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.