use strict;
use warnings;

my $seperator = '/'; # Change this for a non-Unix compatible OS

my @dirs = ("some/long/dir/path");

for my $path ( @dirs ) {

    my @path = split($seperator, $path);

    my $cat_path;

    for my $dir (@path) {

        $cat_path .= $dir;

        unless ( -d $cat_path ) {

            mkdir ( $cat_path ) ||
                die "Can't mkdir '$cat_path': $!\n";

            print "mkdir: created directory `$cat_path'\n";

        }

        $cat_path .= $seperator;

    }

}