Date: Wed, 18 Aug 1999 14:33:39 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To: David Christensen <dchrist AT dnai DOT com>
cc: djgpp AT delorie DOT com
Subject: Re: djgpp, Win98, Perl, and serial port
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On Sun, 15 Aug 1999, David Christensen wrote:

> >Btw, why did you need O_EXCL?
> 
> I've done C/C++ serial stuff under Win32, and the API docs recommend opening
> the serial port in exclusive mode  to avoid the confusion of two processes/
> threads trying to use one port at the same time.  I just assumed that the
> same principal applied to DOS.  Am I missing something here?

AFAIK, O_EXCL doesn't have any effect on character devices, only on disk 
files.  If you want to deny other processes the access to COM1, you 
should use SH_DENYALL, not O_EXCL.

The Win32 API might behave differently.

> BTW Perl -V indicates "djgpp v2 port (perl5004) by Laszlo Molnar, 1997".  Do
> you know which newsgroup(s) he Laszlo hangs out on?

If Laszlo doesn't reply to this thread, try djgpp-workers AT delorie DOT com.