What you have pairs up 'h=s' with a reference to the result of evaluating error_detect("h"). Try 

        'h=s' => \&error_detect("h"),

[download]
(note the ampersand).

the lowliest monk

In reply to Re: how to make -h optional in GetOpt::Long by tlm
in thread how to make -h optional in GetOpt::Long by bahadur

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