Exercise 4
Newsgroups, mailing lists, e-mail and searching the WWW

Newsgroups

We'll practice writing to newsgroups by using the news programme by Opera.

  1. Start Opera
  2. Select News|New
  3. Opera asks you the server that is news.jyu.fi.
  4. An empty widow will open. In the upper left corner there are two buttons. Press All and you'll see all the newsgroups.
  5. Find the jyu hierarchy and there the subdivision jyu.test and there the group jyu.test.
  6. See what kind of messages the other have sent to the group. This group is only for test messages that are to test if the news programme works as it is supposed to. Never send test messages to any other but test groups!
  7. Send (Post) a test message to jyu.test newsgroup
    1. Press Post to send a message
    2. Opera asks first for your e-mail information.
      • Write your username, name and e-mail address to the Account sheet
      • Put for example University of Jyväskylä to the organization field if you like
      • Leave reply-to field empty
      • Put smtp.jyu.fi to the Outgoing server field on the Servers sheet
      • Leave the other settings as they are and accept
    3. Then you can write the actual message. Write Test to the title and anything you like to the message.
    4. If a message was to be sent to several newsgroups all the groups could be listed in News: separated by commas.
    5. When you press Send the message will be sent.
    6. It can take several minutes for the message to appear in the newsgroup. You will get a confirmation by e-mail when your message arrives the test group. If you don't want this confirmation, write ignore to the title of the message. Ordinary newsgroups don't send any confirmations.
  8. While waiting try how to reply someone else's article.
    1. Select a test message
    2. Press the Follow button.
    3. Opera quotes automatically the message you are commenting.
    4. Check from the News line to which newsgroups your reply is going to. Delete possible other groups.
    5. Delete the signature part of the message and write your comment below the actual message.
    6. You can for example write "I'm testing the Follow property of my news programme"
    7. Press Send to post the message.
  9. Your own message is now most likely on the list. Select it and reply to yourself by e-mail: Press the Reply button.
  10. When answering news articles you should always check whether you are answering to the e-mail address of the author or directly to the newsgroup.
  11. It is usually possible to cancel a message after sending it but the Opera news programme can't do that.
  12. Familiarize yourself with the following newsgroups and hierarchies:
  13. Read The seven don'ts of Usenet, or how to excel without doing anything by Jukka Korpela or, well, ask someone to translate... ("Seven prohibitions to newsgroup writers or how to look clever even though you were a moron")
  14. Try reading news in a unix computer by the Tin programme.

Mailing lists

MailMan

MailMan is a mailing list service that is managed via WWW.

  1. Join the test list called "testi" at http://majordomo.cc.jyu.fi/mailman/listinfo/testi/
  2. You will get a mail confirming you are on the list. Reply the message as is supposed.
  3. Send a short mail to the testi list. The address is testi@majordomo.cc.jyu.fi
  4. Wait until you get your own message. Then reply to yourself and ONLY to yourself WITHOUT sending the message to the list. So check to which addresses your reply is going to.
  5. See how to change your mailing list settings on the same site where you joined the list.
  6. See http://majordomo.cc.jyu.fi/mailman/admin/testi to see how the test list is managed. The password is testi. See all the settings you can change and ask the instructor about any unclear things.
  7. Unsubscribe the test list.

Majordomo

Majordomo is a mailing list service that is managed by e-mailing only. Majordomo is reviewed in the lecture notes.

  1. Join the koe@majordomo.jyu.fi test list by sending a following message:
    To      : majordomo@majordomo.cc.jyu.fi
    Cc      : 
    Attchmnt: 
    Subject : 
    ----- Message Text -----
    subscribe koe
    
    All commands concerning the majordomo list must be sent directly to the majordomo server, never to the address of the list!
  2. The address of the list is koe@majordomo.cc.jyu.fi. You will get a confirmation and short instructions for using the list by e-mail from the majordomo. Follow the instructions and order further instructions from majordomo.
  3. Unsubscribe the koe list.

In case you haven't joined the mailing list of the course, do that at http://majordomo.cc.jyu.fi/mailman/listinfo/tietoverkot/

E-mail

Write yourself a .signature file of maximum of four lines to your home directory. Send yourself a mail by using Pine to see if it can automatically add your signature to the end of the message. You can read more about signatures from HOWTO Use Signatures - signature etiquette - learn.to/sign

Filtering e-mails

See how to filter e-mail by Pine.

HOMEWORK: Check the settings of the e-mail programme you use and make sure it doesn't send e-mails in HTML form.

Junkbuster

Try how Internet Junkbuster deletes annoying advertisements from WWW pages. Take the Internet Junkbuster -proxy from the Computing Centre into use. The pages load faster without advertisements.

  1. Start Opera
  2. Set Opera to use the Junkbuster cache from the Computing Centre:
    1. File|Preferences|Connections|Proxy Servers
    2. Write proxy.cc.jyu.fi
      to HTTP
      and 5865 to
      PORT
    3. Accept changes by pressing OK
  3. Now see the following pages in Opera and also Mozilla:

    Mozilla shows all commercial stuff and Opera filteres it.

If you want to use junkbuster on your own computer you can use the proxy from the Computing Centre as above or install Junkbuster to your computer, when you can adjust it as you please. WebWasher is a programme similar to Junkbuster but simpler.

The Computing Centre's Junkbuster only works if you are connected to the University network (as in Kortepohja for instance).

Searching the web

Do the following exercises by utilizing different search procedures of the search engines and also different strategies. First try to find the answer by using Google or another search engine and then use an alternative strategy. Alternative strategies are offered in association with the problems below. Compare the different search strategies. Open the search page to a new browser window. There is a collection of different search engines you can use in the following exercises. Look through the grouping of the search engines on the page.

A short rule of thumb for searching the web:

Easy problems

  1. First try to find the answer by using Google.
  2. Then try browsing according to the hints given.

Tasks

  1. Who directed the movie "Häjyt"

    IMDB knows nearly all movies of the world.

  2. Who Finnish person is known as Hazor?

    Google usually finds best the homepages of individual persons.

  3. What is Voxel? It has to do with computer graphics.

    The best way to search terms of information technology is to use Webopedia.

  4. What is the nutrient content of cooked coffee?

    Fineli knows foodstuffs.

  5. Find a picture of the vice-chancellor (president) of the University of Jyväskylä (Aino Sallinen).

    Google has a separate image search.

  6. You need an image software. From where is it fastest to download a trial version of Paint Shop Pro?

    CNET apparently has the greatest software server where you can download free and shareware software as well as free trial versions of commercial software.

A bit more challenging problems

The following problems aren't necessarily solved by a simple query but you have to find a proper site and then use the search on the site or just browse.

  1. How much is a flying ticket from Finland to Sydney?

    Finnair has a site at <URL: http://www.finnair.fi/> but unfortunately you can't find prices for international fligths by fast browsing there. At <URL: http://www.lloydtours.com/> you can book flights anywhere so there you can also find the prices. By selecting Online-varaukset/Tarjoushinnat ONLINE you can select your destination.

  2. When there goes trains from Stockholm to Hamburg?

    A good guess is to start from the VR site (Finnish railway company). There is a link to European railway search <URL: http://bahn.hafas.de/bin/db.s98/query.exe>

  3. Search the technical spesifications of the IBM portable computer Thinkpad 365XD

    Start from the producer's site at <URL: http://www.ibm.com/>. By giving the search term "thinkpad 365xd" to the search on the IBM site you don't find the direct answer but a link to the thinkpads. By clicking the "support" link you get to a page where you can select the category (Notebooks). Then select 365X/XD from the menu and after that product information from the links on the left. And then put All to Product information by Category. Now there is three links at the bottom of the page and the lowest one is the righ one. Behind that link there is a page containing Product Overview that includes the information needed.

Browser and the search engines

It is clever to add the search engines you use the most to the bookmarks of the browser.

  1. At http://appro.mit.jyu.fi/haku/muokkaa.html you can create a search page for your own purposes. Try it.
  2. At http://appro.mit.jyu.fi/cgi-bin/haku/bookmarklets.cgi you can add validators to your bookmarks so that by selecting the bookmark the respective validator validates the page that is open in the browser window.
  3. At http://appro.mit.jyu.fi/cgi-bin/haku/selain.cgi you can add search engines to your bookmarks so that after selecting the search engine you'll see a dialog that asks for the search terms and sends them without you having to load the search page itself.

Additional exercises

If you still have the time and the enthusiasm, continue with this additional stuff.

PGP

Learn how to use PGP for encrypting e-mails with someone else in your group. The very brief instructions for using PGP will follow. The input from the user is highlighted. Both of you have to create the keys needed and then you can send an encrypted message. PGP can be used in kanto.cc.jyu.fi.

Creating the keys

tukki:~>pgpk -g
Creating /home/peheinon/.pgp...complete.
No randseed file found.
Cannot open configuration file /home/peheinon/.pgp/pgp.cfg
Choose the type of your public key:
  1)  DSS/Diffie-Hellman - New algorithm for 5.0 (default)
  2)  RSA
Choose 1 or 2: 1

Pick your public/private keypair key size:
(Sizes are Diffie-Hellman/DSS; Read the user's guide for more information)
 1)   768/768  bits- Commercial grade, probably not currently breakable
 2)  1024/1024 bits- High commercial grade, secure for many years
 3)  2048/1024 bits- "Military" grade, secure for forseeable future(default)
 4)  3072/1024 bits- Archival grade, slow, highest security
Choose 1, 2, 3 or 4, or enter desired number of Diffie-Hellman bits
(768 - 4096): 3
(Producing a 1024 bit DSS and a 2048 bit Diffie-Hellman key)

You need a user ID for your public key.  The desired form for this
user ID is your FULL name, followed by your E-mail address enclosed in
<angle brackets>, if you have an E-mail address.  For example:
  Joe Smith <user@domain.com>
If you violate this standard, you will lose much of the benefits of
PGP 5.0's keyserver and email integration.

Enter a user ID for your public key: Petri Heinonen <peheinon@mit.jyu.fi>

Enter the validity period of your key in days from 0 - 999
0 is forever (and the default): 0

You need a pass phrase to protect your private key(s).
Your pass phrase can be any sentence or phrase and may have many
words, spaces, punctuation, or any other printable characters.
Enter pass phrase: *******

Enter again, for confirmation: 

Enter pass phrase: *******

.******* .......................................******* .

Keypair created successfully.

If you wish to send this new key to a server, enter the URL of the server,
below.  If not, enter nothing.

tukki:~>
---

Finding out the public key

In the following the public key is revealed when it can be copied to a WWW page by using clip board.

tukki:~> pgpk -xa peheinon
Cannot open configuration file /home/peheinon/.pgp/pgp.cfg
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: PGPfreeware 5.0i for non-commercial use
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=nbkh
-----END PGP PUBLIC KEY BLOCK-----
tukki:~> 

Adding the puplic key of your friend to the keys in use

First save the public key on your friend's WWW page to your own home directory for example as kamu (mate). Then you can add the key to the keys in use like this:


tukki:~> pgpk -a kamu
Cannot open configuration file /home/peheinon/.pgp/pgp.cfg

Adding keys:

Key ring: 'kamu'
Type Bits KeyID      Created    Expires    Algorithm       Use
pub  1024 0xE05D6DE7 2000-10-24 ---------- DSS             Sign & Encrypt 
sub  2048 0x0A0C9BB6 2000-10-24 ---------- Diffie-Hellman                 
uid  Tommi Lahtonen <hazor@iki.fi>

1 matching key found

Add these keys to your keyring? [Y/n] y

Keys added successfully.
tukki:~> 

Sending an encrypted mail

An encrypted mail is best to send as an attachment. In the following example the encrypted message is written as salattu.txt. The message is encrypted to a file called salattu.txt.pgp . After encrypting the message can be mailed.

tukki:~> pgpe -t -r hazor@iki.fi -s -u peheinon salattu.txt
Cannot open configuration file /home/peheinon/.pgp/pgp.cfg
A private key is required to make a signature.
Need a pass phrase to decrypt private key:
  1024 bits, Key ID DC28D721, Created 2000-10-24
   "Petri Heinonen <peheinon@mit.jyu.fi>"
Enter pass phrase: ********
Pass phrase is good.
  1024 bits, Key ID E05D6DE7, Created 2000-10-24
   "Tommi Lahtonen <hazor@iki.fi>"
WARNING: The above key is not trusted to belong to:
Tommi Lahtonen <hazor@iki.fi>

Do you want to use the key with this name? [y/N] y

Creating output file salattu.txt.pgp
tukki:~> 

Decrypting the message

tukki:~> pgpv salattu2.txt.pgp
Cannot open configuration file /home/peheinon/.pgp/pgp.cfg
Message is encrypted.
Need a pass phrase to decrypt private key:
  2048 bits, Key ID 9E4DAEF1, Created 2000-10-24
Enter pass phrase: ********
Pass phrase is good.
Opening file "salattu2.txt" type binary.
Good signature made 2000-10-24 10:32 GMT by key:
  1024 bits, Key ID 44546DC1, Created 2000-10-24
   "phe <peheinon@cc.jyu.fi>"
tukki:~>
 

More information on PGP

Search services

  1. Find a list of WWW search services by using http://www.yahoo.com/
  2. Take a look at the following services:
http://appro.mit.jyu.fi/2001/syksy/tietoverkot/demot/demo4/index.html
© Petri Heinonen ()<URL: http://www.mit.jyu.fi/peheinon/>
30.09.2001 17:17:18