I needed the pcntl module for a project I’m working on in PHP. By default this module is not installed when you install PHP, so you’ll need to compile it. There is a brew package for it, but I couldn’t get it to work, and I think it’s just as simple to compile it.

First you’ll need to download the PHP source. Run php -v to get your PHP version and browse the PHP releases page for your version. In my case it was 5.3.10.

curl -o php-5.3.10.tar.gz http://us1.php.net/distributions/php-5.3.10.tar.gz
tar xzvf php-5.3.10.tar.gz
cd php-5.3.10/ext/pcntl
phpize
./configure --enable-pcntl

Some people reported that they got an error while running ./configure. I did not run into this issue, but if you do, you’ll need to specify your system architecture.

CFLAGS='-arch x86_64' CXXFLAGS='-arch x86_64' LDFLAGS='-arch x86_64' ./configure --enable-pcntl

All that’s left to do is compile, install it, and enable it.

make
make test # optional
sudo make install
sudo echo "extension=pcntl.so" >> /etc/php.ini

If you are using Apache, you will need to restart it to take affect.