Path: utzoo!mnetor!tmsoft!torsqnt!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!elroy.jpl.nasa.gov!usc!cs.utexas.edu!convex!news
From: tchrist@convex.COM (Tom Christiansen)
Newsgroups: comp.lang.perl
Subject: pager pipes
Message-ID: <1991Feb16.210445.7760@convex.com>
Date: 16 Feb 91 21:04:45 GMT
Sender: news@convex.com (news access account)
Reply-To: tchrist@convex.COM (Tom Christiansen)
Organization: CONVEX Software Development, Richardson, TX
Lines: 20
Nntp-Posting-Host: pixel.convex.com

I was trying to set up an automatic pager for STDOUT, and 
it doesn't seem to work.  If I choose a different handle,
it's fine.  Any clues?

    $pager = $ENV{'PAGER'} || 'more';
    open(STDOUT, "| $pager") || die "can't reopen STDOUT to $pager: $!";
    open(STDERR, ">&PIPE") || die "dup failed: $!";
    system 'ps t';
    system 'grep nada nonesuch';
    while (<>) { print; }
    close(STDOUT) || die "close failed: $!";

Notice that I never die of a bad dup even though there is no
PIPE handle.  If you %s/STDOUT/PIPE/g and add an appropriate
select, it all works fine.  This is under both 3.044 and 4.0beta.

--tom
--
Tom Christiansen		tchrist@convex.com	convex!tchrist
 "All things are possible, but not all expedient."  (in life, UNIX, and perl)