#!/usr/bin/perl
my $cmd_httpd="ps ax -O vsz,rss | grep httpd | grep -v grep";
my $cmd_cpu="grep cpu0 /proc/stat";
print "Time | Num proc | Total VSZ | Total RSS | CPU(usr) | CPU(sys) | CPU(idl) | CPU(wai)\n";
my $sleeptime=5;

my $cpu_prev=[];
do {
    my $localsleep=$sleeptime;
    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
    # httpd stats
    my @out=`$cmd_httpd`;
    my $num_proc=scalar @out;
    my $vsz=0;
    my $rss=0;
    foreach (@out) {
        if (/^\s*(\d+)\s+(\d+)\s+(\d+)\s+/) {
            $vsz+=$2;
            $rss+=$3;
        }
    }

    #CPU stats
    my $cpu=[];
    my $out2=`$cmd_cpu`;
    if ($out2=~/^cpu0\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+(\d+)\s+/) {
        my $i;
        foreach $i (1..8) {
            $cpu->[$i]=$$i
        }
    }
    if (scalar @$cpu_prev gt 0) {
        my $cpustats=&get_cpu_stats($cpu,$cpu_prev);
        print "$hour:$min:$sec $num_proc $vsz $rss $cpustats->[0] $cpustats->[1] $cpustats->[2] $cpustats->[3]\n";
    }else{
        $localsleep=1;
    }

    $cpu_prev=$cpu;
    sleep $localsleep;
} while(1);

sub get_cpu_stats {
    my ($cpu,$cpu_prev)=@_;
    my ($usr,$sys,$idl,$wai) = (0,0,0,0);
    my ($pusr,$psys,$pidl,$pwai) = (0,0,0,0);
    my $diff=&cpu_time_diff($cpu,$cpu_prev);
    my $sum=&get_cpu_sum($diff);
    $pusr=int(($diff->[1]/$sum)*100);
    $psys=int(($diff->[3]/$sum)*100);
    $pidl=int(($diff->[4]/$sum)*100);
    $pwai=int(($diff->[5]/$sum)*100);
    my @stats=($pusr,$psys,$pidl,$pwai);
    return \@stats;
}
sub get_cpu_sum {
    my $cpu=shift;
    my $sum=0;
    $sum+=$_ foreach (@$cpu);
    return $sum;
}

sub cpu_time_diff {
    my ($cpu,$cpu_prev)=@_;
    my $diff=[];
    my $i=0;
    foreach $i (1..8) {
        $diff->[$i]=$cpu->[$i] - $cpu_prev->[$i];
    }
    return $diff;
}

sub dump_a {
    my $a=shift;
    print "$_ " foreach(@$a);
    print "\n";
    return;
}
1;