Thank you Ikegami!

Since I am using Active Perl (Win32), IPC::Run did not show up in my package manager. I managed to use IPC::Run3 for the same. Thanks so much for the help. By the way the reason for all this is that dbms_output.put_line adds an extra LF at the end. I needed to strip it out. So the final code looks like this:

use strict;
use warnings;

use IPC::Run3;

my @cmd = qw( sqlplus.exe -s scott/tiger@butthead );

my $in = <<'__END_OF_SQL__';
set echo off
set lines 1000
set trims on
set serverout on size 999999
set feed off
exec dbms_output.put_line('Hello There');
exit;
__END_OF_SQL__

run3 \@cmd, \$in, \my $out;

print $out;
[download]

Thanks again everybody!

Ash