tmux Cheatsheet

Status Bar and Formats

Use this tmux reference while you build software engineering projects, review code, or refresh the syntax you reach for most.

Status Bar

set -g status on
set -g status-position top
set -g status-interval 5
set -g status-justify centre        # left, centre, right
set -g status-style "bg=default,fg=white"
set -g status-left-length 40
set -g status-right-length 80
set -g status-left "#[bold]#S "
set -g status-right "#{?client_prefix,PREFIX ,}%Y-%m-%d %H:%M"
setw -g window-status-format " #I:#W "
setw -g window-status-current-format "#[bold] #I:#W "
setw -g window-status-current-style "fg=black,bg=white"
set -g pane-border-style "fg=colour238"
set -g pane-active-border-style "fg=colour250"
set -g message-style "bg=white,fg=black"

Format Strings

Anything in #{} is interpolated, which is how the status bar and scripts read tmux state.

Format	Value
`#S` / `#{session_name}`	Session name
`#I` / `#{window_index}`	Window index
`#W` / `#{window_name}`	Window name
`#P` / `#{pane_index}`	Pane index
`#{pane_id}`	Unique pane id, like `%3`
`#{pane_current_path}`	The pane's working directory
`#{pane_current_command}`	The running command
`#{pane_pid}`	The pane's process id
`#{host}` / `#{host_short}`	Hostname
`#{client_prefix}`	1 while the prefix is pending
`#{pane_synchronized}`	1 when panes are synced
`#{window_zoomed_flag}`	1 when zoomed
`#{session_windows}`	Window count
`#{b:pane_current_path}`	Basename of the path
`#{d:pane_current_path}`	Dirname of the path
`#(shell command)`	Output of a shell command, re-run each interval
`#{?cond,yes,no}`	Conditional
`#{==:#{a},#{b}}`	Comparison
`#[fg=red,bold]`	Inline style

set -g status-right "#{?window_zoomed_flag,ZOOM ,}#(whoami)@#{host_short} %H:%M"
set -g status-left "#[bold]#S#[default] #{session_windows}w "

Keep #(shell command) cheap. It runs on every status-interval, so a slow command makes the whole status bar stutter.

Colors

set -g default-terminal "tmux-256color"
set -ga terminal-overrides ",*256col*:Tc"
set -ga terminal-features ",*:usstyle"       # underline styles, tmux 3.2+

Color syntax	Means
`colour0`-`colour255`	The 256-color palette
`#ff8800`	A 24-bit hex color
`red`, `green`, `blue`, `white`, `black`	Named basics
`brightred` and friends	The bright half
`default`	Inherit from the terminal
`terminal`	The terminal's own default

tmux info | grep Tc                   # is true color detected
echo $TERM                            # should be tmux-256color inside tmux

If colors look wrong inside tmux but fine outside, the culprit is almost always default-terminal plus a missing terminal-overrides line.

A Readable Status Bar

Everything below uses only built-in formats, so it works with no plugins.

set -g status-position bottom
set -g status-justify left
set -g status-interval 5
set -g status-left-length 30
set -g status-right-length 90

set -g status-style "bg=colour235,fg=colour250"
set -g status-left "#[bold] #S #[default]"
set -g status-right "#{?pane_synchronized,SYNC ,}#{?window_zoomed_flag,ZOOM ,}#[fg=colour245]#{b:pane_current_path} #[fg=colour250]%H:%M"

setw -g window-status-format " #I #W "
setw -g window-status-current-format "#[bg=colour250,fg=colour235,bold] #I #W "
setw -g window-status-activity-style "fg=colour222"
setw -g window-status-separator ""

set -g pane-border-style "fg=colour238"
set -g pane-active-border-style "fg=colour250"
set -g message-style "bg=colour250,fg=colour235"
set -g mode-style "bg=colour250,fg=colour235"

Pane Borders as Labels

set -g pane-border-status top
set -g pane-border-format " #P: #{pane_current_command} "

With four panes open this is often more useful than the status bar, since each pane says what it is running.

Conditionals and Modifiers

Syntax	Does
`#{?cond,then,else}`	Conditional
`#{?#{==:#{a},b},y,n}`	Compare two values
`#{b:var}`	Basename
`#{d:var}`	Dirname
`#{t:var}`	Format a timestamp
`#{=10:var}`	Truncate to 10 characters
`#{=-10:var}`	Keep the last 10 characters
`#{s/foo/bar:var}`	Substitute
`#{e\|+\|:1,2}`	Arithmetic
`#{n:var}`	Numeric length

# Show the git branch, only when there is one
set -g status-right "#(cd '#{pane_current_path}' && git branch --show-current 2>/dev/null) %H:%M"

# Truncate a long path
set -g status-right "#{=-30:pane_current_path}"

Keep the shell call cheap and add 2>/dev/null. It runs every status-interval seconds in every attached client, so a slow or noisy command makes the whole bar stutter.

Themes

Theme	Install
`catppuccin/tmux`	`set -g @plugin 'catppuccin/tmux'`
`dracula/tmux`	`set -g @plugin 'dracula/tmux'`
`tmux-power`	`set -g @plugin 'wfxr/tmux-power'`
`gruvbox`	`set -g @plugin 'egel/tmux-gruvbox'`

A theme is just a large set of status-* and *-style options. Reading one is a good way to learn the format language, and copying the twenty lines you like is often better than adding the dependency.