#!/usr/bin/perl -w
use strict;

my $previous_line = "";
my $line = "";

open (DATA, "/export/home/webadm/scripts/backup_scripts/backup_data/1stnodupe");

while (<DATA>) {
	chop;
	$line = $_;
	if ($line =~ /^\S/) { # if line starts with Non-White Space Character 
		if ($previous_line =~ /^\S/) { 	# if the previous line  also
										# starts with Non-White Space Character  	
			# then do something with your successful finding like...
			print "$previous_line\n";
		} else {
			# do something if not
		}
	}
	$previous_line = $line;
}