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.

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

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