Date: Fri, 03 Apr 1998 07:56:49 -0500 From: David Collier-Brown <davecb@Canada.Sun.COM> To: Jeremy Allison <jallison@whistle.com> Subject: Re: Mapping of RIDs to uid_t and gid_t
Jean-Francois Micouleau wrote:
> I'm still not convince by this idea. I know several sites (like where I
> worked in a previous life) where the uid are allocated in blocks to make
> some delegations to other sysadmin.
This block-allocation is very common at at least
York University and several large commercial sites,
so groups can cooperate on generating unique userids.
This means that the high 4 bits can be taken (although
most people avoid setting bit 31 (:-))
Therefor ((uid+1000) & 28bits) may cause loss of
significant digits. **May**! It's probabilistic...
Are the group and machine ID's randomly distributed, or are
they individually counted up from 0? I'm having a half-baked
thought (;-))
--dave
-- David Collier-Brown, | Always do right. This will gratify some people 185 Ellerslie Ave., | and astonish the rest. -- Mark Twain Willowdale, Ontario | davecb@hobbes.ss.org, canada.sun.com M2N 1Y3. 416-223-8968 | http://java.science.yorku.ca/~davecb