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From: macgy...@MCS.COM (MacGyver)
Newsgroups: comp.os.linux.development
Subject: IPC in Linux.
Date: 15 Aug 1994 13:52:12 -0500
Organization: TOS Enterprises.
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Message-ID: <32odgs$3p6@Venus.mcs.com>
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Hi there folks,

Linux is an excellent OS, by far one of the best I've seen, but what I can't
seem to find, because I don't know if it exists, is IPC tools in Linux.
There's an option in the kernel config to compile in System V IPC...this
implies that the following are supported in Linux:

	message queues -- passing/receiving messages and being able to access
				them.

	semaphores	-- if you don't know what they are, don't ask. :)
	
	shared memory	-- allow processes to share regions of memory.
	
	stream pipes	-- ala pipe() and socketpair() (I know it's got these).
	
	passing file descriptors -- ability to pass open file descriptors
					betwen processes.

Of these, I know that message queues, semaphores, and shared memory are in
the IPC package for Linux as teh linux/ipc.h header file seems to imply and
as examining the kernel source seems to verify.  Stream pipes are already
there via preexisting functions.  However, I DONT see any support for passing
file descriptors at all and it SHOULD be there.  Now, either I'm not looking
at the right place, or it doesn't yet exist.  If it doesn't exist, why not
and will it be in the future?  If not, how does one go about adding such
support.  In my opinion this is an EXTREMELY powerful tool in Unix.

While I'm on the subject, what about streams ala SVR4?  Things like putmsg()
don't seem to exist in Linux either...is it planned?  Same questions as
above...if no one's done it and it's not planned or being worked on, I'd
like to take a crack at it possibly.

Any/all responses appreciated.

HJD.