A simple PHP extension built for PHP extension development students.
For a more comprehensive tutorial please check this link.
Make sure you have installed gcc, php, php-dev (These three should pull with them all the other dependencies needed).
sudo apt-get install build-essential php5 php5-dev
Run listed commands inside the directory
* phpize
* ./configure
* make
* sudo make install
* php -d extension=hello_php.so -r 'hello_php();'
Congratulations!! You have built your first PHP extension!