To find out if another user is logged in and zwritable, you can use the following command:
zlocate username
which will either give you the name of the machine the user is logged in on, or tell you that the user is Hidden or not logged-in. The latter message indicates that the user is either not logged in, is not subscribing to zephyrgrams, or does not want to be zlocated.
Znol can be used to check whether a list of people are logged in. First, you need to create a file called .anyone in your home directory. This file should contain a list of the usernames of all the people you want to look for, with one username on each line and no spaces. Then, you can use the command
znol
at your athena% prompt. You will see a list of all the people in your .anyone file who are logged in. znol requires that you be running Zephyr to use it, with the exception of the znol -l command. The znol -l command may be used at any time and will not subscribe you to login and logout zephyrgrams or require that you be subscribed to messages.
The znol command will also allow you to get zephyrgrams announcing when people in your .anyone file log in and log out, if they announce this information. You can use znol -q to receive login and logout zephyrgrams without listing who is currently logged in. Another useful option to znol is
znol -u username,
which allows you to just check one username and get zephyrgrams when that person logs in and out. This differs from just zlocating that person because you will get login and logout zephyrgrams. It can be done in addition to running znol normally, so you can basically add individual users to the list of people you want to check on without adding them to your .anyone file.
You can use the -f option to use a file other than .anyone
as the list of people. For instance, you might list the usernames of
members of a club in a file called .anyone.club, and check if
any of them are logged in with znol -f ~/.anyone.club.