#include <stdio.h>

int main() {
  FILE *fp;
  char line[80];

  /* Open our device to read*/
  fp = fopen("/dev/virtual_device", "r");

  if(fp==NULL) {
    printf("Error: can't access virtual device\n");
    return 1;
  }
  
  /* read a line from it */
  fgets(line,80,fp);
  printf("%s\n", line);                       

  /* close the device */
  fclose(fp);
  
  /* Open our device to write*/
  fp = fopen("/dev/virtual_device", "w");

  if(fp==NULL) {
    printf("Error: can't access virtual device\n");
    return 1;
  }
  
  /* try to actually write something */
  fprintf(fp,"Testing ............. !!!!!!!!!!!!");

  /* close the device */
  fclose(fp);

  return 0;
}