Introduction to tmux

tmux is a terminal multiplexer that lets you:

• Create multiple terminal sessions in one window
• Split windows into panes
• Detach and reattach sessions (keep processes running)

Key Concepts

• Session: A collection of windows under one tmux instance
• Window: A tab-like container within a session
• Pane: A split section within a window

Basic Usage

Starting tmux

tmux                        # Start new session with default name
tmux new -s mysession       # Start named session
tmux attach -t mysession    # Attach to existing session
tmux ls                     # List all sessions

Prefix Key

All tmux shortcuts use a prefix key. Default is Ctrl+b (press and release, then press the command key).

Essential Commands

Session Management

Shortcut	Action
Ctrl+b d	Detach from session
Ctrl+b $	Rename session
Ctrl+b s	List sessions
Ctrl+b (	Previous session
Ctrl+b )	Next session

Window Management

Shortcut	Action
Ctrl+b c	Create new window
Ctrl+b ,	Rename window
Ctrl+b n	Next window
Ctrl+b p	Previous window
Ctrl+b 0-9	Go to window number
Ctrl+b w	List windows
Ctrl+b &	Close window

Pane Management

Shortcut	Action
Ctrl+b %	Split vertically
Ctrl+b "	Split horizontally
Ctrl+b Arrow	Move between panes
Ctrl+b o	Cycle panes
Ctrl+b x	Close pane
Ctrl+b Space	Toggle pane layouts
Ctrl+b {	Move pane left
Ctrl+b }	Move pane right
Ctrl+b z	Toggle zoom (expand/shrink pane)

Other Useful Commands

Shortcut	Action
Ctrl+b ?	Show all shortcuts
Ctrl+b :	Enter command mode
Ctrl+b [	Enter scroll/copy mode
Ctrl+b ]	Paste from buffer
Ctrl+b t	Show clock

Common Workflows

Split-screen development

tmux                     # Start tmux
Ctrl+b "                 # Split horizontally
# Run server in top pane
Ctrl+b Arrow             # Move to bottom pane
# Run client or tests below

Persistent session (keep processes running)

tmux new -s work         # Create session
# Run your long-running process
Ctrl+b d                 # Detach (process keeps running)
# ... do other work ...
tmux attach -t work      # Reattach later

Multiple project layouts

tmux new -s project1     # Session for project 1
# Set up windows/panes
Ctrl+b d                 # Detach
tmux new -s project2     # Session for project 2
# Switch between: tmux attach -t project1/project2

Configuration

Create ~/.tmux.conf for custom settings:

# Change prefix to Ctrl+a (easier for some)
set -g prefix C-a
unbind C-b

# Enable mouse mode
set -g mouse on

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

# Easier split shortcuts
bind v split-window -h -c "#{pane_current_path}"
bind h split-window -v -c "#{pane_current_path}"

# Vim-like pane navigation
bind h select-pane -L
bind j select-pane -D
bind k select-pane -U
bind l select-pane -R

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

Quick Reference Commands

tmux kill-session -t name    # Kill a session
tmux kill-server             # Kill all sessions
tmux source-file ~/.tmux.conf # Reload config