Thank you Monks, for your great help. I did try NetWallah's code,thanks O great Abbot. I am however getting some errors originating from the subroutine which am sharing here as you had suggested. I previously got such errors while trying different loops but avoided tinkering with the subroutine which works as it is. What should i change in the new code? Here are the exceptions am getting and the subroutine code;

The errors, the line 5852 is the last line in my CSV file
C:\MyScripts\2G3Gdistance.pl
Argument "Longitude" isn't numeric in subtraction (-) at
C:\MyScripts\2G3Gdistance.pl line 53, <COMBINED> line 5852 (#1)
Argument "Latitude" isn't numeric in multiplication (*) at
C:\MyScripts\2G3Gdistance.pl line 80, <COMBINED> line 5852 (#1)
Use of uninitialized value $lon2 in subtraction (-) at
C:\MyScripts\2G3Gdistance.pl line 53, <COMBINED> line 5852 (#2)
(W uninitialized) An undefined value was used as if it were already
defined. It was interpreted as a "" or a 0, but maybe it was a mistake.
To suppress this warning assign a defined value to your variables.
Use of uninitialized value $deg in multiplication (*) at
C:\MyScripts\2G3Gdistance.pl line 80, <COMBINED> line 5852 (#2)
Uncaught exception from user code:
Can't take sqrt of -4.44089e-016 at C:\MyScripts\2G3Gdistance.pl line 71, <COMBINED> line 5852.
main::acos(1) called at C:\MyScripts\2G3Gdistance.pl line 55
main::distance(-0.433525648, 36.968599085, -0.433525648, 36.96859909, "K") called at C:\MyVolume\Development\MyScripts\2G3Gdistance.pl line 150

The subroutine code

 my $pi = atan2(1,1) * 4;

sub distance {
    my ($lat1, $lon1, $lat2, $lon2, $unit) = @_;
    my $theta = $lon1 - $lon2;
    my $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad
+($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
  $dist  = acos($dist);
  $dist = rad2deg($dist);
  $dist = $dist * 60 * 1.1515;
  if ($unit eq "K") {
      $dist = $dist * 1.609344;
  } elsif ($unit eq "N") {
      $dist = $dist * 0.8684;
        }
    return ($dist);
}

#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:
#:::  This function get the arccos function using arctan function   ::
+:
#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:
sub acos {
    my ($rad) = @_;
    my $ret = atan2(sqrt(1 - $rad**2), $rad);
    return $ret;
}

#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:
#:::  This function converts decimal degrees to radians             ::
+:
#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:
sub deg2rad {
    my ($deg) = @_;
    return ($deg * $pi / 180);
}

#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:
#:::  This function converts radians to decimal degrees             ::
+:
#:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+:
sub rad2deg {
    my ($rad) = @_;
    return ($rad * 180 / $pi);

}

print distance(32.9697, -96.80322, 29.46786, -98.53506, "K") . " Kilom
+eters\n";
[download]