I got your point. Actually I thought I was missing something in this compare function, while calculating md5 checksum. That is why I posted that function alone. Here is the full code.

use strict;
use warnings;
use Digest::MD5;

sub compare {
  my $pre_version   =shift;
  my $new_version   =shift;
  print("previous version: $pre_version\n");
  print("new version : $new_version\n");
  my $pre = Digest::MD5->new;
  open (PRE, "$pre_version");
  $pre->addfile(*PRE);
  close(PRE);
  my $pre_digest = $pre->hexdigest;
  #print "pre digest=$pre_digest\n";

  my $new = Digest::MD5->new;
  open (NEW, "$new_version");
  $new->addfile(*NEW);
  close(NEW);
  my $new_digest = $new->hexdigest;
  #print "new digest=$new_digest\n";
  
  if ($pre_digest eq $new_digest) {
    print("Equal\n");
    return 0;
  } else {
    print("Not Equal\n");
    return 1;
  }
}

compare($oldfile_path, $newfile_path);
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Update:variable name updated from $co to $new