Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!uunet!snorkelwacker!tut.cis.ohio-state.edu!oz.cis.ohio-state.edu!jgreely
From: jgreely@oz.cis.ohio-state.edu (J Greely)
Newsgroups: comp.lang.perl
Subject: Re: formats inside an eval
Message-ID: <JGREELY.90Mar21050134@oz.cis.ohio-state.edu>
Date: 21 Mar 90 10:01:34 GMT
References: <1990Mar21.073635.25523@agate.berkeley.edu>
Sender: usenet_news@tut.cis.ohio-state.edu
Reply-To: J Greely <jgreely@cis.ohio-state.edu>
Organization: Ohio State University Computer and Information Science
Lines: 32
In-reply-to: raymond@sunkist.berkeley.edu's message of 21 Mar 90 07:36:35 GMT

In article <1990Mar21.073635.25523@agate.berkeley.edu>
 raymond@sunkist.berkeley.edu (Raymond Chen) writes:
>Now everybody uses eval for dynamic variable settings and subroutines,
>so I figured, hey, why not dynamic formats?

Larry will probably explain this one in greater detail, but the short
version is that it just doesn't work.  Note that you can use 'do' to
accomplish what you want:

&feval(<<'EOF');
format=
@||
$foo
.
EOF
$foo="X";
write;

sub feval {
	local($format,$tempfile) = (@_,"/tmp/feval.$$");
	open(tempfile,">$tempfile") || die "$tempfile: $!\n";
	print tempfile $format;
	close(tempfile);
	do $tempfile;
	die "feval: $@" if $@;
	unlink($tempfile);
}

  Now all we need is an easy way to capture the output of a write.
Maybe a companion named "swrite"?
--
J Greely (jgreely@cis.ohio-state.edu; osu-cis!jgreely)