How to configure Bash login scripts

In Bash, different startup files govern how the shell initializes and behaves for login and non-login sessions. Understanding .bash_profile and .bashrc helps ensure that environment variables, aliases, and other preferences apply correctly. Proper configuration guarantees a consistent and predictable setup across various shell invocations.

The .bash_profile file typically runs once for login shells, setting global environment variables and path adjustments. In contrast, .bashrc is executed for interactive non-login shells, handling functions, aliases, and command completion. Distinguishing their roles prevents configuration conflicts and ensures settings take effect as intended.

Balancing these files allows fine-grained control over the user experience. By carefully placing environment variables, function definitions, and other customizations in the appropriate file, the shell environment remains stable and flexible. A well-structured configuration improves usability, uniformity, and workflow efficiency.

1. Open a terminal on the Linux system.
2. Determine whether you need to set environment variables in .bash_profile or .bashrc.

   $ cat ~/.bash_profile
   $ cat ~/.bashrc

   .bash_profile is often sourced only once per login, while .bashrc is sourced for each interactive shell.

3. Place environment variables in .bash_profile if they should persist for all login sessions.

   $ nano ~/.bash_profile

   Add lines like:

   export PATH=$PATH:/usr/local/custom_bin

4. Add aliases, functions, and command completions to .bashrc.

   $ nano ~/.bashrc

   Separating environment variables and aliases simplifies debugging and maintenance.

5. Source the modified files to apply changes immediately.

   $ source ~/.bash_profile
   $ source ~/.bashrc

6. Open a new terminal or log in again to confirm the correct behavior.

   If variables or aliases do not appear, verify their placement and sourcing logic.