[macOS] PHP双版本，5.6跟7.1

转过来的，原文看这里，https://www.symfony.fi/page/how-to-run-both-php-5-6-and-php-7-x-with-homebrew-on-os-x-with-php-fpm

How to run both PHP 5.6 and PHP 7.x with Homebrew on OS X with PHP-FPM

The latest iterations of PHP in the 7.x branch are great improvement over the last PHP 5 version, which is 5.6. However many applications don't support it and it will be useful to run many versions on a local environment. In my case a laptop running macOS (OS X) and using the Homebrew packet manager. This is how to run both PHP 5.6 and PHP 7.1 simultaneously.

PHP 7.0 was a large release of the popular programming language and platform powering large parts of the web. The new release of PHP brings performance improvements and new features. The PHP community goes to great lengths to make sure that the release is backwards compatible. To a large part this is true, but there are certain incompatibilities which are described in the official Migration Guide.

eZ Publish 5 is a hybrid application with both contemporary PHP as well as older code dating back to 2003. That version was an intermediary step to more to a whole new architecture. Development of new features on eZ Publish was frozen in 2014 when the team focused on the new product known as eZ Platform.

Despite not receiving new features, eZ Publish is still a valid product and will continue to be supported way until 2021. The last major version was released before PHP 7 was launched and will likely never receive (official) support for it. The new Symfony Framework powered eZ Platform is already stable with PHP 7 for development use.

This is the case not only for eZ products, but many developers working with PHP will need to keep many versions of the runtime in action for years to come.

Installing two versions of PHP with Homebrew

Developers working with PHP on OS X (El Capitan) have a number of options for installing PHP. Ranging from enabling the built in PHP to running a dedicated virtual machine for the LAMP environment. One great option is to use the Homebrew packet manager.

Homebrew is a lot like APT or Yum familiar to many Linux users, but for OS X. If you do don't have Homebrew installed yet, then head over to the homepage or the installation guide. As an added benefit to some approaches of running PHP on OS X, you can easily install PHP extensions required to run eZ using brew, such as php-imagick, php-intl, php-xsl and others.

Brew has a number of PHP versions in it's repositories. They are specified in the package names with a number, such as php56 for PHP 5.6 and php70 for PHP 7.0. The "dot releases" in PHP bring new functionalities and can brake backwards compatibility, so in the future there will be packages like php71 for PHP 7.1 in the future.

Once you've got the packet manager up and running it's time to install PHP. Let's start with installing PHP 5.6:

 brew install php56

This will take a while to run, but after that you will have the latest PHP 56 installed. Once this is done you can check that you've now got PHP 56 installed by issuing the php --version command:

janit@turska ~ -  $ php --version
PHP 5.6.18 (cli) (built: Feb  6 2016 06:53:53)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies 

However in this case we'll want to make PHP 7.0 the default version, so we'll need to issue a command to remove symlinks to the PHP files:

janit@turska ~ -  $ brew unlink php56
Unlinking /usr/local/Cellar/php56/5.6.18... 18 symlinks removed

This now removed filesystem links pointing to php56. Next we'll want to install PHP 7.0:

 brew install php70

Once this is done, verify that the default version is now PHP 7:

PHP 7.0.4 (cli) (built: Mar  9 2016 12:26:14) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies

To make it easy for us to run PHP 5.6 on the command line by creating a symlink and using it:

 ln -s /usr/local/Cellar/php56/5.6.NN/bin/php /usr/local/bin/php56

Once this is done you can use PHP 5.6 from the command line with the command php56.

Setting up multiple PHP versions using PHP-FPM

PHP is most often used to power web applications, so we'll need to link our two PHP versions to versions. PHP-FPM is a modern way of running PHP with a process manager and the FastCGI protocol. This enables high performance as well as easy switching between various versions of PHP.

Using PHP-FPM is possible with the Apache web server as well, but in this case we'll use the Nginx web server. To install Nginx with Homebrew, follow these instructions. They contain all that you need to get Nginx and PHP-FPM running on OS X.

By default PHP-FPM is configured to use ports for communication. An IP Addressand a Port together form a Socket, which allows running multiple backends with a single IP. In case of PHP-FPM the default socket used is marked in the virtual host configurations (located in /usr/local/etc/nginx/servers/) with:

fastcgi_pass 127.0.0.1:9000;

This means that FastCGI requests coming in to Nginx will be passed to a PHP process manager listening at IP 127.0.0.1 and port 9000. The port 9000 is just a default value and we can modify it by changing the configurations. We'll leave PHP 7.0 to listen in the default port, but set 5.6 to listen to port 9056.

Open up the configuration file in a text editor: /usr/local/etc/php/5.6/fpm.d/www.conf

listen = 127.0.0.1:9056

Now we've got two PHP-FPMs configured to listening in different ports (9000 and 9056), but they're not running at the moment. You'll need to both of them to processes that will start when booting up the machine. This is done using the standard Homebrew approach.

Create the directory for Launch agents (it might already exist):

mkdir -p ~/Library/LaunchAgents

Copy startup scripts to the LaunchAgents directory:

cp /usr/local/opt/php70/homebrew.mxcl.php70.plist ~/Library/LaunchAgents/
cp /usr/local/opt/php56/homebrew.mxcl.php56.plist ~/Library/LaunchAgents/

Finally launch both PHP-FPM processes - only required this time, they will start automatically on next boot up:

launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.php70.plist
launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.php56.plist

Next you'll want to create two virtual hosts for Nginx and configure them to different ports. In your eZ Platform config, for example you'll only need to switch between the two lines with comments to go from PHP 5.6 to 7.0 and back to 5.6:

# PHP 7.0
fastcgi_pass 127.0.0.1:9000;

# PHP 5.6
# fastcgi_pass 127.0.0.1:9056;

That's it, you can now switch back and forth between different PHP versions when using OS X without the overhead of running virtual machines.