zwgc

zwgc stands for Zephyr Windowgram Client. It is generally pronounced ``zwig-see'' or ``zwigka''. zwgc is the program that actually makes zephyrgrams appear on your screen. By default, zwgc is started automatically when you log into Athena on a workstation running X windows. If you log in through dialup, or for some other reason you do not have an X display, zwgc will not be able to start properly and you will get the error message: zwgc: Unable to open X display - disabling X driver. In order to enable you to receive zephyrgrams in these cases, you can use the -ttymode option to zwgc:

zwgc -ttymode

will start the zwgc program so that you can receive zephyrgrams, but instead of trying to place them in windowgrams that require an X display, it will print them to the screen that you are typing in as text. (This text is treated only as output, i.e. it will not be read in as part of the command you were typing when you received the zephyrgram, or otherwise interfere with your terminal input.) You can also cause zwgc -ttymode to start automatically when you log in through dialup using the following command:

zctl set fallback true

This basically tells zwgc that if it can't startup in X, it should automatically fall back to zwgc -ttymode. Some people prefer to place the line

zwgc -ttymode

in their .startup.tty file, but this is less efficient, because it means that the zwgc process will try to start up in X, fail, and then start up in ttymode, each time you log in on dialup. In any case, using both of these things together is a mistake, as you will wind up running the zwgc -ttymode process twice and getting double zephyrgrams.

Since zwgc is the program that causes the appearance of zephyrgrams on your screen, if you ever want to completely stop receiving zephyrgrams, one way you can do this is to stop running zwgc by killing the process. You could do this by first getting a list of processes using some form of the command ps, and then searching for the process id that zwgc was started with. Also, there is a simple command in the consult locker that kills a process. To kill zwgc with it, you would type

add consult; punt zwgc

The zwgc program is also responsible for setting the appearance of zephyrgrams on your screen. When started, zwgc looks at a file called .zwgc.desc, which was discussed briefly in Section 6, to find the descriptions of how the zephyrgrams should behave. The default .zwgc.desc, which will be read if you do not create a .zwgc.desc with your own customizations, can be found in /usr/athena/lib/zephyr/zwgc.desc. An excellent example of a.zwgc.desc file can be found in /mit/dotfiles/Zwgc.desc/rjbarbal.zwgc.desc; you may need to attach dotfiles before you can access it.