Hack 31 Create Your Own Klik Recipe

Klik might be of interest to you even if the application you need is not on the Knoppix CD.

Originally, klik stood for "KDE-based Live Installer for Knoppix," but it is not really limited to KDE or to Knoppix. Currently, though, klik links work only in native KDE applications such as Konqueror.

The klik server tells a klik client where to download software from and how to install it using klik recipes. A klik recipe is required to install software using klik, and is essentially a shell script that tells the client where to obtain packages and what to do with them. So, to install your own software using klik, you must write your own recipe.

The best way to start writing klik recipes is to learn from existing recipes. You can view sample klik recipes in the point-and-klik software store at http://klik.sf.net. Test your shell script locally, and if it works, please contribute it to klik.

Most Linux software is designed to look for files in places such as /usr, /var, /bin, /etc, and so on. In order to make programs run in nonstandard locations, klik has to run the software using a wrapper script inside each application directory. Each klik recipe has to create its own wrapper script. Sometimes, application binaries even contain hardcoded paths. In these cases, the software must be patched by klik in order to change paths to point to the local application directory. Luckily, KDE applications generally do not use hardcoded paths.

Writing klik recipes by hand for every application is a bit tedious; there should be a better way to manage live-CD software installation. The idea behind klik's serverside-apt project is to automatically generate klik recipes for all software in the Debian distribution on the fly. There is a working development version you can try by pressing Alt-F2 and entering:

klik://packagename

Replace packagename with the name of any Debian package, such as bidwatcher (which is known to work). If you are a programmer interested in advancing serverside-apt, please contact the klik development team.

—Simon Peter