title: why are my environmental variables permanent?
body: <p>This problem has been bothering me for awhile. Occasionally I would set up an environmental variable in my .tcshrc file. As soon as I don't need it any more, I would remove it from my .tcshrc file; however, for some reason the variable became permanent in my shell. I thought that everything in the .tcshrc file were not meant to be permanent once the settings are commented or removed. This specifically happened to a new PATH that I wanted to add. Now that I don't need it any more, removing it from the .tcshrc file does nothing.</p>