Email delivery failure

Do you have email delivery failure notices in your in-box for mail that you've never sent? You might have been getting some emails headed 'Delivery failure', claiming that an email that has been sent somewhere was from you and that it has failed to be sent - even though you know that you have never sent these emails. So, what is going on?

It is one of two things:

• Either it is a spammer using your email address as the sender's address; or,
• it is a spammer sending out such a message to test if your address is genuine.

The latter is doomed to failure in many cases because many email programs have been adapted to stop this type of thing from happening. The former is a way of ensuring that any bounces don't end up back at the spammer's ISP.

By using your email address, it looks as though you are sending spam emails and if any ISP decided that you were getting too many of these, they might investigate you instead of the real spammer.

However, you have nothing to fear from this because the email headers contain information that demonstrate that you were not the source. In the example above, the source appears to be based in Hyderabad in India (although this itself is more likely to be a hijacked machine rather than the real culprit).

Last reboot time

Just when was your computer's last reboot time?

If you share a computer with somebody, you might well lock your account when you leave the machine running. However, you might get back to find that your account isn't running at all. Has the computer been shut down?

There is a way to tell.

The Linux command line has a wealth of small utilities that do a small job well - as opposed to a few enormous programs that do everything with more than just a hint of mediocrity. This UNIX philosophy has led to a very powerful environment that allows you to do just about anything with just a few, well chosen commands.

Surely enough, there is a Linux command that will tell you how long ago the computer was rebooted.

If you open a console and enter 'uptime', you will get the current time and how long the machine has been up, amongst other information. From that, you should be able to work out if the computer was rebooted when you weren't there.

It is as simple as that.

Infrequent reboots

Infrequent reboots can cause problems if you can't remember what to do - you can't be expected to remember exactly what to do on reboot (especially if it was months or years ago) so make a note of it.

Create a text document and store it on your desktop or home directory and write your procedure down in that. Next time you need to reboot (usually a hardware failure), just display the file and follow your own instructions.

Make your instructions fairly verbose and inclusive - don't assume that you will remember even fairly simple things when you are in an unplanned reboot system and need to get the server up and running again before you have to leave to go to work, go to the pub and so on.

Write down command line commands, complete with options and explanations. Write it as though you were writing for somebody else - somebody who is perhaps not as familiar with the machine as your are - you might have disappeared under a bus or be on holiday so it might be somebody else.

Learn to type

Years ago, you might have learned to type using a program like the one on the right - Mavis Beacon (for Windows) from 1993.

These programs were bought and played a happy little tune when you started them up.

Since then, things have changed a little - operating systems have become stable, multi-user, networked, internationalised and free. The layouts have encompassed many variants and, sticking to just English, include Dvorak and other layouts (depending on the OS you use).

You can learn to touch-type on Linux using a program called KTouch. This is part of KDE and if you have it installed, you can find this under 'Edutainment', 'Teaching', 'KTouch'. If you have SUSE, you should see it as one of the programs on your disc set and you don't need to download anything else to install it.

The program itself is easy to configure and there are a number of keyboard layouts to choose from. Click on 'Settings', 'Keyboard Layouts', 'English (en.dvorak)' to get the one you want. There are a number other layouts as well including varieties of Bulgarian, Danish, German, Hungarian and Polish keyboards.

To use the program, select a level and just start typing - no animations, no music, just getting on with teaching you how to type.

Server Message Block

If you've seen Server Message Block (smb://) used as a protocol in Firefox to access Windows shares you might be wondering how it is done because if you use Firefox on Windows, you don't seem to be able to do it.

Server Message Block does run in Firefox if you aren't running Firefox on Windows. It is possible to configure the Window manager in Linux so that it looks and behaves identically to Windows (pretty much any version) so you could convince the casual onlooker that it is running on Windows.

If you are running Linux, you can use Server Message Block as a protocol in Firefox just like typing in any other URL, like so...

smb://machine.name/directory/structure

...and you will get a listing like that in the screenshot on the right.

This works just the same as ftp; or, fancy-indexing in http, in that if you click on a link, it will access that resource, whether it is a directory to open or a file to download.

If you want to access SMB shares from Windows, you are better off using the Windows File Explorer.

Easy image maps

If you are putting together a website that uses an image map to act as links to other pages, you will probably have found out that the coordinates can represent a problem if you are doing it by hand.

However, there is a program that is free, will run on most OSes and make a good, easy job of your task. If you don't already have it installed (you'll find it in the installation media on just about every Linux/UNIX distribution), download the Gimp ( http://gimp-win.sourceforge.net/ for Windows) and load the image you want to map into that (just drag the file and drop it onto the main toolbox window).

When you have your image the size you want it, save it and then right-click on the image and select 'Filters', 'Map', 'ImageMap' (it has been around since Gimp version 1.2.3 (2003) or before and hasn't moved in the menu) and a dialogue box will open with your image on the left and a list box on the right.

When you have finished, another dialogue box will appear allowing you to type in a link or edit the co-ordinates.

When you have finished, click on 'Save' and the file with the image map HTML code in it will be saved so that you can just copy it into your page or use it as a web part in an SSI if you want to use it in many pages and make it easy to edit them all if you want to change the image.

<img src="hkii.png" width="300" height="381" border="0" usemap="#map" />

<map name="map">
<!-- #$-:Image Map file created by GIMP Imagemap Plugin -->
<!-- #$-:GIMP Imagemap Plugin by Maurits Rijk -->
<!-- #$-:Please do not edit lines starting with "#$" -->
<!-- #$VERSION:2.0 -->
<!-- #$AUTHOR:Paul Grosse -->
<area shape="poly" coords="82,82,154,95,127,158,53,143" alt="key pad" 
href="hkii_keys.html" />

{snipped list of areas}

</map>

Simply use the file as an SSI (Server-Side Include) or copy and paste the text into other html files where you need it. By using an SSI, you will be making it easier to edit all of the files used by the image map just by changing the map in the future - say you want to edit a menu or use a different image.

Click here to see an image and map file html fragment in a new window.

Manipulating image maps

The Gimp's image map program produces a small slice of code that is effectively a web-part for your website to use as an SSI (Server-Side Include). Including this image map in a file by using the snippet of html code

<!--include file="immap1.htpart" -->

allows you to change the image and the image web-part - in this case, called 'immap1.htpart' - and have the changes affect your site globally.

In this way, you can add a new menu part to the image, save the image along with the image map web-part and the whole site is updated, along with the new page, straight away - no need to go around, changing every page on your site.

Another advantage of using an image map is that you can use 'Alt' tags. These are just small pieces of text that allows the user - even blind users - to find out more about a link in an image. Most browsers support them and in the screenshot, you can see that this even works on Windows 98SE, so it can't be bad.

Printers and CUPS

YaST2 is good at controlling everything but if you just want to do one simple job, there might be a more lightweight and flexible alternative

Printers on UNIX-like OSes (Mac OS X and most Linux variants) tend to use CUPS (Common UNIX Printing System). This is quite easy to use because, you don't need to load up YaST2 - doing so would include having to type in the root password and so on just to have a look at your printer configuration.

Instead, you just use your favourite web browser with 'http://localhost:631/' as the address and it uses the CUPS server on port 631 for the interface between the browser and the system. Note that this is normally blocked off by the firewall so anybody wanting to access these pages needs physical access to the local machine.

CUPS uses IPP (Internet Printing Protocol) for managing print jobs and queues over your network and uses PPDs (PostScript Printer Descriptions) to convert the output of your programs (which is usually in PostScript) into a form that the printers can understand thus allowing non-PostScript printers to be used with CUPS.

Clicking on the 'jobs' tab displays a list of printer jobs, along with their name, user, size, number of pages and state - the latter being whether or not they have been completed and when.

Adding a string in the search text box and clicking on 'Search' displays print jobs that have that string somewhere in the displayed data - whether it is the name of the job or the user.

You can even add a printer by clicking on the 'Administration' tab and following the wizard. You only need the root password when you are going to commit the new printer to the system. In that way, you can't accidentally edit the system's printer configuration by inputting data erroneously and committing by accident.