Automatic tmux titles

If you’re using tmux as a terminal multiplexer and keeping one window open per host, you might be manually renaming each window to feature the relevant hostname. This is a little annoying to do if you’re dealing with a lot of hosts, so it’s worthwhile to automate it.

In the tmux manual, the following escape code incantation is given to update the window title from within the terminal:

$ printf '\033kWINDOW_NAME\033\\'

In much the same way that you can update the title of an xterm-compatible terminal emulator with control codes as part of the $PS1 variable defining the prompt, you can update the title of a tmux window to the current hostname (or any other relevant text) automatically by prefixing this call to the $PROMPT_COMMAND. This is best done in your .bashrc. The below code assumes you are using either screen or screen-256color as your $TERM string in your .tmux.conf:

case "$TERM" in
        PROMPT_COMMAND="printf '\033k$(hostname)\033\\';"${PROMPT_COMMAND}

After logging out and in again, this will update the title of the window to the hostname of the current machine just before the prompt is presented, saving you the trouble of updating the window title if like myself you never use it for anything besides the machine’s hostname.

Vim command window

The command line in Vim for ex commands can be edited with a few of the GNU Readline key combinations that may be familiar to Bash or Emacs users, so it’s reasonably easy to edit it, for example to type in complex search patterns and replacements.

However, if you want the full facility of Vim editing for your commands, it can be helpful to use Vim’s command line window, which will allow you to enter commands and edit previous ones with the usual normal and insert mode.

You can open the command line window from normal mode in one of four ways:

  • q: — Open with a command history from normal mode
  • q/ — Open with a search history from normal mode (to search forward)
  • q? — Open with a search history from normal mode (to search backward)
  • Ctrl+F — Open with a command history from command mode

Note that this doesn’t work while you’re recording macros, since pressing q stops the recording.

The window is always immediately above the status bar, and its height can be set via the cmdwinheight option.

Command line window

Once the command line window is opened with q:, you can browse through it and press Enter on any line to issue the same command again. You can also edit it beforehand, perhaps to fix a mistyped command. The window will close when this is done, but you can close it with Ctrl+W, C the same as any other window if you change your mind.

Vim command line window

Vim command line window

Note that you can’t move to another window while this one is open, nor can you load another buffer into it.

Search window

Similar to the above, if you open the command window with q/ or q?, it shows a history of your searches, and pressing enter on any line will issue the same again, in the appropriate direction.

Vim search window

Vim search window

For more information on how the command window works, check out :help command-line-window.