I've used Big Brother for almost 3 years to do monitoring of systems. It's a neat program, and I highly reccomend it. However, it's written in C and sh. So i've been porting it to perl. Right now i've finished the client portion, and here's the sub i use for disk space monitoring. It may or may not be helpful to you, but what the hell...

sub DISK {
  my @df = `df`;
  my $red = '95';
  my $yellow = '90';
  my $color = "green";
  my $message;
  #get rid of the header from df(1)
  shift @df;
  #strip off leading whitespace
  foreach my $lines (@df) {
    my $warning;
    $lines =~s/^\s+//;
    my ($device,$usage) =($lines =~m|(/dev/\S+)\s+\d+\s+\d+\s+\d+\s+(\
+d+)|);
    
    if ($usage >= $red) {
      $color = "red";
      $warning = "Warning";
    }
    elsif ($usage >= $yellow) {
      $color = "yellow" unless ($color eq "red");
      $warning = "Caution";
    }
    
    if (defined $warning) {
      $message .= "$warning: $device is at $usage% usage.\n";
    }
  }
  unless (defined $message) {
    $message .= "All filesystems ok.\n";
  }
  foreach (@df) {
    $message .= $_ ;
  }
}
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BlueLines

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