How to Use `bashrc` and `bash_profile`

Understanding and Using `.bashrc` and `.bash_profile`

Whether you're a seasoned developer or just beginning to explore the Linux environment, mastering the configuration of your shell using files like .bashrc and .bash_profile can significantly enhance your command line efficiency and customization. This article covers what these files are, when each one is used, and how to effectively use them for setting up your Linux environment.

What Are `.bashrc` and `.bash_profile`?

On Unix-like operating systems, including Linux and macOS, Bash (short for Bourne Again SHell) is one of the most commonly used shells. It comes with configuration files that initialize shell environments each time a terminal window is opened or a new login occurs.

.bashrc: The "rc" in .bashrc stands for "run command." This file is read and executed by Bash every time a new interactive non-login shell is started. Therefore, it’s primarily used for configuring shell settings related to the working session, like setting up or enabling aliases, functions, shell prompts, and other utilities that you wish to make available in every terminal session.
.bash_profile: On the other hand, .bash_profile or sometimes called profile, is read and executed when Bash is invoked as an interactive login shell (e.g., when you log into your system or invoke bash with the --login option). This file is ideal for actions that need to be set up once per login session, such as setting environment variables, performing tasks that need to run only once during user login, like starting graphical environments or command line tools such as tmux or screen.

When to Use `.bashrc` vs `.bash_profile`?

Use .bashrc for commands that should occur in every interactive non-login shell. This covers things like setting PATH variables incrementally, defining aliases and functions used at the terminal.
Use .bash_profile for commands that should run once at the login. This is suitable for initializing environment variables like PATH, EDITOR, or NODE_ENV, and beginning other login-only dependent processes.

Setting Up and Configuring `.bashrc` and `.bash_profile`

1. Editing `.bashrc`

You can find this file in your home directory (~/.bashrc). If it doesn’t exist, you can create it. Here’s how you can set an alias to make navigation easier:

# Open .bashrc with an editor, here using nano
nano ~/.bashrc

# Add an alias
echo "alias ll='ls -la'" >> ~/.bashrc

After adding your configurations, reload the file:

source ~/.bashrc

This will enable the newly added command.

2. Editing `.bash_profile`

Similarly, this file can be created if it doesn’t exist in your home directory. To add environment variables:

nano ~/.bash_profile

# Set ENV VAR
echo "export PATH=\"$PATH:/home/user/my_scripts\"" >> ~/.bash_profile
echo "export EDITOR='nano'" >> ~/.bash_profile

Load the new settings by sourcing the file:

source ~/.bash_profile

Best Practices

Always remember to source the file after editing to apply changes.
For consistency and to ensure that terminal customizations and environment variables are available in all types of shells, you can source .bashrc within your .bash_profile:
```
if [ -f ~/.bashrc ]; then
   source ~/.bashrc
fi
```
Keep your configuration scripts organized and comment on more complicated setups or uncommon configurations.

Conclusion

Understanding how to properly use .bashrc and .bash_profile will help you create a more responsive and tailored working environment. These files give you control over the behavior of your terminal sessions and can help you automate setup processes and increase productivity. Whether it's customizing the shell prompt, setting paths, or defining aliases, mastering these files is a crucial skill for every Linux and macOS user.

Understanding and Using .bashrc and .bash_profile

What Are .bashrc and .bash_profile?

When to Use .bashrc vs .bash_profile?

Setting Up and Configuring .bashrc and .bash_profile

1. Editing .bashrc

2. Editing .bash_profile