#!/usr/bin/perl
use strict;
use warnings;

use Data::Dumper;
$Data::Dumper::Sortkeys = 1;

# Definition Sub Routinen 
#####################################################################

sub get_cpu_info {
        my ($refSi) = @_;

        my $infile = '/proc/cpuinfo';

        open my $fh, '<', $infile or die "open(r, $infile) failed: $!\n";
        my @relevant_lines = grep( /(^processor|^cpu MHz)/, <$fh> );
        close $fh;

        my $current_cpu;
        foreach my $info (@relevant_lines) {
                if ($info =~ /processor\s*:\s*(\d+)/) {
                        $current_cpu = $1;
                }
                elsif ($info =~ /cpu MHz\s*:\s+(\S+)/) {
                        $refSi->{'Central Processing Units'}->{$current_cpu} = $1;
                }
        }
}

sub get_mem_info {
        my ($refSi) = @_;

        my $infile = '/proc/meminfo';

        open my $fh, '<', $infile or die "open(r, $infile) failed: $!\n";
        my @relevant_lines = grep( /(^MemTotal|^MemFree|^Buffers|^Cached)/, <$fh> );
        close $fh;

        foreach my $info (@relevant_lines) {
                if ( $info =~ /^(\w+):\s+(\d+)\s+(\w+)$/) {
                        my $name = $1;
                        my $amount = $2;
                        my $unit = $3;

                        $refSi->{'Memory Information'}->{$name} = "$amount $unit";
                }
        }
}

sub get_part_info {
        my ($refSi) = @_;

        my $infile = '/proc/partitions';

        open my $fh, '<', $infile or die "open(r, $infile) failed: $!\n";

        my $regex = qr/(\d+)\s+(\d+)\s+(\d+)\s+(\w+)/;
        while ( my $line = <$fh> ) {

                if ( my ($major, $minor, $block, $name ) = $line =~ $regex ) {
                        $refSi->{'Partition Info'}->{$name} = $block;
                }

        }

        close $fh;
}



# Hauptprogramm
#####################################################################


my %SysInfo;
my $output_file = './sysinfo.txt';


get_cpu_info(\%SysInfo);
get_mem_info(\%SysInfo);
get_part_info(\%SysInfo);

# Debug
print Dumper(\%SysInfo);

open my $out_fh, '>', $output_file or die "open(w, $output_file) failed: $!\n";

foreach my $section (sort keys %SysInfo) {

    printf $out_fh "=== %s ===\n", $section;

    foreach my $name ( sort keys %{ $SysInfo{$section} } ) {
        printf $out_fh "%s\t==>\t%s\n", $name, $SysInfo{$section}->{$name};
    }
}
close $out_fh;

exit 0;