perl -MO=Deparse -s simple.pl -test=SET_VIA_-s arg1
    inside BEGIN  @ARGV is [arg1] and $test is [SET_VIA_-s]
    sub BEGIN {
    print "inside BEGIN  \@ARGV is [@ARGV] and \$test is [$test]\n";
    }
    my $test = 'original value';
    print "inside main   \@ARGV is [@ARGV] and \$test is [$test]\n";
    simple.pl syntax OK