Tmux

Getting Started

Tmux is a terminal multiplexer: it runs multiple terminal sessions inside a single window and keeps them alive after you disconnect. It is organized in three layers: sessions contain windows, and windows contain panes.

$ tmux

$ tmux new -s mysession

All keybindings start with the prefix key, which is Ctrl+b by default. Press the prefix, release it, then press the command key.

Sessions

A session is a collection of windows that keeps running in the background after you detach or your connection drops. Reattach later to pick up exactly where you left off.

Key	Description
Ctrl+b d	Detach from current session
Ctrl+b s	List all sessions and switch
Ctrl+b $	Rename current session
Ctrl+b (	Switch to previous session
Ctrl+b )	Switch to next session

$ tmux ls

$ tmux attach -t mysession

$ tmux new -d -s mysession

$ tmux rename-session -t old new

$ tmux kill-session -t mysession

$ tmux kill-server

tmux attach without -t attaches to the most recently used session. kill-server stops tmux entirely, including all sessions.

Windows

Windows are like tabs within a session. Each window runs its own shell and is numbered, starting at 0 by default.

Key	Description
Ctrl+b c	Create a new window
Ctrl+b n	Switch to the next window
Ctrl+b p	Switch to the previous window
Ctrl+b 0-9	Switch to window by number
Ctrl+b l	Switch to the last active window
Ctrl+b w	List all windows and select one
Ctrl+b ,	Rename current window
Ctrl+b .	Move current window to another number
Ctrl+b &	Close current window (with confirmation)

Panes

Panes split a window into multiple terminal areas. Each pane runs its own independent shell.

Key	Description
Ctrl+b %	Split into left and right panes
Ctrl+b "	Split into top and bottom panes
Ctrl+b Arrow	Move to the pane in that direction
Ctrl+b o	Cycle to the next pane
Ctrl+b ;	Jump to the last active pane
Ctrl+b z	Toggle zoom on current pane (full window)
Ctrl+b x	Close current pane (with confirmation)
Ctrl+b {	Swap current pane with the previous one
Ctrl+b }	Swap current pane with the next one
Ctrl+b Space	Cycle through pane layouts
Ctrl+b q	Show pane numbers (press a number to jump there)
Ctrl+b !	Break current pane out into a new window

Resizing Panes

Press the prefix, then an arrow key combined with a modifier. Keep the modifier held to repeat the resize without pressing the prefix again.

Key	Description
Ctrl+b Ctrl+Arrow	Resize pane by 1 cell in that direction
Ctrl+b Alt+Arrow	Resize pane by 5 cells in that direction

The same works from the command prompt, with -D, -U, -L, -R for down, up, left, right.

$ tmux resize-pane -D 10

$ tmux resize-pane -R 10

Copy Mode

Copy mode lets you scroll through output, search it, and copy text. Press Ctrl+b [ to enter it (or Ctrl+b PgUp to enter it scrolled up one page).By default tmux uses Emacs-style keys in copy mode. Most users switch to vi-style keys, which the table below assumes.

$ echo "setw -g mode-keys vi" >> ~/.tmux.conf

Key	Description
q	Exit copy mode
h j k l	Move left, down, up, right
w / b	Move forward / back one word
g / G	Jump to the top / bottom of the history
Ctrl+u / Ctrl+d	Scroll up / down half a page
/	Search forward
?	Search backward
n / N	Next / previous search match
Space	Start selection
Enter	Copy selection and exit copy mode

Outside copy mode, paste the most recently copied text.

Key	Description
Ctrl+b ]	Paste the copied text

Command Mode

Press Ctrl+b : to open the tmux command prompt. Every keybinding is a shortcut for one of these commands, and any of them can be run here directly.

$ new-window -n mywin

$ split-window -h

$ swap-window -t 0

$ select-layout even-horizontal

$ setw synchronize-panes on

synchronize-panes sends your typing to all panes in the window at once. Handy for running the same command on several servers. Turn it off with setw synchronize-panes off.

Configuration

Tmux reads ~/.tmux.conf at server start. Useful options to add:

$ set -g mouse on

$ set -g history-limit 50000

$ set -g base-index 1

$ setw -g pane-base-index 1

mouse on enables clicking panes, dragging borders to resize, and scrolling with the wheel. base-index 1 numbers windows from 1 instead of 0, matching the keyboard layout.Apply changes to a running server without restarting.

$ tmux source-file ~/.tmux.conf