The. profile dates back to the original bourne shell known as sh. Since the gnu shell bash is (depending on its options) a superset of the bourne shell, both shells can use the same startup file. The one possible exception is /etc/profile and. profile, which may be used by multiple different shells (including at least sh and bash).

It says that the /etc/profile file sets the environment variables at startup of the bash shell. The /etc/profile. d directory contains other scripts that contain application-specific startup files, which are.