gnu_getopt(args, shortopts, longopts=[])
getopt(args, options[, long_options]) -> opts, args
This function works like getopt(), except that GNU style scanning mode is used by default. This means that option and non-option arguments may be intermixed. The getopt() function stops processing options as soon as a non-option argument is encountered.
If the first character of the option string is `+', or if the environment variable POSIXLY_CORRECT is set, then option processing stops as soon as a non-option argument is encountered.