#!/usr/bin/perl

use warnings;
use strict;

my @data;
my $file = 'mailbox.txt';

open(my $fh,'<',$file) or die $!;
while(my $line = <$fh>) {  # alles was unten in __DATA__ steht symbolisiert eine Datei
    chomp $line;
    my @array = (split(/\s+/,$line))[0..2]; 

    foreach (@array) {
        s%^\s+%%g; # fuehrende und
        s%\s+$%%g; # abschliessende Blanks entfernen
    } # foreach
  
    push(@data,[@array]);
} # while
close $fh;


my $len_vorname = find_longest(map{$_->[0]}@data);
my $len_nachname = find_longest(map{$_->[1]}@data);
my $len_domain = find_longest(map{$_->[2]}@data);

for my $entry(@data){
    print sprintf("%-*s %-*s %-*s<<\n",$len_vorname,$entry->[0],
                                       $len_nachname,$entry->[1],
                                       $len_domain,$entry->[2]);
}

sub find_longest{
    my $longest = 0;
    for(@_){
         my $length = length($_);
         $longest = $length if($length > $longest);
    }
 
    return $longest;
}