my (%argv,@param);

if ($ENV{'REQUEST_METHOD'} eq 'GET') {
   @param = split /&/, $ENV{'QUERY_STRING'};
} elsif ($ENV{'REQUEST_METHOD'} eq 'POST') {
   read(STDIN, my $env, $ENV{'CONTENT_LENGTH'});
   @param = split /&/, $env;
}

foreach (@param) {
   my ($name,$value) = split /=/, $_;
   $name  =~ tr/+/ /;
   $name  =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
   $value =~ tr/+/ /;
   $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;

   # untaint name and value

   next unless $name =~ /^(\w+)$/;
   $name = $1;

   next unless $value =~ /^([a-zA-Z_0-9 ]+)$/;
   $argv{$name} = $1;
}

# hier habe ich die Betriebssysteme definiert.

my %os = (
   Linux => [ 'SuSE', 'Red Hat', 'Debian', 'Mandrake' ],
   Windows => [ 'WIN95', 'WIN98', 'WINME', 'WINXP' ]
);