#!/usr/bin/perl
#
# $Id$
#
# loadavg.pl
# TiChou <tichou@tichou.org>
#

my $version = "1.0";
my $cmdname = (split('/', $0))[-1];

my $rrdlib = "/var/lib/rrd";

use Getopt::Long;
use RRDs;

sub usage($) {
  my $usage = "Usage: $cmdname [options]
Options:
  -f, --file=FILE  specify RRD file (default $rrdlib/loadavg.rrd)

  -h, --help       display this help and exit
  -v, --version    display version

Report bugs to <tichou\@tichou.org>.\n";

  if (shift) {
    print STDOUT $usage;
    exit 0;
  } else {
    print STDERR $usage;
    exit 1;
  }
}

sub version {
  print "$cmdname $version\n";
  exit 0;
}

my $rrdfile = "$rrdlib/loadavg.rrd";

Getopt::Long::Configure ("bundling");
GetOptions("f|file=s"  => \$rrdfile,
           "h|help"    => \&usage,
           "v|version" => \&version) or &usage(0);

if (not -f $rrdfile) {
  RRDs::create $rrdfile, qw(DS:loadavg1:GAUGE:600:0:U
                            DS:loadavg5:GAUGE:600:0:U
                            DS:loadavg15:GAUGE:600:0:U
                            RRA:AVERAGE:0.5:1:288
                            RRA:AVERAGE:0.5:6:336
                            RRA:AVERAGE:0.5:24:360
                            RRA:AVERAGE:0.5:288:365
                            RRA:MIN:0.5:1:288
                            RRA:MIN:0.5:6:336
                            RRA:MIN:0.5:24:360
                            RRA:MIN:0.5:288:365
                            RRA:MAX:0.5:1:288
                            RRA:MAX:0.5:6:336
                            RRA:MAX:0.5:24:360
                            RRA:MAX:0.5:288:365);
  my $error = RRDs::error;
  die "$0: $error\n" if $error;
}

my ($loadavg1,$loadavg5,$loadavg15) = ("U") x 3;

open(LOAD, "/proc/loadavg") or die "$0: can't open /proc/loadavg: $!\n";
while (<LOAD>) {
  /^(\S+) (\S+) (\S+) \d+\/\d+ \d+$/ && (($loadavg1,$loadavg5,$loadavg15) = ($1,$2,$3));
};
close(LOAD);

RRDs::update $rrdfile, "N:$loadavg1:$loadavg5:$loadavg15";
my $error = RRDs::error;
die "$0: $error\n" if $error;