Greetings Knowledgeable Monks,

I recently shot myself in the foot with Getopt::Long by setting up a hash of default parameters, and then misspelling one of the parameter names in the GetOptions call, like this: 

# set up default values for parameters:
my %pars = (
    item => 'default value',
);    
GetOptions (
    \%pars,
     'items=s', # NOTE MISPELLING-- "items" s/b "item"
) or die "bad GetOptions $!";

# use $pars{item}, which is unaffected by an --items argument

[download]
That is, my typo autovivifies a new entry in the parameter hash, which is then never used. It took a painful amount of time to figure out why the arguments weren't responding correctly!

Does anyone have a clever way of checking for mistakes (typos) of this type? The best I can do is something like this: 

my @opts = (
    { name => 'item1', type => '=s', dval => 'default_value1' },
    { name => 'item2', type => '=s', dval => 'default_value2' },
);

my %pars = map { $opts[$_]{name} , $opts[$_]{dval} } 0..$#opts;
my @args = map { $opts[$_]{name} . $opts[$_]{type} } 0..$#opts;

GetOptions (
    \%pars,
     @args
) or die "bad GetOptions $!";

[download]
but I'd love to see something else that could protect me from my typos, if someone has something better.

In reply to Getopt::Long Gotcha, request advice by kesterkester

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