Add a way to check whether redshift is currently enabled and add a way to disable/enable

[jgandert]

Is your feature request related to a problem? Please describe.
It's related to the problem of having no way (AFAIK) to figure out whether the running instance of Redshift is active / enabled at the moment or not.

Describe the solution you'd like
Some command line option for

• checking the status (is it enabled or not)

and optionally:

• enabling (if it's already enabled do nothing)
• disabling (if it's already disabled do nothing)

Describe alternatives you've considered
Toggling (via pkill -x -USR1 redshift) may work for a lot of things but when you don't really know whether it's running or not toggling is problematic and may do the exact opposite of what you want.

For example, there's an mpv plugin that disables redshift when playing the video but if redshift is currently disabled, the plugin will do the exact opposite.

[jonls]

Blocked on #54. I think probably D-Bus or similar is the most reasonable solution for this.