tmux: The Terminal Multiplexer

tmux solves two problems: sessions that survive your connection dropping, and more terminal space than a single window gives. Both are table stakes for serious remote work.

The model

• Server — the daemon; survives your ssh disconnect.
• Session — a named workspace (tmux new -s work).
• Window — a full-screen tab within a session.
• Pane — a split inside a window.

Attach, do work, detach (Ctrl-b d), the session runs on the server. Reconnect days later: tmux attach -t work — everything still there, logs still scrolling.

The essentials

tmux new -s work           # new session
tmux ls                    # list sessions
tmux attach -t work        # reattach

Inside tmux, everything hangs off the prefix Ctrl-b:

• Ctrl-b % — split vertically; Ctrl-b " — horizontally
• Ctrl-b arrows — move between panes
• Ctrl-b c — new window; Ctrl-b n/p — next/prev window
• Ctrl-b [ — scroll mode (q to quit)

The workflow patterns

• Dev: one window for the editor (or vim), one for the test runner, one for git — all in one ssh connection.
• Long jobs: tmux new -s build then run the deploy — detach, go home, reattach tomorrow.
• Shared session: two people tmux attach to the same session — the original pair-programming remote.

Field notes

• tmux -CC (iTerm2 integration) makes tmux windows native terminal windows — the best of both worlds.
• set -g mouse on in ~/.tmux.conf enables scroll/click for pane selection — the quality-of-life flag everyone adds.
• Nested tmux (tmux inside tmux) works — the inner prefix is Ctrl-b b (send-prefix); you usually don't want it.