[Samba] Man page for idmap_rid

[francis picabia]

I'm reading the man page for idmap_rid over and over and I can't understand
it.  I think it needs a rewrite so a normal user can understand.  Using a
practical example.

Step 1: determine the highest UID in use for your /etc/passwd file
(can we assume everyone has a passwd file?)
Step 2: I don't know...

Optionally at this point, document how to plug that into the formula

RID = ID + BASE_RID - LOW_RANGE_ID

and then show how we set the lines:

range = low - high
base_rid = INTEGER

The man page examples do not line up with any numbers practical outside of
smb.conf

Say my UID on the Linux side would never exceed 70000.  How do I configure
range and base_rid?