Interprocess communication on multi-user machine

Nick Maclaren nmm1 at cus.cam.ac.uk
Fri Jun 30 07:32:02 EDT 2006


In article <ldo-AFFA8C.22542230062006 at lust.ihug.co.nz>,
Lawrence D'Oliveiro <ldo at geek-central.gen.new_zealand> writes:
|> >
|> >Sockets are often accessed via special files, but are not files.
|> 
|> They are files. They are not _regular_ files.

Sigh.  Firstly, look at something like:

    http://www.opengroup.org/onlinepubs/009695399/toc.htm

Start at the entry 'socket' and work from there.

Yes, I know about UNIX-domain sockets, but even when they give the
appearance of being files, 90% of the time that is the API only,
and the underlying facility is very different.  Dammit, processes
are not files just because they happen to have a /proc entry under
many systems!

|> >They may also be accessed by port numbers, for example.
|> 
|> UNIX sockets have no ports.

You mean "UNIX-domain", not "UNIX".  So?  Many sockets do.  Internet-
domain ones always do.

|> I wasn't talking about FIFOs. Even if I was, they _are_ still subject to 
|> regular file permissions (on Linux, at least).

They aren't on most Unices - Linux is not UNIX, you know :-)


I shall not respond further on this.


Regards,
Nick Maclaren.



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