#!/usr/bin/php
<?php
/**
 * check_apc_ups
 * Read out the status of an APC UPS and return info that nagios can parse.
 * Peter Lieverdink <me@cafuego.net>
 * Licensed under the GPL.
 *
 * 2009-06-19	Initial revision.
 */

  $p = @popen("/sbin/apcaccess 2>&1", "r");
  if(!$p) {
    echo "UPS CRITICAL - Unable to execute the /sbin/apcaccess utility. Did you install and configure apcupsd?";
    exit(2);
  }

  // It reads the status into a keyed array or it gets the hose again.
  $status = array();

  while(!feof($p)) {
    $a = fgetcsv($p, 1024, ': ');
    if( trim($a) )
      $status[ trim($a[0]) ] = trim($a[1]);
  }
  pclose($p);

  // I got these via `strings apcupsd'. I hope they match, as my power and UPS have never failed
  // so I don't *actually* know what apcupsd would output :-/
  switch($status['STATUS']) {
    case 'ONLINE':
    case 'SLAVE':
      $ret = 0;
      break;
    case 'ONBATT':
    case 'COMMLOST':
      $ret = 1;
      break;
    case 'OVERLOAD':
    case 'LOWBATT':
    case 'REPLACEBATT':
    case 'NOBATT':
    case 'SLAVEDOWN':
    case 'SHUTTING DOWN':
    default:
      $ret = 2;
      break;
  }

  // Parse the run-time remaining.
  $time = split(' ', $status['TIMELEFT']);
  $time = floatval($time[0]);

  // If we have less than ten minutes of run-time on battery, also go critical.
  if($time < 10) {
    $ret = 2;
  }

  // Assemble a possibly useful status line.
  $info = sprintf("UPS %s - Line: %s; %s; Charge %s; Temp: %s\n",
    $status['STATUS'],
    $status['LINEV'],
    $status['LOADPCT'],
    $status['BCHARGE'],
    $status['ITEMP']
  );

  // If there was an execution issue.... re-join the first rety in $status
  // Bit of a kludge and it drops a colon, but it works well enough.
  // Oh, and go critical.
  if( count($status) == 1 ) {
    $ret = 2;
    foreach($status as $k => $v)
      $error .= sprintf("%s %s", $k, $v);

    $info = sprintf("UPS ERROR - %s\n", $error);
  }

  // Print status line and exit with correct return value.
  echo $info;
  exit($ret);