FD_SEEK

;;; Move the offset of a file descriptor.
  ;;; Note: This is similar to `lseek` in POSIX.
  (@interface func (export "fd_seek")
    (param $fd $fd)
    ;;; The number of bytes to move.
    (param $offset $filedelta)
    ;;; The base from which the offset is relative.
    (param $whence $whence)
    ;;; The new offset of the file descriptor, relative to the start of the file.
    (result $error (expected $filesize (error $errno)))
  )