Composer is a popular tool used for managing package dependencies in the PHP programming language. With Composer, you can easily install and manage third-party libraries and packages for your PHP projects. In this article, we will guide you through the process of installing Composer on Ubuntu 20.04, along with some code examples.
Step 1: Update Ubuntu
Before we do anything, it's important to make sure that our system is up to date. To do this, open your terminal and type the following commands:
sudo apt update
sudo apt upgrade
These commands will update the package list and upgrade any out-of-date packages on your system.
Step 2: Install PHP and related packages
Composer requires that PHP and some related packages be installed on your system. To install these packages, run the following command:
sudo apt install php php-cli php-zip unzip
This command will install PHP, the PHP command line interface, and some additional packages needed for the installation.
Step 3: Install Composer
Now that we have all the necessary prerequisites installed, we can proceed with installing Composer. For this, we will use the installer script provided by the Composer team. Open your terminal and run the following command:
wget -O - https://getcomposer.org/installer | php
This will download the installer script and pipe it directly into the PHP command. After this step is complete, you should see something like this in your terminal:
All settings correct for using Composer
Downloading...
Composer (version 2.X.X) successfully installed to: /path/to/composer.phar
Use it: php /path/to/composer.phar
The installer script will download the latest version of Composer and save it as a file named composer.phar. This file is the main executable for Composer.
Step 4: Make Composer Globally Accessible
To make Composer globally accessible we need to move the composer.phar file to the /usr/local/bin directory so that it can be run from anywhere in the system.
sudo mv composer.phar /usr/local/bin/composer
After running this command we can check the version of Composer installed by running the following command:
composer --version
This should give you output similar to this:
Composer version 2.X.X 2021-XX-XX XX:XX:XX
This confirms that Composer is now installed and globally accessible on your system.
Step 5: Creating A New Project
With Composer installed, let's create a new PHP project that uses some packages that can be installed via Composer. We will create a new directory named myproject and navigate into it.
mkdir myproject
cd myproject
Now, we can initialize a new composer project by running the following command:
composer init
This will start an interactive command-line interface that will ask you some questions about your project. You can press Enter to accept the default values, or enter your own values. Composer will use these values to generate a composer.json file in the current directory. This file will define your project's dependencies.
Next, we will install a package called monolog, which is a popular PHP logging library. To do this, run the following command:
composer require monolog/monolog
This command will download the latest version of the monolog package and its dependencies and install them in the vendor directory of your project. It will also update your composer.json file with the new dependency.
Step 6: Using The Installed Package
Now that we've installed the monolog package, we can start using it in our project. Let's create a script called logging.php in our project directory and add the following code:
<?php
require_once 'vendor/autoload.php';
use Monolog\Logger;
use Monolog\Handler\StreamHandler;
// create a log channel
$log = new Logger('myapp');
$log->pushHandler(new StreamHandler('logs/app.log', Logger::WARNING));
// add records to the log
$log->warning('Foo');
$log->error('Bar');
This code imports the Logger and StreamHandler classes from the monolog package and uses them to create a new logger. The logger is set up to write log messages to a file called logs/app.log. Two log records are added at the end, one with a warning level and one with an error level.
To run this script, we can execute the following command in the terminal:
php logging.php
This will run the script and write the log messages to the file.
Conclusion
That's it! You've successfully installed Composer on Ubuntu 20.04 and used it to install a package and use it in a PHP script. Composer is a valuable tool for simplifying the management of dependencies in PHP projects and allowing you to easily add new functionality to your applications.
Installing the Required PHP Packages
Before installing Composer on Ubuntu 20.04, you need to make sure that you have PHP and its related packages installed on your system. You can easily install these packages using the following command:
sudo apt install php php-cli php-zip unzip
This command will install PHP and its command-line interface, along with the php-zip package which is required by Composer to work with zip archives and the unzip package that is required to extract zip archive files.
Installing Composer
Once you have installed PHP and its related packages, you can proceed to install Composer. There are several ways to install Composer on Ubuntu 20.04, but the easiest and most recommended method is to use the installer script provided by the Composer team.
To download and install the latest version of Composer, run the following command in your terminal:
sudo curl -s https://getcomposer.org/installer | php
This command will download the installer script from the Composer website and pipe it directly to the php command for execution. Once the installation process is complete, you should see a message similar to the following:
All settings correct for using Composer
Downloading...
Composer (version 2.X.X) successfully installed to: /path/to/composer.phar
Use it: php /path/to/composer.phar
This indicates that Composer has been successfully installed on your system and that it is ready to be used.
Making Composer Globally Accessible
To make Composer globally accessible so that you can run it from any directory on the system, you need to move the composer.phar file to a directory that is included in your system's PATH environment variable. In Ubuntu, you can achieve this by moving the composer.phar file to the /usr/local/bin directory as follows:
sudo mv composer.phar /usr/local/bin/composer
After running this command, you can verify that Composer is working correctly by running the following command:
composer --version
You should see the version of Composer that you installed:
Composer version 2.X.X 2021-XX-XX XX:XX:XX
Creating a New Project with Composer
With Composer installed and globally accessible, you can now create a new project and manage its dependencies using Composer. To create a new project, navigate to the directory where you want to create the project and run the following command:
composer create-project --prefer-dist cakephp/app myproject
This command will create a new project in a directory named myproject and will install the necessary dependencies, including the CakePHP framework, using the --prefer-dist option, which tells Composer to download archives instead of cloning repositories. Once the installation is complete, you can navigate to the project directory and start working on your project:
cd myproject
Updating Dependencies
As you develop your project, you may need to update its dependencies to fix bugs or add new features. Composer makes it easy to update your project's dependencies using the following command:
composer update
This command will update all of your project's dependencies, including the dependencies of dependencies, to their latest available versions. By default, Composer will only update the version of a dependency when it satisfies the version constraint specified in your composer.json file. This ensures that updating dependencies does not introduce any compatibility issues or break your project.
Conclusion
In this article, we have shown you how to install Composer on Ubuntu 20.04 and use it to manage dependencies in your PHP projects. We have also discussed the various commands and options available in Composer to create new projects, install dependencies, and update dependencies. With Composer, you can easily manage the dependencies of your projects and keep them up-to-date with the latest versions of packages and libraries.
Popular questions
- What is Composer and what is its purpose?
Composer is a widely-used tool for managing package dependencies in PHP projects. Its purpose is to simplify the process of installing and updating packages and libraries that are required by your project, making it easier to manage and maintain software development projects.
- How do you install Composer on Ubuntu 20.04?
To install Composer on Ubuntu 20.04, you can use the installer script provided by the Composer team. First, make sure you have PHP and its related packages installed on your system. Then, run the following command: sudo curl -s https://getcomposer.org/installer | php. Finally, move the composer.phar file to a directory that is included in your system's PATH environment variable, such as /usr/local/bin.
- How do you create a new PHP project with Composer?
To create a new PHP project with Composer, run the command composer init in the directory where you want to create the project. This will start an interactive command-line interface that will ask you some questions about your project. You can press Enter to accept the default values, or enter your own values. After the process is complete, Composer will generate a composer.json file in the current directory, which defines your project's dependencies. You can then use the composer require command to install additional dependencies for your project.
- How do you update dependencies in your PHP project with Composer?
To update dependencies in your PHP project with Composer, run the command composer update. This will update all of your project's dependencies, including the dependencies of dependencies, to their latest available versions. Composer will only update the version of a dependency when it satisfies the version constraint specified in your composer.json file.
- What are the benefits of using Composer?
Composer simplifies the process of managing package dependencies in PHP projects. With Composer, you can easily install and update third-party libraries and packages, and ensure that your project always has the latest versions of its dependencies. Composer also helps to minimize compatibility issues and makes it easier to maintain and scale software development projects.
Tag
DevOps
