#!usr/bin/perl

my ($name, $vorname, $plz, $tel, $tel49);
my %vars;
while (<DATA>) {
    print;
    chomp;
    ($name, $vorname, $plz, $tel, $tel49) = split /\s*,\s*/, $_, -1;
    @vars{qw/name vorname plz tel tel49/} = ($name, $vorname, $plz, $tel, $tel49);
    my @good = grep {$vars{$_}} keys %vars;
    printf "    %s %s good\n", 
           @good ? join ", ", @good : "No variables", 
                @good == 1 ? "is" : "are";
}

__DATA__
john, stuart, some_plz, 123456, 234557
john, stuart, some_plz, 123456,
john, stuart, some_plz,, 234557
, stuart, , 123456, 234557
, , , , 234557
,,,,