Guide to Installing Multiple Versions of PHP on Mac
Tags: php, beginners, programming, tutorial
Published: 2023-05-25 01:54:50

Installing multiple versions of PHP on your Mac is essential for web developers and designers who work with different projects that require different PHP versions. Sometimes, you may need to maintain an older version of PHP for a legacy project, while simultaneously working on a new project that requires the latest PHP version. 

Installing multiple versions of PHP gives you the flexibility to switch between different versions depending on the project's needs without conflicts. This way, you can ensure that your projects run smoothly and efficiently without any compatibility issues.

![Multiple Mac](https://static01.teamcode.com/blog/multiple_mac_38f4505a94.png)

This guide provides step-by-step instructions on how to install and set up multiple versions of PHP on a Mac without conflicts. It covers the installation of Homebrew, a package manager for macOS, and the use of Homebrew to install different versions of PHP. The guide also explains how to switch between different PHP versions, configure the PHP CLI, and set up a local web server using Apache and PHP.

By the end of this guide, you'll be able to run multiple PHP applications that require different versions of PHP on the same machine with ease.

## List of what is needed before installing multiple PHP versions on Mac
Before installing multiple PHP versions on your Mac, there are some prerequisites that must be met. Here is a list of what you need:

- Homebrew: This is a package manager for macOS that allows you to easily install and manage software packages, including PHP versions.
- Xcode Command Line Tools: These are a set of software tools that provide command-line developer tools for macOS. You can install them by running xcode-select --install in your terminal.
- Autoconf: This tool is used to generate configure scripts that are required for the installation of some PHP extensions.
- ICU4C: This is a library that provides support for Unicode and globalization. Some PHP extensions require this library to be installed.
- Libpng: This is a library used for reading and writing PNG image files. Some PHP extensions require this library to be installed.
- pkg-config: This is a tool used to retrieve information about installed libraries in the system. Some PHP extensions require this tool to be installed.

## Checking what version of PHP is currently installed
Before installing multiple versions of PHP on your Mac, it's important to check what version is already installed. To do this, open up your terminal and type in the following command:

```
php --version
```

This will display the current version of PHP that is installed on your machine. Take note of this version number as you will need it later on when installing additional versions of PHP.

## Installing Homebrew
Homebrew is a package manager for macOS that allows users to easily install and manage various software packages on their Mac. It is a command-line tool that simplifies the installation process and handles any dependencies automatically.

Homebrew is needed because it makes it easy to install software that is not included in the default macOS installation, such as different versions of PHP. It also provides a consistent installation process across different machines and helps to avoid conflicts between different software versions. Overall, Homebrew is an essential tool for macOS users who want to manage their software installations efficiently and effectively.

To install Homebrew, open your Terminal and run the following command:

```
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
```

This will install Homebrew on your Mac. Once installation is complete, you can start using Homebrew to install packages by running the brew install command followed by the package name. For example, to install PHP 7.3, you can run brew install [email protected].

## Installing additional PHP versions using Homebrew
Installing additional PHP versions on a Mac can be a bit tricky, but it's not impossible. For example, to install PHP 7.4, you can run the command brew install php@7.4. To install PHP 8.0, you can run the command brew install php@8.0. 

After installing multiple PHP versions, you can switch between them using the brew unlink and brew link commands. Keep in mind that some PHP extensions might not be compatible with certain PHP versions, so you may need to install or uninstall them accordingly.

To switch to a different PHP version, use the brew unlink and brew link commands followed by the version number:

```
brew unlink php
brew link --overwrite --force php@7.4
```

Alternatively, you can also quickly switch between them by using the Terminal app. Open the Terminal app and enter the following command:

```
$ sudo update-alternatives --config php
```

This command will list all the installed PHP versions on your machine and prompt you to choose the one you want to use. Type the number associated with the PHP version you want to switch to and hit enter. The system will then switch to the selected PHP version, and you can confirm the switch by running the following command:

```
$ php -v
```

This will display the currently active PHP version on your machine. You can repeat the same process to switch between other PHP versions as needed.

## Configuring Apache to use different PHP versions on Mac
After we have installed multiple versions of PHP on our Mac using Homebrew, we need to configure Apache to use them. We can do this by creating separate configuration files for each PHP version in Apache's configuration directory /etc/apache2/other/.

First, we need to create a new configuration file for each PHP version we want to use. We can name the files in the format php{version number}.conf, for example, php7.2.conf and php7.3.conf.

Next, we need to edit each configuration file and add the following lines of code:

```
LoadModule php{version number} /usr/local/opt/php@{version number}/lib/httpd/modules/libphp{version number}.so
AddHandler php{version number} .php
```

We need to replace {version number} with the actual version number, for example, LoadModule php7.2 /usr/local/opt/php@7.2/lib/httpd/modules/libphp7.2.so and AddHandler php7.2 .php for PHP 7.2.

After we have created and edited the configuration files, we need to restart Apache for the changes to take effect. We can do this by running the command sudo apachectl restart in the Terminal.

Now, Apache will be able to use different versions of PHP depending on the configuration file specified in each website's VirtualHost configuration.

## Resolving PHP Version Conflicts on Mac
When installing multiple versions of PHP on macOS, there is a possibility of conflicts between the different versions. This can happen if the same extension is installed in multiple versions of PHP or if there are conflicting configuration files. These conflicts can cause unexpected behavior and errors when running PHP scripts.

To resolve these conflicts, it is important to ensure that each version of PHP has its own separate configuration and extension files. Additionally, it may be necessary to adjust the PATH environment variable to ensure that the correct version of PHP is being used. Ultimately, careful attention to detail during the installation process can help avoid conflicts and ensure that each version of PHP works as intended.

## Skip the Installations with [Lightly IDE](https://www.lightly-dev.com/) for Multiple PHP Versions
Changing between different programming languages and versions can sometimes be very cumbersome. Designed specifically to speed up coding processes, Lightly IDE allows even complete novices to dive into coding with ease.

![PHP Installation](https://static01.teamcode.com/blog/php_installation_a6b8c8991e.png)

One of its standout features is its pre-built environment, which makes it easy to use regardless of your level of experience. With just a few clicks, you can quickly begin programming in Lightly IDE.

Whether you're interested in learning programming or just starting out in the field, Lightly IDE is an excellent place to begin. It provides the optimal platform for mastering programming skills and is particularly well-suited for those who are new to the discipline.

Original article: [Guide to Installing Multiple Versions of PHP on Mac](https://www.lightly-dev.com/blog/install-multiple-versions-of-php-mac/)