Return the match for key in map mapname, or raise an
error (nis.error) if there is none.
Both should be strings, key is 8-bit clean.
Return value is an arbitary array of bytes (i.e., may contain NULLand other joys).
Note that mapname is first checked if it is an alias to another name.
XXX Describe list of all aliases? Internal for the C code, so
I'm not sure it's a good idea.
Return a dictionary mapping key to value such that
match(key, mapname)==value.
Note that both keys and values of the dictionary are arbitary
arrays of bytes.
Note that mapname is first checked if it is an alias to another name.