FD_FDSTAT_GET

;;; Get the attributes of a file descriptor.
  ;;; Note: This returns similar flags to `fcntl(fd, F_GETFL)` in POSIX, as well as additional fields.
  (@interface func (export "fd_fdstat_get")
    (param $fd $fd)
    ;;; The buffer where the file descriptor's attributes are stored.
    (result $error (expected $fdstat (error $errno)))
  )