tmux: Terminal Multiplexer Guide

What is tmux?

tmux, short for 'Terminal Multiplexer,' allows you to use a single terminal screen divided into multiple independent sessions, windows, and panes. It's an essential tool for keeping tasks running even if your SSH connection drops, or for monitoring multiple tasks simultaneously.

3 Core Concepts

tmux has a hierarchical structure: Session > Window > Pane.

Session: The largest unit. A workspace containing multiple windows (e.g., 'project-A'). Even if you detach from a session, the tasks continue to run in the background.
Window: Similar to a tab within a session. A single session can have multiple windows.
Pane: A smaller terminal screen obtained by splitting a window into multiple parts (e.g., top for code editing, bottom for log monitoring).

Prefix Key

The key combination you press first to execute commands within `tmux`. The default is Ctrl+b. (e.g., to create a new window, press Ctrl+b, release, then press c.) In this guide, this key is referred to as [Prefix].

Main Commands (Shell)

Commands entered directly into the terminal (Shell) to manage tmux sessions.

1. Session Management

2. Help/Version

Generated command:

Try combining the commands.

Description:

`tmux` Executes the command.

Combine the above options to virtually execute commands with AI.

Main Keybindings (Inside tmux)

Keybindings used when attached to a `tmux` session. First, press [Prefix] (default Ctrl+b), then press the subsequent key.

Session and Window Management

[Prefix] + d: Detach from session. Tasks continue to run in the background.
[Prefix] + c: Create a new window
[Prefix] + w: View window list
[Prefix] + n: Move to the next window
[Prefix] + p: Move to the previous window
[Prefix] + [0-9]: Jump directly to the window of that number
[Prefix] + ,: Rename current window
[Prefix] + &: Close current window (requires confirmation)

Pane Management

[Prefix] + %: Split current pane vertically (left/right)
[Prefix] + ": Split current pane horizontally (top/bottom)
[Prefix] + [arrow keys]: Move focus to the pane in the direction of the arrow key
[Prefix] + o: Cycle through to the next pane
[Prefix] + z: Toggle current pane full screen (Zoom)
[Prefix] + x: Close current pane (requires confirmation)

Usage Scenario Examples (Shell)

A common flow for starting and managing tmux from the terminal.

Create and Attach to 'my-project' Session

tmux new -s my-project

Detach from Session

Inside a session, press [Prefix] (Ctrl+b) then the 'd' key to detach from the session. The tasks will continue to run.

Check List of Running Sessions

tmux ls

Reattach to 'my-project' Session

tmux attach -t my-project

Forcefully Terminate 'my-project' Session

tmux kill-session -t my-project

Installation

tmux can be easily installed via the package manager of most Linux distributions.

Debian/Ubuntu

sudo apt update && sudo apt install -y tmux

RHEL/CentOS/Fedora

sudo dnf install -y tmux

Arch Linux

sudo pacman -S --needed tmux

openSUSE

sudo zypper install -y tmux

Tips & Cautions

Recommended Settings/Habits

Immediately after SSH connection: If you create a session like `tmux new -s work` immediately after connecting to a remote server, you can safely resume your work even if the connection is lost.
Mouse Mode: Adding `set -g mouse on` to ~/.tmux.conf enables mouse-based pane resizing, window selection, and scrolling.
Configuration File: Configure your own keybindings or themes in ~/.tmux.conf.
Change Prefix: If Ctrl+b is inconvenient, you can change it to `set -g prefix C-a`.