MUSes Computer Lab and Help Pages
lpr -Pch001 doc1.txt
To print on one side of the page only:
lpr -Pch001nd doc1.txt
If you want to print to a printer other than ch001, replace ch001 by the name
of the other printer. The publicly available printers are:
ah130 Altgeld Hall room 130 (duplex) ch001 Coble Hall room 001 (duplex) ch002 Coble Hall room 002 ih225a Illini Hall room 225 ih323 Illini Hall room 323 ih344 Illini Hall room 344
If you have a personal printer, it is named with your username. For example, if user cranston had a personal printer, he would print with the command:
lpr -Pcranston doc1.txt
Also make sure that you are using the proper printing queue. Submitting a job to ah130 will print double-sided. Something you don't want. So submit the job to ah130nd, which is single-sided only.
You should bring the package of transparencies you want to use to the MUSes Staff. So that we can okay it's use in our printers.
Occassionally, this will not work. In this case, open a terminal. This can be done by clicking on the background, then choosing Tools -> Terminal. In the terminal window, type:
This will end your session. Before you do this, please e-mail to help, describing the problem.kill -9 -1
Once pico starts up, you can simply begin typing. There are always menus at the bottom of the screen. To save the file, hold down the control key, and hit the X key. To exit, hold down the control key, and hit the O key. Vi and emacs are considerably more complicated, but also have many more useful capabilities. Click on the links to learn about vi or emacs.pico file.txt
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY! Someone could be eavesdropping on you right now (man-in-the-middle attack)! It is also possible that the RSA1 host key has just been changed. The fingerprint for the RSA1 key sent by the remote host is 75:71:10:85:9b:78:b1:fd:9f:98:57:4f:63:04:ef:55. Please contact your system administrator. Add correct host key in /export/home/user/.ssh/known_hosts to get rid of this message. Offending key in /export/home/user/.ssh/known_hosts:3 RSA1 host key for ssh.math.uiuc.edu has changed and you have requested strict checking. Host key verification failed.Notice the line starting with "Offending key in". You should delete the specified line (in the above example, 3) in the specified file (in the above example, /export/home/user/.ssh/known_hosts) and try again. Note that the file you need to edit may be ~/.ssh/known_hosts2, if your client uses SSH protocol version 2.
Simply click on the "Yes" button. "No" will let you carry on without saving the host key; when you attempt to connect the next time, you will see the same dialog box. Alternately, you can edit certain registry node, but that's not for the faint of heart.
If you use Secure Shell Client (version 3.1), a similar dialog box appears. 
Click on the "Yes" button. Then you will be presented with another dialog box.
Read it, and choose "Yes".
Older versions of Secure Shell Client may present a differnt dialog box. In this case, you can delete the old host key in the Settings dialog box (Global Settings -> Host Keys).
The left two will get you to the normal prompt. The leftmost one will save (overwrite the existing) host key. You should click on either of the left two. Alternately, you can edit the file System Folder:Preferences:NiftyTelnet SSH Known Hosts.
It is important to note that if you are not sure if the remote host changed its host key, it may be a sign of possible compromise. Contact the remote host's system administrator.
ftp ssh.math.uiuc.eduand expect it to work. FTP traffic is allowed only for connections originating from our systems.
Our recent system upgrade was accompanied by firewall installation. In order to allow FTP connections through firewalls, the FTP client must be in so-called passive mode. The ftp program native to Solaris 8 unfortunately does not support this feature. We have installed an alternative called ncftp. It is mostly backward compatible with the old ftp commands and has a few enhancements, such as bookmarks. Click on the ncftp link above for more information.
For incoming mail, your POP3 server will be mail.math.uiuc.edu. You must use secure authentication for the POP3 connection (sometimes called POP3s). In Outlook Express, the Account Properties window has "Advanced" tab. There, click on "This server requires a secure connection (SSL)" checkbox. Some clients may need to have alternate port (port 995) enabled for the SSL connection to work. Outlook and Eudora have similar configuration options for secure e-mail connections.
On PC-Pine, you can specify inbox-path={mail.math.uiuc.edu/pop3/user=jdoe/ssl}INBOX in your pinerc to access your inbox over SSL (adjust jdoe to your login name).
For outgoing mail settings, the outgoing mail (SMTP) server should be set to the server specified by your Internet service provider (ISP). If you use CITES dialup access, configuration instructions for your desktop e-mail program can be found here. If you have connectivity through Insight Communications (cable modem), instructions can be found here. If you have connectivity through SBC/Yahoo! (DSL), instructions can be found here.
To view a postscript file use ghostview. Type the command:lpr -Pch001 file.ps
You may also print the file while you are viewing it in ghostview. To do this, click on the Print All button on the lefthand side, then click the Print button. In addition, you can print selected pages by marking them (right-click on the page number in the page list on the lefthand side) then clicking on the Print Marked button.gv file.ps
Then you can print file2.ps normally.ps2ps file1.ps file2.ps
To print a pdf file, first view it, using acroread. Then from the File menu, select Print... and click the OK button.acroread file.pdf
Then to print example.pdf, simply type:alias lpdf 'acroread -toPostScript < \!^ | lpr'
Another option for printing a pdf file is to convert it to a postscript file then print the postscript file directly:lpdf example.pdf
pdf2ps infile.pdf output.ps
lpr -Pah130 output.ps
This will generate a file named file.dvi. Once you have a dvi file, you will probably want to view it. To do this, type:latex file.tex (or tex file.tex)
You may also want to print it. To do this, type:xdvi file.dvi
To print selected pages (say pages 2 and 3), you can use the command:dvips -Pch001 file.dvi
dvips -pp2,3 -Pch001 file.dvi
This will begin an install program. Read the directions, and after you make each selection, click the next button. If you are unsure about what you should choose for a selection, the default is almost always fine. When the install program has finished, it will add an icon to the bar at the bottom of your screen. In order for this to take effect, you may need to log out and log back in. After you have done this, you should be able to star StarOffice by clicking the new icon at the left end of the bar at the bottom of your screen. Be patient. StarOffice often takes a long time to start up. In the top left corner of your screen you should now see a File menu. From the File menu, choose Open, and select your file. Ideally, now you should be able to print it by selecting Print from the File menu. However, you may need to add a printer. If this is the case, please read the next question: How do I install a new printer for StarOffice?/usr/local/office52/program/setup
cd;/usr/local/office52/program/setupA screen-sized window appears. Within it, you see a dialog box guiding you through the installation process. Click "Next >>".
The next dialog box contains important information. Read the information and click "Next >>".
The next dialog box contains License Agreement. Read it and click "Accept".
Now StarOffice asks you for user information. Fill in as much or as little as you want; some capabilities of the software, such as letter templates, fax and e-mail, depend on the information you provide here. Click "Next >>".
The next dialog box asks you to choose the installation type. Choose the default, "Standard Workstation Installation" and click "Next >>".
Installation directory can be anything you want; the default is recommended. StarOffice asks you if you want to create the directory if it doesn't exist already.
The installation configuration is now complete. When you click on "Complete", you will be asked for Java installation option. The default works fine, so click "OK".
The installation takes a few minutes. When it is done, it will add an icon to the left end of the CDE-frontpanel (the toolbar at the bottom of your screen). Click "OK" to finish installation.
The request_id is shown when you submit the print job, but if you do not remember it you can find it by using the commandcancel request_id
For example, if you type lpstat -o in a terminal window you'll see:lpstat -o
ah130-309 u20.math.uiuc.edu.edu!cranston 837 Apr 30 12:11
ah130-309 is an example of a request_id. To cancel that job you would typeah130-310 u20.math.uiuc.edu.edu!cranston 848 Apr 30 12:11
Please note that you must be logged onto the computer on which the print job was submitted to cancel the job.cancel ah130-309
CDE (Common Desktop Environment) is the windowing system on the MUSes. Here is a first introduction to CDE by Doug West, Getting Started
Most likely, you are running Open Windows, rather than Common Desktop Environment. To fix this, log out. Before you log back in, under the 'Options' menu, click on 'Session' and 'Common Desktop Environment' rather than the default 'User's last desktop'.
It should returnls -ld ~
If it doesn't show that, set the permissions correctly by typingdrwx--x--x 105 your-username your-group 10752 Nov 16 01:56 your-home-directory
Now to set up your web page. In a terminal window, go to your home directory:chmod a+x ~
Create a new directory, called public_html. To do this, type:cd
In order for other people to see your web page, you need to change the permissions of the new directory. By default, when you create a directory (or a file) you are the only one who can look at it or change it. To allow other people to view the contents of the public_html directory, type:mkdir public_html
Now, we need to actually create the your web page. First move into your public_html directory:chmod 755 public_html
Now you need to create a file called index.html. To do this, you can use any unix text editor, or you can upload your index.html file from another computer. We will create a sample index.html using pico, a very simple unix text editor. Type:cd public_html
Once you are using pico, enter the following:pico index.html
Now to save the file and exit, hold down the control key, and hit the X key. Then hold down the control key, and hit the O key.<html> <head> <title> My First Webpage </title> </head> <body> <center> <h1> My First Webpage </h1> </center> This is my first web page. Isn't it beautiful? </body> </html>
Finally, you need to change the permissions on the file index.html so that other people can look at it (before we only changed the permissions on the public_html directory). To do this, type:
Now you should be able to look at your web page through a web browser. Start up netscape. If your username was cranston, in the url box, you would type http://www.math.uiuc.edu/~cranston.chmod 644 index.html
mv .newsrc .newsrc.oldThen go to pine again, to the news folder, where there are now no newsgroups. By saying A add news groups, by ^T you get the list and you can subscribe to a few groups. See the Pine Faq and the online help in pine for more details.
A.J. Hildebrand has written a nice how-to for using spamassassin to filter out spam from your incoming MUSes e-mail. His how-to is available here.
If you are interested in learning more about procmail filtering, you might find some of the following sites useful:
- Procmail home page (especially the section "Interesting and Useful Links")
If you would like help activating spamassassin, please see a consultant on duty.
To change your password, enter the following command:
passwd
You will be asked for your current password once, and then for the new password twice. Here is a sample session where the user fiske changes his password:
u07 11% passwd passwd: Changing password for fiske Enter login(NIS) password: New password: Re-enter new password: NIS passwd/attributes changed on charisma.math.uiuc.edu
In response to each prompt you will type the appropriate password, but these will not be displayed as you type.
Users must select passwords which are difficult to crack. A good password should not be a plain word or name, not in any language. It should be more complicated than a simple change like adding a number, capitalising, or reversing. Examples of bad passwords are Hanna, earth2, retupmoc (computer reversed). The passwd program will reject passwords that it considers to be bad. Pay close attention after you give a new password to be sure it was accepted.
A good password should be trickier than a simple algorithm and should contain upper and lower case alphabetic characters mixed in with numeric and punctuation characters. For example, you could put two words together in a strange way ("Eric Jody" -> "Eri-Jod"), take the first letter of every word in a sentence (I hate using these bloody computers. -> "Ihutbc." Note the period is part of the password.). Passwords should be 6 - 8 characters long.
We make a practice of running a password guessing program. If it gets your password, your account will be locked until you can contact our system administrators to reset it.
If you get trapped in a program and cannot seem to escape, try the folowing keys in the order listed:
cd; du -k
which changes to your home directory, then recursively shows how many kilobytes each file and directory are using. You may also find the following command useful:
cd; du -ks `ls -A` | sort -rn | more
This does much the same thing, but is not recursive, and sorts the results in
order of what is using the most space.
Finally, each user is grouped with other users into a partition. That partition has an allotted amount of space. When the space is used up, none of the users can create or edit files until some of the space becomes free again. For example:
u00 20% cd; pwd
/home/13/cranston
user cranston is in the partition /home/13. To see how much space is available on each partition, use the df command:
u00 21% df -k ~
Filesystem kbytes used avail capacity Mounted on
charisma:/home/13 2078726 1801261 69593 97% /home/13
You should see something like above. In the case of cranston, he sees that
/home/13 still has 91254 kilobytes (about 91 megabytes) free.
You can keep files around in a smaller size by compressing individual files using the gzip command. You can use the tar command to package up an entire directory into a single file, which can then be compressed.
To compress a single file, say thesis.ps, you can use the gzip command, like this:
gzip thesis.psThis turns thesis.ps into thesis.ps.gz, which is typically much smaller. To reverse the process and get thesis.ps back, use the gunzip command, like this:
gunzip thesis.ps.gzGood candidates for compression include postscript files (.ps files), Mathematica notebooks (.nb files), and files with lots of English text, such as old mail files.
Suppose you have many files that you want to compress, and that they are all in one directory, say OldStuff. You can package the directory into an archive file by typing something like this:
tar cvfp OldStuff.tar OldStuffwhere OldStuff.tar is the name of the archive file.
When this is done you should compress the .tar file using gzip as follows:
gzip OldStuff.tarwhich will turn OldStuff.tar into OldStuff.tar.gz
This should greatly reduce the size of the files. However, at this point the files you just compressed will still be taking up space in their original, uncompressed form. You will need to delete them to reduce your disk usage. In this example, the command
rm -r OldStuffshould do the job, by recursively deleting the OldStuff directory.
Later, when you need to use the contents of the OldStuff directory, you can reverse the process as follows:
gunzip OldStuff.tar.gz tar xvfp OldStuff.tarand your OldStuff directory will be restored. At this point, to avoid wasting space, don't forget to delete the archive file, OldStuff.tar.
tar cvfp /tmp/OldStuff.tar OldStuffThis creates OldStuff.tar in the /tmp directory, which generally has more than enough free space. Before you delete your files, you should make sure that the tar archive that you created, actually does contain the files. To do this, you can print the table of contents of the tar archive:
tar tf /tmp/OldStuff.tarYou should see a list of all of the files in the tar archive. Now you can gzip the tar archive, remove the uncompressed copies of your files, and move OldStuff.tar.gz into your home directory:
gzip OldStuff.tar rm -r ~/OldStuff cp /tmp/OldStuff.tar.gz ~
1. cd 2. du -sto see how much disk space you are using. The number will be in kilobytes. 1000 kilobytes = 1 megabyte (mb).
If your entire home directory won't fit, you can always burn subdirectories. Assuming that your home directory will fit, you need to
3. ssh ssh.math.uiuc.edu 4. cd /tmp 5. mkisofs -r -R -l -L -d -T -J -o output.iso ~where output.iso is the name of the output iso image to burn onto cd and ~ is your home directory. You could substitute ~/subdir above if you wanted to burn just a subdirectory. You might want to use a more descriptive name for the iso image like your_login.iso.
You can then go to 108 Altgeld Hall, the public pc lab, to use a cd burner. You'll have to make sure you use on of the pc's with a burner on it. You will then
6. Login as ah108 (instructions shown on the monitor). 7. Use ssh ftp to download the file /tmp/output.iso that you made in step 5 above. 8. Use nero from the program list. 9. Close the wizard. Choose "burn image" from File. 10. Choose the image that you downloaded in step 7 above.Once you have burnt the cd, look at it to make sure it is readable and includes all the files you wanted. Once you have verified the cd delete the iso image on ssh.math.uiuc.edu by doing
11. ssh ssh.math.uiuc.edu 12. rm /tmp/output.isoor whatever you named your iso image in step 5.
nice -19 netscapeOn the other hand, if netscape is already running, and you want to lower its priority, type:
ps -ef | grep netscapeThis will return something like:
cranston 12513 12359 0 13:31:21 pts/6 0:00 /bin/csh -f /usr/local/bin/netscape cranston 12514 12513 0 13:31:21 pts/6 0:02 /usr/local/encap/netscape-4.75/bin/netscapeThe first number in each line is the process number. The second number is the number of the process in charge of that process. So we see that 12513 is in charge of 12514, and is thus the head netscape process. This is the process whose priority we want to change. We do this by typing:
renice -19 12513
If you want keep a copy of your messages on your Math account as well as to forward them, make the second line of the .forward fileyour-username-on-staff@staff.uiuc.edu
Save the .forward file and send yourself an e-mail to make sure everything works properly. Please make sure that the e-mail address to which you are forwarding does not already forward messages back to your Math account causing an infinite loop. The vacation program can also be used to set up e-mail forwarding.\your-username-in-math
If there is ever a problem with any of the computers or printers, please report the problem immediately. If no one reports the problem, no one will fix the problem.
If possible, report problems by e-mail. Descriptions of all problems including software problems, hardware, network and user account problems should be mailed to help@math.uiuc.edu.
When you mail
help@math.uiuc.edu,
you will receive an automated response from the problem-tracking
system. It will contain a line in the Subject field
like: [Math #10] Your problem description.
You should always keep that line in the subject of e-mail you send to help@math.uiuc.edu, regarding your problem. This system will help us better keep track of problems and hopefully make responses quicker.
Last modified August 13, 2004.