#!/usr/bin/perl
use strict;
use warnings;

my $cmd = "/usr/sbin/ntpq -p";
my @ntpout = grep (/^\*/, `$cmd`);  # grep line starting with * sign and put into an array

my $file = 'offset.txt';

open (my $fh, '>' $file) or die "Could not open file '$file' $!";
print $fh "@ntpout\n">
close $fh;    # Written array output into file

my $offset = `cat offset.txt | awk '{print $9}'`; # here expecting 9th cloumn value in variable $offset

print "$offset \n";