While Thomas is headed off to Thailand for a three-week vacation and will probably have a pretty good time there, I’m busy finishing AppFresh Development Preview 4 for release. One of the biggest challenges is to get version detection and parsing right for as many applications as possible to be able to compare your currently installed version to the latest available version in a meaningful way and make the Unknown category a bit emptier.

Version numbers come in different fashions, from simple (“2.3″, “1.5.5″) to pretty complex (“R 2.4.1 GUI 1.18″, “0.8.6a”), they appear in multiple places and variations in your installed application and on the internet (osx.iusethis.com) and often, there is also a revision or build number (“4038″, “327″) that might be useful. AppFresh tries to break down all information it finds and combines the pieces to get the most precise version information for comparison. Some problems cannot be solved, e.g. when the application bundle contains a revision number only, like “4038″, and iusethis only knows about the version number, like “1.5.5″. There’s no way for AppFresh to know which revision belongs to which version, therefore it can’t compare them and will list the application as “Unknown”.

Even if the information is there, it can be difficult to break it down into usable pieces, as there is no standard for defining version numbers. Apple has a Tech Note detailing how version numbers should look like, but a lot of developers don’t follow that at all and come up with their own creations, so the number of these patterns that AppFresh has to understand is larger than we originally thought. AppFresh currently uses complex regular expressions to match certain patterns and I’m trying to improve these expressions so more patterns can be matched. As we can’t install all applications to test the whole version parsing algorithm, we added a built-in “Report as broken” function to AppFresh, which provides us with selective data on failing applications but which isn’t used very much. To be able to test and improve version parsing, I’d like to build a database of version strings which can be automatically matched as I modify the regular expressions.

That’s why I built a small tool which you can run once on your machine to generate a profile of all version strings that occur within all applications in your Applications folder. After double-clicking the tool, the profile will be generated and placed on your Desktop in a file called “Collected Versions” (this might take a few seconds, sorry for the
rudimentary “interface”). To submit the collected information, please upload the generated file here (needless to say, the profile contains no personal information and we don’t save anything but this file). Your contribution is greatly appreciated, especially if you have lots of not-so-widely-used applications on your system. Thanks for your help!

Update: I’ve updated the tool to run on PowerPC and include ~/Applications.

This entry was posted on Tuesday, April 3rd, 2007 at 10:31 pm and is filed under AppFresh. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.