What's the difference between .bashrc, .bash_profile, and .environment?
The main difference with shell config files is that some are only read by "login" shells (eg. when you login from another host, or login at the text console of a local unix machine). these are the ones called, say, .login
or .profile
or .zlogin
(depending on which shell you're using).
Then you have config files that are read by "interactive" shells (as in, ones connected to a terminal (or pseudo-terminal in the case of, say, a terminal emulator running under a windowing system). these are the ones with names like .bashrc
, .tcshrc
, .zshrc
, etc.
bash
complicates this in that .bashrc
is only read by a shell that's both interactive and non-login, so you'll find most people end up telling their .bash_profile
to also read .bashrc
with something like
[[ -r ~/.bashrc ]] && . ~/.bashrc
Other shells behave differently - eg with zsh
, .zshrc
is always read for an interactive shell, whether it's a login one or not.
The manual page for bash explains the circumstances under which each file is read. Yes, behaviour is generally consistent between machines.
.profile
is simply the login script filename originally used by /bin/sh
. bash
, being generally backwards-compatible with /bin/sh
, will read .profile
if one exists.
That's simple. It's explained in man bash
:
/bin/bash The bash executable/etc/profile The systemwide initialization file, executed for login shells~/.bash_profile The personal initialization file, executed for login shells~/.bashrc The individual per-interactive-shell startup file~/.bash_logout The individual login shell cleanup file, executed when a login shell exits~/.inputrc Individual readline initialization file
Login shells are the ones that are read one you login (so, they are not executed when merely starting up xterm, for example). There are other ways to login. For example using an X display manager. Those have other ways to read and export environment variables at login time.
Also read the INVOCATION
chapter in the manual. It says "The following paragraphs describe how bash executes its startup files.", i think that's a spot-on :) It explains what an "interactive" shell is too.
Bash does not know about .environment
. I suspect that's a file of your distribution, to set environment variables independent of the shell that you drive.
Classically, ~/.profile
is used by Bourne Shell, and is probably supported by Bash as a legacy measure. Again, ~/.login
and ~/.cshrc
were used by C Shell - I'm not sure that Bash uses them at all.
The ~/.bash_profile
would be used once, at login. The ~/.bashrc
script is read every time a shell is started. This is analogous to /.cshrc
for C Shell.
One consequence is that stuff in ~/.bashrc
should be as lightweight (minimal) as possible to reduce the overhead when starting a non-login shell.
I believe the ~/.environment
file is a compatibility file for Korn Shell.