Sunday, April 15, 2007

Bypassing Your Browser's Cache

As your browse the web, your browser frequently stores many parts of a web page (content, images, javascript etc.) into a so-called "cache" located in your computer's hard drive. This is done with the belief that certain parts of a web page won't change much, for example a company's logo.

But because of this, you might find that sometimes your browser refuses to download the latest data from a web site but instead uses the outdated data stored in its cache. Refreshing might help, but certain elements of a web page may still be retrieved from the cache.

When this happens, you have to be hard on your browser by forcing it to do a "hard refresh", i.e. bypassing your browser's cache entirely. Listed below are the ways to do this for different browsers.

Internet Explorer

either: Hold the Control key, and press F5.
or: Hold the Control key, and click the Refresh button on the toolbar.

Firefox, Netscape (versions 6.x and 7.x) and SeaMonkey.

either: Hold down the Control key, and press F5. On an Apple Mac, use the Command key instead of Control.
or: Hold down the Control key, and click the Reload button on the navigation toolbar.


either: Hold down the Command and Shift keys, and press R.
or: Hold down the Shift key and click the Reload toolbar button.

Opera doesn't have an option to do a hard refresh, so if a normal refresh does not seem to work, you'll have to clear the cache by going to 'Tools' > 'Delete private data'. Click 'Details', make sure that 'Delete entire cache' is selected, and then choose any other data you want to remove.

Friday, April 13, 2007

Scan a File With Multiple Antivirus Engines

What do you do when you come across a suspicious file that you think contains a virus but your antivirus software gives a negative result? Or when you got a seemingly safe file from a trusted source but your antivirus software says otherwise?

Enter VirusTotal - "a free service for scanning suspicious files using several antivirus engines". Just send them a file, either through the web interface or e-mail, and they'll scan the file using antivirus engines from various companies, which includes:-

Here's a screenshot of a test I carried out:

Click to expand.

Because of the server load, I had to wait a few minutes before my request is processed. The results show that different antivirus engines give varying opinions about whether my file (IEHelp.dll) is infected or not - but when antivirus companies like McAfee and Symantec say it's safe, then it probably is. Therefore, this service is also useful to gauge the effectiveness of different antivirus solutions.

Saturday, March 31, 2007

The Birth of TechnoFries

TechnoFries is a new internet magazine owned by InfoFries. It aims to provide news, articles and more about science, technology and the internet (as provided in the blog description). However, the actual type of content that will appear is still undecided.

I as the manager of InfoFries will be writing in this blog, albeit using a different identity - W. Jaylee. I will be using this webmaster identity to deliver announcements like this. It is also possible in the future that more writers will contribute to TechnoFries.

I hope you will stay tuned to TechnoFries to see the latest developments.