Love, Hate, & tmux

Dan Croak

Many at thoughtbot run their editor+shell combos inside of tmux. Some remote pair program with ssh, vim, and tmux.

Getting started with tmux, these are the questions I’ve had.

How do I get started

Install tmux, read the documentation, and fire it up.

brew install tmux
man tmux
tmux -u

Can I make the environment look good

Yes. We have these lines in tmux.conf in thoughtbot/dotfiles:

# improve colors
set -g default-terminal "screen-256color"

# soften status bar color from harsh green to light gray
set -g status-bg '#666666'
set -g status-fg '#aaaaaa'

# remove administrative debris (session name, hostname, time) in status bar
set -g status-left ''
set -g status-right ''

What’s a prefix

The “prefix” namespaces tmux commands. By default it is Ctrl+b. In our tmux.conf in thoughtbot/dotfiles, we bound it to Ctrl+a:

# act like GNU screen
unbind C-b
set -g prefix C-a

How can I scroll up to see my backtraces

This was non-obvious to me.

Enter “copy mode”:


Use vim bindings to page up and down:


How can I copy text

Add this to your tmux.conf:

# enable copy-paste
# enable RubyMotion
set -g default-command "reattach-to-user-namespace -l zsh"

How can I make tmux act more like vim

Add this to your tmux.conf to use vim’s home-row keys for movement between windows and panes:

# act like vim
setw -g mode-keys vi
bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R
bind-key -r C-h select-window -t :-
bind-key -r C-l select-window -t :+

How do I name sessions

One day I might work on Airbrake. Another day, a client project. I’d like to name my tmux sessions so I can leave one, drop into another, and go back to the original with all my state maintained (files still open in my editor, console/logs I want open, etc.).

Create a new session:

tmux new -s airbrake

Attach to a session:

tmux attach -t airbrake

How do I split and move between windows

Create a window:

prefix c

Move to window 1:

prefix 1

Move to window 2:

prefix 2

Kill a window:

prefix x

I believe in setting my mouse free but it takes time for muscle memory to make this fast.

How do I reload ~/.tmux.conf

After editing ~/.tmux.conf, execute this from a shell:

tmux source-file ~/.tmux.conf

Give it a shot

I’ve had a love-hate relationship with tmux in my first week using it, but the brief moments of flow I’ve experienced so far are enough to keep trying it.

Give tmux a shot and if you have any other tips, I’d love to hear them.