TopolearnDetach/attach is tmux's killer feature: work survives closed laptops and dropped SSH connections.
When you run tmux, it starts a background server (if none is running) and creates a session inside it, then attaches your terminal as a client. Programs run inside the server, not inside your terminal window.
That means you can detach (C-b d, or close the terminal, or lose your SSH connection) and every program in the session keeps running. Later you attach again and find everything exactly as you left it, scrollback included.
The shell commands to know:
tmux new -s workcreates a session namedwork(names beat the default numbers).tmux lslists sessions.tmux attach -t work(ortmux a -t work) reattaches.tmux new -A -s workattaches toworkif it exists, otherwise creates it: ideal for scripts and shell aliases.tmux kill-session -t workends a session and everything in it.
A session ends when its last shell exits; the server exits when it has no sessions left. The typical remote workflow: ssh server, tmux new -A -s main, start a long build or migration, detach, log out, come back tomorrow and attach.
Example
tmux new -s build # new session named 'build'
# ... start a long job, then C-b d to detach
tmux ls # build: 1 windows (created ...)
tmux attach -t build # back where you left off
tmux new -A -s main # attach to 'main' or create it
tmux kill-session -t buildRemember
- Programs run in the tmux server, so they survive detaching
- tmux new -s name, tmux ls, tmux attach -t name
- tmux new -A -s name = attach or create
Watch out for
- Starting tmux inside tmux by accident (e.g. an alias in .bashrc), which nests sessions; check $TMUX first.