About Grex Command Shells

What is a Shell?

Except for the Backtalk interface to the conferencing system, Grex does not support any nice point-and-click mouse interfaces, so you will have to type commands to get Grex to do what you what. The program that reads and executes your commands is called a "shell". The standard Unix command shells are famous for being very terse and cryptic, but also very powerful. Since they aren't easy for beginners to master, Grex also offers a number of custom-built, user-friendly command shells that most people find easy to master.

What Shells are available?

The following shells are available:
menu
a simple menu system. Click here for a very brief description.
lynx
a fancy menu system based on the "lynx" web-browser. Don't choose this unless you are sure you have your terminal type selection right. Click here for a very brief description.
bbs
log directly into the PicoSpan conferencing system.
csh
the standard Unix C shell.
tcsh
an enhanced version of the C shell.
Warning: On Grex, tcsh occasionally crashes on start up, causing your connection to drop right after starting up. It doesn't happen often, and tcsh is a nice shell, so lots of people use it anyway.
sh
the standard Unix Bourne shell.
bash
the GNU enhanced version of the Bourne shell.
Warning: Bash is a nice shell, but it's amazingly slow starting up. We've had reports of it taking as long as five minutes to finally give you a prompt after logging in when Grex is very heavily loaded. If you use it, be patient. It works fine once it finally gets going.
ksh
David Korn's enchanced version of the Bourne shell.

Which Should I Choose?

First, don't stress out - it doesn't really matter that much. Anything that can be done from one shell, can be done from all the rest, including temporarily going into any other shell. If you aren't happy with your first choice, it is easy to change shells with the "change" program.

Unless you're an experienced Unix user, you'll probably want the "menu", "bbs" or "lynx" shells; they will allow you to start using the system quickly without mucking around with Unix books and such.

Even experienced unix users may want to start out with the "menu" or "lynx" shells, since they make it easier to find Grex's special services. You can always change shells later using the "change" command.

If all this is confusing to you and you don't know which to pick, just choose the "menu" shell and you'll be fine.