From: dave@horsfall.org (Dave Horsfall)
Subject: [TUHS] fstat(2) on pipes?
Date: Mon, 15 Aug 2016 10:41:02 +1000 (EST) [thread overview]
Message-ID: <alpine.BSF.2.11.1608151037130.10703@aneurin.horsfall.org> (raw)
In-Reply-To: <20160815001140.GA16138@minnie.tuhs.org>
On Mon, 15 Aug 2016, Warren Toomey wrote:
> All, sorry this is slightly off-topic. I'm trying to find out what
> fstat(2) returns when the file descriptor is a pipe. The POSIX/Open
> Group documentation doesn't really specify what should be returned. Does
> anybody have any pointers?
I always thought it was undefined, but my Mac says:
BUGS
Applying fstat to a socket (and thus to a pipe) returns a zero'd buffer,
except for the blocksize field, and a unique device and inode number.
And my FreeBSD box is the same; I haven't checked my Penguins.
> P.S. Why? xv6 has fstat() but returns an error if the file descriptor
> isn't associated with an i-node. I'm trying to work out if/how to fix
> it.
Probably not much use to you, but back in Ed6 I did modify it to return
the amount of data in the pipe.
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."
next prev parent reply other threads:[~2016-08-15 0:41 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-15 0:11 Warren Toomey
2016-08-15 0:41 ` Dave Horsfall [this message]
2016-08-15 0:54 ` Warren Toomey
2016-08-15 17:53 ` Clem Cole
2016-08-15 0:27 Noel Chiappa
2016-08-15 0:59 ` Warren Toomey
2016-08-15 14:04 Noel Chiappa
2016-08-15 15:14 ` Random832
2016-08-15 16:56 ` Michael Kjörling
2016-08-15 17:47 Norman Wilson
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