Path: utzoo!attcan!uunet!mcvax!hp4nl!botter!star.cs.vu.nl!maart
From: maart@cs.vu.nl (Maarten Litmaath)
Newsgroups: comp.unix.questions
Subject: Re: 'peeking' in on a pipe
Message-ID: <2847@kappl.cs.vu.nl>
Date: 8 Jul 89 09:19:58 GMT
References: <6.24B47361@seaeast.WA.COM>
Organization: V.U. Informatica, Amsterdam, the Netherlands
Lines: 25

Tim.Evans@f112.n138.z1.WA.COM (Tim Evans) writes:
\I would like to 'peek' in on a pipe, to see what is happening in it, WHILE
\IT EXECUTES. I tried something like this, but no luck:
\ 
\  some_stuff | tee `tty` | more_stuff
\ 
\I would like to do this while it executes, not tee to a file and see it
\later. Does anyone have any ideas how this might be done?

This is funny!
Did you ever ls(1) your directory after issuing the pipeline command above?
I bet you'd find three files you didn't expect:

	a
	not
	tty

stdin of the `tty` command is a pipe, hence the message "not a tty", so
tee(1) sees 3 `filenames' to duplicate stdout to!
Solution:

	foobie | tee /dev/tty | bletch
-- 
   "... a lap-top Cray-2 with builtin    |Maarten Litmaath @ VU Amsterdam:
cold fusion power supply"  (Colin Dente) |maart@cs.vu.nl, mcvax!botter!maart