welcome to the cs labs!
We, the CS Lab staff, like to maintain liberal policies for users, but we do have a few user rules:
1. Use the system in good faith. Experiment all you want, but don't
try to override existing security. The Computer Science (CS) network
is maintained by students, not a professional staff; please be
considerate in your use of it.
2. Give computer science top priority. Someone wishing to use a
workstation for a computer science project has priority
over anyone who is using the system for any other purpose, such as
reading news or sending electronic mail. Game playing is allowed but
is lowest priority; all academic users should feel free to ask game
players to relinquish their machine. The UNIX machines are a computer science
lab, not a campus computing facility.
3. Respect other users' directories. You should not browse through
other users' directories unless they have given you specific permission
to do so. In other words, /home/user directories are private. To
ensure the privacy of your own files, be sure to set the permission
flags accordingly (e.g., chmod 700 /home/username). Type man
chmod for further information.
4. Please protect your account! Even if you think there is nothing
valuable in your home directory, keeping your account secure is still
critical to the security of the entire system. For example, many
hackers first find access to a system they want to break into through a
valid user account (such as yours), and then use that account to do
further damage.
To protect your account, we ask that you:
- Use only secure methods of accessing the system. Using secure methods (such as ssh and scp, instead of telnet and ftp) protects your password from network eavesdroppers. Please see connecting to the cs machines for more information on ssh and scp.
- Use xlock. If you're working in the CS Lab and you need a short break, but don't want to log out, always use xlock to password lock your terminal (just type xlock at the command prompt). Also, make sure you log out completely when you leave the CS Lab (i.e., make sure you see the login screen come back up).
- Don't share your account. Accounts are for the exclusive use of the account holder. Permitting more than one user on each account is an unacceptable security risk for the whole system. Furthermore, anyone who uses your account will introduce themselves as YOU to potentially millions of people around the world via the Internet.
- Choose a good password. A good password is one that is at least eight characters long, has upper-case, lower-case, and non-alphabetic characters in it, and can not be found in any dictionary. See choosing good passwords for more information on good passwords. The command for changing your password is passwd, and it must be run on allspice.
5. Please print only CS-related documents on the CS Lab printer.
Computer Science has a limited fund for printing supplies. Use the
Beardsley public-area printers for other printouts.
6. Don't take the books out of the lab. A small library of books is kept in
the CS Lab for your use; please feel free to read them, but don't take
them. This way we know where they are, and students are able to find
them when they need them.
To help you efficiently use the computers, we have prepared several
documents that explain various features of the system. You should only
need to start up a browser to view these documents. For
example, if you are currently logged in at one of the UNIX machine consoles,
just type "firefox" -- your default homepage should be pointing to
http://www.cs.swarthmore.edu/, just click on help.
This page provides information on
topics such as logging in and out, ssh, printing, choosing good
passwords, and where to go for more help.
If you have any general questions about the Computer Science systems,
please feel free to contact any cs system administrators by email
or phone. You can also send email to
and a sysadmin or CS faculty member will try to answer your questions
(although specific questions about course work should be sent to your
Professor). We're here to help. Thanks and enjoy!