PC Plus HelpDesk - issue 268
This month, Paul Grosse gives you more insight into some of the topics dealt with in HelpDesk.
From the pages of HelpDesk, I look at:
- On-line file conversion;
- Finding things quickly;
- On-line banking safety;
- Windows IIS Server;
- That all-important Jalebi ('ਜਲੇਬੀ') recipe; and,
- Sniff the net.
On-line file conversion
If you run Windows and Linux, you might find that support for some media file formats is not consistent between the platforms - Windows supports some that are proprietary and haven't been analysed by the Open Source people yet; and some are Open Source and Microsoft either brought out its latest version of Windows before the file format was released and therefore does not support it or, it has no intention of supporting it.
So, this brings us to the issue of either having codecs for each platform or changing the file format so that the file works on the desired platform.
Unfortunately, the workings of many codecs are secrets and are only written for one or two operating systems (usually Windows and Mac - other OSes have to rely upon the good will of the codec manufacturers or on people being able to fathom out how the media files work and then build each codec from scratch).
However, there is a solution to this and if, for large files, you don't have a problem with bandwidth, it is quite easy to use.
There are a number of sites that will provide you with a free media file conversion.
One is at http://media-convert.com/ and in amongst the adverts, you just fill in the source file location and, if necessary the format, and it will convert it for you.
Formats include text, sound, video and so on; and will convert PDFs to Flash SWF format if you really want - you can put these on your website as alternatives to each other.
Anything that you see in the conversion format combo should work and as there is no program installation involved, it should work with pretty much any browser on any operating system.
We tried this out with various video formats, picture files and even converted a PDF eNovel to Flash - all working well.
One problem that was encountered occurred with utf-8 characters from text documents going into html as the encoding was not set to utf-8 but there was no such problem with PDF documents with utf-8 characters going into Flash - it all appeared perfectly.
Finding things quickly
Finding things quickly is essential in the poorly organised mess that your home directory has turned into over time.
On any operating system, your home directory is like a teenager's bedrooms - it started off with good intentions but there comes a time when finding something is just too much effort.
On the command line, there are tools like 'find' but in a world where the GUI is king and users think the command line is for geeks only, Kerry Beagle comes to the rescue.
Kerry Beagle has been around for a while and on new installations, experienced users have either turned it off or ignored it, leaving it for the noobies to use. However, as your system's entropy level increases in accordance with the second law of thermodynamics, things become harder to find.
Kerry Beagle works by producing an index of your system as a background process so that when you want to find something, it only needs to search that.
The search process is quite quick and the absence of organisation in your part of the real file system doesn't slow it down. As with any search engine, just type in the search term and click on the go button.
Clicking on the information button expands any entry and if you hover the mouse over that result's icon, you will see a preview of it. Clicking on the result will open it up in the default program or right-clicking on it gives you a menu.
On-line banking safety
On-line banking is convenient but some sites claim that their services are secure. Can they be? Does the little padlock icon really mean that a transaction can be secure as the banks would like us to feel?
Whilst it is perfectly true that you can do on-line banking at four o'clock in the morning in your underpants and eating Jalebi (see the Jalebi recipe), the security side of it is not quite so sweet (there isn't a lot that is quite as sweet as Jalebi).
Secure transactions over the Internet, using a web browser, rely upon public key encryption which, in principle, is fairly secure - it makes getting hold of the session data for any particular transaction, cost spectacularly more than any attacker is likely to gain by breaking it.
There are various attacks on specific browsers making a hijacked session appear to be real by displaying the visual clues that users rely upon and, there are always attacks using other vectors such as phishing or key loggers from email attachments. However, if you are lucky and careful to the point of paranoid, the communications between your browser and the server will reasonably secure (but not totally).
The real problem then becomes, what happens to your data once the banks, or anybody else for that matter has it. Most of us can remember the Nationwide being find £1 million a year ago for the loss of a laptop in August 2006 but this sort of ineptitude is not limited to banks or building societies.
Her Majesty's Revenue & Customs managed to lose banking, building society and personal details for 25 million people and, TJX, the company that runs TkMaxx, managed to lose the details of over 45 million credit cards - there are plenty of others. It is fair to say that these could happen whether you used on-line or off-line transactions but when it comes to on-line banking you don't gain from increasing your attack surface.
So, whilst the services cannot be 100 per cent secure and the little padlock icon was hacked a long time ago, the browser might not be the weakest link.
Windows IIS Server
Although Apache rules the Internet, Microsoft also has its own version of the humble webserver. If you have the right version of Windows, you should be able to run it once it's installed.
Higher versions of Vista come with IIS. Click on 'Start', 'Settings', 'Control Panel', 'Programs and Features' and then, in the dialogue box's left pane, click on 'Turn Windows features on or off'.
Click on 'Continue' and then wait for the Windows Features list box to populate itself.
Check the IIS box and click on 'OK' then wait.
The wait takes several minutes (if you are unlucky, you will have time to make Jalebi) and shouldn't include a reboot (although it did when I uninstalled the program).
Once the dialogue box disappears, you should have a running installation of IIS.
You can check this out by opening up your favourite web browser and typing 'localhost' in the address bar.
You should get something like the screenshot on the right.
The next thing is where it hides its files. We are all used to Apache putting its files in /srv/ or /var/www or similar but this is a Windows system and you need to navigate to C:\inetpub\wwwroot\.
In there, you will see that the html document you have seen in your browser is called 'iisstart.htm' - this displays the image 'welcome.png'.
You can add your own document called 'index.htm' or even 'index.html' and that will be displayed in preference.
With this up and running, you can now play around with it, developing your own site in a live directory that you can view using the server so you know that it works when you are using extensions such as scripting languages and so on.
That all-important Jalebi ('ਜਲੇਬੀ') recipe
If you want to sit around at four o'clock in the morning in your underpants, doing your on-line banking, eating Jalebi ('ਜਲੇਬੀ' pronounced 'Ja-Lay-Bee' with the emphasis on the second syllable), you will probably want to find a source of Jalebi. So, here is one.
First of all, I know that not all readers of PC Plus are adults so, as this recipe uses hot sugar solution and hot oil, you really need to get an adult to help you. Remember to turn off the heat under the oil when you have finished.
So, assuming that you can do this recipe safely, you will need the following...
- 1 cup of plain white flour;
- 1 heaped tablespoon of rice flour and/or gram flour*;
- 1 teaspoon of yeast or baking powder**;
- If you are using yeast, 1 teaspoon of sugar;
- 1 teaspoon of sunflower oil; and,
- Warm water (cold water if you are using baking powder instead of yeast).
- Sunflower oil for frying;
* if the white flour you get is strong - bread-making flour - you will need to reduce the protein content (specifically the gluten) by adding another flour that doesn't have gluten in it. Whilst gram flour has a lot of protein in it (around 22%), there is no gluten in it so it will dilute down the wheat flour all right. If you don't reduce the gluten content, the batter you will make can end up quite thick and 'gloopy' which does not pipe too well.
** this is to make it expand a bit. With the yeast, it saturates the batter with CO2 and when it hits the hot oil, that comes out of solution and foams. The baking powder has the same effect. Note that the water in the batter will boil and expand as well.
- 1 cup of sugar;
- 1/2 cup water;
- 1 teaspoon yellow food colouring - some recipes use saffron instead; and,
- 1 pinch green cardamom powder.
- a small frying pan - around 10" will do;
- a bowl to mix the batter in;
- a large spoon to put the batter in the Jalebi bag with;
- a Jalebi bag or, a piping bag (icing)***;
- a spatula for handling Jalebis in the oil;
- a milk pan;
- a fork for holding the Jalebis down in the syrup and then fishing them out afterwards; and,
- a dish to put the final product on.
*** Some people have used those tomato sauce squeezy containers. You just want something that you can put the batter in and squeeze without the hole changing its size - you need a hole around 3 or 4 mm in diameter. A plastic bag will not do because the nozzle needs to be a stable size - you don't want it to grow when you squeeze harder as the cut-off corner of a plastic bag would do.
First, make the batter.
In a mixing bowl, mix the flours. If you are using baking powder instead of yeast, add that as well. Then, add the teaspoon of sunflower oil.
Next, fill a cup (1/3rd of a pint) with water. If you are using baking powder, make it cold water. If you are using yeast, make it warm water and add the yeast to it - live yeast is better because it gets to work quicker.
Add the water to the flour and mix, adding more water as needed until a batter consistency is achieved - (not too gloopy, not too runny - you've all seen the consistency of the batter they use in a fish and chip shop, try for that but a little bit runnier - it will thicken up).
Next leave it for an hour but get on with the next stage.
Next, make the syrup.
In the milk saucepan, put the sugar, water, food colouring/saffron and green cardamom and put it on a medium heat. Stir it occasionally until it comes to the boil and all of the sugar has dissolved. If you are not familiar with green cardomon, you should now find out for yourself that it smells like ginger. Take it off the heat (but don't let it get cold). I have found that I need to use roughly 1.5 times the above quantities for the syrup but if you make too much, it will keep (think of jam, there is so much sugar in it that it doesn't go off). When you have finished, just let it cool down and then pour it into a jam jar through a sieve - when you come to use it again, simply reheat it as though you had just made it.
Now make the Jalebis.
In the same what that you would when making pancakes you need to set up a production line of sorts
I do this by having the batter on one side of the stove, next to the frying pan, then a piece of kitchen towel, then the syrup and then the dish. Make sure that you don't have the kitchen roll so close to the frying pan that it catches fire.
This means that you are not trailing dripping batter in your syrup or syrup into your hot oil (insert your own favourite disaster scenario here..) and so on.
Put around 1/2" (1.5cm) depth of sunflower oil in the frying pan. Heat it up until putting a drop of batter in it makes the batter come to the surface within 5 seconds or so but that the oil is not so hot that it browns straight away. The browning time should be 2 to 3 minutes.
Half fill your piping/Jalebi bag and then pipe it into the hot oil, using a quick, spiralling motion.
When you do this, don't do perfect spirals, run a radial line across the spirals so that there is at least something holding them together - the idea is that you are making something that will hold together in one piece when you pick it up, not something that is a fried starch version of a spring.
Alternatively, you can make loops like a daisy or, anything you like - there are plenty of videos on the Internet showing you people making these. The more 'inter-loop cross-linking' there is, the more stable it is when you pick it up.
When the batter has started to harden, separate the Jalebis so that they are easier to handle.
After a minute or two, the underside will have browned and you can turn them over. If you had left them as one large sheet, it would splash hot oil when it turned over.
Once they have cooked on both sides, take them out and rest them on the paper towel for a few seconds (literally just 2 seconds or so, we are trying to mop up some of the oil without letting them cool down - they need to be hot for the next stage).
Then, put them in the hot syrup. They should make a sizzling sound (the water in the syrup boiling).
Put the fork on top of them straight away to hold them down so that they are completely submerged.
The next thing that happens is that the steam inside the Jalebi collapses and sucks the hot syrup inside it.
Once they look like the one on the right, pick them up with the fork and allow them to drain for a few seconds and then put them in the dish (don't put kitchen towel in this dish - they will just stick to it).
The Jalebis will cool down and the syrup will harden slightly (this is from water loss caused by the sugar syrup being hot ... cold sugar syrup => soggy Jalebis).
Remember to turn off the heat under the oil.
The next step is to eat them. They are best eaten whilst they are still a bit warm (but not too hot - remember that they have hot sugar syrup in them when they have just been made).
They will keep for a day or two but not much longer than that (water in the atmosphere will make them go soft).
Heath Warning :-)
When thinking about how much to make, remember that you are making something that has a limited life-time and that the main ingredients are: sugar; starch; and, oil.
Would you sit down and eat your way through a pound of barley sugars?
If you want to find out just how much oil you have used, when you let the oil cool down and pour it back into its bottle (it's only had fried starch in it so it is not tainted at all), just look at how far down it has got.
This recipe has been adapted for PC Plus from my (Paul's) own collection of recipes.
Sniff the net
Have you ever wondered what your firewall has to put up with? You might occasionally see a broadband firewall report of a port scan that has been blocked and odd attacks but you could be curious to see what is actually going on.
In order to look at your network traffic, you will need a packet sniffer like the one on the right (WireShark). A packet sniffer is a network tool used by administrators to look at the actual traffic on your network and, contrary to a popular myth, there is nothing illegal about them.
To look at your network connection, probably one of the easier ways of doing it is to get a Linux/UNIX machine, give it the IP address that your firewall uses on the Internet and let it monitor the traffic.
In order to do that, first of all, reconfigure a spare network card on it so that it has the same IP address as your firewall - remember to make sure that your machine is protected by your software firewall. You can get your IP address from your firewall or you can look at sites such as http://whatismyipaddress.com/ .
Next, open up a console as root and type...ifconfig eth1 126.96.36.199
substituting 'eth1' with the network card name that you want to use and '188.8.131.52' with whatever your external IP address is.
After that, unplug your LAN from your modem and plug in your network card using a crossover patch lead.
Launch a program such as Wireshark and monitor your modem.
Each packet that is received is given a number, the time logged and various details are gleaned from its contents.
Each layer of each packet is analysed and you can see these on the right.
You will probably not see any traffic for other users on your ISP's subnet, even with the card in promiscuous mode, but you will see any port scans, pings and anything else that is going on that is aimed at your IP address.
When you have finished, remember to put everything back the way it was.
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