Keyboard key pressed

Hello I created a robot model in gazebo, and also a plugin through which I can control the model. There is also a ROS application which communicates with plugin by messages. In that application, I should catch the keyboard input, send the masseges based on input, and finally, control the model. I dont know how to catch keyboard input. Is there something like "isPressed("key")" function? Ubuntu 12.04, ROS Groovy, c++ **EDIT:** Now I have another problem. Is there a way to find out that there is no key pressed? Something like timeout for *getch()* function? In the example explained in the post bellow, the *while()* loop stops on the *int c = getch();* line and waits for inupt. Thank you!