Whether your application needs fast access or specialized access from GPIO, a C/C++ program is the most convenient way to go. Python programs likewise can have direct access with the help of a module.
This chapter looks at how to access the GPIO ports directly from within a program, starting with the unfinished business of using the uevent file, to detect input GPIO changes with the help of interrupts behind the scenes.
The previous chapter introduced the uevents pseudo file that the GPIO driver provides. There it was explained that you needed to use one of the system calls poll(2) ...