fam_next_event() returns the next pending FAM
event. The function will block until an event is available which can
be checked for using fam_pending().
fam_next_event() will return an array that contains
a FAM event code in element 'code', the path of the
file this event applies to in element 'filename' and
optionally a hostname in element 'hostname'.
The possible event codes are described in detail in the
constants part of this section.