use Date::Calc qw(Delta_Days);

my ($dir_date,$directory) = "";

my ($mday,$mon,$year) = (localtime(time-60*60*24*7*8))[3..5];    #get the current time minus 8 weeks (ca. 2 months)

#convert the strings into the right format
$year += 1900;
$mon += 1;

    #if the length of the string mon and mday are only 1, add a leading 0
    if (length($mon) == 1)
    {
       $mon="0$mon";
    }
    if(length($mday) == 1)
    {
       $mday="0$mday";
    }

#get all the directory's from the startup_config
@configs = `ls -l /home/confbackup/startup_configs/`;

    foreach (@configs)
    {
        if (!($_ =~ /total/))
        {
        $length = @informations = split (/\s/,$_);    #split each line and get also the number of arguments splitted
        
        $dir_date = $informations[$length-3];    #get the create date from the directory
        
        $directory = $informations[$length-1];    #get the directory name
        $directory = "/home/confbackup/startup_configs/".$directory;    #add an absolute path to the directory
        
        ($dir_year,$dir_mon,$dir_mday) = split (/\-/,$dir_date);
        
        #get the difference between the create_date of the directory and the date 8 weeks ago
        $Dd = Delta_Days($dir_year,$dir_mon,$dir_mday, 
               
          $year,$mon,$mday);
        
            #if the difference is positive, the directory is older than 8 weeks
            if ($Dd > 0)
            {
            opendir(DIR,"$directory");
            @files=readdir(DIR);
            closedir(DIR);
               
 
               
 #delete all files from the directory
               
 foreach(@files)
               
 {
               
 unlink("$directory/$_");
               
 }
            
            #delete the directory itself
            rmdir("$directory");            
            }
        }
    }

opendir (DIR, $directory) or die "Error: couldn't open dir '$directory': $!\n"
...
unlink ("$directory/$_") or warn "Error: couldn't unlink file '$directory/$_': $!\n";
...
rmdir ($directory) or warn "Error: couldn't unlink '$directory': $!\n";

@configs = `ls -l /home/confbackup/startup_configs/`;

my $command = "ls -l /home/confbackup/startup_configs/";
unless (open(CMD, "$command |")) {
  die "Error in executing command: $!\n";
}
@configs = <CMD>; chomp(@confix);
close(CMD);

$ /pfad/zum/script > cd ../
$ /pfad/zum > /pfad/zum/script/script.pl

$Dd = Delta_Days($dir_year,$dir_mon,$dir_mday,$year,$mon,$mday);

my $last_modify = -M $file;