How to install and configure PHP

PHP is a general-purpose scripting language well-suited for Web development since PHP scripts can be embedded into HTML. This guide explains how to install and configure PHP in an Ubuntu System with Apache2 and MySQL.

Prerequisites

Before installing PHP you should install Apache (or a preferred web server) and a database service such as MySQL.

Install PHP

PHP is available on Ubuntu Linux, but unlike Python (which comes pre-installed), must be manually installed.

To install PHP – and the Apache PHP module – you can enter the following command into a terminal prompt:

sudo apt install php libapache2-mod-php

Install optional packages

The following packages are optional, and can be installed if you need them for your setup.

  • PHP-CLI
    You can run PHP scripts via the Command Line Interface (CLI). To do this, you must first install the php-cli package. You can install it by running the following command:

    sudo apt install php-cli
    
  • PHP-CGI
    You can also execute PHP scripts without installing the Apache PHP module. To accomplish this, you should install the php-cgi package via this command:

    sudo apt install php-cgi
    
  • PHP-MySQL
    To use MySQL with PHP you should install the php-mysql package, like so:

    sudo apt install php-mysql
    
  • PHP-PgSQL
    Similarly, to use PostgreSQL with PHP you should install the php-pgsql package:

    sudo apt install php-pgsql
    

Configure PHP

If you have installed the libapache2-mod-php or php-cgi packages, you can run PHP scripts from your web browser. If you have installed the php-cli package, you can run PHP scripts at a terminal prompt.

By default, when libapache2-mod-php is installed, the Apache2 web server is configured to run PHP scripts using this module. First, verify if the files /etc/apache2/mods-enabled/php8.*.conf and /etc/apache2/mods-enabled/php8.*.load exist. If they do not exist, you can enable the module using the a2enmod command.

Once you have installed the PHP-related packages and enabled the Apache PHP module, you should restart the Apache2 web server to run PHP scripts, by running the following command:

sudo systemctl restart apache2.service 

Test your setup

To verify your installation, you can run the following PHP phpinfo script:

<?php
  phpinfo();
?>

You can save the content in a file – phpinfo.php for example – and place it under the DocumentRoot directory of the Apache2 web server. Pointing your browser to http://hostname/phpinfo.php will display the values of various PHP configuration parameters.

Further reading