TMUX: A Screen Redux by Stephen Coley 

What is TMUX? “A terminal multiplexer is a software application that can be used to multiplex several virtual consoles, allowing a user to access multiple separate terminal sessions inside a single terminal window or remote terminal session.” - Wikipedia 

Why? Useful for dealing with multiple programs from a command line interface, and for separating programs from the shell that started them 

Mice Are Stupid 

Keyboards Are Awesome 

MOBI Development Worth Noting ● Context switching - Features, Bugs, Tasks ● Development, Demo, Production Console Programs ● Terminal for Git ● IRB/PRY Console ● Tailing a Log ● Resque Workers, Solr, Mailcatcher ● Text Editor (optional, ya wuss) 

Vocabulary Sessions - Persistent, detachable workspaces Windows - “Tabs” that occupy the entire Session window Panes - Partitions within Windows Prefix - Keystroke that precedes TMUX commands * Default is Ctrl-b. This presentation uses Ctrl-a Command Line TMUX Keystrokes 

Sessions Create a new session: tmux new -s * Immediately attaches to the new Session Detach from current session: Ctrl-a + d or tmux detach * Does not destroy the session List sessions: tmux list-sessions * This will display the name or id of the sessions and # of windows Attach to session: tmux attach -t * If you only have one session: tmux attach Invoke session switcher: Ctrl-a + s * This lets you cycles through open sessions Command Line TMUX Keystrokes 

Windows Create a new window: Ctrl-a + c Rename current window: Ctrl-a + , * Window names default to currently running process Switch to window: Ctrl-a + * Window numbers start with 0 by default Kill current window: Ctrl-a + & Invoke window switcher: Ctrl-a + w TMUX Keystrokes Command Line 

Panes Split horizontally: Ctrl-a + “ == Remap ==> Ctrl-a + h Split vertically: Ctrl-a + % == Remap ==> Ctrl-a + v (ahem..Natively) Switch to another pane: Ctrl-a + o Swap pane locations: Ctrl-a + Ctrl-o Kill current pane: Ctrl-a + x Kill all except current pane: Ctrl-a + ! Command Line TMUX Keystrokes 

...but Screen? Screen is considered a dead project ● Not actively maintained ● Heavy resource consumption ● S'ghetti code ○ Discourages bugfixes and improvements ● Config is notoriously obtuse ● No vertical splits, whaaaa? ○ There's a patch to make this work, but it has not been added to the official codebase ○ 4.1 discussed in Feb 07 

Screen is Dead 

...but TMUX! “The most impressive thing about tmux, in my view, is how frustrating the code audit was. In 2 hours, I found only one or two that had very minor security consequences. It was not accepted into the tree based on license alone. It is high quality code” - Theo de Raadt, founder and project lead for OpenBSD 

TMUX’s Case vs Screen ● Client-Server Model: Windows are independent entities which may be attached simultaneously to multiple sessions and viewed from multiple clients, as well as moved freely between sessions within the same tmux server ● Consistent, well-documented command interface, with the same syntax for interactivity, key binding, and from the shell ● Multiple paste buffers ● Emacs or vi key layout. AKA Developer Heaven ● Nice status line syntax - with dynamic output ● A cleaner, modern, easily extended, BSD-licensed codebase. ● Status bar on by default ● Native vertical splits! 

Remote Pairing Demo 

Happy TMUXing! 

Questions?