#!/usr/bin/perl


my $blanked = 0;
open (my $in, "xscreensaver-command -watch |") || die;
while (<$in>) {
  if (m/^(BLANK|LOCK)/) {
    if (!$blanked) {
      system ("/home/andrzej/scripts/switch-bg.sh");
      $blanked = 1;
    }
  } elsif (m/^UNBLANK/) {
    # system ("sound-on");
    $blanked = 0;
  }
 sleep 3; 
}