Insight: Raspberry Pi Basics—Mastering alias and unalias for Beginners

Insight: Raspberry Pi Basics—Mastering alias and unalias for Beginners

Hey there, fellow Raspberry Pi explorers! Ever feel like typing out those long, winding commands in the terminal is slowing down your awesome projects? Well, I've got a couple of neat tricks up my sleeve that will make your command-line life a whole lot easier: the alias and unalias commands. Think of them as your personal shortcuts for the Raspberry Pi terminal!

What's an Alias Anyway?

Imagine you have a favorite command you use all the time, maybe something like sudo apt update && sudo apt upgrade. It's super useful for keeping your Pi up-to-date, but typing it out repeatedly can get a bit tedious. That's where alias comes to the rescue!

An alias is simply a shortcut you create for a longer command (or even a series of commands). Once you define an alias, you can just type the short alias, and the system will automatically run the longer command behind the scenes. Pretty cool, right?

Let's Get Aliasing!

Using the alias command is straightforward. The basic syntax looks like this:

Bash

alias shortcut='long command to run'   

Notice a few important things here:

• There are no spaces around the equals sign (=).
• The long command to run is enclosed in single quotes ('). This is important, especially if your command contains spaces or special characters.

Let's create a practical alias for updating and upgrading your system. 

Open up your Raspberry Pi terminal and type:

Bash

alias updatepi='sudo apt update && sudo apt upgrade -y'   

Now, whenever you want to update and upgrade your Pi, all you have to do is type:

Bash

updatepi   

Hit Enter, and watch the magic happen! The system will execute the full sudo apt update && sudo apt upgrade -y command. The -y flag in the full command automatically answers "yes" to any prompts during the upgrade, making it even quicker.

Making Your Aliases Stick (Persistently!)

The alias we just created will only last for your current terminal session. Once you close the terminal, the updatepi alias will be gone. If you want your aliases to be available every time you log in, you need to add them to a special configuration file.

The most common file for this is your shell's configuration file. For most Raspberry Pi users, this will be Bash, and the configuration file is usually either .bashrc or .bash_aliases in your home directory (/home/pi).

Here's how to make your updatepi alias permanent:

Open the configuration file using a text editor like nano:

Bash

nano ~/.bashrc   

or

Bash

nano ~/.bash_aliases   

(If .bash_aliases doesn't exist, you can create it.)

Go to the end of the file and add your alias definition:

Bash

alias updatepi='sudo apt update && sudo apt upgrade -y'   

Save the file and exit the text editor (in nano, press Ctrl+X, then Y for yes, and then Enter).

For the changes to take effect in your current terminal session, you need to source the configuration file:

Bash

source ~/.bashrc   

or

Bash

source ~/.bash_aliases   

Now, every time you open a new terminal window, your updatepi alias will be ready to use!

Seeing Your Current Aliases

Want to see a list of all the aliases you've currently defined? Just type the alias command without any arguments:

Bash

alias   

This will display a list of all active aliases in your current session.

Saying Goodbye to an Alias with unalias

Sometimes, you might create an alias that you no longer need or want. That's where the unalias command comes in handy. The syntax is simple:

Bash

unalias shortcut   

For example, to remove the updatepi alias (for the current session), you would type:

Bash

unalias updatepi   

If you want to permanently remove an alias, you'll need to go back to your .bashrc or .bash_aliases file, delete the alias definition, save the file, and then source it again.

Cool Alias Ideas to Get You Started

Here are a few more alias ideas to spark your imagination:

Navigate quickly:

Bash

alias home='cd ~' alias desktop='cd ~/Desktop' alias logs='cd /var/log'   

List files with more detail:

Bash

alias lsa='ls -alFh'   

Reboot and shutdown easily:

Bash

alias rbpireboot='sudo reboot' alias rbpishutdown='sudo shutdown -h now'   

Check disk space:

Bash

alias diskfree='df -h'   

Wrapping Up

The alias and unalias commands are powerful little tools that can significantly improve your command-line experience on your Raspberry Pi. By creating shortcuts for frequently used commands, you'll save time, reduce typing errors, and feel like a true terminal ninja! So go ahead, experiment, create some aliases, and make your Raspberry Pi command line your own! Happy tinkering!

Need Raspberry Pi Expertise?

We'd love to help you with your Raspberry Pi projects.  Feel free to reach out to us at info@pacificw.com.

Written by Aaron Rose, software engineer and technology writer at Tech-Reader.blog.