In article <5b0ti3F2qp1iiU1@mid.uni-berlin.de>,
jt@toerring.de (Jens Thoms Toerring) wrote:

> Steven Woody <narkewoody@gmail.com> wrote: 
>
> I don't see any reason at the moment why you shouldn't be able to
> open the same serial port from one process in read mode and from
> another in write mode. As far as I can see there shouldn't be any
> difference to one process opening in read/write mode. On the other
> hand I haven't tried it myself...

But the reader process won't normally get what the writer process wrote.
When you write to a serial port, it sends to the device at the other end
of the serial cable.  When you read from a serial port you get what the
device sent.

So unless the device is echoing everything it received back (which is
what a loopback cable does), the serial port can't be used to
communicate directly between processes.

--
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
*** PLEASE don't copy me on replies, I'll read them in the group ***

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