This function checks whether the specified timer exists and whether it is enabled.

You can pass either a timer number or name. If the timer does not exist, this function returns undef, so you can distinguish the case of a non-existant timer from a disabled one.

If the timer exists, then the function returns 0 or 1 depending on whether it is enabled or not. If you pass a name, and there are several timers with the same name, it returns a list with one value for each timer with that name, and each value is 0 or 1 depending on the state of the timer.