cpumon_light reimplementation to avoid fork

[debian6500.git] / master / root / bin / cpumon_light

#!/usr/bin/perl

use strict;

my @cpu_stat_t0 = proc_stat();
sleep 1;
my @cpu_stat_t1 = 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;

sub proc_stat() {
    return grep {s/^cpu\d+\s//} read_file('/proc/stat');
}

sub read_file($) {
    my ($file) = @_;
    open FILE, "<$file";
    my @content = <FILE>;
    close FILE;
    return @content;
}