tmux Sessions: Create, Attach, Detach, and Manage Windows

Start a long process on a server and disconnect from SSH — the process keeps running. Come back an hour later, reconnect to the same session, and see everything exactly as you left it. That is what tmux is for. But between 'create a session' and 'manage sessions efficiently' lies a whole set of commands worth knowing.

Installation

Debian / Ubuntu:

sudo apt install tmux

RHEL / CentOS / Rocky:

sudo dnf install tmux

Arch Linux:

sudo pacman -S tmux

Check version:

tmux -V

Create a Session

Start tmux without a name — the session gets a number:

tmux

Start with a name — easier when multiple sessions are running:

tmux new -s myproject

Meaningful names like backend, logs, deploy work better than numbers when you have five sessions open.

Create a session and immediately run a command inside it:

tmux new -s monitoring -d "htop"

The -d flag creates the session in the background — does not switch to it immediately.

List Running Sessions

tmux ls

Shows name, number of open windows, and creation time for each session.

Attach to a Session

By name:

tmux attach -t myproject

By number:

tmux attach -t 0

If only one session is running — the name can be omitted:

tmux attach

Attach to the most recently used session:

tmux attach -t $(tmux ls | tail -1 | cut -d: -f1)

Detach From a Session

Leave the session running and return to the regular terminal — keyboard shortcut inside tmux:

Ctrl+b  d

Press Ctrl+b, release, then press d. The session keeps running in the background, all processes inside stay alive.

Detach another user from a session without leaving it yourself:

tmux detach-client -t myproject

Rename a Session

From outside tmux:

tmux rename-session -t old_name new_name

Inside the active session — keyboard shortcut:

Ctrl+b  $

An input prompt appears, type the new name and press Enter.

Kill a Session

From the command line outside tmux:

tmux kill-session -t myproject

From inside the active session:

Ctrl+b  :kill-session

Kill all sessions at once:

tmux kill-server

Multiple Windows Inside One Session

A session is a container for windows. One session, several windows — each in its own tab.

Create a new window inside the session:

Ctrl+b  c

Switch between windows:

Ctrl+b  n   — next
Ctrl+b  p   — previous
Ctrl+b  0   — by number (0-9)

Show window list:

Ctrl+b  w

Close the current window:

Ctrl+b  &

Split a Window Into Panes

A window can be split into multiple panes — separate terminals on the same screen.

Split horizontally (one above the other):

Ctrl+b  "

Split vertically (side by side):

Ctrl+b  %

Navigate between panes:

Ctrl+b  arrow keys

Close the current pane:

Ctrl+b  x

Share a Session With Another User

tmux allows multiple users to attach to the same session — useful for pair programming or remote assistance. Both see the same screen in real time.

First user creates the session:

tmux new -s shared

Second user attaches:

tmux attach -t shared

Both control the terminal simultaneously — both see all output.

~/.tmux.conf: Basic Configuration

Change the prefix from Ctrl+b to Ctrl+a — easier on the fingers during long sessions:

set-option -g prefix C-a
unbind C-b
bind C-a send-prefix

Number windows from 1 instead of 0 — matches keyboard layout more naturally:

set -g base-index 1

Enable mouse support and increase command history:

set -g mouse on
set -g history-limit 10000

Apply changes without restarting tmux — inside a session:

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

Quick Reference