Re: bin/54564: cp of a fifo yields an empty file

[Jan Schaumann <jschauma%netmeister.org@localhost>]

The following reply was made to PR bin/54564; it has been noted by GNATS.

From: Jan Schaumann <jschauma%netmeister.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/54564: cp of a fifo yields an empty file
Date: Mon, 23 Sep 2019 13:26:54 -0400

 Robert Elz <kre%munnari.OZ.AU@localhost> wrote:
   
 >  copy_file() in /bin/cp first stat's the source, and if it is empty
 >  (size 0), simply makes the output file, and exits.
 
 Hmm, but it still blocks until data appears in the
 fifo, doesn't it?
 
 If cp(1) just creates an empty file and never reads,
 how come it blocks?