[title]
Identify idle users


[description]
Identify users who are logged in but are not active.
Each logged-in user occupies a terminal that could
otherwise be used by another user.


[param idle_time]
Specifies the maximum idle time to be tolerated.
Valid values are positive integers followed by d, h, m, or s for
days, hours, minutes, or seconds.

If a user exceeds this idle time, an exception message is issued.


[param users]
A blank-separated list of user IDs for which the idle times are checked.
If the list is empty, all users are checked.


[param tty]
A blank-separated list of terminals for which idle users are identified.
Terminals are specified by their device node without the leading /dev/.
If the list is empty, all terminals are checked.
