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

[Robert Elz <kre%munnari.OZ.AU@localhost>]

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

From: Robert Elz <kre%munnari.OZ.AU@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: bin/54564: cp of a fifo yields an empty file
Date: Tue, 24 Sep 2019 00:18:00 +0700

     Date:        Mon, 23 Sep 2019 14:40:00 +0000 (UTC)
     From:        jschauma%netmeister.org@localhost
     Message-ID:  <20190923144000.CE16B7A202%mollari.NetBSD.org@localhost>
 
 copy_file() in /bin/cp first stat's the source, and if it is empty
 (size 0), simply makes the output file, and exits.  It never attempts
 any kind of read - though it much prefers to use mmap() over read()
 preferring read() only if the file is too big to mmap() sanely.
 
 It should probably be smarter about the type of file it is copying,
 and simply read()/write() to EOF on the read() for anything that
 isn't a regular file.
 
 kre