You didn't mention your linux distro.
I have 3 text editors I use. In Linux Mint gedit is the default editor. How do I make another editor the default?
for redhat, fedora
export EDITOR=your editor
for ubuntu & debina
sudo update-alternatives --config editor
I have two applications that will open .doc files. How do I select which application will open the .doc file when clicked on?
right click on file goto properties ->openwith tab
choose your application