Adjust border thickness in tmux

tmux

By default, the active pane in tmux has a thin green border, as pictured below.

I tried to change the color by adding the following lines to ~/.tmux.conf:

set-option -g pane-active-border-style "bg=colour208"
set-option -ag pane-active-border-style "fg=black"

(colour208 is the shade of orange in the picture)
However, the new borders look like this:

The orange highlighting is far thicker than the green highlighting there is by default. Is there any way to adjust this, so that the border color is orange, but the highlighting is still thin? I'm using tmux 2.5 on ubuntu 16.04.3.

Best Answer

Those border lines are made up of rows and columns in the console and they are indivisible. In a text-based terminal there is no structural element smaller than one character "cell" (which is about the size of that block cursor). The only way to reduce the size of the borders is to reduce the size of all rows/columns.

Fortunately, we can manipulate the colors to give the appearance of a thinner border: set the foreground to the desired color (colour208 in your case) and set the background to the background color of your panes. For the latter default is often sufficient.

That gives us...

set -g pane-active-border-style fg=colour208,bg=default

If there's a color mismatch replace default with the actual pane background color.

(You can, of course, configure the non-active borders similarly. Replace pane-active-border-style with pane-border-style and change the foreground color as desired.)

Here's a screen shot taken after I applied the above setting..

Update: I originally listed two ways to configure the border colors. The second way...

set -g pane-active-border-bg default
set -g pane-active-border-fg colour208

...should be avoided as it will no longer work in tmux 2.9 or later. The one exception is if you are using an ancient tmux build as the newer syntax isn't available prior to tmux 1.9

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Automatically adjust window width in tmux

There does not seem to be a way to do this automatically. You can, however use the mouse:

 mouse-resize-pane [on | off] 
    If on, tmux captures the mouse and allows panes to be
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Tmux – Kill and Select Another Tmux Session

I think this is close to what you want:

bind-key X confirm-before -p "Kill #S (y/n)?" "run-shell 'tmux switch-client -n \\\; kill-session -t \"#S\"'"

Your #3 approach is along the right lines, but the problem is that confirm-before does not do status-left-style substitutions (e.g. #S) in its command string.

A caveat for the above binding is that since everything is done in from run-shell, the commands are run outside the context of any particular client or session. It really only works because the “default” client (for switch-client) and “default” session (for #S) are the most recently active ones. This works out as you would expect as long as you only have a single active client (e.g. a single user that does not type into another tmux client until after the shell commands have finished running); it could fail dramatically if (e.g.) you trigger the binding in tmux client A, but new input is received by tmux client B before the shell started by run-shell has had a chance to run its commands.

This particular race condition seems like a nice motivation for providing client/session/window/pane information to run-shell commands. There is a TODO entry about getting if-shell and run-shell to support (optional?) status_replace() (i.e. status-left-style substitutions), though maybe a better choice would be format_expand(), which is kind of a newer super-set of status_replace (offers #{client_tty}, etc.).

Best Answer

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Automatically adjust window width in tmux

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