In interactive mode bash executes some startup scripts. First thing to know is if it is a login shell or not a login shell:
* login shell: (executes more things)
(1) general settings for all users are in: /etc/profile
(2) personal settins may be in: (first one readable)
~/.bash_profile
~/.bash_login
~/.profile
(3) before logout: ~/.bash_logout
* non-login:
>bash => ~/.bashrc
>bash => ~/.bashrc
>bash --norc => nothing
>bash --rcfile filename => specify another rc file
>bash --rcfile filename => specify another rc file