<a href="https://getcomposer.org/" target="_blank" rel="noreferrer noopener" aria-label=" (opens in a new tab)">Composer</a> is a dependency manager for PHP (similar to npm for Node.js or pip for Python). Composer will pull in all the required PHP packages your project depends on and manage them for you.



In this tutorial, we’ll show you how to install and use Composer on an Ubuntu 18.04 machine. The same steps can be used for Ubuntu 16.04.



<h2 id="prerequisites">Prerequisites</h2>



Before continuing with this tutorial, make sure you are logged in as a&nbsp;user with sudo privileges&nbsp;and you have&nbsp;PHP installed on your Ubuntu 18.04&nbsp;system.



<h2 id="installing-php-composer">Installing PHP Composer</h2>



If you are in a hurry and you don’t want to verify the file integrity scroll down to the&nbsp;Installing Composer - Quick Way&nbsp;section.



To install Composer on your Ubuntu system, perform the following steps:



01. Before downloading and installing Composer, first update the packages index and install the necessary requirements:



<pre class="wp-block-code"><code>sudo apt update
sudo apt install wget php-cli php-zip unzip</code></pre>



02. Now that we have php cli installed on our machine, we can download the composer installer with:



<pre class="wp-block-code"><code>php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"</code></pre>



The command above will download the&nbsp;<code>composer-setup.php</code>&nbsp;file in the current working directory.



03. Next, we need to verify the data integrity of the script by comparing the script <code>SHA-384</code> hash with the latest installer hash found on the <a href="https://composer.github.io/pubkeys.html" target="_blank" rel="noreferrer noopener" aria-label=" (opens in a new tab)">Composer Public Keys / Signatures</a> page.



We will use the following&nbsp;wget command&nbsp;to download the expected signature of the latest Composer installer from the Composer’s Github page and store it in a variable named&nbsp;<code>HASH</code>:



<pre class="wp-block-code"><code>HASH="$(wget -q -O - https://composer.github.io/installer.sig)"</code></pre>



Now run the following command to verify that the installation script is not corrupted:



<pre class="wp-block-code"><code>php -r "if (hash_file('SHA384', 'composer-setup.php') === '$HASH') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"</code></pre>



If the hashes match, you will see the following output:



<pre class="wp-block-code"><code>Output:
Installer verified</code></pre>



If the hashes don’t match you will see&nbsp;<code>Installer corrupt</code>. In this case you will need to redownload the Composer installation script and double check the value of the&nbsp;<code>$HASH</code>&nbsp;variable with&nbsp;<a href="https://linuxize.com/post/echo-command-in-linux-with-examples/"><code>echo $HASH</code></a>. Once the installer is verified, you can continue with the next step.



04. The following command will install Composer in the <code>/usr/local/bin</code>directory:



<pre class="wp-block-code"><code>sudo php composer-setup.php --install-dir=/usr/local/bin --filename=composer</code></pre>



<pre class="wp-block-code"><code>Output
All settings correct for using Composer
Downloading...

Composer (version 1.8.5) successfully installed to: /usr/local/bin/composer
Use it: php /usr/local/bin/composer</code></pre>



The&nbsp;<code>composer</code>&nbsp;is installed as a system-wide command and it will be available for all users.



05. The last step is to verify the installation:



<pre class="wp-block-code"><code>$ composer</code></pre>



The command above, will print the Composer’s version, commands and arguments.



<pre class="wp-block-code"><code>Output
______
/ ____/___ ____ ___ ____ ____ ________ _____
/ / / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__ ) __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
 /_/
Composer version 1.8.5 2019-04-09 17:46:47

Usage:
 command [options] [arguments]</code></pre>

Composer is a dependency manager for PHP (similar to npm for Node.js or pip for Python). Composer will pull in all the required PHP packages your...

How To Install and Use PHP Composer on Ubuntu 16/18/19