install composer globally ubuntu

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 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.

Prerequisites

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

Installing PHP Composer

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

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

$ sudo apt update
$ sudo apt install wget php-cli php-zip unzip

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

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

The command above will download the composer-setup.php file in the current working directory.

3. Next, we need to verify the data integrity of the script by comparing the script SHA-384 hash with the latest installer hash found on the Composer Public Keys / Signatures page.

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

$ HASH="$(wget -q -O - https://composer.github.io/installer.sig)"

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

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

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

output:

Installer verified

If the hashes don’t match you will see Installer corrupt. In this case you will need to redownload the Composer installation script and double check the value of the $HASH variable with echo $HASH. Once the installer is verified, you can continue with the next step.

4. The following command will install Composer in the /usr/local/bin directory:

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

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

The composer is installed as a system-wide command and it will be available for all users.

5. The last step is to verify the installation:

$ composer

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

output:

______
/ ____/___  ____ ___  ____  ____  ________  _____
/ /   / __ \/ __ `__ \/ __ \/ __ \/ ___/ _ \/ ___/
/ /___/ /_/ / / / / / / /_/ / /_/ (__  )  __/ /
\____/\____/_/ /_/ /_/ .___/\____/____/\___/_/
                    /_/
Composer version 1.8.5 2019-04-09 17:46:47

Usage:
    command [options] [arguments]