tmux Cheatsheet

Prefix key: Ctrl-b (referred to as C-b below)

Starting / Attaching

tmux                          # New unnamed session
tmux new -s farm              # New session named "farm"
tmux ls                       # List sessions
tmux a                        # Attach to last session
tmux a -t farm                # Attach to session named "farm"
tmux kill-session -t farm     # Kill session
tmux kill-server              # Kill everything

Sessions

Keys	Action
`C-b d`	Detach from session
`C-b $`	Rename session
`C-b s`	List/switch sessions
`C-b (`	Previous session
`C-b )`	Next session

Windows (tabs)

Keys	Action
`C-b c`	New window
`C-b ,`	Rename window
`C-b &`	Kill window
`C-b w`	List windows (interactive picker)
`C-b n`	Next window
`C-b p`	Previous window
`C-b 0-9`	Jump to window by number
`C-b l`	Last active window

Panes (splits)

Keys	Action
`C-b %`	Split vertical (left/right)
`C-b "`	Split horizontal (top/bottom)
`C-b x`	Kill pane
`C-b o`	Cycle to next pane
`C-b ;`	Toggle to last active pane
`C-b q`	Show pane numbers, then press number to jump
`C-b z`	Zoom/unzoom pane (fullscreen toggle)
`C-b {`	Move pane left
`C-b }`	Move pane right
`C-b Space`	Cycle pane layouts
`C-b !`	Convert pane to its own window

Resizing panes

Keys	Action
`C-b C-arrow`	Resize by 1 cell
`C-b M-arrow`	Resize by 5 cells

Copy / Scroll Mode

Keys	Action
`C-b [`	Enter copy/scroll mode
`q`	Exit copy mode
`Space`	Start selection (in copy mode)
`Enter`	Copy selection and exit
`C-b ]`	Paste buffer
`/`	Search forward (in copy mode)
`?`	Search backward (in copy mode)
`g`	Jump to top
`G`	Jump to bottom

Arrow keys and Page Up/Down work in copy mode.

The in-copy-mode keys above (Space, Enter, /, ?, g, G) are the vi copy-mode bindings. tmux defaults to mode-keys emacs (vi only when $EDITOR/$VISUAL names vi), where the equivalents are C-Space to select, M-w to copy, C-s / C-r to search and M-< / M-> for top / bottom — or add set -g mode-keys vi (see Useful Options).

Running Long Processes on Farm

Fire and forget

# Start session, kick off process, detach
tmux new -s deploy -d 'cd ~/projects/bodmail && npm run build'

# Check on it later
tmux a -t deploy

Multi-window workflow

# Create a session with named windows
tmux new -s farm -n logs -d
tmux new-window -t farm -n build
tmux new-window -t farm -n monitor

# Send commands to specific windows
tmux send-keys -t farm:logs 'tail -f /var/log/app.log' Enter
tmux send-keys -t farm:build 'npm run build' Enter
tmux send-keys -t farm:monitor 'htop' Enter

# Attach when ready
tmux a -t farm

Run command in existing session

tmux send-keys -t farm:0 'npm test' Enter

Wait for a command to finish

# Run in a pane and get notified
tmux set -t farm monitor-activity on
# Now switch to another window — tmux highlights the window when activity occurs

Capture output from a pane

tmux capture-pane -t farm:0 -p > output.txt         # Current visible
tmux capture-pane -t farm:0 -p -S -1000 > output.txt # Last 1000 lines

Useful Options

# Mouse support (scrolling, clicking panes, resizing)
tmux set -g mouse on

# Increase scrollback buffer
tmux set -g history-limit 50000

# Start window numbering at 1
tmux set -g base-index 1
tmux set -g pane-base-index 1

# vi keys in copy mode (Space / Enter / g / G as listed above)
tmux set -g mode-keys vi

Put these in ~/.tmux.conf to make them permanent.

Quick Reference: Common Combos

C-b d           → detach (go do other stuff, come back later)
C-b c           → new window
C-b %           → split side by side
C-b "           → split top/bottom
C-b z           → zoom a pane to fullscreen (again to unzoom)
C-b [           → scroll up through output
C-b w           → visual window/session picker
C-b s           → session picker