#!/usr/bin/perl
use strict;
use warnings;
use Symbol qw( delete_package );
                                                                                                   
eval {
  do './foo_name_space.dat';
  print "within eval: ",$foo_name_space::data,"\n" if $foo_name_space::data;
  delete_package('foo_name_space');
};
if( $@ ){
  print "Oops [$!]","\n";
}
if($foo_name_space::data){
  print "outside eval: ",$foo_name_space::data,"\n"
}else{
  print "no such namespace\n";
}