$ORIGINAL = 123 ;

  my %original_entries = Reset::scan_pack_entries('main') ;
  
  $NEW = 456 ;
  print ">> $ORIGINAL # $NEW\n" ;
  
  Reset::clean_pack_news('main' , %original_entries) ;

  print ">> $ORIGINAL # $NEW\n" ;

package Reset ;

sub scan_pack_entries {
  my ( $packname ) = @_ ;
  
  $packname .= '::' unless $packname =~ /::$/ ;
  no strict "refs" ;
  my $package = *{$packname}{HASH} ;
  return unless defined $package ;
  
  no warnings ;
  local $^W = 0 ;
  
  my @entries ;

  my $fullname ;
  foreach my $symb ( keys %$package ) {
    $fullname = "$packname$symb" ;
    if ( $symb !~ /::$/ && $symb !~ /[^\w:]/ && $symb !~ /^[1-9\.]/ &&
+ $symb !~ /^[0-9]+$/ ) {
      eval {
        if (defined &$fullname) { push(@entries , "\&$fullname") ;}
        if (*{$fullname}{IO}) { push(@entries , "\*$fullname") ;}
        if (defined *{$fullname}{ARRAY}) { push(@entries , "\@$fullnam
+e") ;}
        if (defined *{$fullname}{HASH}) { push(@entries , "\%$fullname
+") ;}
        if (defined $$fullname) { push(@entries , "\$$fullname") ;}
      };
    }
  }

  return map { $_ => 1 } @entries ;
}

sub clean_pack_news {
  my ( $packname , %skip_entries ) = @_ ;
  
  $packname .= '::' unless $packname =~ /::$/ ;
  no strict "refs" ;
  my $package = *{$packname}{HASH} ;
  return unless defined $package ;
  
  local(*NULL) ;
  my $tmp_sub = sub{} ;
  
  no warnings ;
  local $^W = 0 ;

  my $fullname ;
  foreach my $symb ( keys %$package ) {
    $fullname = "$packname$symb" ;
    if ( $symb !~ /::$/ && $symb !~ /[^\w:]/ && $symb !~ /^[1-9\.]/ &&
+ $symb !~ /^[0-9]+$/ ) {
      
      eval {
        if ( !$skip_entries{"\&$fullname"} && defined &$fullname) {
          #print "CLS>> \&$fullname\n" ;
          if (my $p = prototype $fullname) { *{$fullname} = eval "sub 
+($p) {}" ;}
          else                             { *{$fullname} = $tmp_sub ;
+}
          undef &$fullname ;
        }

        if ( !$skip_entries{"\*$fullname"} ) {
          #print "CLS>> \*$fullname # ". $skip_entries{"\*$fullname"} 
+ ."\n" ;
          untie *{$fullname} if tied *{$fullname} ;
          #if (*{$fullname}{IO}) { close $fullname ;}
        }
        
        if ( !$skip_entries{"\@$fullname"} && defined *{$fullname}{ARR
+AY}) {
          #print "CLS>> \@$fullname\n" ;
          untie @$fullname if tied @$fullname ;
          undef @$fullname ;
        }

        if ( !$skip_entries{"\%$fullname"} && defined *{$fullname}{HAS
+H}) {
          #print "CLS>> \%$fullname\n" ;
          untie %$fullname if tied %$fullname ;
          undef %$fullname ;
        }
        
        if ( !$skip_entries{"\$$fullname"} ) {
          #print "CLS>> \$$fullname\n" ;
          untie $$fullname if tied $$fullname ;
          undef $$fullname ;

        }
      };
    }
  }
  
}
[download]

>> 123 # 456
>> 123 #
[download]