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 Wed, 11 Mar 2020 13:48:09 -0700 (PDT)
To: cygwin AT cygwin DOT com
Subject: Setting termios VMIN > 0 and VTIME > 0 on non blocking file
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Date: Wed, 11 Mar 2020 21:48:05 +0100
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Hello all,

opening a file (serial port) with O_NONBLOCK and subsequently setting 
termios VMIN and VTIME > 0 makes read() never ever return any data 
(returns EAGAIN indefinitely).

Don't ask my why one would want to do something like this but apparently 
the "screen" program think this is a good way of doing things...

Nevertheless not returning any data ever seems wrong.

Any insight on how it is supposed to work is welcome.

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