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Questions and Answers from the Computing Help Desk

This chapter is a collection of Questions & Answers that have been treated by the
Computing Help Desk (UCO) managed by the User Support group.

Some PC "Tips"

Hannes Schwarzbauer IT/User Support

Question   -   CERN PC Virus Page
Where can I get information on possible PC viruses at CERN (and solution)?

Answer   -   In the "CERN PC Virus Page" at URL:

http://pcvirus.web.cern.ch/pcvirus/



Answer   -   Normally, the Divisional PC representative is able to change an "Admin" password, provided (s)he is in the list of authorised accounts.

To see the list of authorised people, go from any NT account into:

start - system management - NICE NT domain administration -



If this isn't the case (there are indeed rare exceptions), then  Nice.Support@cern.ch should be contacted.

Remark: please make sure that you have really got NT installed. (This sounds obvious, but on one occasion it was discovered that this wasn't the case!)

Question   -   disable CD drive "auto insert" mode
When I enter a CDROM into my PC's drive it starts playing/executing automatically. How can I disable this and decide to play/execute afterwards whenever I want?

Answer   -   From the control panel, choose:

- System
- dev. manager
- CDRom: click the + (plus) sign
- Double click on the CD drive
- settings


and re-boot.

Some Unix "Tips"

Nicole Crémel and Roger Woolnough IT/user Support

Question   -   Install/run ROOT on private UNIX workstations
How can I install/run ROOT on my UNIX workstation?

Answer   -   ROOT does not require local installation if AFS is available on your workstation. The details can be found from the ROOT home page

http://root.cern.ch   -> "Status & Availability"


Basically it is something like:
• set up the environment variable to point to
/afs/cern.ch/na49/library.4/ROOT/pro/hp700_ux102_aCC/root


• run /bin/root

Question   -   PArC Registration
How can I be registered to use the PArC engineering cluster on RSPLUS ?

Answer   -   There is only a small group of people able to do this registration. It is in effect the persons responsible in IT/CE section as well as those in  User.Registration. Therefore it is recommended for users requesting accounts to send a mail to  User.Registration@cern.ch where they can be quickly registered.

Question   -   AFS bin directory
With AFS how can I run the same program (executable) on different platforms (e.g. DEC/DXPLUS or IBM/RSPLUS)?

Answer   -   Obviously you must compile your program on both platforms and produce two executable modules, one for DEC, one for IBM. Then, to be able to run the same command on different platforms, we introduced at CERN a system variable called @sys. On every system this is set to the local UNIX name. E.g. on RSPLUS and RSBATCH it is defined as rs_aix41. On the PArC IBM node it is  rs_aix41 and on the PArC DEC nodes it is set to  alpha_dux40. However, we have made a directory  bin in every home directory which is a link to  @sys/bin and all you need to do is put executables into your bin directory on a given machine.

So, on an RSPLUS node create (compile and link) your program and put the executable in bin and do the same on a DXPLUS node (DXPLUS are DEC Alphas) or create the executable in a batch job that you submit to a DEC node. Then you just execute

\$HOME/bin/your_program


on any machine (can be in a batch job) and it automatically finds the right version (usually this bin directory is in your "search path").

N.B. In case the setting for such a bin directory (link to @sys/bin) is not correct for your login, then you can use the command "uco -home" to reset the structure of your Home directory (type "man uco" for more details).

Question   -   Password on HP Workstations (e.g. ATLAS cluster)
A short time ago, I changed my password on the  atlas.cern.ch cluster, using the "passwd" command. I am now unable to log on. Please provide me with a new password and instructions for how to change it.

Answer   -   This problem is probably due to the (annoying) fact that HP passwords disallow a few characters which AFS passwords allow (e.g. #). The "passwd" program authenticates directly to AFS from a logged-in session, but when you next log in the HP login program first gets to read your password before passing it on to the AFS authentication, and refuses some characters. When this happens you should contact the Computing Help Desk (78888) who can provide a new password for you. Please then avoid using special characters like #!

Note there is a detailed section regarding "Passwords" (and "How can I choose a good password?") in the document CERN Security Handbook at URL:

http://consult.cern.ch/writeup/security/main.html



Question   -   Submit MAD jobs to PArC in batch - bsub command
How can I execute the command "madbatch"? What is the recommended way to use the MAD (Methodical Accelerator Design) software at CERN?

Answer   -   The command  "madbatch" is part of the PArC environment. If you have not set this up (you must execute the command "parc_apps" once to add it to your path) you will not see it. What it does is submit single MAD jobs to PArC batch.

However, note that this is not enough for users who set multiple MAD runs which pass data between them via the EPIO package.

You can run your jobs on PArC nodes by just changing the queue names. Instead of

bsub -q 1nd track.scr


use
bsub -q e-1nd track.scr


The e in the queue name means an engineering node.

Now, there is a complication. There are about 9 machines that run the e- batch queues, 8 are DEC alphas and 1 is an IBM like the current RSBATCH machines you are using. Another 2 IBM machines will be added next week. The bsub command above will go to any machine. Either you must restrict usage to one of these two UNIXes or you must build executables for each machine and put these files in the corresponding bin (link to @sys/bin) on a given machine.

N.B. If you want to restrict usage to the DEC machines you need

bsub -q e-1nd -R type=Digital-UNIX track.scr


and to restrict usage to the IBM machines you need
bsub -q e-1nd -R type=IBMAIX4 track.scr


MAD works on both and "madbatch" allows to execute on either.

It is, unfortunately, not possible to submit to the e-1nd queue from a DXPLUS machine but you can just have a window there to make the executables then submit from an RSPLUS window.

Note that there are more DEC than IBM in the PArC cluster, and each one is faster, so it is probably worth making a DEC version. Your job will run as it is now if you use :

bsub -q e-1nd -R type=IBMAIX4 track.scr


but you will probably not be able to run as many as you want.

Question   -   PCSF Service
Where can I get information about the PCSF service?

Answer   -   PCSF is the Pentium Central Simulation Facility. It provides batch processing resources based on LSF and Windows NT technology. You can get more information in the "PCSF" Web page, at URL:

http://wwwinfo.cern.ch/pdp/pc/Services/PCSF/Welcome.html


For PCSF matters or problems you can also send messages to the mailing list pcsf-support@listbox.

Question   -   AFS Access
A person in my group has left and I would like to get the rights to look at some of his files without changing the password.

Answer   -   It is possible to set accounts with privilege to modify the ACLs of any user. You must send such a request to the Help Desk (Helpdesk@cern.ch, 78888).

Some DeskTop Publishing "Tips"

Andreas Wagner IT/User Support

Question   -   Include file in an HTML document
How do I include a file in an HTML document ?

Answer   -   The Apache Web-Server supports so called "Server Side Includes" (SSI). Here is how to use it:

In the directory in which the file(s) are located add/create a file .htaccess containing (at least):

Options +Includes



This assumes that documents containing the includes have the extension '.shtml'. Here is a simple example file using SSI:

<html>
<body>
<hr>
<!--#include file="test-incl" -->
<hr>
</body>
</html>



The statement "<!--#include file="test-incl" -->" will include the file named "test-incl".

For further information see also the article about SSI in ApacheWeek, i.e.: http://www.apacheweek.com/features/ssi and the Apache documentation (FAQ): http://www.apache.org/docs/misc/FAQ.html#ssi-part-i

Question   -    ZapfDingbats Font in LaTeX
How can I access the characters of the font  ZapfDingbats in LaTeX ?

Answer   -   Use the package "pifont", e.g:


\documentclass{article}
\usepackage{pifont}
\begin{document}
\ding{43}
\end{document}



The argument of the \ding command is the decimal number of the character in the ZapfDingbats font. In the attached tables (Table 7.1 and Table 7.2) you can see these characters codes. Similarly, you can use the characters in the Symbol font. For the latter table you can write \Pisymbol{psy}{167} and obtain the character expected.

Question   -   EURO Symbol in LaTeX
Is the EURO symbol available in LaTeX?

Answer   -   There are several packages providing the euro symbol for LaTeX. Installed at CERN is the package textcomp, e.g.


\documentclass{article}
\usepackage{textcomp}
\begin{document}
\texteuro
\end{document}



Miscellaneous

Collected by the IT/User Support Team

Question   -   Mailing Lists (Listbox and "MOWGLI")
I have an issue with a mailing list; I would like to:

• create/modify/delete it
• view its membership
• send a problem I encounter when using it
Where do I find the relevant information?

Answer   -   "Listbox" is a central service provided by IT Division in order to operate and manage "public" mailing lists (as opposed to the private ones built in personal addressbooks).

"MOWGLI" is the acronym chosen to baptize the Web interface used by users to deal with those lists.

There are several advantages to this approach, some of which may be attractive to you:

• lists are publicly sharable (no more "my list has different addresses/membership than yours")
• a variety of easily customized configuration parameters allow different levels of confidentiality, central archiving, anti-spam protection, upper limits to sizes of distributed postings, etc
The Web entry point describing the service features and how to start using it can be found at:
http://consult.cern.ch/service/mail/advanced/listbox/



Question   -   Video-conferencing
I would like to install a video conferencing camera and card on a NICE PC at CERN to enable video conferencing between there and RAL. Is there a service for that? Do you have any advice regarding suitable hardware or software?

Answer   -   In the context of our LCB Videoconferencing Project, we have set up the Virtual Room Videoconference System (VRVS). This system provides a Web-based user interface, and uses the well-known vic/rat audio/video public domain applications that are supported by Windows and most Unix versions.

The VRVS URL is  http://vrvs.cern.ch/. Documentation is available on-line.

Please note that a VRVS redistribution node (called a reflector'') is already installed at RAL. Among others, Steve Fisher (s.m.fisher@rl.ac.uk) and Rob Edgecock (rob.edgecock@rl.ac.uk) have been using the system at RAL.

Concerning hardware, the video card we have been running with vic is Win/TV by Hauppauge Inc. (see  http://www.hauppauge.com) which cost about 180 CHF. Any video camera with a video composite or s-video connector can be connected to the Win/TV card. Please note that a video card is useful for sending video. Receiving video requires no special hardware. For audio, a Sound-blaster compatible card is Ok. A comfortable PC is a 300 MHz Pentium II with 64 MB RAM and at least 4 MB on the Graphics card.

What is the CERN policy regarding the access to Web-servers from outside CERN?

Answer   -   As announced in different newsgroups, access to Web-servers (port 80) from outside CERN is now blocked by default for all Web servers that have not been registered with the Web Office.

If you wish you may verify the registration by following these instructions.


1) Browse http://network.cern.ch/register
3) Fill in the "host name", then click on SEARCH


This will normally present you with a page of information concerning the host name entered. On the line "External TCP/IP connectivity: " you will see indications such as OUTGOING or INCOMING and then, if this host is an external Web-server, you will see the text "and EXTERNAL_WEB_SERVER". For example:
External TCP/IP connectivity:       OUTGOING and EXTERNAL_WEB_SERVER


You may register a Web-server at any time by printing out and filling in the form at:-
         http://www.cern.ch/WebOffice/Registration/


send it to your Divisional Webmaster who will forward it to the Web Office. Your server will then become one of those that will be visible from outside CERN. Please allow time for this to happen.

Question   -   Software Development Code Engineering Tool
Is there a source code engineering tool available and recommended at CERN for C, C++ or Java development?

Answer   -   The Software Development Tools Service provide access to the SNiFF+ programming environment (commercial tool) for Java, C, C++ and Fortran, and it seems to be very successful.

For more information on SNiFF see:  http://www.takefive.com/sniff/

For more information on the "Software Development Tools Service" see the Web (URL=http://www.cern.ch/PTTOOLS/).