use strict;
my ($percnt,$threshhold @p,$cntr, $flag, $CF, $alertaddr, $Esubject,);

my $log       = qq(/var/adm/USE_monitor.csv);
my $cntrF     = qq(/var/adm/USE_monitor.cntr);
open LOG, "+<", $log   or die "'$log' did not open $!\n";

... {snip} ...       
if ( $percnt >= $threshhold ) {
     write (LOG);
     push @p, $percnt;
}


if ( -s $log ) {
    $cntr = 0;
    $flag = 1;
    open $CF, ">>", $cntrF or die "'$cntrF' did not open $!\n";
    print $CF "$flag\n";
    sleep 1;
    close $CF;
    sleep 1;
    open $CF, "+<", $cntrF or die "'$cntrF' did not open $!\n";
    print $cntr;
    while (<$CF>) {
        while (m/\b$flag\b/g) {
            $cntr++;
        }
    }
    print $cntr;
    if ( $cntr <= 2 ) {
        _mailme($alertaddr, $Esubject, $log);
        $CF->close;
    }
    elsif ( $cntr > 2 ) {
         for (@p) {
              if ( $_ >= 99 ) {
                  _mailme($alertaddr, $Esubject, $log);
                  last;
              }
         }
    $CF->close;
    }
    else {
        $CF->close;
    }