# this source was developed by Rob Meerwijk, Netherlands
# you can freely distribute it
# I have tested this script on my readynas NV+
# It is intended for a graceful shutdown of Linux systems connected to a APC BACKUPS HS-500VA
# There is no warranty from me for any data loss as a direct or indirect result of using this script
# call it similar like this from cron every minute:
# "/usr/bin/perl /<home-dir>/bin/ups-gracefull-shutdown >>/log/ups_log" using the correct paths
# check the correct path of your init script, mine is /sbin/init
# good luck!!!
 
use LWP::Simple;
 
# load status from webpage
$status = get('http://ups-1/status.cgi');
 
# get Local time
my $Timestamp=localtime();
 
# get battery status for remaining power
$status =~ /align=absmiddle> (\d{1,}). %/;
$battery_status=$1;
 
if ( $status =~ /Available/ ) {
   if ( $status =~ /On Line/ ) {
   # Power normal
      if ($Timestamp =~ /:00:/ or $battery_status < 100) {
         # only on the hour write the status to the log
         print "ups-gracefull-shutdown: $Timestamp Normal operation: $battery_status %\n";
      }
      exit 0;
   }
   else {
      if ( $status =~ /On Battery/ ) {
      print "ups-gracefull-shutdown: $Timestamp Battery operation: $battery_status %\n";
      if ($battery_status < 40) {
         # shutdown, or die, battery power too low
         print "ups-gracefull-shutdown: $TimeStamp Shutting down, low battery\n";
 
         # send a mail
         system("/bin/echo ups-1 down | mail -s \"Power loss\" yourname\@yourdomain.somecountry");
 
         # wait a bit before going down
         system("/bin/sleep 6");
         system("/sbin/init 0");
         exit -1;
       }
     }
   }
}
else {
 
   #webpage probably unavailable
   print "ups-gracefull-shutdown: $Timestamp Status page unavailable\n";
   exit -2;
}