Understanding Linux Login: The Order of Profile and Bash Files Explained

When logging into Linux, the system first executes /etc/profile, then one of the user’s startup files: ~/.bash_profile, ~/.bash_login, or ~/.profile. The typical order is ~/.bash_profile → ~/.bash_login → ~/.profile.

If ~/.bash_profile exists, it usually sources ~/.bashrc with the following code:

if [ -f ~/.bashrc ] ; then
. ./bashrc
fi

Inside ~/.bashrc, the system‑wide /etc/bashrc is often sourced:

if [ -f /etc/bashrc ] ; then
. /etc/bashrc
fi

Thus the full execution chain is:

/etc/profile → ( ~/.bash_profile | ~/.bash_login | ~/.profile ) → ~/.bashrc → /etc/bashrc → ~/.bash_logout

File responsibilities:

/etc/profile : Sets environment for all users at first login and reads scripts from /etc/profile.d.

/etc/bashrc : Executed for every Bash shell instance; runs each time a new terminal opens.

~/.bash_profile : User‑specific login shell configuration; runs once per login and typically calls ~/.bashrc.

~/.bashrc : Contains settings for interactive non‑login shells; read on each new shell.

~/.bash_logout : Executed when exiting a Bash session.

The system also reads /etc/environment, which defines system‑wide environment variables independent of any user login. While /etc/profile configures user‑specific settings, /etc/environment applies globally.

Changing LANG in /etc/profile makes login prompts appear in English; moving it to /etc/environment makes the change affect all users regardless of login method.

In summary, for a user’s shell initialization the order is /etc/profile then /etc/environment, whereas for the whole system /etc/environment is considered first.