3. Courtesy, Ethics, and Security

1.C: Logging Out

Contents

§ 2: The JCCL Unix/Linux Environment

The JCCL Unix/Linux computer environment is a group of Linux and Solaris machines (also known as "boxes"). You use the same userid and password to log on to any of them; however, this "Unix password" is different from the one you use to log into the NT machines. Essentially, your account has two sides to it, one for Windows NT and one for Unix/Linux. So even when you run an XWin32 session from NT, you are in fact connecting to a Unix/Linux machine, and thus you'll need to use your "Unix password" to log in.

These "Unix passwords" are created at the beginning of each semester and correspond to the password you had on solix at that time. solix is used to generate usernames for the university-email, and these usernames are also used in the JCCL account generation. To this end, a program is run that scans through the list of users on solix, and for those who are taking at least one computer class, an account is created in the JCCL. Since solix is just another Unix machine, it is possible to copy your encrypted password and use it as a default for the JCCL's Unix/Linux side. However, for Windows NT there is no way of decrypting this password, and thus you get a different one for that side of your account.

If your solix password does not let you log into the Unix/Linux machines, try you social security number without dashes. In case that also fails, go to ECS 258 to have your password reset.

At present the JCCL machines include:

Sun stations:

weasel.aul.fiu.edu
mongoose.aul.fiu.edu (for webserver classes)

Gateway PC's:

quebec.aul.fiu.edu
havana.aul.fiu.edu
ocelot.aul.fiu.edu (for remote logins only)
paris.aul.fiu.edu
monkey.aul.fiu.edu
cougar.aul.fiu.edu (network fileserver, no logins)

Note that solix is in no way part of the JCCL Unix/Linux environment. If you change your password on solix, it will not affect your password on any of the JCCL machines. It also means that any files you keep on your JCCL U: drive will not be available on solix. However, all the computers in the JCCL use a common file space. This means that you work with the same file regardless of the machine you are on - the same thing you're used to from the NT machines.

The best way to get into weasel or ocelot is through ssh (or an XWin32 session in weasel's case). Either way, these machines are in a separate room and cannot be used directly. But once you're a little more comfortable with Unix, feel free to give the Linux boxes a try. There are a few special commands that are only available on weasel, but for general purposes, the Linux machines are just as suited. (Plus, you get your "own" machine, while weasel is shared :) ).

If you compile or interpret your programs (as happens when you run Prolog or gcc or Perl), you should get essentially the same environment and results regardless of the machine. However, if you compiled a C or C++ program on weasel, which is a Sun station, it won't run on the Linux machines, because they are Gateway PC's. If you try to run an executable program on the wrong architecture, you should get an error message (unless you are unlucky).

In order for each Unix/Linux machine to run just right for you, it must have so-called dotfiles to give the right parameters to the operating system and the windowing system on that particular machine (you will learn more about these later). These files are automatically placed in the user's file space ( you U: drive, which is called "home directory" in Unix) when his or her account is first created. In addition, some other files that control the Windows NT aspects of the user's JCCL environment are put into the U: drive/home directory as well. Normally, these files simply do their job, and it's best not to interfere with them or to delete them.

If you think you accidentally deleted some of these default files, you can send an email to request@cs.fiu.edu asking to have them restored to your home directory. We strongly suggest you do so before you continue with this tutorial, as you might get some unexpected results otherwise.

As you will find out in this tutorial, the dotfiles can be modified by the user to suit his or her needs. However, please restrain that urge for individuality until you really know what you are doing. Once you feel you "must" have that custom look at any cost right now, then please keep a backup copy of the original files. Changes that may seem harmless may prevent you logging in to the Unix/Linux machines again!

3. Courtesy, Ethics, and Security

1.C: Logging Out

Contents