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

use Cwd;

use Getopt::Std;
use vars qw($opt_f $opt_h $opt_d);

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

if (! getopts('f:hd:'))
{
}

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

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

unless (defined($opt_h) || defined($opt_f))
{
opendir(DIR, "$dir");
my @array = readdir(DIR);
closedir(DIR);

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

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

foreach(@array)
{
        my $i = 0;
        $hash{$_} = (-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 $_;
}