.bashrc vs .zshrc: Shell Configuration Files

Your shell runs a configuration file every single time it starts, and once you know how to edit it, you can customize almost everything about your command line experience. Bash uses .bashrc, while Zsh uses .zshrc. You'll learn how to edit and reload these files and use them to create persistent aliases.

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.bashrc vs .zshrc

Bash and Zsh both have configuration files that run automatically each time you start a new shell session. These files are used to set up your shell environment. They can be used to set up aliases, functions, and environment variables.

These files are located in your home directory (~) and are hidden by default. The ls command has a -a flag that will show hidden files:

ls -a ~

• If you're using Bash, .bashrc is probably the file you want to edit.
• If you're using Zsh, .zshrc is probably the file you want to edit or create if it doesn't yet exist.

Which one do you have? Linux distros typically default to Bash, while macOS has shipped with Zsh as the default since Catalina. If you're not sure, run echo $SHELL and see which one comes back.

How to Edit Your .bashrc or .zshrc

You can use the nano command to edit files right in your terminal:

nano ~/.bashrc
# or, if you're using Zsh:
nano ~/.zshrc

In nano, use Ctrl+O to save the file (confirm any prompts with Enter), then Ctrl+X to exit. The command list is at the bottom of the screen.

Not sure which config file your shell is actually loading? There's a simple trick to confirm it. Add the following line to the bottom of the file you think is your shell configuration file:

echo "Hello from the shell!"

Close your terminal and open a new one. If you see the message Hello from the shell!, you've found the right file! Just remember to remove the line afterward so you don't see that message every time you open a new shell.

Reload .bashrc or .zshrc

You don't need to close your terminal after every edit. Run source with the file that belongs to your shell:

source ~/.bashrc
# or
source ~/.zshrc

This executes the configuration file in your current shell, so its changes take effect immediately. Opening a new shell session works too.

What Is a Shell Alias?

A shell alias is a command shortcut. Aliases are useful for shortening commands you run all the time. Maybe you always run ls with the same flags:

alias ll="ls -la"

Now you can run ll, and the shell will expand it to ls -la. This creates a temporary alias for the current shell session. Running alias without any arguments lists all the aliases in your current session:

alias

You can remove an alias with unalias:

unalias ll

To make the ll alias persistent, add alias ll="ls -la" to your shell configuration file and reload it as described above. Aliases should make commands shorter, not surprising, so don't create an alias for a destructive command like rm that quietly adds aggressive flags.

If you're editing your shell config to make a PATH change permanent, the PATH environment variable article covers the exact export command and how to avoid overwriting your existing directories. And if you're choosing between a shell and a terminal emulator, Shell vs Terminal explains why changing one doesn't change the other.