Occasionally Relevant Insights from a Software Builder


Proprietary Zip Compression

I recently received a Zip file which could not be opened with WinZip or WinRar. This wasn’t entirely unexpected since I knew that WinZip and PKWARE developed their own high end Zip compression algorithms. When you use the maximum compression feature in these programs, your files will be compressed using a proprietary technology which will require the original application to decompress it. For instance, you if use the maximum compression on a file using WinZip, you woulnd’t be able to uncompress it using Pkzip.

If you receive Zip files, you’ll need to have both applications to handle the most common archives. WinZip is a commercial application which will require you to purchase it to legally use. The cost is only $29.95 USD so it’s not unreasonable. Fortunately, PKWARE released Zip Reader which is a free utility to uncompress their archives.


Setting Runlevel for MySQL in Fedora 5

I had lots of fun trying to get MySQL to work properly in Fedora 5. The problem I had was that when a user logged out, MySQL would stop running. You need to set the Runlevel to 3 that the database server will continue running when a user logs out.

The default settings for MySQL in Fedora 5 are incorrect. You can view the runlevel with chkconfig –list mysqld. Runlevel 5 is set on as a default and everything else is off.

The command below will fix the Runlevel in MySQL:

chkconfig –level 3 mysqld on


Displaying a Web Site in an IFrame

In an earlier post, I demonstrated a simple technique to create a scrollable region on a web page using CSS. While this is a good way to display static text, it doesn’t work for displaying another web page. The inline frame (IFrame) element in HTML will allow you to do this.

IFrames are typically used for displaying content from another page, such as an advertising banner. You can use frames to accomplish this, but frames are not good for use in cross-browser applications.

The following is an example of the code and output using the IFrame element. You need to specify the size of the window and the web page that will be displayed. The text in between iframe tags is what will appear on web browsers that can’t display the iframe contents.


Installing the Microsoft Loopback Adapter in Windows XP

Some server applications require a network connection to function. Adenium Systems DFS is an online planroom that needs to see a network for full functionality. Normally, this isn’t a problem when your connected to a large network at work, but if you have a laptop on the road, you’ll need to create a network connection.

This can be done by hardwiring a loopback adapter, or using the one implemented by software in Windows XP. The Microsoft Loopback Adapter is primarily a testing tool for creating a virtual network for your computer. It’s not obvious how it can be installed, so I’ve outlined it in the following steps.

  1. Open Control Panel.
  2. Select Add Hardware and click Next.
  3. Select Yes, I have already connected the hardware and click Next.
  4. Scroll to the bottom of the Installed hardware list and select Add a new hardware device. Click Next.
  5. Select Install the hardware that I manually select from a list (Advanced), and click Next.
  6. Scroll down Common hardware types and select Network adapters. Click Next.
  7. Select Microsoft from the Manufacture, and then select Microsoft Loopback Adapter from the Network adapter list. Click Next.
  8. A message will be displayed that your about to install the loopback adapter. Click Next.
  9. The driver is then installed. Press Finish to complete the process.

That’s it! This is quite a few steps to install but worth the effort. You may see the network icon with a warning symbol appear in your system tray. This is just indicating limited or no connectivity. It’s nothing to worry about.

What you might want to do next is open your Network Connections (it’s normally on the desktop) and edit loopback adapter name. It will be given a default name, such as Local Area Connection 3. You can right click on it and rename it Microsoft Loopback Adapter. This is just for easily identifying it among other network drivers that are installed.