use strict;
use warnings;

# for portable path and filename operations
use File::Spec;

my @paths = qw(
                /home/units/bakery/cake.pl
                /home/units/bakery/pie.pl
                /home/units/bakery/plumcake.pl
                /home/units/fruitjunction/juice.pl
                /home/units/fruitjunction/icecream.pl
                /home/units/bakery/choclate.pl
                /home/bakery/fruitjunction/not_a_bakery.pl
                /home/units/foo/bar.pl
            );

my $current_dir = '';

foreach my $path ( @paths )
{
    chomp $path;

    # retrieve the last directory in the path
    my $dir = get_dir( $path );

    # print a start label if this is the first path
    if( $current_dir eq '' )
    {
        $current_dir = uc( $dir );
        print "# $current_dir\n";
    }

    # change labels if required
    if( uc( $dir ) ne $current_dir )
    {
        print "# END $current_dir\n";
        $current_dir = uc( $dir );
        print "# $current_dir\n";
    }

    print "$path\n";
}

print "# END $current_dir\n";

sub get_dir
{
    my ( $path ) = @_;

    # extract the directory portion of the path
    my ( undef, $dirs, undef ) = File::Spec->splitpath( $path );

    # remove trailing directory separators
    $dirs = File::Spec->canonpath( $dirs );

    # split the path on directory separators
    my @dir = File::Spec->splitdir( $dirs );

    return $dir[-1];
}