Installing PHP Composer on Debian

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PHP Composer is a powerful dependency manager for PHP applications, akin to npm and bower for JavaScript. By using a composer.json file in your project’s root directory, you can manage dependencies, author information, licenses, and more efficiently.

With just a single command, you can install all the libraries you need to build a robust PHP application. This tutorial will guide you through installing Composer on Debian 11, with steps applicable to other Debian-based distributions.

Prerequisites

Before proceeding with the installation, ensure you have root access to a Linux shell, either on a native Linux installation or through a virtualized environment like VirtualBox on a Debian host.

Step 1. Updating the System

To start, open your terminal using Ctrl+Alt+T or search for terminal in the application menu. Execute the following commands to update your system:

sudo apt-get update
sudo apt-get upgrade

Once the update completes, we’ll proceed to install PHP and necessary modules that enable Composer functionality.

Execute these commands to install PHP and additional modules:

sudo apt install php -y
sudo apt install curl git unzip wget php-common php-zip php-cli php-xml php-gd php-mysql php-bcmath php-imap php-curl php-intl php-mbstring -y

Step 2. Install PHP Composer

With your system up-to-date, we can install PHP Composer. Start by downloading the Composer installer script with either curl or wget:

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"

Or

wget -O composer-setup.php https://getcomposer.org/installer

These commands prepare the composer-setup.php file in your current directory. To install Composer globally, run:

php composer-setup.php --install-dir=/usr/local/bin --filename=composer
chmod +x /usr/local/bin/composer

This installation places Composer in the /usr/local/bin directory, accessible from anywhere in your terminal. Alternatively, for project-specific installations, execute:

cd /path/to/the/specific/project/php-application && mkdir -p bin
php composer-setup.php --install-dir=bin --filename=composer
chmod +x bin/composer

Replace /path/to/the/specific/project/ with your actual project path. To verify Composer installation, execute:

composer -v

You might get a warning about running Composer as root; proceed by typing ‘Y’ if needed. A successful installation outputs version information:

Install PHP Composer

Step 3. Updating PHP Composer

To keep PHP Composer up-to-date, use its self-update feature:

composer self-update

If you’re already up-to-date, you’ll see a confirmation message:

Updating PHP Composer

Step 4. Testing the PHP Composer Installation

Let’s verify our Composer installation with a sample project. Create a new directory and navigate into it:

mkdir example-project && cd example-project

Choose a package from Packagist.org—for instance, sebastian/comparator—and install it:

composer require sebastian/comparator

Composer downloads the package and its dependencies into the project directory:

Testing PHP Composer

Now, list the files in your project directory:

ls

This should display:

  • composer.json – Contains project metadata.
  • vendor – Houses downloaded packages and dependencies.
  • composer.lock – Stores package version details.

Example output:

Testing the PHP Composer

Conclusion

You’ve successfully installed and configured PHP Composer on Debian 11. Additionally, you learned how to update Composer. For questions or feedback, please leave a comment below.

Frequently Asked Questions

  • What is PHP Composer?
    Composer is a dependency manager for PHP, simplifying library management and installation.
  • Is Composer similar to npm?
    Yes, Composer works similarly to npm for JavaScript, managing packages and dependencies.
  • Why should I use Composer?
    It automates dependency management, ensuring your project uses compatible versions and installs updates seamlessly.
  • Can I install Composer locally for just one project?
    Yes, use the local installation commands to set up Composer within a specific project directory.
  • How do I know if Composer is installed correctly?
    Run composer -v and verify the version output or any error messages for issues.