How To Install Composer On Pop!_OS 22.04 LTS

In today’s tutorial, you’ll learn how to install Composer step-by-step on Pop!_OS 22.04 LTS.

Introduction

Composer is a well-known open-source dependency management tool for PHP, created mainly to help distribute and maintenance of project dependencies. It checks which packages a specific project depends on and installs them using the right versions required by the project. PHP frameworks such as Laravel and Symfony use Composer to generate new projects. 

Requirements

You will need access to a Linux system as a non-root sudo user, to follow this tutorial.

Step 1 — Install PHP and Additional Dependencies

Composer requires php-cli to enable you to execute PHP scripts in the terminal, and also to extract zipped archives. You will also need to make sure you have git and curl installed already.

You can check if git and curl are installed by running git -v && curl -V. If you don’t have them installed, you can run sudo apt-get install git && curl to install git and curl on your Linux system.

Now you can go ahead and install the php-cli.

First, update the package lists by running:

sudo apt update

Next, run the command below to install the required packages:

sudo apt install php-cli unzip

You will receive a prompt to confirm installation; type Y and then ENTER to confirm and proceed.

Once the prerequisite dependencies are installed, you can install Composer.

Step 2 — Download and Install Composer

Composer is installed using an installer script written in PHP. We’ll download and verify that it’s not corrupted before we use it to install Composer.

Be sure you are in your home directory, then curl to access and download the installer:

cd ~

curl -sS https://getcomposer.org/installer -o /tmp/composer-setup.php

Next, we need to verify that the installer we downloaded matches the SHA-384 hash for the latest installer found on the Composer Public Keys / Signatures page. To help the verification step, you can run the following command in your terminal to programmatically obtain the latest hash from the Composer page and store it in a shell variable:

HASH=`curl -sS https://composer.github.io/installer.sig`

If you want to verify the obtained value, you can run the following:

echo $HASH

Output

e0012edf3e80b6978849f5eff0d4b4e4c79ff1609dd1e613307e16318854d24ae64f26d17af3ef0bf7cfb710ca74755a

Now, verify that the installation script is safe to run by running the following PHP code provided on the Composer download page:

php -r "if (hash_file('SHA384', '/tmp/composer-setup.php') === '$HASH') 
{ echo 'Installer verified'; } else { echo 'Installer corrupt'; 
unlink('composer-setup.php'); } echo PHP_EOL;"

You’ll see the following output in your terminal:

Output

Installer verified

If the output reads Installer corrupt, then you’ll need to download the installation script again and cross-check that you’re using the correct hash. Afterwards, repeat the verification process. Continue only when you have a verified installer. 

Moving on to install composer globally, run this command:

sudo php /tmp/composer-setup.php --install-dir=/usr/local/bin --filename=composer

This will download and install Composer as a system-wide command named composer, under /usr/local/bin:

After the command runs successfully, you’ll see output similar to this:

Output

All settings correct for using Composer

Downloading...

Composer (version 2.2.9) successfully installed to: /usr/local/bin/composer

Use it: php /usr/local/bin/composer

Finally, to test your installation, run:

composer

Output

   ______
  / ____/___  ____ ___  ____  ____  ________  _____
 / /   / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__  )  __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
                    /_/
Composer version Composer version 2.2.9 2022-03-15 22:13:37
Usage:
  command [options] [arguments]

Options:
  -h, --help                     Display this help message
  -q, --quiet                    Do not output any message
  -V, --version                  Display this application version
      --ansi                     Force ANSI output
      --no-ansi                  Disable ANSI output
  -n, --no-interaction           Do not ask any interactive question
      --profile                  Display timing and memory usage information
      --no-plugins               Whether to disable plugins.
  -d, --working-dir=WORKING-DIR  If specified, use the given directory as working directory.
      --no-cache                 Prevent use of the cache
  -v|vv|vvv, --verbose           Increase the verbosity of messages: 1 for normal output, 2 for more verbose output and 3 for debug
...

This output verifies that Composer was installed successfully on your Linux system and is available globally or system-wide.