Toggle Redshift with Keyboard Shortcut

Redshift is a screen-tinting program that achieves similar goals to the popular f.lux¹ program.

I perused through the redshift man-pages and noticed there is no documented way to toggle redshift. Of course one can click the notification area icon when using redshift-gtk or SIGTERM the redshift process, but neither is very user friendly. (The mouse is not user friendly.) After some awkward DuckDuckGo-ing and Googling I found an obvious solution on the redshift homepage²: simply send SIGUSR1 to the redshift or redshift-gtk process. When using redshift-gtk, one can choose to send SIGUSR1 to either redshift or redshift-gtk.

This is the script I came up with:

#!/bin/sh
set -eu
if ! pkill -x -SIGUSR1 redshift; then
    echo 'Could not find redshift process to toggle.' >&2
    exit 1
fi

After installing the script into my system’s PATH, now all I have to do is add a line to my Xbindkeys³ configuration file (~/.xbindkeysrc.scm) such as:

(xbindkey '(Mod4 F2) "toggle-redshift")

Now I can type Mod4-F2 and toggle Redshift.