Path: utzoo!mnetor!uunet!husc6!hao!gatech!mcnc!uvaarpa!virginia!scl
From: scl@virginia.acc.virginia.edu (Steve Losen)
Newsgroups: comp.unix.questions
Subject: Re: Detecting pipe closure in shell script
Message-ID: <553@virginia.acc.virginia.edu>
Date: 18 Jan 88 15:12:38 GMT
References: <380@dlhpedg.co.uk>
Reply-To: scl@virginia.edu
Organization: University of Va., Charlottesville, VA
Lines: 33

In article <380@dlhpedg.co.uk> cl@datlog.co.uk (Charles Lambert) writes:
>I have a shell script with the following fragment in it:
>
>    | tee $TFILE | more
>
>If I quit more(1) before output from tee(1) is complete, I want to
>scrap $TFILE,  else I want to move it to another name.  I've tried

Try this in the bourne shell:

... | 
if tee $TFILE; then
	mv $TFILE newname
else
	rm $TFILE
fi | more

If you quit out of more, tee gets a SIGPIPE and a non-zero exit status,
causing the "else" arm of the conditional to be executed.  Note that in
/bin/sh you can pipe into and out of if, while, for, and case statements.

If you don't mind destroying the file "newname" when you quit out of more,
use this simpler solution:

... | (tee newname || rm newname) | more

in /bin/sh "||" and "&&" have short-circuit evaluation, so you can
conditionally execute commands based on the exit status of a previous
command.

-- 
Steve Losen     scl@virginia.edu
University of Virginia Academic Computing Center