Using the set-option command

The main way in which options are set and configured within tmux is through the appropriately named set-option command.

This command can be called on its own to set an option temporarily. However, most of the time, we will use it to set options within a tmux configuration file so each time we launch tmux, the options are set the way we would like.

For a taste of using the set-option command to set an option temporarily, open a terminal window and launch tmux; alternatively, if you've been following along through Chapter 1, Jump Right In, just type the following command in the window:

$ tmux set-option status off

Once you do this, the status bar will disappear! This setting is only temporary, so if you leave it as is, end the session, and restart tmux or create a new session, it will not load this setting. In other words, a status bar will appear.

What you have done is that you've told tmux to set the option status to a value of off. You can use this command to set any tmux option on the fly in this manner. Having no status bar can be a bit unsettling, so let's turn it back on:

$ tmux set-option status on

If we want these configuration options to persist through tmux restarts and sessions, we need some way to tell tmux what their values should be. We will do that by creating a tmux configuration file.