The help flag? ...You get it for free.

So you have the code below and you see nothing about a help flag. But, in fact, it's there. Go ahead. Try typing in something that doesn't work. Or use the -h or -? flag. 
require 'optiflag'

module DBChecker extend OptiFlagSet
  flag "log"
  flag "password"
  flag "user"

  and_process!
end 
puts "The user's user name is #{ ARGV.flags.user }"
puts "The user's password is #{ ARGV.flags.password }"
puts "The log directory is #{ ARGV.flags.log }"

What the user types in, and the results (notice that we are purposely leaving out the required flag 'log'):
> ruby dbchecker.rb -user wluser -password ch3ckM8 
Errors found:
Missing Flags:
   -log

Help for commands:
  -user       (Required, takes 1 argument)
  -password   (Required, takes 1 argument)
  -log        (Required, takes 1 argument)
  -h          (Optional, takes 0 arguments)
                  Help

Or, with the -h or -? flag:

> ruby dbchecker.rb -? 
Help for commands:
  -user       (Required, takes 1 argument)
  -password   (Required, takes 1 argument)
  -log        (Required, takes 1 argument)
  -h          (Optional, takes 0 arguments)
                  Help

Or, you can target the -? flag to a specific option, (for instance, 'user'):

> ruby dbchecker.rb -? user 
----------------
           Flag:        -user (Required, takes 1 argument) 
      Long Form:        --user