What is a Device Driver?

A device driver is software that lies between the application and the device. These device drivers provide a uniform interface to interact with the hardware. In UNIX specifically, hardware devices are accessed through device files, hence the the common linux-ism, everything is a file.

      int main(void) {
        int handle = open("/dev/fb0", O_RDONLY);
        if (handle == -1)
          perror("unable to open '/dev/fb0'");
      }
    

As seen above, the method in which you interact with a device file is the same as you would a normal file.

The Need for Device Drivers

Imagine a