zmakes your current pane full screen. Running it again makes it go back to the size that it was.C-b C-<arrow key>lets you resize your current pane in the direction of the arrow key you type.