If you are a Python user, you can program GPIOs with API provided by RPi.GPIO.
RPi.GPIO is a module to control Raspberry Pi GPIO channels. This package provides a class to control the GPIO on a Raspberry Pi. For examples and documents, visit http://sourceforge.net/p/raspberry-gpio-python/wiki/Home/.
Test whether RPi.GPIO is installed or not, type in python:
In Python CLI, input “import RPi.GPIO”, If no error prompts, it means RPi.GPIO is installed.
Then, type in RPi.GPIO.VERSION to check its version.
If you want to quit python CLI, type in: