{
    package packageA
    my %hash_map = (
      "name" => "path",
      ......,
    );
    sub new{
      ........
    }
    sub get{
      my $class = shift;
      my $componentName = @_;
	
      my $path = $component_path{$componentName};
#error:
#Use of uninitialized value $path in pattern match (m//) at below...
		if($path =~ m/HKEY_LOCAL_MACHINE/){
			dosomthing;		  
		}
    }
}