When  bash  is invoked as an interactive login shell, or as a non-
interactive shell with the --login option, it first reads and exe-
cutes  commands  from  the file /etc/profile, if that file exists.
After  reading  that   file,   it   looks   for   ~/.bash_profile,
~/.bash_login,  and  ~/.profile, in that order, and reads and exe-
cutes commands from the first one that  exists  and  is  readable.
The  --noprofile  option  may be used when the shell is started to
inhibit this behavior.