use Fcntl ':flock';
use diagnostics;
my @sw_lockarray;
use vars qw($verbose);

sub lock_file {
  my $filename=shift;
  my $lock;
  if (! open($lock, "> $filename")) {
    print "ERROR: Can't open lockfile $filename: $!\n";
    return(0);
  }
  if (flock($lock, LOCK_EX | LOCK_NB)) {
    print "Lock erhalten\n" if $verbose;
    push(@sw_lockarray, $lock);
    print($lock "$$\n");
    chmod 0666,  $filename;
    return(1);
  } else {
    warn "Lock $filename nicht erhalten\n";
    return(0);
  }
}