CSSE Unix Notes

Unix^® Unix is an operating system that runs on most computers. The primary Unix server we use runs Linux, but note that this is just a version of Unix. This document introduces you to the basics of getting on, getting off, and getting around a unix system. See here for links to more resources. We also have a list of frequent problems and their solutions.

Background

The Unix system most commonly used on campus Io. This is an Intel-based Linux system located in the basement of Gardner Hall. Its full name is io.uwplatt.edu, and you can use that name to access it from anywhere on the internet.

Logging In and Logging Out

Use PuTTY to log in to Io - see here. Other SSH-compatible terminal programs should work as well, but see the PuTTY notes for entering your username and password. When you're successful, you'll see various messages followed by a prompt like

        101 name:

where name is your username.

Note that you will stay logged in to Io until you log out or break the connection. The preferred way to log off is to just type "logout" at the prompt. This ensures another student won't get access to your files! The system will not completely log you out automatically if you just kill PuTTY, so you need to use the logout command. If you get a message saying "There are suspended jobs.", type logout a second time; this will kill the extra jobs.

Accessing your Novell Netware files from Io

You can access your Novell Netware files from Io (that is, the files on the J: and S: drives) by typing the command

        nwmount

This will "mount" your J: and S: drives (after prompting you for your Novell Netware password) so you can access your files from Io using the same Unix commands that you use on other files. This means you can edit your files using Windows (or probably even Macintosh) applications and then run them against Linux commands from a PuTTY window. To unmount the two drives when your done accessing them, type

        nwumount

Other commands that you might find useful:

`df`	List mounted volumes - this can be useful to double-check that your Netware volume is mounted
`nwdir -v`	Give additional information about Netware files
`ncopy`	Copy files on a Netware volume without transferring them to Io - this can be useful for very large files
`nwgrant`	Assign Netware permissions to files
`nwrevoke`	Remove Netware permissions from files

As usual, see the man pages for the above for more details.

Transferring Your Files with WinSCP

Because Io requires SSH-based connections when typing in your password, standard FTP (File Transfer Protocol) applications such as WS_FTP will not work. The solution is to use WinSCP. This is available through Start|Applications on campus, or you can download your own copy. To run it,

Enter the host name: io.uwplatt.edu
Enter your username - don't enter your password unless you're on a computer no one else uses!
Make sure the File protocol is set to SFTP
Click on the Login button

You'll then get a window you can use to drag files back and forth between Io and your local system. You can also right-click on a file to open, rename, delete, or edit it. (But note that can use the nwmount command as described above to edit the files in Windows but access them directly from Linux.)

Warning: Be very careful when using WinSCP to not click on the button with two blue arrows on
it button. This button will attempt to "synchronize" your local directory with the current directory on the Unix system, deleting files willy-nilly and generally making a mess of things. Worse, this command is not undoable. Careful users select Options|Toolbars|Commands Buttons to remove this tool bar.

Learning More

Being able to log in and transfer files is pretty much sufficient for many classes. However, there are some other commands you might find useful:

list files in current directory: ls (like DOS dir)
copy files: cp source destination (like DOS copy)
rename/move files: mv oldname newname (like DOS rename and move)
remove files: rm filename (like DOS del)
view file on the screen: more filename (like DOS more)

To learn more about these commands, type "man ls" or "man cp". In general, man command gives you a description of the given command. Try "man man" to get a description of the man command.

There are various ways to edit files on Unix systems. A simple one is to use WinSCP as described above. But as you get more advanced you'll find it's more direct to use one of the Unix editors; the editor most students use is joe, short for "Joe's Own Editor" (no relationship to Dr. Clifton). To use joe, simply type

joe

at the prompt. If you then press Control-K H (hold down the Control key, press K, release the Control key, press H), you'll get a help panel showing you the list of commands. For examle, Control-K X saves your file and exits. Regular characters just insert themselves (like Notepad). Edit existing files by typing

        joe filename

There are alternatives that are worth knowing about:

emacs; this is probably the most powerful editor available on Unix, and maybe anywhere in the known parts of space. It isn't all that hard to use, but it does take a little time to get started. Simply type emacs at the command prompt to get started and run through the tutorial. See here for more information about why you might even want to use Emacs on Windows. The great thing about emacs is that it "grows" with you: the more you use it, the more you learn, and the faster you get. Emacs is built on Lisp, allowing users to extend it to solve any computable problem. The full emacs manual is also available. Emacs also runs on Windows.
nano: This might be the simplest to use editor on Unix; just type
```
        nano file
```
where file is the name of the file to edit. The commands (control codes) are printed at the bottom of the screen. Unfortunately, nano has no way to "undo" edits, so if you make a big mistake about all you can do is quit.
vi: this might be necessary for system administrators, but it's probably one of the hardest editors to learn to use. It's only mentioned here because a lot of Unix users think this is the only editor available. They couldn't be more wrong.

For more information about Unix, visit one of the following links:

If all else fails, you might try reading a book! The library contains a number of good books, and O'Reilly^® publishes Learning the Unix Operating System, a short and sweet guide covering Unix basics.

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