Composer will pull in all the required PHP packages your project depends on and manages them for you. It is used in all modern PHP frameworks and platforms such as Laravel, Symfony, Drupal, and Magento.
This article explains how to install Composer on Debian 10 systems. We will also cover how to use Composer to create and manage PHP projects.
Installing Composer on Debian
Before installing Composer, ensure that you have all the necessary packages installed on your Debian system:
sudo apt update
sudo apt install wget php-cli php-zip unzip
Composer offers an installer written in PHP that we’ll use to install Composer.
Download the installer with
wget -O composer-setup.php https://getcomposer.org/installer
The command above will save the file as
composer-setup.php in the current working directory .
Composer is a single file CLI application that can be installed either globally or as part of the project. The global installation requires sudo privileges .
To install Composer globally as a system-wide command that will be available for all users, simply place the file in a directory that is in the system
PATH. The following command installs Composer in the
sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer
All settings correct for using Composer Downloading... Composer (version 1.10.10) successfully installed to: /usr/local/bin/composer Use it: php /usr/local/bin/composer
You can now use Composer by running
composerin your terminal.
To install composer locally, download the file in your project root directory:
sudo php composer-setup.php --install-dir=/path/to/project
This will download a file named
composer.phar. To use Composer navigate to the project directory and run
When a new Composer version is available, you can update the installation using the following command:
sudo composer self-update
Getting Started with Composer
Now that you have Composer installed on your Debian system, we will show you how to create a PHP project.
Start by creating a directory that will be the project root and hold the
composer.json file. This file describes your PHP project, including the PHP dependencies and other metadata.
Run the following commands to create the project directory and switch to it with:
Next, we’ll initialize a new
composer.json file using the
composer require <package name> command and specify the package we want to download. In this example, we will create a sample application that will print the current time using a package named carbon .
Run the following command to initialize a new
composer.json file and install the carbon package:
composer require nesbot/carbon
./composer.json has been created Loading composer repositories with package information Updating dependencies (including require-dev) Package operations: 5 installs, 0 updates, 0 removals - Installing symfony/translation-contracts (v2.1.3): Downloading (100%) - Installing symfony/polyfill-php80 (v1.18.1): Downloading (100%) - Installing symfony/polyfill-mbstring (v1.18.1): Downloading (100%) - Installing symfony/translation (v5.1.3): Downloading (100%) - Installing nesbot/carbon (2.38.0): Downloading (100%) symfony/polyfill-mbstring suggests installing ext-mbstring (For best performance) symfony/translation suggests installing symfony/config symfony/translation suggests installing symfony/yaml symfony/translation suggests installing psr/log-implementation (To use logging capability in translator) Writing lock file Generating autoload files 5 packages you are using are looking for funding. Use the `composer fund` command to find out more
As shown in the output, Composer creates the
composer.json file and downloads and installs carbon and all its dependencies.
If you list your project’s directory with
ls , you’ll see that it contains two files
composer.lock, and a
-rw-r--r-- 1 linuxize users 60 Aug 17 21:02 composer.json -rw-r--r-- 1 linuxize users 6851 Aug 17 21:02 composer.lock drwxr-xr-x 5 linuxize users 4096 Aug 17 21:02 vendor
vendor– the directory where the project dependencies are stored.
composer.lock– a file containing a list of all installed packages including the version of the packages.
composer.json– a file describing the PHP project and all PHP dependencies.
Composer provides autoload capabilities that allow you to use PHP classes without the need to
include the files.
Create a file named
testing.php and paste the following code:
<?php require __DIR__ . '/vendor/autoload.php'; use Carbon\Carbon; printf("Now: %s", Carbon::now());
Let’s analyze the code line by line.
In the first line after the opening php tag we are including the
vendor/autoload.php file that was automatically generated by Composer. This file will autoload all the required libraries.
Next, we are aliasing
Carbon, and in the last line, we are printing the current time using the Carbon
Run the script by typing:
The output should look something like below:
Now: 2020-08-17 21:08:45
Later, if you need to update the project packages, enter:
The command above will check for newer versions of the installed packages, and if a newer version is found and the version constraint match with the one specified in the
composer.json, Composer will update the package.
We have shown you how to install Composer on Debian 10 and how to use it to create a basic PHP project.
For more information about Composer, visit the official documentation page.
If you have any questions, please leave a comment below.