PHP is one of the most widely used server-side scripting languages, crucial for web development. If you’re working with Ubuntu and need to upgrade or install PHP, this guide will walk you through the process.

Step 1: Check the Current Version of PHP

Before making any changes, it’s always a good idea to check which version of PHP is already installed. Open a terminal and run:

php -v

This command will display the current PHP version installed on your system. If PHP is not installed, you will receive a command-not-found message.

Step 2: Update Your Package List

Before upgrading or installing new software, it’s always a good idea to update your package lists. Run the following command to make sure your system is up-to-date:

sudo apt update

Step 3: Install PHP (If Not Already Installed)

If PHP is not yet installed on your system, you can install it by running:

sudo apt install php

This command installs the default version of PHP available in the Ubuntu repository, which might not be the latest one. You can also specify a specific version, for example:

sudo apt install php7.4

Replace 7.4 with the version you wish to install.

Step 4: Adding a PPA for Newer PHP Versions

If the version available in the default Ubuntu repository is outdated and you need a newer PHP version (like PHP 8.0 or 8.1), you’ll need to add a third-party PPA repository. One commonly used repository for this is maintained by Ondřej Surý.

To add the repository, run:

sudo add-apt-repository ppa:ondrej/php
sudo apt update

Now you can install newer PHP versions.

Step 5: Install or Upgrade to a Specific PHP Version

Once the repository is added, you can install a specific version of PHP. For example, to install PHP 8.1, you would run:

sudo apt install php8.1

To install additional PHP modules (for example, php8.1-mysql, php8.1-xml, php8.1-curl, etc.), you can use the following command:

sudo apt install php8.1-mysql php8.1-xml php8.1-curl

Step 6: Set the Default PHP Version

If you have multiple PHP versions installed on your system and want to switch between them, you can use the update-alternatives command. To configure the default PHP version, run:

sudo update-alternatives --set php /usr/bin/php8.1

Replace php8.1 with the version you want to use as the default. You can check the PHP version that is now set as default with:

php -v

Step 7: Restart Apache or Nginx

If you are using Apache or Nginx to serve your web applications, you need to restart the web server for the changes to take effect.

For Apache:

sudo systemctl restart apache2

For Nginx:

sudo systemctl restart nginx