package Log;

my $singleton;

sub new{

    my ($class,$logpath) = @_;

    unless ( ref $singleton eq 'Log' ) {
        $singleton = {};
        bless( $singleton, $class );
        $singleton->create_path($logpath);
    }

    return $singleton; 
}

sub create_path{

    my ($self,$logpath) = @_;
    my $logfile = $logpath . 'yyyymmdd' . '.txt';

    $self->{'log'} = $logfile;

    return;
}

sub get_log_instance {
    $singleton ||= (shift)->new();
}

sub log {

    my $self  = shift;
    my $error_msg   = shift;
    my $logfile = $self->{'log'};
    my $handle;

    open ( $handle, '>>', $logfile ) or die "Can't open $logfile: $!";

        print {$handle} "ERROR: $error_msg\n";

    close $handle;

    return;

}

1;




package DoStuff;
use Log;

sub new {

    my $class   = shift;
    my $log_obj = Log->get_log_instance(); 

    my $self = bless {}, $class;
    # Store log object. Is this OK to do?
    $self->{'log_obj'} = $log_obj; 

    return $self;
}

sub get_log_obj {
    my $self = shift;
    return $self->{'_log_obj'};
}

sub do_something {
    my $self = shift;
    .....
# Get log object and pass error msg to it's log sub routine
    $self->get_log_obj()->log('Error Error Error'); 
# Do some logging
    .....
    return;
}

1;