tmux: Persistent Terminal Sessions for Developers

Two things make tmux worth learning. Sessions survive after you close your terminal or lose an SSH connection — your processes keep running and you reconnect to find everything exactly where you left it. And you can split a single terminal into multiple panes and windows without juggling tabs.

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Install

# Debian / Ubuntu
sudo apt install tmux

# RHEL / Fedora / Rocky
sudo dnf install tmux

# macOS
brew install tmux

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Core concepts

tmux has three levels:

• Session — a collection of windows. One session per project is the natural fit.
• Window — a full-screen view inside a session. Think of it like a browser tab.
• Pane — a split region within a window. One window can hold several panes.

The prefix key is how you send commands to tmux without the keystrokes going to the program running inside it. The default is Ctrl+B. Press it, release, then press the command key.

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Start and attach to sessions

Create a new named session:

tmux new -s myproject

Detach (session keeps running in the background):

Ctrl+B  d

List sessions:

tmux ls

Reattach by name:

tmux attach -t myproject

Short form: tmux a -t myproject. With only one session, tmux a is enough.

Kill a session:

tmux kill-session -t myproject

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Windows

Action	Keys
New window	Ctrl+B c
Next window	Ctrl+B n
Previous window	Ctrl+B p
Go to window by number	Ctrl+B 0–9
Rename current window	Ctrl+B ,
Close current window	Ctrl+B &

Windows appear in the status bar at the bottom. The active one has a * next to its name.

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Panes

Action	Keys
Split top/bottom	Ctrl+B "
Split left/right	Ctrl+B %
Move between panes	Ctrl+B arrow keys
Resize pane	Ctrl+B Ctrl+arrow keys
Zoom to full screen	Ctrl+B z (toggle)
Close current pane	Ctrl+B x

Zoom is one of the most useful shortcuts — it temporarily expands a pane to fill the entire window without closing the others. Hit it again to return to the split view.

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Scrollback and copy mode

Mouse scroll does not work inside tmux by default. To scroll:

Ctrl+B  [

This enters copy mode. Arrow keys and Page Up/Page Down navigate. Press / to search, n for the next match, q to exit.

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Auto-start a session on login

tmux sessions do not survive a reboot. For development machines where you always want a session waiting:

# add to ~/.bashrc or ~/.zshrc
if [ -z "$TMUX" ]; then
  tmux attach -t main 2>/dev/null || tmux new -s main
fi

The [ -z "$TMUX" ] guard prevents tmux from launching inside an existing tmux session, which would nest them.

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~/.tmux.conf

A minimal config that most people find immediately useful:

# Start window and pane numbering at 1 instead of 0
set -g base-index 1
setw -g pane-base-index 1

# Enable mouse: click to focus panes, drag to resize
set -g mouse on

# Increase scrollback
set -g history-limit 10000

# Status bar: show session name on the left, time on the right
set -g status-left "[#S] "
set -g status-right "%H:%M"

Reload the config without restarting:

Ctrl+B  :source-file ~/.tmux.conf

Mouse support is the single option worth enabling immediately if you are used to a GUI terminal. It makes pane navigation and resizing click-based while you build up the keyboard shortcuts.