zctl

zctl stands for Zephyr Control program. It is usually pronounced ``zeekootle'' or ``z'ctul'' (Try reading zctl as a word, and however you pronounce it will probably be about right, as long as you still have your tongue.) As we have mentioned in previous sections, you can use zctl to modify your Zephyr subscriptions and to change your Zephyr exposure level. The zctl program can be called in two ways: either by typing the arguments to zctl at the command line (i.e. zctl add mail pop, or by just typing zctl at the prompt, and then typing the rest of the command. The second method allows you to type ? at the zctl: prompt and get a list of possible commands to type if you are unsure of the exact command you want to use, among other things. Other useful options in the zctl command include:

zctl flush_locs

This removes ``ghost'' zlocates you might have left over from being on a dialup machine. It removes all zlocate information, so you need to use zctl unhide to make yourself zlocateable again after this.

zctl new_server

This allows you to change Zephyr servers, which might be necessary if you know someone is logged in but for some reason you seem unable to zwrite them. Often this means that the Zephyr server you are using (one of a few machines that control the transmission of all the Zephyr messages on Athena) is having some problems. Changing servers will hopefully help you work around the problems you are experiencing.

zctl retrieve

This lists all of your current Zephyr subscriptions, so you can tell if you have temporarily lost any of them because of problems with the Zephyr servers. Many of the subscriptions listed by this command are not zephyrgram subscriptions, but subscriptions made by the file system, which can be ignored for all practical purposes.

zctl wg_read

This rereads the information from the .zwgc.desc file and updates the behavior of the windowgrams according to it.

zctl wg_shutdown

This shuts zwgc down, so that you no longer receive any zephyrgrams.

zctl wg_startup

This reverses zctl wg_shutdown and starts zwgc again.

zctl add class instance recipent

This subscribes you to the class, instance, recipient triplet and adds it to your .zephyr.subs file. so that in future login sessions you will be subscribed to that triplet.

zctl delete class instance recipient

This unsubscribes you from the class, instance, recipient triplet and removes it to your .zephyr.subs file. so that in future login sessions you will not be subscribed to that triplet.

zctl sub class instance recipient

This subscribes you to the class, instance, recipient triplet, but only for the current login session.

zctl unsub class instance recipient

This unsubscribes you from the class, instance, recipient triplet, but only for the current login session.

zctl load

This is used to reread your Zephyr subscriptions from your .zephyr.subs file.