#!/usr/bin/perl
# Author: Christian Külker
# License: GPLv3
# 0.1.0 2024-03-01 Initial release
use strict;
use warnings;
use JSON;
use Chart::Gnuplot;

my $json_text = qx(iostat -d -o JSON sdb 1 60);

my @io_stats = map { $_->{'disk'}[0]{'tps'} }
   @{ decode_json($json_text)->{'sysstat'}{'hosts'}[0]{'statistics'} };

my $chart = Chart::Gnuplot->new(
    output => "iostat-tps-json-gnuplot-0.1.0.png",
    title  => "Disk IO Statistics",
    xlabel => "Time [sec]",
    ylabel => "Transfers per Second [tps]",
    bg => 'white',
    yrange => [ -1, "*" ],
);

my $dataSet = Chart::Gnuplot::DataSet->new(
    ydata => \@io_stats,
    title => "sdb",
    style => "lines",
    width => 5,
);

$chart->plot2d($dataSet);