Subscribing to classes and instances

When you are subscribed to a class or instance, you will see messages sent to that class or instance. There are two commands to subscribe to a class or instance:

zctl sub class instance recipient

which lasts for your current login session, and

zctl add class instance recipient

which adds this subscription permanently.

To reverse zctl sub, you can use zctl unsub. If you want to reverse zctl add, you can do it permanantly using zctl delete. To unsubscribe temporarily to a class or instance that you are currently subscribed to using, you can use zctl unsub

One additional way to subscribe and unsubscribe to Zephyr classes and instances is to modify your .zephyr.subs file directly. The commands zctl add and zctl delete make permanent changes because they alter the list of subscriptions in this file. The format of a subscription in the .zephyr.subs file is class,instance,recipient (note that there are no spaces between words). To update Zephyr subscriptions directly from this file, you must use the command zctl load. If you want to list other Zephyr subscriptions in a file other than .zephyr.subs, you can load those subscriptions using zctl load ~/filename. Only the subscriptions in your .zephyr.subs file are read when you first log in and run Zephyr; if you want to read subscriptions from another file automatically, you would need to put the zctl load ~/filename command in one of your startup files.