Using the Shell

What is unix and where do I read more?

Unix is a multi-user operating system created back in the '70s at Bell Laboratories. It is still the best operating system around for many tasks, including accessing the Internet.

There are many books about unix that are worth noting. Among them are:

• When You Can't Find Your System Administrator
  Published by O'Reilly & Associates.
• The 4.4BSD reference set.
  Published by O'Reilly & Associates.
• UNIX Communications and Networking
  by Kevin Reichard and David Burnette, published by MIS: Press, ISBN 1-558828-388-9 is recommended by one user.

There is online help available with the man command. Use man man for more info. There is also help available with the info command. Use man info or info info for more info.

The unix system used at Idiom, is FreeBSD version 3.5-RELEASE.

WWW documentation is available:

• UNIXhelp from the University of Edinburgh

WWW links to that might be helpful:

• The FreeBSD web site
• Unix tools reference page
• Northwestern University's Unix Reference Desk
• University of Texas Unix Resources page

Reading mail

If you aren't using Eudora over PPP, then there are four mail user agent programs available on idiom.com: elm, pine, Mail, and dmail. Of these elm is the prettiest to use, and pine is the easiest.

Reading netnews

There are four news readers supported: trn, tin, pine, and nn. Of the four, trn is the most powerful, tin is the prettiest, and pine is the simplest. If you connect through PPP, then you can read news using a reader on your local system. There is a problem with this though: news is only fetched in groups that people appear to be reading based on examination of .newsrc files.

Editing files

Buy a book on UNIX and learn to use vi or emacs. There is a very simple editor available called pico, but it's so bad you might not want to bother.

If you wish to change your default editor to pico, use the following command:

echo setenv EDITOR /usr/local/bin/pico >> .cshrc
source .cshrc

If you mess up, you can get a new .cshrc file with:

cp /home/.cshrc .

Setting your backspace key

The command to set your backspace key if it isn't already correct is: "stty erase KEY" where KEY is the key that you want to be backspace.

Browsing the Internet from the Shell

From the shell, there is only one decent browser and it's not nearly as good as using a browser like Netscape. Try: lynx.

Secure login over the Internet

When you log in over the Internet, it is possible for your password to be sniffed by a cracker watching packets go by. To prevent this, you can use one-time passwords. There is a package called S/Key that manages one-time password use. To use it, you generate 100 passwords at a time and print them out. Each time you log in over an insecure channel, you use one more.

To generate the passwords, log in over a secure link (a modem will do) and type keyinit. Make sure the initialization password you give it is exactly eight characters long. Get a list of the session passwords using keyinfo or keyprint. Or, if you have S/Key installed on another system, you can figure out what session password is by running the key program and giving it the initialization password you used for keyinit. Session key generation programs are available for Macintosh, MS-DOS, and unix.

For reasons unknown, keyinit doesn't always work. If you think you typed the right passwords and it did not let you log in, it may be S/Key's fault. Give yourself a new password and try again. If it works once, it will work for the entire 100 password sequence.

When you have one-time passwords available, you can log in using either one of your one-time session passwords or your normal password. If you want to use a one-time session password, hit return and it will ask for the password again, but this time it will echo characters so you can see what you type.