How to Install PHP (8.1, 7.4 & 5.6) on Ubuntu 20.04

PHP 8.1 is the latest stable release available. Say thanks to Ondřej Surý for maintaining PPA of most the popular PHP versions on launchpad. If you want to install specific or multiple versions of PHP, then this article can be helpful for you. This article will help you to install PHP 8.1, 8.0, 7.4, 7.3, 7.2, and 5.6 on Ubuntu 20.04 Focal Fossa system via PPA.

You can install multiple PHP versions on Ubuntu system and then switch PHP version as per your requirements. You can also configure Apache to run PHP web applciation’s with different-2 PHP versions.

Prerequsities

You must have sudo or root privileged account access on Ubuntu 20.04.

First of all, open a terminal and update the current packages with the following commands:

sudo apt update && sudo apt upgrade 

Installing PHP on Ubuntu 20.04

PHP installation on Ubuntu systems is pretty straightforward. You just need to add the required PPA and you can install any PHP version on the Ubuntu system.

Follow these steps to complete PHP installation on Ubuntu:

1. Install few dependencies required by this tutorial with the below-mentioned command:

   sudo apt install software-properties-common ca-certificates lsb-release apt-transport-https 
   

2. Add the Ondrej PPA to your system, which contains all versions of PHP packages for the Ubuntu systems.

   LC_ALL=C.UTF-8 add-apt-repository ppa:ondrej/php 
   

3. Now, update the Apt package manager cache.

   sudo apt update 
   

4. The SURY repository contains PHP 8.1, 8.0, 7.4, 7.3, 7.2. 7.1, 7.0 & PHP 5.6. As the latest stable version of PHP is 8.0, but a large number of websites still required PHP 7. You can install any of the required PHP versions on your system.
   • Install PHP 8.1:

     sudo apt install php8.1 
     

   • Install PHP 7.4:

     sudo apt install php7.4 
     

   • Install PHP 7.2:

     sudo apt install php7.2 
     

   • Install PHP 5.6 (EOL):

     sudo apt install php5.6 
     

   Replace version 8.1, 7.4, 7.2, or 5.6 with the required PHP version to install on Ubuntu. Even you can install multiple PHP versions on a single Ubuntu system.

5. Some applications required other PHP extensions, that can also be added using below-mentioned syntax:

   sudo apt install php7.4-[extension]
   

   Replace [extension] with the extension you want to install, if you want to add multiple extensions then include them in braces, I am going to install 「php-mbstring, php-mysql, php-xml, and php-curl」 by running the below-mentioned command:

   sudo apt install php7.4-mysql php7.4-mbstring php7.4-xml php7.4-curl 
   

   Users have installed different PHP version, need to replace 7.4 with required PHP versions.

Check Active PHP Version

To view the current active PHP version run the following command:

php -v

Ouput:
PHP 7.4.29 (cli) (built: Apr 21 2022 10:16:36) ( NTS )
Copyright (c) The PHP Group
Zend Engine v3.4.0, Copyright (c) Zend Technologies
    with Zend OPcache v7.4.29, Copyright (c), by Zend Technologies

Change Default PHP Version for CLI

You can use update-alternatives command to set the default PHP version. Use this tutorial to read more details about switching PHP version for CLI and Apache.

sudo update-alternatives --config php

There are 4 choices for the alternative php (providing /usr/bin/php).

  Selection    Path             Priority   Status
------------------------------------------------------------
  0            /usr/bin/php8.1   81        auto mode
  1            /usr/bin/php5.6   56        manual mode
  2            /usr/bin/php7.2   72        manual mode
* 3            /usr/bin/php7.4   74        manual mode
  4            /usr/bin/php8.1   81        manual mode

Press  to keep the current choice[*], or type selection number: 4

The above output shows all the installed PHP versions on your system. Selection number 4 set PHP 8.1 as the default PHP version for the command line.

Uninstall PHP

If any PHP version is no more required, can be removed from the system. That will free the disk space as well as system security.

To uninstall any PHP version just type:

sudo apt remove php5.6 

Also uninstall all the modules for that version with the following command:

sudo apt remove php5.6-* 

Conclusion

This tutorial helps you to install PHP 8.1, 8.0, 7.4, 7.3, 7.2 or PHP 5.6 on Ubuntu 20.04 Linux system. Additionally provides you instructions to change default PHP version.