my $directory = concat($machine->work_dir, "/subdir/", $machine->software_version, "/");

That sounds an awful lot like perl's built in join function, called like so:

my $directory = join "", $machine->work_dir, "/subdir/", $machine->sof
+tware_version, "/";
[download]

cheers
davis
It's not easy to juggle a pregnant wife and a troubled child, but somehow I managed to fit in eight hours of TV a day.