Brew's PHP 7.1, 7.2 and 7.3 all have INTL enabled by default.
Most probably, you're just using your Mac OS' bundles version of PHP.
Run
ls -l $(which php)
to find out where the current PHP binary is located and whether it is symlinked to a Brew installation or not. In my case, for example:
lrwxr-xr-x 1 27 May 23 16:30 /usr/local/bin/php -> ../Cellar/php/7.3.5/bin/php
Meaning that my php is linked to Brew's 7.3.5 version.
If you are NOT using Brew's PHP, you'll see something like
-rwxr-xr-x 1 11169664 Mar 21 07:09 /usr/bin/php
Installing PHP through Brew
Find out whether you've already installed PHP:
brew list | grep php
If there is any output, and your version of PHP is present, go to step 2, or use step 1 to update PHP to the latest version.
1. Install Homebrew's PHP
brew install php@7.3
(or 7.2, 7.1). If Brew complains about not being able to find a formula, you might have messed with taps. Instead of php@7.3, you could try to supply the full path to the current php formula:
brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/master/Formula/php.rb
Still not working, check whether you are running a recent version of Homebrew brew --version.
Homebrew 2.1.3-31-geaf2370
Homebrew/homebrew-core (git revision fd1ef; last commit 2019-05-25)
Homebrew/homebrew-cask (git revision 16d50; last commit 2019-05-26)
2. Link Homebrew's PHP
Now, to have php 'in your path', there are two options.
a) Either homebrew's version must be linked from its install location (/usr/local/bin/Cellar/php....) to a directory in your path (e.g., /usr/local/bin). To do this, run:
brew link --force php@7.3
If you are not able to link, this is typically caused by set permissions or System Integrity Protection. In the first case, try sudo chown "$USER":admin /usr/local/bin/php.
b) Or, add the /usr/local/opt/php@7.3 directory (opt-prefix) to your $PATH variable. E.g., for Bash:
echo 'export PATH="/usr/local/opt/php@7.3/bin:/usr/local/opt/php@7.3/sbin:$PATH"' >> ~/.bash_profile
source ~/.bash_profile
3. Validate installation
ls -l $(which php)
should show that php is linked to a Homebrew PHP installation in /usr/local/bin/Cellar.
php -v
should show the recently installed version of PHP. Try to restart your terminal if that's not the case.
php -i | grep -i intl
should show some information about the current install of intl.
If you're using webservers and/or PHP FPM, this is the time to restart those services. (Or restart your system, if you don't know how to do that and cannot figure out).
Possible issues
If you still get warnings about missing extensions (Unable to load dynamic library, etc.), then your php.ini is messed up.
Find the current location of php's ini
$ php -i | grep \.ini
Configuration File (php.ini) Path => /usr/local/etc/php/7.3
Loaded Configuration File => /usr/local/etc/php/7.3/php.ini
Scan this dir for additional .ini files => /usr/local/etc/php/7.3/conf.d
Additional .ini files parsed => /usr/local/etc/php/7.3/conf.d/ext-opcache.ini
....
Edit /usr/local/etc/php/7.3/php.ini and find the offending extension load (e.g., extension="myext.so"). Comment out those that cannot be found.
Homebrew permissions
Some argue that it's a good idea to chown /usr/local.
sudo chown -R "$USER":admin /usr/local
This will make installing things here, by hand and through Homebrew, a lot easier, but also a bit less secure too, since non-root processes are now allowed to write here too.
Your web-application is using a different version of PHP.
Make sure that it doesn't... The configuration of this depends on the used webserver. A first step would be to output the current PHP configuration in your web-application with <?php phpinfo();.
This explains steps for Apache.
Another way to get a webserver + PHP stack running quicly is using Laravel Valet.
Installing additional extensions
To install additional PHP extensions, use PEAR.
pear -V
should output the current PEAR and PHP version.
PEAR Version: 1.10.9
PHP Version: 7.3.5
Zend Engine Version: 3.3.5
Now, to install an extension, for example, PHP's yaml extension:
pear install yaml
