#!/usr/bin/perl

use warnings;
use strict;

open(my $outfile,">","UpdatedFile") || die " \n";
open (my $infile,"<","RawFile") or die "Cannot open: $!\n";

while(<$infile>){
        chomp;
        my @fieldsvar =split(/\t/);
        foreach (@fieldsvar) {
          if ($_ eq ""){$_="Missing"}
        }
        print $outfile "@fieldsvar\n";
};