my $result = GetOptions (
          "c=s" => \&COMPT1,
          "t=s" => \&COMPT2,
          '<>' => sub {print "\nThat is not a valid parameter\n";},
    );

sub COMPT1 {
    my ($optname, $value) = @_;
    print "Option -$optname is value=$value\n";

    # replace error handler for -t with real handler
    $optname->{linkage}{t} = sub {
        my ($optname, $value) = @_;
        print "Option -$optname is value=$value\n";
    };
};

sub COMPT2 { # error handler
    print "Option -t requires option -c\n";
};

__END__
$ ./888928.pl -c foo -t bar
Option -c is value=foo
Option -t is value=bar

$ ./888928.pl  -t bar
Option -t requires option -c