+ # do some validation of the input
+ die "The directory $root doesn't exist, please RTFM" unless -d $root;
+ die "$root/local doesn't exist, please RTFM" unless -d "$root/local";
+ die "$root/local/DXVars.pm doesn't exist, please RTFM" unless -e "$root/local/DXVars.pm";
+
+ mkdir "$root/local_cmd", 0777 unless -d "$root/local_cmd";
+
+
+ # try to create and lock a lockfile (this isn't atomic but
+ # should do for now
+ $lockfn = "$root/local/cluster.lck"; # lock file name
+ if (-e $lockfn) {
+ open(CLLOCK, "$lockfn") or die "Can't open Lockfile ($lockfn) $!";
+ my $pid = <CLLOCK>;
+ chomp $pid;
+ die "Lockfile ($lockfn) and process $pid exist, another cluster running?" if kill 0, $pid;
+ close CLLOCK;
+ }
+ open(CLLOCK, ">$lockfn") or die "Can't open Lockfile ($lockfn) $!";
+ print CLLOCK "$$\n";
+ close CLLOCK;
+
+ $is_win = ($^O =~ /^MS/ || $^O =~ /^OS-2/) ? 1 : 0; # is it Windows?
+ $systime = time;