#!/usr/bin/perl -w
# Reik Keutterling

use strict;
use warnings;
use Getopt::Long;

my @return_codes = qw( OK WARNING CRITICAL UNKNOWN );
my ($warning, $critical, $string) = &get_cmd_params();
my ($warning_min, $warning_max)   = (split(/:/, $warning), "0");
my ($critical_min, $critical_max) = (split(/:/, $critical), "0");
map{defined($_)?$_+0:0}($warning_min, $warning_max, $critical_min, $critical_max);
($warning_max, $warning_min) = ($warning_min, $warning_max) if ($warning_max == 0);
($critical_max, $critical_min) = ($critical_min, $critical_max) if ($critical_max == 0);
my $threads = 0;
my $status = 0;
my $msg = '';

if (open(PS_ELF, "ps -eLf|")) {
  foreach (<PS_ELF>) {
    if ($_ =~ m/\Q$string\E/ and $_ !~ m/\Q$0\E/) {
      $threads++;
    }
  }
  close(PS_ELF);
  if ($threads > $critical_max or $threads < $critical_min) {
    $status = 2;
  }
  elsif ($threads > $warning_max or $threads < $warning_min) {
    $status = 1;
  }
  else {
    $status = 0;
  }
  $msg = "$threads threads containing '$string'";
} else {
  $status = 3;
  $msg = 'ERROR';
}

print "$return_codes[$status] - $msg ","|threads=$threads;$warning_max;$critical_max;$status\n"; 
exit $status;

#######################################################################

sub get_cmd_params {
  my ($warning, $critical, $string) = ('','','');
  my $result = GetOptions( 'w=s' => \$warning,
                           'c=s' => \$critical,
                           'a=s' => \$string );
  my $usage = <<EXIT;
Usage: 
 check_threads -w [<minthreads>:]<maxthreads> -c [<minthreads>:]<maxthreads> -a <string>

Examples:
 check_threads -w 2:2 -c 2:1024 -a java
  Warning if != 2 threads containing 'java'
  Critical if < 2 or > 1024 threads

 check_threads -w 10 -c 50 -a java
  Warning if > 10 threads containing 'java'
  Critical if > 50 threads 

EXIT
  
  die $usage if($warning eq '' || $critical eq '' || $string eq '');
  return ($warning, $critical, $string);
}