Introduction

In this quickstart guide, we’ll install Composer on an Ubuntu 20.04 server.

For a more detailed version of this tutorial, with more explanations of each step, please refer to How To Install and Use Composer on Ubuntu 20.04.

Prerequisites

To follow this guide, you’ll need access to an Ubuntu 20.04 server as a sudo user.

Step 1 — Install Dependencies

Start by updating your package manager cache and installing the required dependencies, including php-cli:

sudo apt update
sudo apt install php-cli unzip

Step 2 — Download and Install Composer

Make sure you’re in your home directory, then retrieve the Composer installer using curl:

cd ~
curl -sS https://getcomposer.org/installer -o composer-setup.php

Next, we’ll verify that the downloaded installer matches the SHA-384 hash for the latest installer found on the Composer Public Keys / Signatures page.

Using curl, fetch the latest signature and store it in a shell variable:

HASH=`curl -sS https://composer.github.io/installer.sig`

Now execute the following PHP code to verify that the installation script is safe to run:

php -r "if (hash_file('SHA384', 'composer-setup.php') === '$HASH') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"

You’ll see the following output:

Installer verified

Note: If the output says Installer corrupt, you’ll need to repeat the download and verification process until you have a verified installer.

The following command will download and install Composer as a system-wide command named composer, under /usr/local/bin:

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

You’ll see output similar to this:

Output
All settings correct for using Composer
Downloading...

Composer (version 1.10.5) successfully installed to: /usr/local/bin/composer
Use it: php /usr/local/bin/composer

To test your installation, run:

composer

Output
   ______
  / ____/___  ____ ___  ____  ____  ________  _____
 / /   / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__  )  __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
                    /_/
Composer version 1.10.5 2020-04-10 11:44:22

Usage:
  command [options] [arguments]

Options:
  -h, --help                     Display this help message
  -q, --quiet                    Do not output any message
  -V, --version                  Display this application version
      --ansi                     Force ANSI output
      --no-ansi                  Disable ANSI output
  -n, --no-interaction           Do not ask any interactive question
      --profile                  Display timing and memory usage information
      --no-plugins               Whether to disable plugins.
  -d, --working-dir=WORKING-DIR  If specified, use the given directory as working directory.
      --no-cache                 Prevent use of the cache
  -v|vv|vvv, --verbose           Increase the verbosity of messages: 1 for normal output, 2 for more verbose output and 3 for debug
...

This verifies that Composer was successfully installed on your system and is available system-wide.

Related Tutorials

Here are links to more detailed guides related to this tutorial:

• Initial Server Setup on Ubuntu 20.04
• How To Install and Use Composer on Ubuntu 20.04
• How To Install Linux, Nginx, MySQL, PHP (LEMP stack) on Ubuntu 20.04
• How To Install Linux, Apache, MySQL, PHP (LAMP) stack on Ubuntu 20.04