use strict;
use warnings;
use Cwd;
use Getopt::Long;
use File::Spec;   # this will automatically load OS-appropriate functions

# ... [snip] ...

# Get the current working directory
my $home_dir = getcwd;

# Change to the test directory
chdir($testdir) or die "$0: chdir $testdir: $!";

# Set up test dirs if they do not exist
for my $t ( qw/test test1/ ) {
    mkdir $t or die "mkdir ". File::Spec->catfile($testdir, $t) .": $!\n";
}

# Change to the test area
chdir("test") or die "chdir test: $!\n";

# Directory Manipulation
for my $dir ( 0 ..  $num-1 ) {
    my $dirname = "directory$dir";

    # Make the directory
    if (!-d $dirname ) {
        mkdir $dirname or 
            die "mkdir ". File::Spec->catfile( $testdir, "test", $dirname ) .": $!\n";
    }
    #...