one (<constant>NULL</constant> terminated) with the session
identifiers of the sessions and one with the user identifiers of
the Unix users the sessions belong to. An additional parameter may
- be used to return the number of entries in the latter array. The
- two arrays and the latter parameter may be passed as
+ be used to return the number of entries in the latter array. This
+ value is the same the return value, if the latter is nonnegative.
+ The two arrays and the last parameter may be passed as
<constant>NULL</constant> in case these values need not to be
determined. The arrays and the strings referenced by them need to
be freed with the libc