How do I find out which version of JACK I am using?

If you are on a forum or on IRC trying to troubleshoot an issue with JACK, you may be asked which version you are using. A lot of people that are using Qjackctl to control JACK, look for the version number there. This however is the version number for Qjackctl and not for JACK. To find out which version of JACK you are using, open up a terminal, type in the command

jackd -V

and then press enter. This will tell you which version you are using. JACK versioning numbers might seem a bit confusing at first. My read out from the above command is

jackd version 0.124.2

This means I am using JACK 1. JACK 1 version numbers approach version 1.0

If you get a read out such as

jackdmp version 1.9.10

This means you are using JACK 2, as JACK 2 version numbers approach version 2.0.