Q:

Boost asio receive HTTP POST?

Is it possible for one PHP script to post data to a c++, boost asio program using HTTP?

A:

PHP is perfectly capable of communicating with other servers / programs using POST. Check out  cURL here for more details on how to do it.
Another alternative is to use FSock. Have a look at this command for establishing a connection.
Those links should get you started. If you have any trouble getting them working post back with a specific question.

