#!/usr/bin/perl

open PROC_STAT, "</proc/stat";
my @proc_stat=<PROC_STAT>;
close PROC_STAT;
my @cpu_stat_t0 = grep {s/^cpu\d+\s//} (@proc_stat);
sleep 1;
open PROC_STAT, "</proc/stat";
my @proc_stat=<PROC_STAT>;
close PROC_STAT;
my @cpu_stat_t1 = grep {s/^cpu\d+\s//} (@proc_stat);

my $total = 0;
for (my $cpu_i=0; $cpu_i<(scalar @cpu_stat_t0); $cpu_i++) {
    my @stat_t0 = split /\s+/, $cpu_stat_t0[$cpu_i];
    my @stat_t1 = split /\s+/, $cpu_stat_t1[$cpu_i];
    my ($t0_idle, $t1_idle) = ($stat_t0[3], $stat_t1[3]);
    my ($t0_total, $t1_total) = (0, 0);
    $t0_total += $_ foreach @stat_t0;
    $t1_total += $_ foreach @stat_t1;

    my $load = ($t1_total - $t0_total == 0) ? 100: int((100 * (($t1_total - $t0_total) - ($t1_idle - $t0_idle))/($t1_total - $t0_total)) + 0.5);
    print " +" unless ($cpu_i == 0);
    printf "% 5.1f%% ", $load;
    $total += $load;
}
printf " = % 6.1f%%\n", $total;