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Using MIT’s Athena Computing System

Naveen Sunkavally and Gabriel Daleson

STAFF REPORTERS

This is the fifth article in The Tech’s series aimed at helping freshmen adjust to life at the Institute.

Athena, MIT’s academic computing system initiated in 1982, may pose a challenge to freshmen. Accustomed to the passive click-drag-and-pull Windows operating system in the mass market, and surrounded by upperclassmen practicing all sorts of dumb UNIX tricks, not only may you find Athena non-intuitive but also frustrating. It’s alright. Take it easy. Step away from the keyboard. Here we present some of the basic and common uses of Athena to get you rolling.

First, if you need help, you can always use the man [command name] command to see a description of the command syntax and what it does.

Forget AOL instant messager, say hello to zephyr

Zephyr is MIT’s instant messaging system. Most freshmen understand the zwgc -ttymode and the punt zwgc command to enable and disable the zephyr service on the dialups (zwgc runs by default on cluster machines). Most freshman usually grasp the zwrite and zlocate commands, used to compose zephyrs and find out if someone is online.

In Zephyr, there are classes, instances, and recipients. A user is a recipient, but classes and instances are multiple users -- the analog of a mailing list. To use these, you subscribe, using the commands zctl add [classname] \* \*, zctl add message instance \*, for classes and instances respectively.

A common class, for example, is “help,” which is used to ask questions about Athena. Thus, to subscribe to the “help” class, a user types zctl add help \*\*. To send a message to the help class, type the command zwrite -c help.

A rather popular zephyr instance is “white-magic,” a sort of zephyr society where a great deal of subjects are discussed. To subscribe to the instance, users type zctl add message white-magic \*. To write to it, type zwrite -i white-magic.

Another common use of Zephyr is to notify you automatically when your mail arrives by sending you a zephyr. The command for zephyr notification of new mail is zctl add mail pop or zctl add mail popret. The first sends a zephyr to users when new mail is received so that it can be incorporated. The second is similar -- in addition to the first command, it also also informs a user of the subject, sender, and recipient.

Another staple of MIT life is a user’s .anyone file. Using emacs, create and save a .anyone file with a list of the usernames of your friends. Whenever a user whose username matches one of those in your .anyone file, you will be notified via Zephyr. Typing the command znol after creating a ‘.anyone’ file will show you a list of those on your .anyone file who are currently logged in.

Another useful tool is the .away file, which works in conjunction with the zaway command. The zaway command is used if you are away from the computer and wish to offer those zephyring you (and wondering where you’ve gone) some sort of explanation. First create a .away file using Emacs and specify the text of the message. Then, when you are about to leave, type the zaway command. When other users zephyr you while you are gone, they will receive an automatic zephyr from you with the text in your .away file.

Improving e-mail

Like Zephyr, Athena mail offers several neat user customizations.

One of the most common mail customizations is creating a signature, a simple footer which appears at the bottom of every mail you send out. To do this, create a components file using Emacs in your Mail directory. Then type in the signature that you want to appear at the bottom of the file after the common to:, subject: and cc: headers that you will probably still want to include at the top of your mail.

Another staple of MIT is mailing lists. A simple, menu-driven way to use them is the command mailmaint. A command-line based alternative is blanche, but it is less easy to use. Simply, blanche list -i gets information on the list, and blanche list -a myusername adds you to the list, though there are many other options.

Inessential guide to tracking other users

Whether we’d like to admit it or not, most of us are interested in what other users are doing on-line. And, even we don’t, it’s always helpful to know what other users may be doing to inspect your Athena activities.

If you type the command add consult and type lastlog [username], you can find out when a user last logged in. Be warned that the results of lastlog are somewhat unreliable since it does not record the actual last login, but accesses to the user’s home directory.

If you type the command add [username], and then do ls /mit/[username] you can view the top-level contents of username’s directory unless they have disabled public listing access.

Another interesting command is znol -l, which allows you to perform the normal znol function but also works when you have punted zwgc. This command allows you to view other users online without being visible over zephyr yourself.

The w command gives useful information about other users on the machine you are using. Try w | grep username to see the entry for username or just w to see who you are sharing a dialup with.