TMUX is a terminal multiplexer that allows you to have a GNU-like experience while staying entirely within your terminal client. It works hand in hand with VIM (or emacs) and gives you a lot of powerful tools that are typically only available to you if you use a GUI.


$ brew install tmux

$ tmux -V
# > tmux 2.7 when I did this

Getting Started

  1. Entering TMUX session: $ tmux new (Note: you must type $ source activate to use some packages, your Conda environment, etc.)

  2. Exiting TMUX session: $ tmux exit. This is not the only way to return to your original terminal session. In fact, one of the strengths of TMUX is that you can run a TMUX session in the background.

Using TMUX Commands

  1. Control + b to enter a TMUX command. Nothing will visually change
  2. After pressing Control + b, can type : to get the TMUX prompt

Managing Sessions

After you’ve created a session, you can temporarily exit or detatch this session. To do this, press Control + b then d to detatch.

To see a list of suspended sessions, you can type $ tmux ls. To get back to a sesion, type $ tmux attach-session -t <id> (shortcut: $ tmux a -t <id>). You can also use $tmux a # to go to the most recent session.

Switching Between Session

Once you’re in a TMUX session, you can press Control + b and s to get a dialogue of the open sessions with a preview of what they look like. You can also use Control + b and (/) to move left/right between existing session. To get a read-only list from your main shell, you can type $ tmux ls.

To kill the session you’re currently in, type: Control + b and : kill-session. You can also do this from your main shell: $ tmux kill-session -t <name or id>.

To kill all sessions, type: $ tmux kill-server.


Instead of relying on ambiguous ID numbers, you can also attach names to session. To start a session using a name, type: $ tmux new -s <name of session>. To get back to that session, use the name of the session in place of the ID: $tmux a -t <name of session>.


  • Split horizontally: Control + b then "
  • Split vertically: Control + b then %
  • Move pane left/right: Control + b then {/}
  • Move between panes using Control + b and any of the arrow keys
  • Show pane numbers Control + b then q
  • Switch to pane Control + b, q, then <pane number>
  • Close pane: Control + b then x
  • Resizing: Control + b then :resize-p <direction> <num-cells>. The direction is -U, -D, -L, or -R for up, down, left, and right, respectively.
  • In my .tmux.conf file, I turned on mouse interaction so I can switch panes using my mouse clicks. You can also drag to resize panes.

Copy Mode

One of the other strengths is that you can enter “copy mode” to copy certain parts of the terminal. To enter this mode, press Control + b and [. You can now navigate using VI bindings press Enter to copy. There are a number of helpful commands that you can use that can be found here:


Posted in Developer Tools with Terminal