How to send a keystroke or a mouse event to another running process in Ubuntu? I want to write a C program that reads data from the USB port sent by AVR Micro Controller board continuously.In response to that it checks the data received and sends a command to another process running on the computer? Example,when the program reads 101 from the USB port it sends left mouse button down to the VLC media player window that is currently running? Can anybody explain the whole process in detail?? I would be very thankful...