print _stringFormat('12345', 10) ;
print _stringFormat('huhu longlongbimbambuhh', 15);
print _stringFormat('bimbam'), 20) . "\n";
print _stringFormat('123', 10) ;
print _stringFormat('huhu', 15);
print _stringFormat('bimbam'), 20) . "\n";

sub _stringFormat {
    my $c = ($_[1] - length($_[0])) < 0 ? 0 : $_[1] - length($_[0]);
    $_[0] = substr($_[0], 0, $_[1]-4) . "... " if (length($_[0]) >= $_[1]);
    return $_[0] . " " x $c;
}