Learn Tmux - Session, Window & Pane Lifecycle Basics

#Introduction

In episode 2 we dissected the tmux architecture: the client-server model, the session → window → pane hierarchy, communication over a Unix socket, and how the status bar is rendered. In this episode we start driving the machine: managing the lifecycle of sessions, windows, and panes — the three levels you'll touch every day.

Why does this matter in the real world? When you start work on a production server, you usually create a session named after the task context (e.g. deploy, migrasi, debug-api), open a few windows for the editor, logs, and top, then split panes to monitor several things at once. The create → use → detach → re-attach → destroy cycle is every engineer's daily pattern. You'll do it hundreds of times in your career — so make it automatic.

#Session Lifecycle

A session is the unit of persistence: this is what you create, attach, detach, and destroy. Its entire lifecycle can be controlled from the command line, inside tmux, or via scripts.

#Creating a Session

tmux new -s deploy
tmux new -s migrasi

tmux new -s <nama> creates a session with an easy-to-recognize name. Descriptive names matter because you'll pick that session again when attaching. If no name is given, tmux assigns sequential numbers (0, 1, ...).

tmux new-session -d -s deploy "sudo systemctl status nginx"

tmux new-session -d -s proyek -c ~/proyek/web

The -d (detached) flag creates the session in the background without attaching a client — very useful for bootstrapping a work environment from a script. We'll dig into this automation in episode 11.

#Attach & Detach

To enter an existing session:

tmux attach -t deploy
tmux attach
tmux a -t deploy

tmux attach without -t attaches to the only running session. tmux a is its shorthand alias.

To temporarily leave a session without closing it: press Ctrl+B then d. You're back at the shell prompt, but all processes inside the session keep running.

#Listing Sessions

tmux ls
 
deploy: 2 windows (created Mon Aug  2 08:00:00 2026)
migrasi: 1 windows (created Mon Aug  2 08:05:00 2026)

tmux ls (or tmux list-sessions) shows all sessions along with their window counts.

#Destroying a Session

tmux kill-session -t migrasi
tmux kill-server

tmux kill-session -t <nama> kills the session and all processes inside it — use it with care. tmux kill-server kills the server along with every session.

#Working Directory per Session

Each session (and window) has its own working directory. When creating a session, tmux takes the working directory from where you ran tmux new. For explicit control:

tmux new -s proyek -c ~/proyek/web
tmux new-window -c ~/proyek/api

This matters: an editor window, a log window, and a CLI window can start from different directories without manual cd.

#Window Management

Windows are the "tabs" in a session. Everything is controlled via the prefix key.

#Creating a Window

The new window is immediately active with a shell prompt in the session's working directory.

#Window Navigation

#Rename & Find

Ctrl+B then f is very useful when many windows are open — type a fragment of text shown in the target window, and tmux jumps there.

#Closing a Window

Just like sessions, closing a window terminates the processes in all its panes. tmux asks for confirmation before closing.

#Pane Management

Panes are split viewports within a window. This is where tmux offers mouse-free "dual screen".

#Vertical & Horizontal Split

Note: % creates a vertical dividing border (panes left & right), while " creates a horizontal dividing border (panes top & bottom). Both can be combined repeatedly:

Ctrl+B + %   Ctrl+B + "   Ctrl+B + % di pane kiri
 
+----------+----------+     +------+------+------+
|    a     |    b     |     |  a   |  b   |  c   |
|          |          |     |      |      |      |
+----------+----------+     +------+------+------+

#Pane Navigation

Ctrl+B then q shows each pane's number — very helpful when navigating a complex layout. Ctrl+B then z (zoom) temporarily magnifies one pane: edit a file without distractions, then return to the layout.

#Closing a Pane

#Quick Reference Table

#Practice Exercises

1. Create a session: tmux new -s latihan, then create 3 windows (Ctrl+B then c three times).
2. Window navigation: practice Ctrl+B then n / p / 0-3 until it's effortless.
3. Rename a window: Ctrl+B then ,, type the name, Enter.
4. Split a pane: in one window, Ctrl+B then %, then Ctrl+B then ", then Ctrl+B then panah to move around.
5. Zoom: Ctrl+B then z to magnify, press again to return.
6. Detach & re-attach: Ctrl+B then d, then tmux attach -t latihan. The processes stay alive.
7. Clean up: tmux kill-session -t latihan.

#Common Pitfalls

1. exit in the last pane kills the session. If you only want to pause, use detach (Ctrl+B then d), not exit.

2. Wrong session name in -t. tmux kill-session -t salah fails with can't find session. Check tmux ls first.

3. Creating a new session when you could just attach. You have a deploy session, but running tmux new -s deploy again actually creates a second session (tmux auto-renames it). If you want to return to old work, always tmux attach -t deploy.

4. Not naming windows/sessions. The status bar becomes a confusing pile of numbers when the session is busy. Get used to -s <nama> and Ctrl+B then ,.

5. Confusing split directions. % splits left-right (vertical border), " splits top-bottom (horizontal border). Remember: % is the "tall" split, " is the "wide" split.

6. Closing a pane without making sure no process is running. Ctrl+B then x kills the process in the pane. Make sure the build/deploy process in that pane is really finished.

#Conclusion

In episode 3 you mastered the tmux lifecycle basics: creating and managing sessions (new, attach, ls, detach, kill-session), navigating windows like tabs (c, n/p/0-9, , rename, f find), and splitting and navigating panes (% vertical split, " horizontal split, arrows, z zoom). The create → use → detach → re-attach → destroy cycle is now at your fingertips.

Key points to take away:

• Detach (Ctrl+B then d) ≠ exit — detach saves, exit destroys.
• Descriptive names for sessions and windows are a small investment with big returns.
• % = vertical split, " = horizontal split — combining them creates complex layouts.
• Ctrl+B then q shows pane numbers; Ctrl+B then z gives focused zoom.
• The chained rule pane → window → session: destroying a deeper level can destroy an outer one.

Now you can "live" inside tmux. In episode 4, we'll cover Prefix Key & Keybindings — understanding tmux's keybinding system, viewing and searching shortcuts (Ctrl+B then ?), the basics of bind-key and unbind-key, adding custom keybindings in ~/.tmux.conf, all the way to layered keybinding combinations. Stay excited, because full control of the tmux keyboard will soon be in your hands!