Ask SIPB - March 7, 2003

This week, we continue the two-part series about Zephyr, covering more advanced configiuration issues, and other Zephyr clients.

What is exposure, and how do I change it?

Exposure is a Zephyr setting that allows you to control how visible you are to other people. There are six levels of exposure (from least to greatest): none, opstaff, realm-visible, realm-announced, net-visible, and net-announced. By default, you are set to realm-visible.

In this section, we will use the term "MIT Zephyr users" to indicate people zephyring using their Athena accounts. Users who are not "MIT Zephyr users" include (for example) Zephyr users at Carnegie-Mellon University.

The exposure level "none" is generally not useful, since this setting not only prevents other users from seeing you, but also prevents you from receiving zephyrs. Any zephyrs other users send will appear to be successfully sent, but will NOT show up. The "opstaff" level can be used if you wish to hide your presence online, while still being able to receive zephyrs. "realm-visible" means that MIT Zephyr users can zlocate you. "realm-announced" is a superset of realm-visible, but now people who have you listed in their .anyone file (both inside and outside MIT) will also receive a zephyrgram telling them when you have logged in.

"net-visible" is the same as "realm-announced", with the addition that now people from outside MIT can zlocate you. "net-announced" is the same as "net-visible" for all practical purposes.

To set or change your exposure, type (for example):

athena% zctl set exposure realm-announced
In this example, your exposure is changed to "realm-announced". This allows MIT Zephyr users (but not non-MIT Zephyr users) to zlocate you, and announces your login or logout to anyone who has your username in their .anyone file. Many users find the "realm-announced" exposure level (which is not the default) to be the most useful setting.

The exposure setting is permanent until you change it again.

What is fallback, and why should I use it?

The fallback setting controls whether Zephyr falls back to a text-based version when X is unavailable for Zephyr popup windows. For example, you typically encouter this situation when you log into a dialup machine at

By default, fallback is disabled, so you cannot to receive zephyrgrams while on a dialup. While you can manually activate Zephyr by typing:

athena% zwgc -ttymode
However, it may be more convenient to have Zephyr always automatically "fall back" to text-based mode when X is unavailable. To cause this fallback, type:
athena% zctl set fallback true
After doing so, text-based Zephyr will always be activated on dialups, or any other text-based terminals. The one downside is that anything you are doing on the dialup will be interrupted by incoming zephyrgrams overwriting the screen. Pressing Ctrl+L will usually refresh the screen.

I want to run Zephyr over an ssh connection but don't have X windows, and zwgc -ttymode is really annoying. Are there any other Zephyr clients I should consider?

Yes! We recommend "owl" as an easy-to-use text-mode Zephyr client. owl is in the ktools locker and can be run like this:
athena% add ktools
athena% owl
The most important command to know in owl is 'h', which brings up the online help. Here is quick summary of the other commonly used keys:

<up> <down>move up and down between zephyrgrams
<left> <right>scroll around within long zephyrgrams
zsend a zephyrgram (you can use -C, -c and -i just as with zwrite)
rreply to current zephyrgram
dmark current zephyrgram for deletion
xdelete marked zephyrgrams
lshow list of online users (equivalent of znol)
:q<enter>quit owl

If you are interested in learning more about owl, check out the owl webpage:

Can I use Zephyr on Windows?

Yep! You can get WinZephyr, which is currently in beta (and therefore unsupported), to send and receive zephyrs on the Windows platform. Go to, and click the link that says "WinZephyr," ignoring other pages that might tell you it is unavailable.

Note that you must have Kerberos tickets before WinZephyr will start. If you have not done so already, get Kerberos for Windows from the same software download page. After installing it, run Leash32 to get tickets.

How can I configure WinZephyr's preferences?

To configure preferences, right-click the blue Z and choose Preferences. Here, you can specify the subscription triplets you wish to subscribe to, which users you wish to receive login and logout messages for, how zephyrgrams show up, as well as some of the configuration options previously mentioned on Athena.

How do I send zephyrgrams with WinZephyr?

To send zephyrgrams with WinZephyr, right-click the blue Z that appears in the system tray area of the taskbar (the bottom-right corner of the screen), and choose Sender.

The top of the Sender box has three text boxes, each for one of the three components of zephyr triplets. To send zephyrgrams to an individual user, simply type the username in the RECIPIENT box, and leave the other two boxes blank (or set them to MESSAGE and PERSONAL). To send zephyrgrams to a class or instance instead, type the name of the class or instance in the correct box, and leave the others blank.

After having specified the recipient, type your message in the large MESSAGE text box. You may find the checkbox marked "Auto" helpful, so that your text is auto-cleared after you send zephyrgrams, and so that you don't accidentally send duplicate zephyrgrams.

If you receive a zephyr and wish to reply, you can also click the "Reply" link that shows up, which will also bring up the sender box with the recipient boxes automatically filled in. If the message was sent to a class or instance, WinZephyr will default to responding to the same class or instance. Replying to personal zephyrgrams will by default respond to the original sender.

How do I get a list of online users with WinZephyr?

To use WinZephyr's equivalent of Athena's znol command, right-click the blue Z and choose ZNOL. Some users have experienced problems with this, however, and WinZephyr will instead list a few users and stop. You may want to SSH into a dialup machine and run znol there instead.

Is a Macintosh zephyr client available?

Yes. MacZephyr, available for download at, is a MacOS classic based zephyr client. It has three display modes: As entries in a list (the default); As a TTY window; or as popup windows. More information is available from

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