Frequently
Asked Questions

Undergraduate Projects Laboratory
Computer Sciences Department
University of Wisconsin - Madison

This FAQ file is maintained by The UPL (upl@cs.wisc.edu)
Mail upl@cs.wisc.edu with comments or questions.

Contents:

Introduction

This is the FAQ for the UPL. Within are several questions with answers to common questions dealing with account policies and "how to" questions. All UPL members are responsible for all information contained within this FAQ, and are expected to follow the policies indicated within.

What is a FAQ?

FAQ stands for Frequently Asked Questions. In general, it refers to this list of questions which have come up repeatedly in the past and are therefore put into this one document with answers for easy reference.

This is the first place you should check when you have a question.

What should I read?

If you are new to the UPL, read this entire document. Especially the parts on accounts, account policy, passwords, mail, and disk space. Some sections won't apply to new users, but most of the information should be fairly helpful.

If you have had an account at the UPL for a while, you should still read the sections on account policy, passwords, mail, and disk space. You should also read any sections with questions you want answered. Of course, you might just want to skim the whole file just to see what's in it.

Where can I get the latest version?

This document is being kept for ftp from data.upl.cs.wisc.edu.

The UPL

The Undergraduate Projects Lab is a place where undergraduate students can go to learn about computers, to work on computer related projects beyond their course work, and to meet other people with similar computer interests. We offer full UNIX accounts to all undergrad students on campus. This includes email, USENET news, interactive communication, and a wide variety of other services.

The work done in the lab ranges from UNIX programming to computer modeling and graphics to cryptography. You can come to learn about the systems on just about any level. You can also learn programming on many levels. The best way to learn in the UPL, though, is to come in and talk with other people there. You can usually find some sort of discussion going on.

Where is the UPL?

Physically:
The UPL is in the Computer Science building, unit 3, ground floor, room 1341. It's in the room with the glass windows at the top of the ramp coming from the entrance facing Union South.

Virtually:
The UPL is a subnet in the main Computer Science network. We have three primary user boxes: dukat, yar, and picard.

World Wide Web:
http://www.upl.cs.wisc.edu/

By Electronic Mail:
upl@upl.cs.wisc.edu

By Postal Mail:
The Undergraduate Projects Lab
Computer Sciences Room 1341
1210 West Dayton St.
Madison, WI 53706

Who runs the UPL?

We have more than 250 accounts. That's a good sized group. So we have some administrators, called "coordinators" or "coords" who handle the paperwork, system administration, and other tasks, like unlocking the door. There are always exactly twelve coords; the current coords are the following people with their login names:

Our faculty advisor is Professor Bart Miller (bart@cs.wisc.edu)

The UPL coordinators are all volunteer students who put in an enormous number of hours keeping the machines in nearly stable conditions. Try to keep this in mind when something doesn't work.

What physical resources are available in the UPL?

Name Model Memory Disk OS Use Date Obtained Source Obtained
dukat PPro/200 128 Mb 5000 Mb Solaris secondary user machine 08/96 CSL
garak PPro/200 64 Mb 2000 Mb Linux and Windows NT Linux and Windows NT development 08/96 CSL
vger Sun UltraSPARC 64 Mb 2000 Mb   UPL projects 08/96 Sun Microsystems
picard Windows NT
minuet Macintosh 867 1.2GB Mac 9.2/OSX user machine 12/01 Apple/DoIT
smokedsalmon Windows2000 12/99 Microsoft
war WindowsXP Microsoft
death WindowsXP Microsoft
famine WindowsXP Microsoft 
At any time, we have one or more serial terminals connected to various machines.

Printed Resources:

Do not remove books from the UPL. Many books are the personal property of various UPL members who are generously making them available. You are welcome to read any book in the UPL, but keep in in the UPL.

What sources of help are available in the UPL?

The first place to check when you have a question is this file. If your question is not to be found in here, there are several options available:

The UPL has a home page for the World Wide Web. From a computer with network access and a web browser (such as Lynx, Mosaic, Netscape), use the browser to connect to the CS Department home page (http://www.cs.wisc.edu/) and follow the link to the UPL (http://www.upl.cs.wisc.edu/).

To email all the coords, mail to upl@cs.wisc.edu.

To email all the coords, Professor Miller, and a few people at CSL, email upl-coords@cs.wisc.edu. We recommend you do not use this address except when absolutely necessary.

When is the UPL open?

In brief, almost all the time.

Each coordinator has set two hours a week as office hours; at these times the UPL will be open. Office hours are posted on the door to the UPL and are available online.

Most coords spend a lot more than two hours a week in the UPL though. The lab is usually open from late morning to late night every day. Any time the UPL door is open, you can come in to talk to a coord or use the lab facilities.

Note that during the summer months and during school holidays, the lab is open far more sporadically. Remote access is still possible though.

Accounts

Can I get a UPL account?

UPL accounts are available to all undergraduate students in the University of Wisconsin - Madison. To get an account, come to the UPL with five dollars and fill in an account form. If you have any other account within the CS department, your username for the UPL will be the same as your other CS account(s) username. The account should be usable within a few days. All persons applying for an account must have a project in mind. However, World Wide Web pages are not projects, nor is talk or email access.

How do I edit files?

We provide access to three main editors: pico, vi, and emacs. Pico is the easiest to learn, provides most of the features you'll need, but is the least powerful of the three editors. Vi is arcane and can be a bit daunting to learn, but is very fast and very powerful. If you're going to be doing a lot of programming and UNIX work, you should probably be familiar with vi basics. The most powerful editor is emacs. It is also the biggest and the slowest, and almost as arcane as vi. Emacs will do almost anything you want, and if it doesn't, it includes a programming language so you can write the functionality yourself. It also has a game built in, can read your mail, etc.

We also have several other editors available that you can explore, but you might not want to use them regularly: ed is a line editor upon which vi is based, and jove is a frill-less version of emacs, but is unsupported by the UPL or by the CSL.

The DoIT helpdesk has information and manuals for these editors if you so desire. They also have staplers and scotch tape.

Here are the full paths for the editors. You shouldn't need to use full paths in most cases. 


pico      /s/std/bin/pico
vi        /usr/ucb/vi
emacs     /s/std/bin/emacs

Can I read and post news?

Usenet news is a collection of thousands of news groups on virtually any subject you can think of, and a decent number more. It is a very powerful resource, but be warned that you can waste a lot of time reading news.

Again, three main programs available: tin, rn, and trn. Rn is very old, and it's fairly arcane. Trn is very much like rn, but it offers threading of articles that are related to each other. tin is a newer program that offers a full menu based interface. We strongly recommend tin if you are new to USENET.

Before posting, you should definately read the information on USENET ettiquette in the news group called news.newusers. Failure to do so could cause you to be embarassed, or even harassed by those who read your message throughout the world.

Malicious or especially wasteful posting can result in disciplinary action, up to and including account deletion.

Can I use bbs, irc, talk, ytalk, tf, and tintin?

talk and ytalk are currently permitted, but we do not provide accounts for users to just use talk and ytalk, and reserve the right to limit or prohibit their use even on a user to user basis.

IRC, MUD, and BBS use is prohibitted by UPL policy. This includes the IRC program tintin. This was done because these programs use a large amount of network resources, as well as a fair amount of CPU resources. If even a couple of people ran IRC on one UPL machine, our system performance was severely degraded.

If you wish to obtain your own IRC client to use with your student DoIT account, you can obtain browsers from ftp to yar.cs.wisc.edu, the DoIT ftp site, and other locations:

MSDOS:

Macintosh:

MUD playing is strictly prohibitted by UPL policy. Any MUD clients found running will be terminated, and their account will be locked and deleted.

MUD, BBS, and IRC clients connect to well known sites in well known ways, so please do not try to hide them from us, because we will detect them.

Yes, that's right, we will detect them.

If you are unsure if an activity is allowed under this policy, please ask a coordinator first.

What about my DoIT / instructional accounts?

UPL accounts are completely separate from other accounts in the department, such as instructional and research accounts, and accounts elsewhere in the university, such as from DoIT or CAE. Your email in the UPL is completely separate from your email on other accounts. We do not administer any accounts outside the UPL.

Account Policy

The UPL was established for students to learn about computers. While we support exploration of the system, it is important to be considerate of the other users of the system and the security needs of the UPL. The following rules represent guidelines on appropriate and inappropriate behavior. Violation of these rules may lead to your account being locked or deleted.

UPL accounts may not be used for completing any university course work.

You may not break into other accounts, break into other computers, use UPL resources to crack passwords, or otherwise use UPL resources to subvert any established security system. You may not attempt to steal passwords, files, or other system or user information from these or other computers.

You may not delete any other user's files, or disrupt the accessibility, usability, or performance of another user's account. You may not harass or threaten any other user either here or at another site.

You may not disrupt the accessibility, usability, or performance of any UPL resources.

Distasteful or offensive displays, printouts, or stored files are not permitted, and will be removed.

Passing of copywrited material to another ("pirating") is prohibited.

Note that the above does not constitute a definitive list of prohibited activities. UPL coordinators may view, modify, and delete user files and private email, and add and delete user accounts for any or no reason.

If you have an interest in testing system security, or you want to use UPL resources in a way that may disrupt performance, please contact a coordinator to make appropriate arrangements.

Can I change my real name?

The chfn command can be used to change your finger information , i.e. the information given about you when your account is fingered. You must keep your real name in the real name field. This is by CSL and UPL policy. If you don't use your real name, your account will be locked. You are free to change other information via the 'chfn' command, though, provided it does not violate other UPL policy.

In your real name field, it is sufficient to have your first initial and your full last name.

Be sure to run chfn from dukat, as our setup will erase any changes that are made on any other of the general use macines.

Can I let other people use my account?

No!! Your UPL account is for your use only. You may not share your password, or give access to your account to anyone else through other means. If you do, your account will be removed permanently.

Can I have another UPL account?

No. The UPL is available primarily for students to learn how to use computers, learn UNIX, and program. There is no legitimate need for anyone to have two accounts.

Can I use my UPL account to set up an FTP site?

No. However, we do provide anonymous ftp access to picard and yar. If you wish to make something available for ftp, then contact a coord with your request.

To contact the ftp server to download files, type 'ftp picard' or 'ftp yar' and log in as anonymous. Use your email address as the password.

Can I use my UPL account to set up a mailing list?

No. Mailing lists consume a large amount of network resources, resources which the UPL does not have. Note that attempting to create a fake mailing list by adding many people to your .forward file is also prohibited. Note that DoIT can provide mailing lists for student organizations or other groups at their discretion.

What about chain letters?

Sending chain letters by email is against UPL policy, CS department policy, UW-Madison policy, and also against Internet appropriate use policy. It also consumes disk and network resources. Please don't send chain mail. If you receive chain mail, please delete it. If we receive complaints about chain mail letters being sent, we will lock and probably remove your account.

Logging In

Can I log in from home?

The easiest way to do this is to get a DoIT/WISCWorld dialup account. Then you can dial in and type ssh dukat.upl.cs.wisc.edu or ssh data.upl.cs.wisc.edu after you have entered your WISCWorld user name and password, or you can use any ssh client.

Those using the software from DoIT should use the ssh program included with their WiscWorld package, entering the appropriate address.

If you require help with the DoIT software or WiscWorld services, please call (26)4-HELP.

You may find however that some labs around campus have difficulties logging into your UPL account. This is not a problem we can readily address, as the problem lies with security software recently installed by the CSL.

How do I log in from outside the UPL?

If you have a login account on another machine, you can use the ssh command to access data or dukat. The exact command depends on the other computer. If you are on a personal computer in a public lab, you can use ssh as an application or program on that computer.

In either case, you will probably need to use the full address of the UPL machine, which will be dukat.upl.cs.wisc.edu, or data.upl.cs.wisc.edu.

Passwords

Passwords are the main key to keeping your files secure and making sure no one else can use your account. This section describes how to change your password, and what separated a good password from a bad one.

How do I change my password?

You should use the command passwd. This command should change your password on both data and dukat.

How do I pick a password?

You should choose a password that is easy for you to remember, so you won't have to write it down, but not so easy that someone else, or someone else's program, can guess it.

Choose a password that is at least 5 characters long. It should include at least one non-alphabetic character (e.g. numbers, spaces, punctuation). Using mixed lower case and upper case letters is also helpful.

It is important to realize that passwords are secure only if they cannot be guessed. There are programs available that will try to guess your password. Your best choice for a password is something that is essentially random to anyone but you. In any case, the following list describes some of the most common passwords, which you should avoid.*

You should NOT use:

You should NOT use: *This list is mostly from Practical UNIX Security by Simson Garfinkel and Gene Spafford.

I forgot my password. What do I do?

Under AFS, we have to work with the CSL in order to change a users password. If you forget your password, go to the CSL (second floor of unit 3 of the CS building), and talk to them. Be sure to tell them that it is a UPL account being dealt with, and to bring your University ID.

Can anyone else get my password?

One way for your password to be cracked is if you log in over long distances and you go through a compromised machine. This is not very likely to happen, but there have been some recent warnings of crackers using machines in this manner. Because of this we recommend that you change your password every few weeks or months. You should also not use the same password on different systems.

Passwords are like toothbrushes. Don't share them with anybody else, and change them every few months.

Mail

The UPL machines have access to electronic mail. This section contains some useful information on using it.

Can I send electronic mail?

We have three mail programs available: mail, elm, and pine.

New users are reccomended to use pine due to its ease of use and power.

mail is very simple, and somewhat arcane. If you want to read your incoming mail, just type mail. If you want to send mail, type mail user@address. Type the subject, then type your message. Type a control-d on a new line to end your message.

elm and pine offer much nicer menu based interfaces. pine is newer than elm, so you might want to use pine. In both programs, you can send mail by selecting an option from the menus inside the program.

What is my mailing address?

Your email address is based on your login name. If your login name is sally, then your email address would be sally@upl.cs.wisc.edu. You can read your mail on either data or dukat.

How do I delete my mail?

If you use the mail program, you can type d n where n is the number of the message you want to delete. For example, d 1 will delete the first message. Just typing d will delete the current message.

If you use elm or pine, there is a delete option in the menu to delete the current message.

You should get in the habit of either saving or deleting your mail, otherwise your incoming mail file can get rather large. Also, keep in mind that incoming mail files may be deleted, accidentally or deliberately. Thus it is a good idea to get incoming mail out of your incoming mail file and into your home directory quickly.

How do I read my mail?

If you use pine or elm, just run the program and move to the "folder" with the mail you wish to read. If you use mail, either type 'mail' to read your incoming mail, or type 'mail -f filename' to read the mail in a certain file. For example, 'mail -f ~/mbox' will open the file where mail is stored by default after you have read it.

Can I use Eudora to check my mail?

Yes, you can. Open Eudora as usual, by clicking on Eudora settings. Go to the Special menu, and click on configuration. In the space that has either your-user-name-here@students.wisc.edu or your students account address on it, type your login name, followed by @data.cs.wisc.edu. Hit return or click the mouse on the OK button. Check mail as usual (Check Mail under the File menu), using your UPL password when a password is requested. To send messages, go to New in the Message menu. One very important thing to remember, is that you need a disk of your own (or the hard disk on your Mac) for the messages to be copied to. If you are using a floppy disk, make sure you quit Eudora (Quit under the File menu), or the machine may get all pissy about ejecting your disk when you want to leave. A similar method can be used for the NuPop program for DOS, again changing the machine that is to be used to check your mail (and the username to use).

How do I save my mail?

You can save mail to your own files, or "folders" as pine and elm call them. From pine and elm, use the save command from the appropriate menu. A message that is still in the INBOX folder (for pine) is not saved in your home directory.

Can I forward my mail to another account?

Yes. Create a file in your home directory called .forward, and place as the first line, the address you wish to forward your mail to. Make this file executable by chmod 755 ~/.forward.

Why doesn't my mail doesn't arrive at my UPL account?

Well, y'see there are many mail queues all living in the building and the mail queue that is pop.students.wisc.edu gets all the mail first. Unfortunatly, this is where it'll stay unless you call the help desk(264-HELP) and ask them to please forward it to your new account location. After it gets forwarded though, NuPop won't be able to be used to check your mail anymore because there will be no more mail in the queue there. It will all be residing on our machines here.

Disk Space and Files

The UPL has very limited disk resources. Therefore, we must impose a disk usage quota on accounts.

It should be noted that mail and USENET news readers often generate quite a lot of files in their directories. You should pay special attention to the size of your News/, mail/, and Mail/ directories. (The actual names will depend on the readers you use.)

You should keep very large files in the /tmp directory. This is on the assumption that all large files are going to be on UPL machines for a short time and that they will eventually be moved to your own machine. Do not use /tmp to store important files or ones you plan to keep on the UPL computers for an extended period of time as all old files are periodically deleted from /tmp.

If you are working on a project that would require a larger disk usage please don't hesitate to mail upl@upl.cs.wisc.edu to make arrangements. We reserve a fair amount of disk space for project use, and thus can probably accomodate you easily.

How do I check my disk space usage?

Type the command /usr4/adm/bin/quota to provide an accurate listing of the size of your files in your directory, and your mail files. This information is useful for determining if you are over quota.

Typing 'du' from your home directory will provide a listing of the disk use for each of your subdirectories. The last number listed is your total disk use in blocks, usually in kilobytes ("K"). This is useful for determining where your large files are in your directory. Note that the number given by du may be inaccurate. Use the relative size to determine which directories are taking up a lot of space.

How do I remove files?

The UNIX command for removing files is rm. Users familiar with DOS should be careful not to use del. del does not remove files: it moves them into the directory .gone/, which it will create if there isn't one available. The problem here is that .gone/ will not show up with a simple directory listing using ls. You must use ls -a, though du will show the disk use of .gone/. These files can become quite large in a short period of time. Moral: don't use del.

An entire directory and its files may be removed with the command rm -rf directory-name. The -r means "recursive," i.e., it will move down to the bottom of any subdirectories, removing files all the way. The -f means "force," which means it will not ask you if you wish to remove the files. If you are at all unsure of the contents of the directory you wish to remove only use rm -ri directory-name. The 'i' stands for interactive. Note that 'f' overrides 'i'.

rmdir will remove an empty directory.

Learning UNIX

There is no one really good way to learn UNIX. It depends a lot on how you learn in general. Our systems have extensive online manuals, plus there are many books and manuals in the UPL. You can learn a lot, though, just by watching others, exploring around the system, and asking questions.

Two manuals that users may wish to look for Unix for Dummies or UNIX for the Impatient. The latter is more advanced, and is more reccomended for users who already know a little UNIX.

How do I use the online manuals?

You get the man page for a particular command or system file by typing man commmand where command is the name of the command. You can find out what man pages are available for a certain topic by using man -k topic or apropos topic.

What books and manuals are available in the UPL?

We have several available texts. We have several copies of The C Programming Language by Kernighan and Ritchie, and manuals for C++ and other languages. We have the X windows manuals 1-4. We also have UNIX administration handbooks and programming references for a number of systems.

Commands

Most of the programs we have available are maintained by CSL, which runs the CS department's computers.

CSL maintains a database of all the users in the department. The UPL is a part of that database. This means that all our user names must be unique in the department. It also means that we need to work with CSL to add users and change passwords.

This section talks about commands in UNIX, and discusses some common problems with the commands we provide.

Where can I find this command?

There is a difference between a command not working and a command not being found. If you get a "command not found" error message for a command that used to work, then you need to add the directory in which the command lives to your path. Your path is defined in your .cshrc or .profile file, depending on whether you use csh or tcsh or another shell.

Here are the paths in which almost all the commands on the system live: 


/s/std/bin /usr/bin /usr/ucb /bin /usr/afsws/bin /usr/ccs/bin 
/opt/SUNWspro/bin /s/elm/bin /s/perl/bin /usr/local/bin /usr/games
/usr/X11/bin

Keep in mind that the order in which the directories in your path are listed can affect which version of a command you run. The first path in which a command is found is the path that will be used.

Why doesn't tin work? How can I use a different news server?

Tin is trying to look in a file to get the name of the NNTP server, but that file doesn't exist anymore. You should tell tin where to find news by adding the following line to your .cshrc or .login:

setenv NNTPSERVER spool.cs.wisc.edu

If you wish to change your default NNTP server, you can change the server to one which you prefer, such as news.doit.wisc.edu

Users of bash, ksh, and sh, need to use slightly different commands.

How do I find commands?

If a command is in your path, you can type which command to find its full path. For example, which who will print out /bin/who. Another similar way to get this information is whereis. Whereis will print out all the occurences of the command in your path, not just the one that will run. For example, whereis who will print out who: /bin/who /usr/bin/who.

If a command is not in your path, the whatdir command will attempt to find it. For example, whatdir jove will print out jove: /usr/unsup/bin/jove even if /usr/unsup/bin is not in your path.

Users of tcsh (most new users now), can use the command where with a command to obtain similar information.

If you don't know the name of the command you want to use, your best bet is to find someone who knows the system, such as a coordinator.

How do I kill a running command?

If you are currently running a command that you want to kill, such as talk, use control-C to cancel the process. If you want to suspend the process, but not kill it, use control-Z. Then you can resume the process in the foreground or background with fg and bg.

If you want to kill a process that is running in the background, use the kill command. First, find out the process ID number with ps -ux or ps -aef; the PID is in the second column. Then, type kill pid where pid is the process ID number. If the command does not die, use kill -9 pid. The -9 specifies the SIGKILL signal, which cannot be ignored by the process.

If you have stopped a process with control-Z, when you log out the shell will tell you you have stopped jobs. Type logout again to kill those processes and log out, or handle the processes yourself.

There are some situations in which stopped jobs will not die when you exit. To check if you have stopped jobs, type ps -ux or ps -aef and look for any process with a T in the eighth column, under STAT.

Another useful control sequence is control-D. This sends an "end of terminal" message to the current foreground process. In mail, this will terminate the message and send it. Other programs interpret the signal differently. Csh and tcsh, for example, will print out a list of commands starting with what you have already typed. In general, any program that takes input from the keyboard will consider the input to be done when you type control-D.

User Names

Can I change my user name?

Changing user names is somewhat more difficult now that we are using AFS. If you really need to change your user name, contact a coordinator. If you don't really need to change it, we would prefer if you continue using your old name. In any case, we cannot provide forwarding of mail from your old account to your new one. Make sure that your username is a username you are willing to live with for a long time, especially if you plan on taking courses in the CS department. Once you pick a username, you are stuck with that name for a long time.

The World Wide Web

What is the difference between Internet Explorer, netscape, WWW, and the Web?

Internet Explorer and netscape are graphical browsers for navigating the Web. WWW stands for World Wide Web, which is sometimes just called the Web.

How can I access WWW?

Three main programs are available to access the WWW. Netscape and IE are available on most machines in the lab and around campus. Also, lynx is a non-graphical browser that can be used easily and over text only terminals types, such as vt100.

Can I make a home page for WWW?

Users can create a subdirectory from their home directory called ~/public_html. Make sure this directory has permissions 755 (readable and executable by everyone). To do this, type chmod 755 ~/public_html. Then, you can place in that directory your html documents. The default home page document should be named index.html. Be sure that your html documents are readable by chmod a+r ~/public_html/* Also, your home directory must be executable. To do this, type: chmod a+x ~

Remeber: all space for WWW pages counts against your disk quota. No extensions will be given for WWW pages. Further, WWW pages are not considered projects. Also, coords are unlikely to be overly helpful towards questions about html and web pages. For information on that, look up the documents online from the Computer Science Department Home Page. They have links to documents that teach how to make WWW pages, and also some WWW ettiquette for constructing pages. Note however, that because our directory setup is different from the rest of the CS department, the instructions for directory setup given by the CS department do not apply to UPL accounts.

Note that DoIT provides web pages for student organizations upon request. Such pages should not be made at the UPL.

End of FAQ