-- | Construct a usage message header.
header :: String -> String
header progName = intercalate "\n"
    [ "The DROID Signature File Minimizer - filter a signature file based on"
    , "a list of PUIDs and keep only entries for those file formats that you"
    , "really need."
    , ""
    , "Usage: " ++ progName ++ " [options] [signature-file]"
    , ""
    ]
header :: String -> String
header progName = intercalate "\n"
    [ "The DROID Signature File Minimizer - filter a signature file based on"
    , "a list of PUIDs and keep only entries for those file formats that you"
    , "really need."
    , ""
    , "Usage: " ++ progName ++ " [options] [signature-file]"
    , ""
    ]
header progName = intercalate "\n"
    [ "The DROID Signature File Minimizer - filter a signature file based on"
    , "a list of PUIDs and keep only entries for those file formats that you"
    , "really need."
    , ""
    , "Usage: " ++ progName ++ " [options] [signature-file]"
    , ""
    ]