#!/usr/bin/perl -w
use strict;
my $filename = 'regex_data.txt';

open INPUTFILE , $filename or die "Cannot Open : $filename : $!";

while ( <INPUTFILE> )
{
   chomp $_;
   print "$2\n" if ( $_ =~ /^.*(start\:)(.*)(stop\:)/gi )
}
close INPUTFILE;