Using Bash Aliases

Dec 24, 2023

To get yourself acquainted with the command line, you may want to refer to this post first.

After using the command line for some time, you may have the following questions in mind.

  • Some of these commands are incredibly long and tedious. How do I shorten them?

  • I keep getting errors when I type in the command line. How do I reduce them?

From the above issues, we can observe that having to memorise and write long commands is a chore and often error-prone. It will be convenient to collate a personalised set of quick-access shortcuts that can perform highly complex tasks. This is where aliases come in handy. For the rest of this article, I will be guiding you on how to create and use Bash aliases.

Creating Your First Alias

Step 1: Open your preferred shell configuration file

For Bash users, this can be one of the following:

  • .bash_profile, accessed at ~/.bash_profile

  • .bashrc, accessed at ~/.bashrc (Preferred)

Differences between the two files:

  • .bash_profile is executed for login shells. It is typically used to set environment variables and execute commands that should be run once when you log in.

  • .bashrc is executed for interactive non-login shells. It is often used for setting aliases and functions that should be available in every new Terminal session. This file is usually sourced by .bash_profile.

For ZSH users,

  • .zshrc, accessed at ~/.zshrc.

To ensure that your aliases are available in both login and non-login shell sessions, you can set up your .bash_profile to source the commands in your .bashrc.

# Open your .bash_profile to source your .bashrc
$ vi ~/.bash_profile
# .bash_profile

# Source .bashrc if it exists
if [ -f ~/.bashrc ]; then
    . ~/.bashrc
fi

# Other .bash_profile configurations
# Open your .bashrc to start adding aliases
$ vi ~/.bashrc

Step 2: Defining your alias

Let's say you have a nodejs application that you wish to run in test mode, with a specific set of environment variables.

# long and tedious command that runs your nodejs application in test mode
$ PORT=8000 SERVER='TEST_SERVER' NODE_ENV='TEST' WORKERS=5 npm run start

You can save yourself the hassle of repeatedly running a long/cumbersome command by creating a function and alias combo in your .bashrc.

# .bashrc

# Functions for initialising different sets of environment variables
function test() {
    export PORT=8000
    export SERVER='TEST_SERVER'
    export NODE_ENV='TEST'
    export WORKERS=5
    echo 'Initialised Test Environment'
}

function prod() {
    export PORT=3000
    export SERVER='PROD_SERVER'
    export NODE_ENV='PROD'
    export WORKERS=5
    echo 'Initialised Production Environment'
}

# Shortened command to run nodejs application
alias 'npm run start'='nrs'

Step 3: Save and Reload your Shell Configuration

$ source ~/.bashrc

Step 4: Test and verify your newly created aliases in a new Terminal

Initialise your development environment with the test function.

# Initialise test configuration
$ test
Initialised Test Environment

# Verify environment variables
$ echo $PORT
8000

$ echo $SERVER
TEST_SERVER

$ echo $NODE_ENV
TEST

$ echo $WORKERS
5

Proceed to run your application using the new alias.

# Short and sweet
$ nrs

Congratulations! You have created a combination of functions and alias for running your nodejs application in different environments.

Some aliases that I frequently use

# .bashrc

# Filesystem
alias ll='ls -lha' # List directory contents in detail
alias cls='clear' # Clear Terminal
alias c='code .' # VSCode
alias e='exit' # Exit Terminal
alias h='history' # History of commands used
alias home='cd ~' # Home directory
alias work='cd ~/work' # Work directory
alias vibrc='vi ~/.bashrc' # Open .bashrc file
alias sourcebrc='source ~/.bashrc' # Save .bashrc file

# Archive and Compression
alias untar='tar -zxvf'       # Extract tar.gz files
alias unzip='unzip -q'        # Quietly unzip files

# Process Management
alias psa='ps aux'            # Display all processes
alias psg='ps aux | grep'     # Search for a process

# Git
alias gcl='git clone'
alias gbr='git branch'
alias gfo='git fetch origin'
alias gco='git checkout origin'
alias gst='git status'
alias gci='git commit -m'
alias gps='git push'
alias gpsf='git push -f origin' # Force push
alias gpl='git pull'
alias gsh='git stash'
alias gsp='git stash pop'
alias grhh='git reset --hard HEAD~1'
alias grsh='git reset --soft HEAD~1'

# Go
# Assumes Makefile defines the following actions:
# 1) build 2) run 3) run-test
alias mb='make build'
alias mr='make run'
alias mrt='make run-test'

# Javascript
# Assumes package.json defines the following actions:
# 1) start 2) test 3) lint
alias nrs='npm run start'
alias nrt='npm run test'
alias nrl='npm run lint'

Conclusion

I hope this tutorial managed to give you sufficient insight on how to write aliases and apply them to real-world scenarios. Aliases make working on the command line so much easier as there is less time spent and fatigue from writing repetitive and long commands. Once you start leveraging them, you will be impressed by how much of a game-changer aliases are to your command-line experience. Happy coding! 🧙💻✨