add: if (CheckCameraOpen() == FALSE) return FALSE;
context: gboolean get_clock(GtkWidget* widget,		   GdkEvent* event,		   gpointer data) {  unsigned short int buffer[7];  if (ControlMessageRead(0xcc00, (char*)buffer, 14, TIMEOUT) == FALSE) {    Log("get_clock failed");    return FALSE;  }  printf("Camera time\n");  printf("Year: %d\n", buffer[0]);  printf("Month: %d\n", buffer[1]);  printf("Day: %d\n", buffer[2]);  printf("%02d:%02d:%02d\n", buffer[3], buffer[4], buffer[5]);  printf("Day of week: %02d\n", buffer[6]);  return TRUE;}