Tmux

Terminal multiplexer for managing multiple terminal sessions, windows, and panes in a single interface.

tmux terminal multiplexer session productivity

Overview

Tmux is a terminal multiplexer that allows you to run multiple terminal sessions, windows, and panes within a single terminal window. It’s essential for remote work, development environments, and maintaining persistent sessions.

Installation

# Ubuntu/Debian
sudo apt install tmux

# macOS
brew install tmux

# CentOS/RHEL
sudo yum install tmux

# Arch Linux
sudo pacman -S tmux

Basic Concepts

Hierarchy

Session: Top-level container for windows
Window: Contains one or more panes
Pane: Individual terminal instance

Default Prefix Key

Prefix: Ctrl+b (can be customized)
All tmux commands start with the prefix key

Session Management

Creating Sessions

# Create new session
tmux new-session
tmux new

# Create named session
tmux new-session -s session_name
tmux new -s work

# Create detached session
tmux new-session -d -s background

Listing Sessions

# List all sessions
tmux list-sessions
tmux ls

# Show sessions in tmux
Ctrl+b s

Attaching to Sessions

# Attach to last session
tmux attach
tmux a

# Attach to specific session
tmux attach -t session_name
tmux a -t work

# Attach or create session
tmux new-session -A -s session_name

Detaching from Sessions

# Detach from current session
Ctrl+b d

# Detach from command line
tmux detach

Session Control

# Kill session
tmux kill-session -t session_name

# Kill all sessions
tmux kill-server

# Rename session
Ctrl+b $

Window Management

Creating Windows

# Create new window
Ctrl+b c

# Create window with name
Ctrl+b c
# Then rename: Ctrl+b ,

Navigating Windows

# Next window
Ctrl+b n

# Previous window
Ctrl+b p

# Go to window by number
Ctrl+b 0-9

# Go to window by name
Ctrl+b f

# List windows
Ctrl+b w

Window Control

# Rename window
Ctrl+b ,

# Kill window
Ctrl+b &

# Move window
Ctrl+b .

Pane Management

Creating Panes

# Split horizontally (top/bottom)
Ctrl+b "

# Split vertically (left/right)
Ctrl+b %

# Split with custom command
Ctrl+b "
# Then type command

Navigating Panes

# Move between panes
Ctrl+b arrow keys
Ctrl+b h/j/k/l  # vim-style (if configured)

# Go to next pane
Ctrl+b o

# Go to previous pane
Ctrl+b ;

# Show pane numbers
Ctrl+b q

Resizing Panes

# Resize pane (arrow keys)
Ctrl+b Ctrl+arrow keys

# Resize by 5 cells
Ctrl+b Alt+arrow keys

# Make pane full screen
Ctrl+b z

# Balance panes
Ctrl+b Alt+1  # horizontal
Ctrl+b Alt+2  # vertical

Pane Control

# Kill pane
Ctrl+b x

# Break pane to new window
Ctrl+b !

# Move pane to another window
Ctrl+b :
move-pane -t window_name

# Swap panes
Ctrl+b {  # swap with previous
Ctrl+b }  # swap with next

Copy Mode

Entering Copy Mode

# Enter copy mode
Ctrl+b [

# Search in copy mode
Ctrl+b Ctrl+s  # forward
Ctrl+b Ctrl+r  # backward

# Move cursor
Arrow keys
h/j/k/l  # vim-style

# Page up/down
Page Up/Page Down
Ctrl+b/Ctrl+f  # vim-style

# Go to line
g  # beginning
G  # end

Selecting and Copying

# Start selection
Space

# Copy selection
Enter

# Paste
Ctrl+b ]

# Show paste buffer
Ctrl+b =

Command Mode

Entering Command Mode

# Command prompt
Ctrl+b :

# Common commands
:new-window
:kill-window
:split-window
:resize-pane

Useful Commands

# List commands
:list-commands

# Show key bindings
:list-keys

# Reload config
:source-file ~/.tmux.conf

# Show options
:show-options

Configuration

Basic Configuration (~/.tmux.conf)

# Change prefix key
set -g prefix C-a
unbind C-b
bind C-a send-prefix

# Enable mouse support
set -g mouse on

# Start windows and panes at 1
set -g base-index 1
setw -g pane-base-index 1

# Renumber windows
set -g renumber-windows on

# Increase history limit
set -g history-limit 10000

# Enable vi mode
setw -g mode-keys vi

# Fast pane switching
bind -n M-Left select-pane -L
bind -n M-Right select-pane -R
bind -n M-Up select-pane -U
bind -n M-Down select-pane -D

Status Bar Configuration

# Status bar
set -g status-interval 1
set -g status-justify centre
set -g status-style bg=black,fg=white

# Status left
set -g status-left-length 40
set -g status-left '#[fg=green]#S #[fg=blue]#I #[fg=cyan]#P'

# Status right
set -g status-right '#[fg=cyan]%d %b %R'

# Window status
setw -g window-status-style fg=cyan,bg=black
setw -g window-status-current-style fg=white,bg=red

Key Bindings

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

# Vim-style copy mode
bind-key -T copy-mode-vi 'v' send -X begin-selection
bind-key -T copy-mode-vi 'y' send -X copy-selection

# Better splitting
bind | split-window -h
bind - split-window -v

Common Workflows

Development Setup

# Create development session
tmux new-session -d -s dev

# Split into multiple panes
tmux split-window -h
tmux split-window -v
tmux select-pane -t 0
tmux split-window -v

# Run different commands in each pane
tmux send-keys -t 0 'vim' Enter
tmux send-keys -t 1 'npm start' Enter
tmux send-keys -t 2 'npm test' Enter
tmux send-keys -t 3 'git status' Enter

# Attach to session
tmux attach -t dev

Remote Work

# Create persistent session on remote server
ssh user@server
tmux new-session -d -s remote-work

# Run long-running processes
tmux send-keys 'python train_model.py' Enter

# Detach and logout
tmux detach
exit

# Later: reconnect and attach
ssh user@server
tmux attach -t remote-work

Advanced Features

Session Scripting

#!/bin/bash
# Create development environment
tmux new-session -d -s dev -x 120 -y 40

# Create windows
tmux new-window -t dev:1 -n 'editor'
tmux new-window -t dev:2 -n 'server'
tmux new-window -t dev:3 -n 'tests'

# Setup editor window
tmux send-keys -t dev:1 'cd ~/project && vim' Enter

# Setup server window
tmux send-keys -t dev:2 'cd ~/project && npm start' Enter

# Setup tests window
tmux send-keys -t dev:3 'cd ~/project' Enter

# Attach to session
tmux attach -t dev

Plugins (TPM)

# Install TPM (Tmux Plugin Manager)
git clone https://github.com/tmux-plugins/tpm ~/.tmux/plugins/tpm

# Add to ~/.tmux.conf
set -g @plugin 'tmux-plugins/tpm'
set -g @plugin 'tmux-plugins/tmux-sensible'
set -g @plugin 'tmux-plugins/tmux-resurrect'

# Initialize TPM
run '~/.tmux/plugins/tpm/tpm'

# Install plugins: Ctrl+b I
# Update plugins: Ctrl+b U

Troubleshooting

Common Issues

Prefix key not working

# Check if prefix is set correctly
tmux show-options -g prefix

# Reset prefix
tmux set-option -g prefix C-b

Colors not working

# Check terminal colors
echo $TERM

# Set in ~/.tmux.conf
set -g default-terminal "screen-256color"

Mouse not working

# Enable mouse in config
set -g mouse on

# Reload config
tmux source-file ~/.tmux.conf

Debugging

# Show tmux info
tmux info

# Show server info
tmux show-options -g

# List clients
tmux list-clients

# Show messages
tmux show-messages

Quick Reference

Essential Commands

# Sessions
tmux new -s name          # Create session
tmux ls                   # List sessions
tmux attach -t name       # Attach to session
Ctrl+b d                  # Detach from session

# Windows
Ctrl+b c                  # Create window
Ctrl+b n/p               # Next/previous window
Ctrl+b 0-9               # Go to window number

# Panes
Ctrl+b %                  # Split vertically
Ctrl+b "                  # Split horizontally
Ctrl+b arrow keys        # Navigate panes
Ctrl+b x                  # Kill pane

# Copy mode
Ctrl+b [                  # Enter copy mode
Space                     # Start selection
Enter                     # Copy selection
Ctrl+b ]                  # Paste

Useful Key Bindings

Ctrl+b ?                  # Show help
Ctrl+b t                  # Show time
Ctrl+b q                  # Show pane numbers
Ctrl+b z                  # Toggle pane zoom
Ctrl+b {/}               # Swap panes
Ctrl+b !                  # Break pane to window

Tips and Tricks

Productivity Tips

Use named sessions for different projects
Create shell aliases for common tmux commands
Use tmux scripting for consistent environments
Learn vim-style navigation for efficiency
Use mouse mode for quick operations

Best Practices

Keep sessions organized and named
Use different windows for different tasks
Regularly detach from sessions when not needed
Configure tmux to match your workflow
Use plugins to extend functionality