IPC facilities

[Dominick Samperi]

I've used the System V IPC facilities (shared memory and semaphores) on
an AT&T 3B2, and on an AT-compatible running Microport's UNIX, but had
some difficulty porting the programs to SCO Xenix. In the Xenix environment
a parent process can create a shared memory segment, and attach it, but
a forked child process gets an "invalid argument" error when it tries to
attach the same segment. The child process does indeed use the same segment
identifier that the parent did. (I'm using the AT&T-type IPC calls under
Xenix, not the native Xenix ones.)

Has anyone used the SCO Xenix IPC facilities? More generally, what kind
of applications have the IPC facilities (on any System V machine) been
used for? I haven't seen any applications programs that use them.
-- 
Dominick Samperi, Manhattan College, NYC
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