Command line options and arguments parsing. This function return
    a list of options and the list of arguments (pattern, filenames).

def create_argument_parser():
    """
    Command line options and arguments parsing. This function return
    a list of options and the list of arguments (pattern, filenames).
    """
    parser = argparse.ArgumentParser(prog='lograptor', description=__description__, add_help=False)
    parser.usage = """%(prog)s [options] PATTERN [FILE ...]
    %(prog)s [options] [-e PATTERN | -f FILE] [FILE ...]
    Try '%(prog)s --help' for more information."""

    group = parser.add_argument_group("General Options")
    group.add_argument(
        "--conf", dest="cfgfiles", action='append', default=None, metavar="FILE",
        help="use a specific configuration file"
    )
    group.add_argument(
        "-d", dest="loglevel", default=2, type=int, metavar="[0-4]", choices=range(5),
        help="Logging level (default is 2, use 4 for debug). A level of 0 suppress also "
             "error messages about nonexistent or unreadable files."
    )
    group.add_argument('-V', '--version', action='version', version=__version__)
    group.add_argument('--help', action='help', help="show this help message and exit")

    group = parser.add_argument_group("Scope Selection")
    group.add_argument(
        "-a", "--apps", metavar='APP[,APP...]', type=comma_separated_string,
        default=[], help="process the log lines related to a list of applications"
    )
    group.add_argument(
        "--hosts", metavar="HOSTNAME/IP[,HOSTNAME/IP...]", type=comma_separated_string,
        default=[], help="process the log lines related to an hostname/IP"
    )
    group.add_argument(
        "-F", "--filter", metavar="FIELD=PATTERN[,FIELD=PATTERN...]",
        action="append", dest="filters", type=filter_spec, default=[],
        help="process the log lines that match all the conditions for rule's field values"
    )
    group.add_argument(
        "--time", metavar="HH:MM,HH:MM", type=TimeRange, action="store", dest="time_range",
        help="process the log lines related to a time range"
    )
    group.add_argument(
        "--date", metavar="[YYYY]MMDD[,[YYYY]MMDD]", action="store", dest="time_period",
        type=date_interval_spec, help="restrict the search scope to a date or a date interval"
    )
    group.add_argument(
        "--last", action="store", dest="time_period", type=last_period_spec,
        metavar="[hour|day|week|month|Nh|Nd|Nw|Nm]",
        help="restrict the search scope to a previous time period"
    )

    group = parser.add_argument_group("Matcher Selection")
    group.add_argument(
        "-G", "--ruled", dest='matcher', action=StoreOptionAction,
        help="use patterns and application rules (default)"
    )
    group.add_argument(
        "-X", "--unruled", dest='matcher', action=StoreOptionAction,
        help="use patterns only, skip application rules"
    )
    group.add_argument(
        "-U", "--unparsed", dest='matcher', action=StoreOptionAction,
        help="match the patterns, don't match any application rule"
    )

    group = parser.add_argument_group("Matching Control")
    group.add_argument(
        "-e", "--regexp", metavar="PATTERN", dest="patterns", default=[],
        action="append", help="use PATTERN for matching"
    )
    group.add_argument(
        "-f", "--file", metavar="FILE", dest="pattern_files", default=[],
        action="append", help="obtain patterns from FILE"
    )
    group.add_argument(
        "-i", "--ignore-case", action="store_true", dest="case", default=False,
        help="ignore case distinctions"
    )
    group.add_argument(
        "-v", "--invert-match", action="store_true", dest="invert", default=False,
        help="invert the sense of patterns regexp matching"
    )
    group.add_argument(
        "-w", "--word-regexp", action="store_true", dest="word", default=False,
        help="force PATTERN to match only whole words"
    )

    group = parser.add_argument_group("General Output Control")
    group.add_argument(
        "--output", default=['stdout'], metavar='CHANNEL[,CHANNEL...]', dest='channels',
        type=comma_separated_string, help="send output to channels (default: ['stdout'])"
    )
    group.add_argument(
        "-c", "--count", action="store_true", default=False,
        help="print only a count of matching lines per FILE"
    )
    group.add_argument(
        "--color", default='auto', nargs='?', choices=['auto', 'always', 'never'],
        help="use markers to highlight the matching strings"
    )
    group.add_argument(
        "-L", "--files-without-match", action="store_false", dest="files_with_match", default=None,
        help="print only names of FILEs containing no match"
    )
    group.add_argument(
        "-l", "--files-with-match", action="store_true", dest="files_with_match",
        help="print only names of FILEs containing matches"
    )
    group.add_argument(
        "-m", "--max-count", metavar='NUM', action="store", type=positive_integer, default=0,
        help="stop after NUM matches"
    )
    group.add_argument(
        "-o", "--only-matching", action="store_true", default=False,
        help="show only the part of a line matching PATTERN"
    )
    group.add_argument(
        "-q", "--quiet", action="store_true", default=False, help="suppress all normal output"
    )
    group.add_argument(
        "-s", "--no-messages", action="store_const", const=0, dest='loglevel',
        help="suppress error messages (equivalent to -d 0)"
    )

    group = parser.add_argument_group("Output Data Control")
    group.add_argument(
        "--report", metavar='NAME', nargs='?', default=False,
        help="produce a report at the end of processing"
    )
    group.add_argument(
        "--ip-lookup", action="store_true", default=False,
        help="translate IP addresses to DNS names"
    )
    group.add_argument(
        "--uid-lookup", action="store_true", default=False,
        help="translate UIDs to usernames"
    )
    group.add_argument(
        "--anonymize", action="store_true", default=False,
        help="anonymize defined rule's fields value"
    )

    group = parser.add_argument_group("Output Line Prefix Control")
    group.add_argument(
        "-n", "--line-number", action="store_true", default=False,
        help="print line number with output lines"
    )
    group.add_argument(
        "-H", "--with-filename", action="store_true", dest="with_filename", default=None,
        help="print the file name for each match"
    )
    group.add_argument(
        "-h", "--no-filename", action="store_false", dest="with_filename", default=None,
        help="suppress the file name prefix on output"
    )

    group = parser.add_argument_group("Context Line Control")
    group.add_argument(
        "-T", "--thread", action="store_true", default=False,
        help="the context is the log thread of the application"
    )
    group.add_argument(
        "-B", "--before-context", metavar='NUM', type=positive_integer, default=0,
        help="print NUM lines of leading context"
    )
    group.add_argument(
        "-A", "--after-context", metavar='NUM', type=positive_integer, default=0,
        help="print NUM lines of trailing context"
    )
    group.add_argument(
        "-C", "--context", metavar='NUM', type=positive_integer, default=0,
        help="print NUM lines of output context"
    )
    group.add_argument(
        "--group-separator", metavar='SEP', default='--',
        help="use SEP as a group separator. By default SEP is double hyphen (--)."
    )
    group.add_argument(
        "--no-group-separator", dest="group_separator", action="store_const", const='',
        help="use empty string as a group separator"
    )

    group = parser.add_argument_group("File and Directory Selection")
    group.add_argument(
        "-r", "--recursive", action="store_true", default=False,
        help="read all files under each directory, recursively"
    )
    group.add_argument(
        "-R", "--dereference-recursive", action="store_true", default=False,
        help="likewise, but follow all symlinks"
    )
    group.add_argument(
        "--include", metavar='GLOB', default=[], action="append",
        help="search only files that match GLOB"
    )
    group.add_argument(
        "--exclude", metavar='GLOB', default=[], action="append",
        help="skip files and directories matching GLOB"
    )
    group.add_argument(
        "--exclude-from", metavar='FILE', default=[], action="append",
        help="skip files matching any file pattern from FILE"
    )
    group.add_argument(
        "--exclude-dir", metavar='DIR', default=[], action="append",
        help="exclude directories matching the pattern DIR"
    )

    parser.add_argument(
        'files', metavar='[FILE ...]', nargs='*',
        help='Input files. Each argument can be a file path or a glob pathname. '
             'A "-" stands for standard input. If no arguments are given then processes '
             'all the files included within the scope of the selected applications.'
    )
    return parser