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From: Simon Wright <simon@pushface.org>
Newsgroups: comp.lang.ada
Subject: Re: Exclusive file access
Date: Fri, 28 Aug 2015 22:06:23 +0100
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Date: 2015-08-28T22:06:23+01:00
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Anh Vo <anhvofrcaus@gmail.com> writes:

> I would suggest to wrap it in a protected object. It checks for task
> id of a process opening and reading must be the same. Otherwise, the
> unidentified task will be blocked from accessing the file.

That won't help, because the OP wants to protect the file from being
opened by another *process*, not another task, and POs are for managing
access in-process.

As another data point, on OS X it seems that only the output from the
last process to close the file actually appears.

Perhaps GNAT.Lock_Files might help?