How to install PHP 8.1 on Debian 11

In this tutorial, I am going to show you how to install the current stable release version of PHP 8.1 on Debian 11.

PHP is a general-purpose scripting language suitable for web development. Most websites out there are programmed using PHP language because it is:

• Fast – PHP is fast because it runs on its own memory space. Also PHP has Zend engine that parses PHP code and turns it into opcodes which are then interpreted.
• Flexible – PHP is flexible because it allows to almost all databases. MySQL being the de-facto database to connect to because it is open source.
• Free and open source
• PHP is forgiving – Why do we say PHP is forgiving? It is forgiving meaning its learning it is not so hard therefore suitable to almost all programmers starting out.
• PHP supports major communication protocols i.e LDAP, IMAP, POP3.

Prerequisites for Installing PHP 8.1

• Before you can use PHP you must have web server installed. Apache web server is the most widely used with PHP.
• Database must be there for PHP to run. It works well on all databases such Oracle, MySQL, PostgreSQL.
• PHP parser must be there. What is PHP parser if you can ask? PHP Parser is a library that takes a source code written in PHP, passes it through a lexical analyzer and creates its respective syntax tree.

PHP 8.1 is a major update release version. It contains many new features and optimizations e.g

• It introduced Enumerations feature. Enumerations or Enum feature allow a developer to define a custom type that is limited to one of the discrete number of possible values. This is helpful while defining domain model.
• Improvement of RFC readonly property version 2. This prevents modification of the property after initialization.
• Introduction of RFC fibers call action. This seeks to eliminate synchronous and asychronous function call by allowing functions to become interruptible without affecting the entire fuction.
• Introduction of a non return type. This indicates that a function either exits, throws an exception or doesn’t terminate.
• Introduction of first class collable actions.
• Introduction of fsync and fdatasync functions
• Introduction of array_is_list functions
• Introduction of explicit octal numeral notation

Related Articles

• How to install PHP 8.1 on CentOS 8/RHEL 8
• How to install PHP 8.1 on Ubuntu 21.04
• How to Install PHP 8 on Ubuntu 21.04
• How to install PHP 8.1 on Ubuntu 21.10
• How to install PHP 8.1 on Ubuntu 20.04

Installing PHP 8.1 on Debian 11

1. Run system updates

To begin with let’s update system repositories in order to make them up to date.

$ sudo apt update && apt upgrade -y

2. Install Php dependencies

For PHP in Debian, we need to install some dependencies into our system. We will install the following dependencies.

$ sudo apt install apt-transport-https lsb-release ca-certificates curl

# output 
Building dependency tree... Done
Reading state information... Done
apt-transport-https is already the newest version (2.2.4).
ca-certificates is already the newest version (20210119).
curl is already the newest version (7.74.0-1.3+deb11u1).
lsb-release is already the newest version (11.1.0).
lsb-release set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

3. Download Sury PPA

Lets now download PPA to be used to install PHP 8.1

$ sudo wget -O /etc/apt/trusted.gpg.d/php.gpg https://packages.sury.org/php/apt.gpg

4. Create PHP file directory

Create a PHP file directory where all PHP files will be located.

$ sudo sh -c 'echo "deb https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list'

We need to run system updates again so that changes will take effect immediately

$ sudo apt update 

5. Install PHP 8.1 on Debian 11

Now we can install PHP 8.1 on Debian with the following command;

$ sudo apt install php8.1

# output
The following additional packages will be installed:
  apache2 apache2-bin apache2-data apache2-utils bzip2 libapache2-mod-php8.1 libapr1 libaprutil1 libaprutil1-dbd-sqlite3
  libaprutil1-ldap libgdbm-compat4 libjansson4 liblua5.3-0 libperl5.32 libsodium23 mailcap mime-support perl
  perl-modules-5.32 php-common php8.1-cli php8.1-common php8.1-opcache php8.1-readline ssl-cert
Suggested packages:
  apache2-doc apache2-suexec-pristine | apache2-suexec-custom www-browser bzip2-doc php-pear perl-doc
  libterm-readline-gnu-perl | libterm-readline-perl-perl make libtap-harness-archive-perl
The following NEW packages will be installed:
  apache2 apache2-bin apache2-data apache2-utils bzip2 libapache2-mod-php8.1 libapr1 libaprutil1 libaprutil1-dbd-sqlite3
  libaprutil1-ldap libgdbm-compat4 libjansson4 liblua5.3-0 libperl5.32 libsodium23 mailcap mime-support perl
  perl-modules-5.32 php-common php8.1 php8.1-cli php8.1-common php8.1-opcache php8.1-readline ssl-cert
0 upgraded, 26 newly installed, 0 to remove and 0 not upgraded.
Need to get 14.3 MB of archives.
After this operation, 77.2 MB of additional disk space will be used.
Do you want to continue? [Y/n] 

Lets check the version of installed PHP now.

$ php --version
PHP 8.1.2 (cli) (built: Jan 27 2022 12:22:31) (NTS)
Copyright (c) The PHP Group
Zend Engine v4.1.2, Copyright (c) Zend Technologies
    with Zend OPcache v8.1.2, Copyright (c), by Zend Technologies

Conclusion

We have learned how to install PHP 8.1 on Debian 11, now you can proceed to write your programs using this awesome language. Consult PHP documentation in case you experience any difficulty. I hope you have learned something new today.