How To Install and Configure The Composer on Ubuntu 16.04

In this article, we will learn how to install and configure Composer, a dependency management tool for PHP. Composer facilitates the installation and update of project dependencies while ensuring appropriate versions are maintained for project requirements.

Prerequisites

• Ubuntu 16.04 machine

• Non-root user with sudo privileges

Installing Dependencies

Before installing Composer, update your system packages:

sudo apt-get update

Install the required packages to run Composer:

sudo apt-get install curl php-cli git -y

Reading package lists... Done
Building dependency tree
Reading state information... Done
git is already the newest version (1:2.7.4-0ubuntu1).
curl is already the newest version (7.47.0-1ubuntu2.2).
The following NEW packages will be installed:
  php-cli
0 upgraded, 1 newly installed, 0 to remove and 112 not upgraded.
Need to get 2,920 B of archives.
After this operation, 11.3 kB of additional disk space will be used.
Get:1 http://in.archive.ubuntu.com/ubuntu xenial/main amd64 php-cli all 1:7.0+35ubuntu6 [2,920 B]
Fetched 2,920 B in 0s (9,032 B/s)
Selecting previously unselected package php-cli.
(Reading database ... 92686 files and directories currently installed.)
Preparing to unpack .../php-cli_1%3a7.0+35ubuntu6_all.deb ...
Unpacking php-cli (1:7.0+35ubuntu6) ...
Setting up php-cli (1:7.0+35ubuntu6) ...

Installing Composer

Download the Composer installer script to the /tmp directory:

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

Install Composer globally in /usr/local/bin:

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

All settings correct for using Composer
Downloading...

Composer (version 1.4.1) successfully installed to: /usr/local/bin/composer
Use it: php /usr/local/bin/composer

Verify the installation:

composer --version

Composer version 1.4.1 2017-03-10 09:29:45

Clean up by removing the installer file:

rm -rf /tmp/composer-setup.php

How Composer Works

Composer manages project dependencies through the following process:

• Identifies required libraries for the application

• Searches for suitable packages in Packagist.org (the official Composer repository)

• Resolves compatible dependency versions

• Updates composer.json and installs packages automatically

Installing Packages

Create a project directory and navigate to it:

cd ~
mkdir demoproj
cd demoproj

Install a package using Composer. This example installs the cocur/slugify library:

composer require cocur/slugify

Using version ^2.4 for cocur/slugify
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 1 install, 0 updates, 0 removals
  - Installing cocur/slugify (v2.4): Cloning f11f22d4e6 from cache
Writing lock file
Generating autoload files

Using the Autoloader

Composer generates an autoload script that handles class loading automatically. Include vendor/autoload.php in your PHP scripts:

<?php
require __DIR__ . '/vendor/autoload.php';

// Now you can use installed packages
use Cocur\Slugify\Slugify;

$slugify = new Slugify();
echo $slugify->slugify('Hello World');

Test the autoloader by creating a simple script:

echo "<?php require __DIR__ . '/vendor/autoload.php'; echo 'Hello World, Composer is working!';" > test.php
php test.php

Hello World, Composer is working!

Conclusion

You have successfully installed Composer on Ubuntu 16.04 and learned how to manage PHP dependencies. Composer automatically handles package installation, version resolution, and autoloading, making PHP project management significantly easier and more reliable.