Presentation software isn't complicated compared to a word processor or spreadsheet. It doesn't need to be. Maybe that's why OpenOffice.org's Impress offers a variety of views of your work.

You can use the convert command that comes with ImageMagick to extract parts of an image. You can cut out a 100-pixel-wide chunk from somewhere in the middle of an image:

If I play video games they're usually pretty low tech ones. One of the few games I miss from the old days is Duke Nukem, and I'm talking about the Duke before he went 3D. If you have an old DOS game that you'd like to run, or for that matter any old DOS program, check out DOSBox. Even if you don't have any DOS programs that you'd like to run, you might want to try downloading some of the old DOS games that are now available free online.

I just wrote a bit of Python to generate some reports from the contents of a database. The one program that was more than just "display the data" was the one to print the transaction log. It included some sub-totals for various fields and paginated output. The one task remaining was to give it some options. That is, to pass it some criteria that would modify the report.

When running bash scripts that take a long time to run it's often useful to know how long it took for the script to run. In addition to the overall run time, it's also often useful to know how long certain parts of the script took to run. The time command doesn't really help because it's meant to time a single command, not a sequence of commands. By using the %s format

The other day, a client called upon me to perform a hardware and software inventory on all of the computers on his network. There weren't that many machines to inventory, but we needed to gather quite a bit of information about each one.

Everywhere you turn there are "brain training" games that claim to help you "lower your brain age" or "boost your brain power" and other such marketing hyperbole. Much like saying a certain breakfast cereal is "more satisfying" than other cereals, these claims are basically meaningless.

When writing bash scripts you sometimes need to run commands in the background. This is easily accomplished by appending the command line to be run in the background with an ampersand "&". But what do you do if you need to run multiple commands in the background? You could put them all into a separate script file and then execute that script followed by an ampersand, or you can keep the commands in your main script and run them as a sub-shell.

If you don't care much about whitespace bash is great: it normally turns multiple whitespace characters into one and it breaks things into words based on white space. If on the other hand you'd like to preserve whitespace bash can be a bit difficult at times. A trick which often helps is using a combination of bash's eval and set commands.

If you try to unmount a partition and get a message like this: # umount /media/usbdisk/ umount: /media/usbdisk: device is busy use the lsof command to find out what programs are using what files:

Once upon a time, one computer was all you needed. All of your documents lived on that computer, or a stack of floppies or CD-Roms nearby, and nowhere else. Those days are gone, much like the one-car, one-TV, and one-iPod days.

One of the comments to my last post about adjusting the fan speed on your NVidia graphics card was that what was needed was a script to adjust the speed based on the temperature. The script presented here does just that.

I have an original Asus EeePC 701 4G. I've talked about it and written about it before. I tend to like a full operating system on the Eee, and have had several different Linux distributions installed on it. I'm constantly looking for the best mix of form and function.

If you need to transfer an entire filesystem from one machine to another, for example, when you get a new computer, do the following steps. 1) Boot both PCs with any Linux live CD (for example, Knoppix), and make sure they can access each other via the network.

If you've got an NVidia graphics card and it has a fan that sounds like a jet engine, or, if as in my case your fan starts at full speed when the computer boots but then turns off after 20 seconds or so, you need nvclock.

To search a list of RPM files for a particular file, execute the following command:

Recently I needed to create a script that processed two input files. By processed I mean that the script needed to get a line from one file, then get a line from the second file, and then do something with them. Sounds easy enough, but it's not that easy unless you know about some of bash's extended redirection capabilities.

Part of an ongoing series of on open-source geographic information system (GIS) programs, this article offers an introduction to uDig GIS. uDig is for GIS users of all levels, from beginners to advanced.