Perl Getopt Long The module check wrong argument…

Perl Getopt::Long.

The module check wrong argument but does not check when no argument is provided.
In order to check if there is no argument as well as wrong argument,
check the argument also.

GetOptions( 'test=s' => \$option_test )
    or exit(1);

defined($option_test)
    or die("Missing argument -t");

http://www.perlmonks.org/?node_id=789974