Perl script help on adding variables in a loop

Hello Experts,

I need your help. I'm trying to write a Perl script which will get me the disk free space information in a solaris machine. But I'm stuck. Basically i would like to know the way for adding a particular variable cumulatively in a foreach loop. Below given is the portion of my code (full program attached in as file), where in a foreach loop, I'm matching some pattern from prtvtoc output of each disk and trying to extract a value in a variable $sect_cnt and then i want to do a cumulative addition of this variable, by which i can find the number of free sector available in the disk. Could you please help me in this?

foreach(@prtres)
        {
                if($_ =~ m/^[^\*]/)
                {
                 ($somethg, $slce, $tag, $flags, $first_sect, $sect_cnt, $Lst_sect, $mntdir)=split /\s+/, $_;
                        print "$dsknum[$i]:$_", "\n";
                        print $sect_cnt += $sect_cnt, "\n";
                }
        }
 $i++;
}


Thanks,
Ashok
diskfree.txt