struct file_info {
  const struct input_dev *iop;	/* Input operations */
  const struct output_dev *oop;	/* Output operations */

  /* Structure used for input blocking */
  struct {
    int blocklg2;		/* Blocksize log 2 */
    size_t offset;		/* Current file offset */
    size_t length;		/* Total file length */
    uint16_t filedes;		/* File descriptor */
    uint16_t _filler;		/* Unused */
    size_t nbytes;		/* Number of bytes available in buffer */
    char *datap;		/* Current data pointer */
    char buf[MAXBLOCK];
  } i;

  /* Output file data */
  struct {
    int rows, cols;		/* Rows and columns */
  } o;

  /* FS specific data */
  void* fs;
};