none [kbd-scrolllock] kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrllock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock 
  #   ˆl–Ãa¾”d*h¥4 Y¸Ø.2ú˜´o¿„@ ÿÅÄ ?÷     """Base classes for server/gateway implementations"""

from .util import FileWrapper, guess_scheme, is_hop_by_hop
from .headers import Headers

import sys, os, time

__all__ = [
    'BaseHandler', 'SimpleHandler', 'BaseCGIHandler', 'CGIHandler',
    'IISCGIHandler', 'read_environ'
]

# Weekday and month names for HTTP date/time formatting; always English!
_weekdayname = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
_monthname = [None, # Dummy so we can use 1-based month numbers
              "Jan", "Feb", "Mar", "Apr", "May", "Jun",
              "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]

def format_date_time(timestamp):
    year, month, day, hh, mm, ss, wd, y, z = time.gmtime(timestamp)
    return "%s, %02d %3s %4d %02d:%02d:%02d GMT" % (
        _weekdayname[wd], day, _monthname[month], year, hh, mm, ss
    )

_is_request = {
    'SCRIPT_NAME', 'PATH_INFO', 'QUERY_STRING', 'REQUEST_METHOD', 'AUTH_TYPE',
    'CONTENT_TYPE', 'CONTENT_LENGTH', 'HTTPS', 'REMOTE_USER', 'REMOTE_IDENT',
}.__contains__

def _needs_transcode(k):
    return _is_request(k) or k.startswith('HTTP_') or k.startswith('SSL_') \
        or (k.startswith('REDIRECT_') and _needs_transcode(k[9:]))

def read_environ():
    """Read environment, fixing HTTP variables"""
    enc = sys.getfilesystemencoding()
    esc = 'surrogateescape'
    try:
        ''.encode('utf-8', esc)
    except LookupError:
        esc = 'replace'
    environ = {}

    # Take the basic environment from native-unicode os.environ. Attempt to
    # fix up the variables that come from the HTTP request to compensate for
    # the bytes->unicode decoding step that will already have taken place.
    for k, v in os.environ.items():
        if _needs_transcode(k):

            # On win32, the os.environ is natively Unicode. Different servers
            # decode the request bytes using different encodings.
            if sys.platform == 'win32':
                software = os.environ.get('SERVER_SOFTWARE', '').lower()

                # On IIS, the HTTP request will be decoded as UTF-8 as long
                # as the input is a valid UTF-8 sequence. Otherwise it is
                # decoded using the system code page (mbcs), with no way to
                # detect this has happened. Because UTF-8 is the more likely
                # encoding, and mbcs is inherently unreliable (an mbcs string
                # that happens to be valid UTF-8 will not be decoded as mbcs)
                # always recreate the original bytes as UTF-8.
                if software.startswith('microsoft-iis/'):
                    v = v.encode('utf-8').decode('iso-8859-1')

                # Apache mod_cgi writes bytes-as-unicode (as if ISO-8859-1) direct
                # to the Unicode environ. No modification needed.
                elif software.startswith('apache/'):
                    pass

                # Python 3's http.server.CGIHTTPRequestHandler decodes
                # using the urllib.unquote default of UTF-8, amongst other
                # issues.
                elif (
                    software.startswith('simplehttp/')
                    and 'python/3' in software
                ):
                    v = v.encode('utf-8').decode('iso-8859-1')

                # For other servers, guess that they have written bytes to
                # the environ using stdio byte-oriented interfaces, ending up
                # with the system code page.
                else:
                    v = v.encode(enc, 'replace').decode('iso-8859-1')

            # Recover bytes from unicode environ, using surrogate escapes
            # where available (Python 3.1+).
            else:
                v = v.encode(enc, esc).decode('iso-8859-1')

        environ[k] = v
    return environ


class BaseHandler:
    """Manage the invocation of a WSGI application"""

    # Configuration paramet