Getting rid of nasty proxy settings

I recently had the problem that some application was not able to connect to the internet although all other applications could. It took me some time to realize that somehow this application was using an old proxy-server setting. Checking in the network preference pane I found that there was no proxy in the settings.

Yet the application still persisted in using this proxy server. As googling this was no use I continued to play around until I found out that on the terminal there was a system variable called $http_proxy set, which pointed at exactly this proxy server. Checking the .bash_profile was unsuccessful, the variable was not set there. But where else? Well, some time ago I wrote a blog post about setting environment variables. And there I explained how the stuff works: in the users home directory there is a hidden directory called .MacOsx. And in this directory there is a plist-file called environment.plist — everytime the user logs on to the system, this property list is read in and the environment variables are set. It appears that when I entered the proxy settings in the network prefpane OSX automatically set the environment variable for the proxy here too. So deleting the entry and logging out and in again solved the problem.