TMUX

Somewhere between upgrades in the last couple of days, tmux changed how it handles split-window: ‘size’ no longer has a separate option for percentage (-p) but -l can do by-percentage if you include ‘%’ in the arg value (IIRC, -l was for size-by-number-of-lines).

This gave me enough of a reason to talk a bit about tmux.

‘Prefix-key’ (^B)

You can remap the prefix key to something more comfortable (or familiar) in your tmux.conf.

I use C-a (like GNU screen), which is less of a stretch of the hand:

unbind-key C-b
set-option -g prefix C-a

If you do this, you may have to also configure a way to send those key-codes to whatever you’re running in tmux, which you can do with send-prefix.

I actually have it set to something other than C-a (for another reason), so I use plain a:

unbind-key a
bind-key a send-prefix

Quick Window Switching

I set a to send-prefix so that I can set C-a to last-window:

bind-key C-a last-window

This means I can double-tap the prefix-key to quickly switch back-and-forth between windows.

Slightly Different New Window

Creating a new window is prefix c, but each new-window starts in the current session’s ‘path’ (which can be queried with tmux list-sessions -F '#{session_path}')

If you would prefer that the default would be to have new windows open in the working directory of the current window (well, pane), you can use a similar action:

unbind-key c
bind-key c new-window -c "#{pane_current_path}"

Heavy-handed Shortcuts

One thing I like to do is map the same action for a key additionally to include the control modifier so that I don’t have to worry about lifting my finger off the control key.

For things like detach-client (prefix d) and new-window (prefix c), this is pretty straightforward:

unbind-key C-d
unbind-key C-c
bind-key C-d detach-client
bind-key C-c new-window -c "#{pane_current_path}"

For selecting between sessions (prefix s), it’s a little bit more different, since choose-session isn’t a thing.

Instead, there’s another command to use: choose-tree.

unbind-key C-s
bind-key C-s choose-tree -Zs

This is the same way that tmux does it with prefix s, so look up choose-tree in the tmux manual to figure out what the flags really do.

Pane Pain

The keys for splitting windows don’t make a lot of sense to me, but I suppose there’s some reason for choosing them.

One thing I find kind of annoying is navigating between panes is tiresome thanks to having to start each movement with prefix.

My personal solution is to map pane management keys to bare Alt-key combos, without having to prefix them. This is due partly to almost none of my terminal programs requiring alt-key combos.

To wit, splitting windows is mapped to keys more symbolic: - for vertical split (cutting across), and \ for horizontal split (cutting down, but also for my en_us keyboard, | is the same key as \ minus the shift modifier).

bind-key -n M--  split-window -vc "#{pane_current_path}"
bind-key -n M-\\ split-window -hc "#{pane_current_path}"

I favor pane cycling over directional navigating, so rather than mapping hjkl I just map tab to cycle up/down:

bind-key -n M-Tab  select-pane -t :.+
bind-key -n M-BTab select-pane -t :.-

The last part is just a simple way to swap the current pane with the first pane:

bind-key n M-Enter swap-pane -s :. -t :.0 -d

All Together

All of this pretty much covers the bulk of my tmux set up. I avoid plug-ins and themes, and the rest of my configuration covers most of that.

As well, I greatly simplify session management with a few terminal scripts/functions, so there’s none of that as well.

The whole keybinding configuration:

# change prefix
unbind-key C-b
set-option -g prefix C-a

# send prefix to program
unbind-key a
bind-key a send-prefix

# window jumping
unbind-key C-a
bind-key C-a last-window

# new windows
unbind-key c
unbind-key C-c
bind-key c   new-window -c "#{pane_current_path}"
bind-key C-c new-window -c "#{pane_current_path}"

# extra variations
unbind-key C-s
unbind-key C-d
bind-key C-s choose-tree -Zs
bind-key C-d detach-client

# window splitting
unbind-key '"'
unbind-key %
bind-key -n M--  split-window -vc "#{pane_current_path}"
bind-key -n M-\\ split-window -hc "#{pane_current_path}"

# window cyling, move
bind-key -n M-Tab   select-pane -t :.+
bind-key -n M-BTab  select-pane -t :.-
bind-key -n M-Enter swap-pane -s :. -t :.0 -d