taken from: https://www.zend.com/building-and-installing-php-extension

Building and Installing the opaque extension

This extension skeleton can be compiled without any changes. The first “phpize” command is a part of the PHP build we created in the first step. (It should still be in the PATH.) 

$ phpize
$ ./configure
$ make
$ make install

These commands should build our shared extension “opaque.so” and copy it into appropriate directory of our PHP installation. To load it, we need to add a line into our custom php.ini 

$ vi ~/php-bin/DEBUG/etc/php.ini

Add the following line:

extension=opaque.so

 Check that extension is loaded and works. “php -m” command prints the list of loaded extensions: 

$ php -m | grep opaque
opaque
