#!/usr/bin/perl

use strict;
use warnings;

my $string = 'datei.bas';

print right($string,2),"\n", left($string,4);

sub right{
    my ($string,$nr) = @_;
    return substr $string, -$nr, $nr;
}

sub left{
    my ($string,$nr) = @_;
    return substr $string, 0, $nr;
}