.bash_profile
and .bashrc
are specific to bash
, whereas .profile
is read by many shells in the absence of their own shell-specific config files. (.profile
was used by the original Bourne shell.) .bash_profile
or .profile
is read by login shells, along with .bashrc
; subshells read only .bashrc
. (Between job control and modern windowing systems, .bashrc
by itself doesn’t get used much. If you use screen
or tmux
, screens/windows usually run subshells instead of login shells.)
The idea behind this was that one-time setup was done by .profile
(or shell-specific version thereof), and per-shell stuff by .bashrc
. For example, you generally only want to load environment variables once per session instead of getting them whacked any time you launch a subshell within a session, whereas you always want your aliases (which aren’t propagated automatically like environment variables are).
Other notable shell config files:
/etc/bash_profile
(fallback /etc/profile
) is read before the user’s .profile
for system-wide configuration, and likewise /etc/bashrc
in subshells (no fallback for this one). Many systems including Ubuntu also use an /etc/profile.d
directory containing shell scriptlets, which are .
(source
)-ed from /etc/profile
; the fragments here are per-shell, with *.sh
applying to all Bourne/POSIX compatible shells and other extensions applying to that particular shell.