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

use Cwd;

my $test=0;
my $name;
my $wert;
my $dir;

use Getopt::Std;
my %opts;

getopts('hd:f:m', \%opts);

if ($opts{h})
{
    print "Usage:\n";
    print "filesize.pl -h for help\n";
    print "filesize.pl -f [filename] to show the size of [filename]\n";
    print "filesize.pl -d [directory] to show the sizes of all files in [directory]\n";
    print "filesize.pl to show the sizes of all files in the current directory\n";
}
elsif ($opts{f})
{
    my $f = getcwd;
    opendir(DIR, "$f");
    my @dir = readdir(DIR);
    closedir(DIR);
    foreach (@dir)
    {
        if ($_ eq $opts{f})
        {
            $test=1;
        }
    }
    if ($test)
    {
        $_ = (-s "$opts{f}");
        $wert = &size($_);;
        $name = $opts{f};
        write;
    }
    else {
        print "Datei $opts{f} exisiert nicht!\n";
    }
}

$dir = getcwd unless(defined($opts{d}));
if (defined($opts{d}))
{
    if (-d "$opts{d}")
    {
        $dir = $opts{d};
    } else {
        print "$opts{d} existiert nicht oder ist kein Verzeichniss!\n";
        exit 0;
    }
}

unless (defined($opts{h}) || defined($opts{f}))
{
#    opendir(DIR, "$dir") or die $!;
    opendir(DIR, ".") or die $!;
    my @array = readdir(DIR);
    closedir(DIR);

my %hash;
my %for;
my @size;

format STDOUT_TOP =
Dateiname               Dateigroesse
====================================
.

    foreach(@array)
    {
        my $i = 0;
        if ($opts{d})
        {
            chdir $dir;
        }
        $hash{$_} = (-s $_);
        my $file = (-s $_);
        $for{$file} = $_;
        $i++;
        push @size, $file;
    }
    my @sort = sort { $a <=> $b } @size;

    foreach(@sort)
    {
    
        if (-f "$for{$_}")
        {
            my $data = $_;
            &size($_);
            $name = $for{$data};
            $wert = $_;
            
format STDOUT =
@<<<<<<<<<<<<<<<<< @>>>>>>>>>>>>>>>>
$name,          $wert
.
            write;
        }
    }    
}

sub size
{
if ($_ < 1024)
    {
            $_ .= " bytes";
        } elsif ( $_ > 1024 && $_ < 1048576)
        {
            $_ = sprintf("%.2f", $_ / 1024);
            $_ .= " kb";
        } elsif ( $_ > 1048576 && $_ < 1099511627776)
        {
            $_ = sprintf("%.2f", $_ / 1048576);
            $_ .= " mb";
        } else
        {
            $_ = sprintf("%.2f", $_ / 1099511627776);
            $_ .= " gb";
    }
return $_;
}