Advent 2023: tmux

I use terminal-based programs a lot.

It should be obvious to anyone following my blog that I use editors in the vim family. But there are a slew of other tools I use from the CLI: docker, phpunit, phpcs, psalm, pandoc, ssh, ngrok, and more. Often, I'll be editing a file, and need to run another program, and reference what I'm editing: running unit tests, linters, or static analysis often fall in this category.

Sure, I could use a tabbed terminal, but then I can't have the results of running the program right next to the editor. So for this, I use a terminal multiplexer; specifically, I use tmux.

Terminal multiplexer?

A terminal multiplexer allows multiple pseudo-terminal sessions within a single display. It's kind of like a window manager for a terminal. At its most basic, it offers multiple windows that you can switch between. However, most terminal multiplexers also allow you to split a window into multiple panes, each with its own session. A good terminal multiplexer allows you to arrange the panes side by side, stacked vertically, or a combination of the two. Additionally, many allow you to run one or more sessions, which you can detach from and re-attach to; you can even have multiple people attach at the same time (which is a fun way to screenshare!).

The terminal multiplexer I was first introduced to was screen. It's been around for longer than I've been using Linux, and mostly gets the job done. However, another project has largely supplanted it: tmux. It offers all the same features, and, by default, behaves essentially the same way as screen. However, it has a number of improvements, including the ability to extend its feature set, which makes it a compelling replacement.


Yes, extensions.

I use several, but the following are the ones that have been most useful:

  • tmux-continuum and tmux-resurrect give me continuous and on-demand saving of my session, as well as restoration of sessions. With these in place, I can be reasonably safe from things like my machine crashing or power outages, as whatever I was doing will be present when I start the session again. (Within reason; things like docker sessions will of course need to be restarted.)
  • tmux-open allows me to navigate my cursor to a filename, and open it with the system default program, or $EDITOR.
  • tmux-yank copies text I highlight using tmux's visual highlighting to the system clipboard. It's rare I don't want this!
  • tmux-tilish provies auto-tiling of panes. This means that spawning a new pane will position it in a predictable location.
  • tmux-navigator allows me to switch between panes using vim navigation bindings; coupled with the vim/nvim plugin vim-tmux-navigator, I can jump between vim/nvim panes and tmux panes as if they were the same thing.
Where to learn more?

I've used tmux for over a decade. In 2016, Brian Hogan published a fantastic book via Pragmatic Bookshelf, tmux 2: Productive Mouse-Free Development. I can't recommend it highly enough; most of my configuration was cribbed from the examples he provided, and it's written in a way that gently reveals features as you need them.