def _show_list_message(resolved_config):
    """
    Show the message for when a user has passed in --list.
    """
    # Show what's available.
    supported_programs = util.get_list_of_all_supported_commands(
        resolved_config
    )
    msg_line_1 = 'Legend: '
    msg_line_2 = (
        '    ' +
        util.FLAG_ONLY_CUSTOM +
        ' only custom files'
    )
    msg_line_3 = (
        '    ' +
        util.FLAG_CUSTOM_AND_DEFAULT +
        ' custom and default files'
    )
    msg_line_4 = '    ' + '  only default files (no symbol)'
    msg_line_5 = ''
    msg_line_6 = 'Programs supported by eg: '

    preamble = [
        msg_line_1,
        msg_line_2,
        msg_line_3,
        msg_line_4,
        msg_line_5,
        msg_line_6
    ]

    complete_message = '\n'.join(preamble)
    complete_message += '\n' + '\n'.join(supported_programs)

    pydoc.pager(complete_message)
Show the message for when a user has passed in --list.