tmux - Resize pane to specific width and height

February 20, 2012

This post was automagically converted from Blogger. There may be dragons. Check any code you copy.

Quick post on how to resize a tmux-pane to a specific width and height.
I’m presuming you only have one session and that you’ve changed base-index to 1 and your prefix key combo to ctrl+a (ctrl+b is silly).

.tmux.conf

# 1 is easier to reach than 0  
set -g base-index 1  
# make tmux behave more screen-like  
unbind C-b  
set -g prefix C-a  
bind-key C-a last-window  
# run nested multiplexers and send prefix with ctrl+a a as in screen  
bind-key a send-prefix  
# make pane right size  
bind-key k run-shell "/path/to/the/script/below.sh"

I use this to set my irssi-pane to the correct width and height when I resize my client. I have a 3-pane setup with one pane to the left and two panes to the right split vertically so I really only need to resize this one pane and the other two will follow along.

$ses is session id. I guess changing it to a sessionname should work, have yet to try it though.
$win is the window in which your pane resides.
$id* is pane id within the window which you can get with ctrl+a q.
$height is the height you want your pane to be.
$width … duh.

You might want to take these variables from stdin, I just couldn’t be bothered.

#!/bin/bash
ses=0
win=1
id=2
height=50
width=80

paneWidths=$(tmux list-panes -t $ses:$win | awk '{print $2}' | cut -c 2- | cut -f 1 -d'x')
paneHeights=$(tmux list-panes -t $ses:$win | awk '{print $2}' | cut -c 2- | cut -f 2 -d'x' | cut -f 1 -d']')

currentWidth=$(echo $paneWidths | awk "{ print \\$($id+1) }")
currentHeight=$(echo $paneHeights | awk "{ print \\$($id+1) }")

resizeNumW=$(expr $currentWidth - $width)
resizeNumH=$(expr $currentHeight - $height)

if [ ${resizeNumW} -ge 0 ]; then
 dirw="R"
else
 dirw="L"
 resizeNumW="$((-${resizeNumW}))"
fi

if [ ${resizeNumH} -ge 0 ]; then
 dirh="D"
else
 dirh="U"
 resizeNumH="$((-${resizeNumH}))"
fi

## DEBUG
#echo ws: $paneWidths
#echo hs: $paneHeights

#echo cw: $currentWidth
#echo ch: $currentHeight

#echo rw: $resizeNumW
#echo rh: $resizeNumH

#echo dw: $dirw
#echo dh: $dirh

if [ ${resizeNumW} -ne 0 ]; then
 tmux resize-pane -t $ses:$win.$id -$dirw $resizeNumW
fi

if [ ${resizeNumH} -ne 0 ]; then
 tmux resize-pane -t $ses:$win.$id -$dirh $resizeNumH
fi

I might expand on this at a later time… maybe.