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Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!hanauma!stew
From: stew@hanauma.UUCP (Stewart Levin)
Newsgroups: net.unix-wizards
Subject: Re: Rumor about AT&T Validation
Message-ID: <106@hanauma.UUCP>
Date: Sat, 9-Aug-86 23:42:07 EDT
Article-I.D.: hanauma.106
Posted: Sat Aug  9 23:42:07 1986
Date-Received: Mon, 11-Aug-86 04:20:08 EDT
References: <2842@brl-smok.UUCP>
Organization: Stanford U. Geophysics
Lines: 14


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 I missed the beginning of this discussion, but for BSD Unix I never
 found any 100% sure-fire way of using fstat(2) to detect a pipe.
 The best I ever did was about 95% accuracy.  To get 100% accuracy
 under 4.1BSD I cribbed a trick from tee(1) of lseek'ing on the
 file descriptor and checking for an ESPIPE error.  4.2 broke this
 by returning EINVAL but this is fixed in 4.3, I'm told, and also
 in one of my 4.2 Bug Reports distributed on the 84.2 Usenix tape.
 Now I'm just waiting for Convex's next system release....

 			... decvax!hanauma!stew