GETEVENTCOUNTER
This function return one status line with the current values of the
event counters. The event counters are useful to avoid polling by
delaying a poll until something has changed. The values are decimal
numbers in the range 0
to UINT_MAX
and wrapping around to
0. The actual values should not be relied upon; they shall only be used
to detect a change.
The currently defined counters are are:
ANY
KEY
CARD