How to install Composer on Linux

Don’t like the intro? Skip to the Tutorial (install Composer on Linux) here.

Back then with PHP development, you would want to use other PHP libraries to include into your project. The process is usually pretty time-consuming:

• First, download the zipped PHP library file;
• Then extract it into the project directory;
• Use require_once function to include the library to the project;
• Upload the whole project with the library files when deploying it online;

Not to mention that, when a library gets an update, you have to re-download it, and overwrite the files again, which is very unproductive.

Composer, a popular PHP dependency manager, helps solving these issues real easy and effective.

As the above short brief on what Composer can do, it is a PHP dependency manager. As a dependency tool:

• Composer helps install, include, update PHP dependency libraries in a project;
• Composer can declare dependencies in a PHP package/project easily;

Not only can Composer can handle a project’s dependency on external libraries, it can handle libraries depend on other libraries as well, which is extremely helpful.

As Official Composer Introduction page, Composer can:

In short, Composer is a must-use tool if you plan to develop with PHP.

Composer supports Windows, Linux and MacOS. This in-depth article will guide you on how to install Composer on Linux-based operating systems.

Composer has general system requirements on Linux-based operating systems.

• You must have at least PHP 7.2.5 installed
• php.ini settings should be properly set. If you install PHP using general methods as dnf, yum, apt-get, it should work fine.

It is possible to use old Composer versions for legacy PHP versions, but at least it has to be PHP 5.3.2. Although so, it is recommended to use a newer PHP version for better compatibilities, as not many PHP libraries use older PHP versions anymore.

Quick Solution: From the Official Composer Download page, you just need to run these commands (either line-by-line or all at once works) in Linux terminal:

*These commands will be updated as Composer updates, however, it’s better to get the latest commands from, again, the Official Composer Download page, as they might be updated making the hashes on this page obsolete.

The page also explains how these command works in details, so we will just quote them here:

After finished running the commands, copy the composer.phar into your Linux’s $PATH directory, so it can be called globally:

Quick tips: To view your $PATH directory, run this command:

The system will return a number of global paths that you can copy the composer.phar file to. For example:

After successfully copying the composer.phar file, the installation can be considered completed. We will verify if Composer works in the next step.

To check if Composer is probably installed, open Linux terminal and run this command:

Alternatively, composer -V (V in capitalized) can be used. If you see the similar message telling Composer version, it has been successfully installed:

If the command returns “not found” error, check if you have copied the composer.phar to the correct $PATH directory on your Linux system. See the Quick tips on the previous section on how to locate it.

To update Composer on Linux, you can follow the above steps again to download the latest Composer version and replace it with your current version.

This quick example will show you on how to use Composer.

Let’s say we have a PHP project that needs URL slug creation functionality, which turns words into a slug URL for SEO purposes (eg. an example project to an-example-project). Instead of having to write this functionality from scratch, we will use a great PHP package, which is ausi/slug-generator library by GitHub user ausi.

On the root project folder, enter this command in Linux terminal:

This command will tell Composer to:

• Download the PHP package ausi/slug-generator located on Packagist.org (main Composer package repository)
• Copy it into our project directory under the vendor folder,
• Record dependency information into composer.json file
• Record the package’s version, time and hashes into composer.lock file to keep track of its states
• Generate necessary dependency inclusion into vendor\autoload.php file

Compared to downloading the package manually and copying it into the project folder, this is very efficient. To use the package, all we need is including the autoload.php file into the project, as this example:

That’s how Composer works. Extremely convenient.

The tutorial on how to install Composer on Linux for PHP dependency management is now over. As a PHP developer, using Composer is a must to keep your project clean and maintain good PHP packages dependency.

We will constantly update this article as new information releases. Thanks for reading, and hopefully this tutorial is helpful for your PHP development process.