bash has a rather complicated way of working out which init files to read when it starts up. This is documented in the man page, but since that is 900 lines long, this page summarises how it works, so that you can find which file(s) to modify for the effect you want.
Login shell vs normal shell
First, you need to know whether your shell is a login shell or not. As the name suggests, a login shell is the one you get when you log in on the console. You can also obtain [continued…]