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From: mouse@thunder.mcrcim.mcgill.edu (der Mouse)
Subject: Re: How do I tell if STDIN is a PIPE?
Message-ID: <1991Jun7.145414.24293@thunder.mcrcim.mcgill.edu>
Organization: McGill Research Centre for Intelligent Machines
References: <1991May26.172328.713@arizona.edu> <23190@shlump.lkg.dec.com>
Distribution: world,local
Date: Fri, 7 Jun 91 14:54:14 GMT
Lines: 25

In article <23190@shlump.lkg.dec.com>, lan_csse@netrix.nac.dec.com (CSSE LAN Test Account) writes:
> In article <653@eskimo.celestial.com> nanook@eskimo.celestial.com (Robert Dinse) writes:
>> if(s.st_mode & S_IFIFO)
> On this machine (Ultrix 4.1) and on the next one over (Ultrix 3.1),
> this code says "Stdin is not a pipe.\n". On investigation, the status
> struct was *entirely* filled with null bytes.

mtXinu 4.3+NFS stat(2) manpage:

.SH BUGS
Applying
.I 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.

It seems other systems (like your Ultrices and probably vanilla 4.3) do
this as well.

					der Mouse

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