[Boston.pm] script works ok on command line, hangs when run from shell script

This may very well be a unix thing, not a perl thing,
but I'm not a unix expert, so I'm not sure.

I have a tool I run in a shell script.

-------------------------------------------------------
#!/bin/csh

tool -options -nobuffer
-------------------------------------------------------

The -nobuffer is trying to get it to flush its output
to STDOUT, rather than buffer it a block at a time.

It prints out extremely long lines to STDOUT.

So, I made a perl script that takes in stdout,
does a s/// on the input, and sends it back to stdout.

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#!/opt/perl_5.8.8/bin/perl
use warnings;
use strict;
# turn off stdout buffering... hopefully.
$|=1;

if(scalar(@ARGV)==0){
	$piped=1;
} elsif(scalar(@ARGV)==1){
	$piped=0;
	my $inname = $ARGV[0];
	$outname = $inname.'.short.log';
}

my $content;

while(<>){
	my $line = $_;
	my $orig=$line;
	if($line=~s///){
		if($line=~s///}){
		}
	}

	if($piped){
		print $line;
	} else {
		$content .= $line;
	}
}

if($piped==0){
	open(my $outh, '>'.$outname) or
                die "ERROR: unable to open for write '$outname'";
	print $outh $content;
	close($outh);
}
-------------------------------------------------------

So, when I run it on the command line, it works fine:

prompt> tool -options -nobuffer | filter.pl

The output looks exactly like I want.
And when I hit <control>-C, it exits immediately.

But when I put it into the shell script:

-------------------------------------------------------
#!/bin/csh

tool -options -nobuffer | filter.pl
-------------------------------------------------------

It looks fine, but it hangs when I hit <control>-C.

I don't know if this is a side effect of the way the shell script works.
If its a side effect of the perl script.
if its something to do with flushing STDOUT.

If I hit control-c when its clearly not in the regular expression area,
I can sometimes get it to exit immediately. But once the tool reaches
a certain point, every line is going through the regular expression,
and at that point, control-C seems to stop execution, but refuses
to give me a prompt back.

I don't think I've ever written a perl script that takes a pipe input
so I don't know if there is some side effect about pipes, perl, and
control-C maybe?

Any ideas?

Greg London