text: """An FTP client class and some helper functions.
  
  Based on RFC 959: File Transfer Protocol (FTP), by J. Postel and J. Reynolds
  
  Example:
  
  >>> from ftplib import FTP
  >>> ftp = FTP('ftp.python.org') # connect to host, default port
  >>> ftp.login() # default, i.e.: user anonymous, passwd anonymous@
  '230 Guest login ok, access restrictions apply.'
  >>> ftp.retrlines('LIST') # list directory contents
  total 9
  drwxr-xr-x   8 root     wheel        1024 Jan  3  1994 .
  drwxr-xr-x   8 root     wheel        1024 Jan  3  1994 ..
  drwxr-xr-x   2 root     wheel        1024 Jan  3  1994 bin
  drwxr-xr-x   2 root     wheel        1024 Jan  3  1994 etc
  d-wxrwxr-x   2 ftp      wheel        1024 Sep  5 13:43 incoming
  drwxr-xr-x   2 root     wheel        1024 Nov 17  1993 lib
  drwxr-xr-x   6 1094     wheel        1024 Sep 13 19:07 pub
  drwxr-xr-x   3 root     wheel        1024 Jan  3  1994 usr
  -rw-r--r--   1 root     root          312 Aug  1  1994 welcome.msg
  '226 Transfer complete.'
  >>> ftp.quit()
  '221 Goodbye.'
  >>>
  
  A nice test that reveals some of the network dialogue would be:
  python ftplib.py -d localhost -l -p -l
  """
  
  #
  # Changes and improvements suggested by Steve Majewski.
  # Modified by Jack to work on the mac.
  # Modified by Siebren to support docstrings and PASV.
  # Modified by Phil Schwartz to add storbinary and storlines callbacks.
  # Modified by Giampaolo Rodola' to add TLS support.
  #
  
  import sys
  import socket
  from socket import _GLOBAL_DEFAULT_TIMEOUT
  
  __all__ = ["FTP", "error_reply", "error_temp", "error_perm", "error_proto",
             "all_errors"]
  
  # Magic number from <socket.h>
  MSG_OOB = 0x1                           # Process data out of band
  
  
  # The standard FTP server control port
  FTP_PORT = 21
  # The sizehint parameter passed to readline() calls
  MAXLINE = 8192
  
  
  # Exception raised when an error or invalid response is received
  class Error(Exception): pass
  class error_reply(Error): pass          # unexpected [123]xx reply
  class error_temp(Error): pass           # 4xx errors
  class error_perm(Error): pass           # 5xx errors
  class error_proto(Error): pass          # response does not begin with [1-5]
  
  
  # All exceptions (hopefully) that may be raised here and that aren't
  # (always) programming errors on our side
  all_errors = (Error, OSError, EOFError)
  
  
  # Line terminators (we always output CRLF, but accept any of CRLF, CR, LF)
  CRLF = '\r\n'
  B_CRLF = b'\r\n'
  
  # The class itself
  class FTP:
  
      '''An FTP client class.
  
      To create a connection, call the class using these arguments:
              host, user, passwd, acct, timeout
  
      The first four arguments are all strings, and have default value ''.
      timeout must be numeric and defaults to None if not passed,
      meaning that no timeout will be set on any ftp socket(s)
      If a timeout is passed, then this is now the default timeout for all ftp
      socket operations for this instance.
  
      Then use self.connect() with optional host and port argument.
  
      To download a file, use ftp.retrlines('RETR ' + filename),
      or ftp.retrbinary() with slightly different arguments.
      To upload a file, use ftp.storlines() or ftp.storbinary(),
      which have an open file as argument (see their definitions
      below for details).
      The download/upload functions first issue appropriate TYPE
      and PORT or PASV commands.
      '''
  
      debugging = 0
      host = ''
      port = FTP_PORT
      maxline = MAXLINE
      sock = None
      file = None
      welcome = None
      passiveserver = 1
      encoding = "latin-1"
  
      # Initialization method (called by class instantiation).
      # Initialize host to localhost, port to standard ftp port
      # Optional arguments are host (for connect()),
      # and user, passwd, acct (for login())
      def __init__(self, host='', user='', passwd='', acct='',
                   timeout=_GLOBAL_DEFAULT_TIMEOUT, source_address=None):
          self.source_address = source_address
          self.timeout = timeout
          if host:
              self.connect(host)
              if user:
                  self.login(user, passwd, acct)
  
      def __enter__(self):
          return self
  
      # Context management protocol: try to quit() if active
      def __exit__(self, *args):
          if self.sock is not None:
              try:
                  self.quit()
              except (OSError, EOFError):
                  pass
              finally:
                  if self.sock is not None:
                      self.close()
  
      def connect(self, host='', port=0, timeout=-999, source_address=None):
          '''Connect to host.  Arguments are:
           - host: hostname to connect to (string, default previous host)
           - port: port to connect to (integer, default previous port)
           - timeout: the timeout to set against the ftp socket(s)
           - source_address: a 2-tuple (host, port) for the socket to bind
             to as its source address before connecting.
          '''
          if host != '':
              self.host = host
          if port > 0:
              self.port = port
          if timeout != -999:
              self.timeout = timeout
          if source_address is not None:
              self.source_address = source_address
          self.sock = socket.create_connection((self.host, self.port), self.timeout,
                                               source_address=self.source_address)
          self.af = self.sock.family
          self.file = self.sock.makefile('r', encoding=self.encoding)
          self.welcome = self.getresp()
          return self.welcome
  
      def getwelcome(self):
          '''Get the welcome message from the server.
          (this is read and squirreled away by connect())'''
          if self.debugging:
              print('*welcome*', self.sanitize(self.welcome))
          return self.welcome
  
      def set_debuglevel(self, level):
          '''Set the debugging level.
          The required argument level means:
          0: no debugging output (default)
          1: print commands and responses but not body text etc.
          2: also print raw lines read and sent before stripping CR/LF'''
          self.debugging = level
      debug = set_debuglevel
  
      def set_pasv(self, val):
          '''Use passive or active mode for data transfers.
          With a false argument, use the normal PORT mode,
          With a true argument, use the PASV command.'''
          self.passiveserver = val
  
      # Internal: "sanitize" a string for printing
      def sanitize(self, s):
          if s[:5] in {'pass ', 'PASS '}:
              i = len(s.rstrip('\r\n'))
              s = s[:5] + '*'*(i-5) + s[i:]
          return repr(s)
  
      # Internal: send one line to the server, appending CRLF
      def putline(self, line):
          if '\r' in line or '\n' in line:
              raise ValueError('an illegal newline character should not be contained')
          line = line + CRLF
          if self.debugging > 1:
              print('*put*', self.sanitize(line))
          self.sock.sendall(line.encode(self.encoding))
  
      # Internal: send one command to the server (through putline())
      def putcmd(self, line):
          if self.debugging: print('*cmd*', self.sanitize(line))
          self.putline(line)
  
      # Internal: return one line from the server, stripping CRLF.
      # Raise EOFError if the connection is closed
      def getline(self):
          line = self.file.readline(self.maxline + 1)
          if len(line) > self.maxline:
              raise Error("got more than %d bytes" % self.maxline)
          if self.debugging > 1:
              print('*get*', self.sanitize(line))
          if not line:
              raise EOFError
          if line[-2:] == CRLF:
              line = line[:-2]
          elif line[-1:] in CRLF:
              line = line[:-1]
          return line
  
      # Internal: get a response from the server, which may possibly
      # consist of multiple lines.  Return a single string with no
      # trailing CRLF.  If the response consists of multiple lines,
      # these are separated by '\n' characters in the string
      def getmultiline(self):
          line = self.getline()
          if line[3:4] == '-':
              code = line[:3]
              while 1:
                  nextline = self.getline()
                  line = line + ('\n' + nextline)
                  if nextline[:3] == code and \
                          nextline[3:4] != '-':
                      break
          return line
  
      # Internal: get a response from the server.
      # Raise various errors if the response indicates an error
      def getresp(self):
          resp = self.getmultiline()
          if self.debugging:
              print('*resp*', self.sanitize(resp))
          self.lastresp = resp[:3]
          c = resp[:1]
          if c in {'1', '2', '3'}:
              return resp
          if c == '4':
              raise error_temp(resp)
          if c == '5':
              raise error_perm(resp)
          raise error_proto(resp)
  
      def voidresp(self):
          """Expect a response beginning with '2'."""
          resp = self.getresp()
          if resp[:1] != '2':
              raise error_reply(resp)
          return resp
  
      def abort(self):
          '''Abort a file transfer.  Uses out-of-band data.
          This does not follow the procedure from the RFC to send Telnet
          IP and Synch; that doesn't seem to work with the servers I've
          tried.  Instead, just send the ABOR command as OOB data.'''
          line = b'ABOR' + B_CRLF
          if self.debugging > 1:
              print('*put urgent*', self.sanitize(line))
          self.sock.sendall(line, MSG_OOB)
          resp = self.getmultiline()
          if resp[:3] not in {'426', '225', '226'}:
              raise error_proto(resp)
          return resp
  
      def sendcmd(self, cmd):
          '''Send a command and return the response.'''
          self.putcmd(cmd)
          return self.getresp()
  
      def voidcmd(self, cmd):
          """Send a command and expect a response beginning with '2'."""
          self.putcmd(cmd)
          return self.voidresp()
  
      def sendport(self, host, port):
          '''Send a PORT command with the current host and the given
          port number.
          '''
          hbytes = host.split('.')
          pbytes = [repr(port//256), repr(port%256)]
          bytes = hbytes + pbytes
          cmd = 'PORT ' + ','.join(bytes)
          return self.voidcmd(cmd)
  
      def sendeprt(self, host, port):
          '''Send an EPRT command with the current host and the given port number.'''
          af = 0
          if self.af == socket.AF_INET:
              af = 1
          if self.af == socket.AF_INET6:
              af = 2
          if af == 0:
              raise error_proto('unsupported address family')
          fields = ['', repr(af), host, repr(port), '']
          cmd = 'EPRT ' + '|'.join(fields)
          return self.voidcmd(cmd)
  
      def makeport(self):
          '''Create a new socket and send a PORT command for it.'''
          err = None
          sock = None
          for res in socket.getaddrinfo(None, 0, self.af, socket.SOCK_STREAM, 0, socket.AI_PASSIVE):
              af, socktype, proto, canonname, sa = res
              try:
                  sock = socket.socket(af, socktype, proto)
                  sock.bind(sa)
              except OSError as _:
                  err = _
                  if sock:
                      sock.close()
                  sock = None
                  continue
              break
          if sock is None:
              if err is not None:
                  raise err
              else:
                  raise OSError("getaddrinfo returns an empty list")
          sock.listen(1)
          port = sock.getsockname()[1] # Get proper port
          host = self.sock.getsockname()[0] # Get proper host
          if self.af == socket.AF_INET:
              resp = self.sendport(host, port)
          else:
              resp = self.sendeprt(host, port)
          if self.timeout is not _GLOBAL_DEFAULT_TIMEOUT:
              sock.settimeout(self.timeout)
          return sock
  
      def makepasv(self):
          if self.af == socket.AF_INET:
              host, port = parse227(self.sendcmd('PASV'))
          else:
              host, port = parse229(self.sendcmd('EPSV'), self.sock.getpeername())
          return host, port
  
      def ntransfercmd(self, cmd, rest=None):
          """Initiate a transfer over the data connection.
  
          If the transfer is active, send a port command and the
          transfer command, and accept the connection.  If the server is
          passive, send a pasv command, connect to it, and start the
          transfer command.  Either way, return the socket for the
          connection and the expected size of the transfer.  The
          expected size may be None if it could not be determined.
  
          Optional `rest' argument can be a string that is sent as the
          argument to a REST command.  This is essentially a server
          marker used to tell the server to skip over any data up to the
          given marker.
          """
          size = None
          if self.passiveserver:
              host, port = self.makepasv()
              conn = socket.create_connection((host, port), self.timeout,
                                              source_address=self.source_address)
              try:
                  if rest is not None:
                      self.sendcmd("REST %s" % rest)
                  resp = self.sendcmd(cmd)
                  # Some servers apparently send a 200 reply to
                  # a LIST or STOR command, before the 150 reply
                  # (and way before the 226 reply). This seems to
                  # be in violation of the protocol (which only allows
                  # 1xx or error messages for LIST), so we just discard
                  # this response.
                  if resp[0] == '2':
                      resp = self.getresp()
                  if resp[0] != '1':
                      raise error_reply(resp)
              except:
                  conn.close()
                  raise
          else:
              with self.makeport() as sock:
                  if rest is not None:
                      self.sendcmd("REST %s" % rest)
                  resp = self.sendcmd(cmd)
                  # See above.
                  if resp[0] == '2':
                      resp = self.getresp()
                  if resp[0] != '1':
                      raise error_reply(resp)
                  conn, sockaddr = sock.accept()
                  if self.timeout is not _GLOBAL_DEFAULT_TIMEOUT:
                      conn.settimeout(self.timeout)
          if resp[:3] == '150':
              # this is conditional in case we received a 125
              size = parse150(resp)
          return conn, size
  
      def transfercmd(self, cmd, rest=None):
          """Like ntransfercmd() but returns only the socket."""
          return self.ntransfercmd(cmd, rest)[0]
  
      def login(self, user = '', passwd = '', acct = ''):
          '''Login, default anonymous.'''
          if not user:
              user = 'anonymous'
          if not passwd:
              passwd = ''
          if not acct:
              acct = ''
          if user == 'anonymous' and passwd in {'', '-'}:
              # If there is no anonymous ftp password specified
              # then we'll just use anonymous@
              # We don't send any other thing because:
              # - We want to remain anonymous
              # - We want to stop SPAM
              # - We don't want to let ftp sites to discriminate by the user,
              #   host or country.
              passwd = passwd + 'anonymous@'
          resp = self.sendcmd('USER ' + user)
          if resp[0] == '3':
              resp = self.sendcmd('PASS ' + passwd)
          if resp[0] == '3':
              resp = self.sendcmd('ACCT ' + acct)
          if resp[0] != '2':
              raise error_reply(resp)
          return resp
  
      def retrbinary(self, cmd, callback, blocksize=8192, rest=None):
          """Retrieve data in binary mode.  A new port is created for you.
  
          Args:
            cmd: A RETR command.
            callback: A single parameter callable to be called on each
                      block of data read.
            blocksize: The maximum number of bytes to read from the
                       socket at one time.  [default: 8192]
            rest: Passed to transfercmd().  [default: None]
  
          Returns:
            The response code.
          """
          self.voidcmd('TYPE I')
          with self.transfercmd(cmd, rest) as conn:
              while 1:
                  data = conn.recv(blocksize)
                  if not data:
                      break
                  callback(data)
              # shutdown ssl layer
              if _SSLSocket is not None and isinstance(conn, _SSLSocket):
                  conn.unwrap()
          return self.voidresp()
  
      def retrlines(self, cmd, callback = None):
          """Retrieve data in line mode.  A new port is created for you.
  
          Args:
            cmd: A RETR, LIST, or NLST command.
            callback: An optional single parameter callable that is called
                      for each line with the trailing CRLF stripped.
                      [default: print_line()]
  
          Returns:
            The response code.
          """
          if callback is None:
              callback = print_line
          resp = self.sendcmd('TYPE A')
          with self.transfercmd(cmd) as conn, \
                   conn.makefile('r', encoding=self.encoding) as fp:
              while 1:
                  line = fp.readline(self.maxline + 1)
                  if len(line) > self.maxline:
                      raise Error("got more than %d bytes" % self.maxline)
                  if self.debugging > 2:
                      print('*retr*', repr(line))
                  if not line:
                      break
                  if line[-2:] == CRLF:
                      line = line[:-2]
                  elif line[-1:] == '\n':
                      line = line[:-1]
                  callback(line)
              # shutdown ssl layer
              if _SSLSocket is not None and isinstance(conn, _SSLSocket):
                  conn.unwrap()
          return self.voidresp()
  
      def storbinary(self, cmd, fp, blocksize=8192, callback=None, rest=None):
          """Store a file in binary mode.  A new port is created for you.
  
          Args:
            cmd: A STOR command.
            fp: A file-like object with a read(num_bytes) method.
            blocksize: The maximum data size to read from fp and send over
                       the connection at once.  [default: 8192]
            callback: An optional single parameter callable that is called on
                      each block of data after it is sent.  [default: None]
            rest: Passed to transfercmd().  [default: None]
  
          Returns:
            The response code.
          """
          self.voidcmd('TYPE I')
          with self.transfercmd(cmd, rest) as conn:
              while 1:
                  buf = fp.read(blocksize)
                  if not buf:
                      break
                  conn.sendall(buf)
                  if callback:
                      callback(buf)
              # shutdown ssl layer
              if _SSLSocket is not None and isinstance(conn, _SSLSocket):
                  conn.unwrap()
          return self.voidresp()
  
      def storlines(self, cmd, fp, callback=None):
          """Store a file in line mode.  A new port is created for you.
  
          Args:
            cmd: A STOR command.
            fp: A file-like object with a readline() method.
            callback: An optional single parameter callable that is called on
                      each line after it is sent.  [default: None]
  
          Returns:
            The response code.
          """
          self.voidcmd('TYPE A')
          with self.transfercmd(cmd) as conn:
              while 1:
                  buf = fp.readline(self.maxline + 1)
                  if len(buf) > self.maxline:
                      raise Error("got more than %d bytes" % self.maxline)
                  if not buf:
                      break
                  if buf[-2:] != B_CRLF:
                      if buf[-1] in B_CRLF: buf = buf[:-1]
                      buf = buf + B_CRLF
                  conn.sendall(buf)
                  if callback:
                      callback(buf)
              # shutdown ssl layer
              if _SSLSocket is not None and isinstance(conn, _SSLSocket):
                  conn.unwrap()
          return self.voidresp()
  
      def acct(self, password):
          '''Send new account name.'''
          cmd = 'ACCT ' + password
          return self.voidcmd(cmd)
  
      def nlst(self, *args):
          '''Return a list of files in a given directory (default the current).'''
          cmd = 'NLST'
          for arg in args:
              cmd = cmd + (' ' + arg)
          files = []
          self.retrlines(cmd, files.append)
          return files
  
      def dir(self, *args):
          '''List a directory in long form.
          By default list current directory to stdout.
          Optional last argument is callback function; all
          non-empty arguments before it are concatenated to the
          LIST command.  (This *should* only be used for a pathname.)'''
          cmd = 'LIST'
          func = None
          if args[-1:] and type(args[-1]) != type(''):
              args, func = args[:-1], args[-1]
          for arg in args:
              if arg:
                  cmd = cmd + (' ' + arg)
          self.retrlines(cmd, func)
  
      def mlsd(self, path="", facts=[]):
          '''List a directory in a standardized format by using MLSD
          command (RFC-3659). If path is omitted the current directory
          is assumed. "facts" is a list of strings representing the type
          of information desired (e.g. ["type", "size", "perm"]).
  
          Return a generator object yielding a tuple of two elements
          for every file found in path.
          First element is the file name, the second one is a dictionary
          including a variable number of "facts" depending on the server
          and whether "facts" argument has been provided.
          '''
          if facts:
              self.sendcmd("OPTS MLST " + ";".join(facts) + ";")
          if path:
              cmd = "MLSD %s" % path
          else:
              cmd = "MLSD"
          lines = []
          self.retrlines(cmd, lines.append)
          for line in lines:
              facts_found, _, name = line.rstrip(CRLF).partition(' ')
              entry = {}
              for fact in facts_found[:-1].split(";"):
                  key, _, value = fact.partition("=")
                  entry[key.lower()] = value
              yield (name, entry)
  
      def rename(self, fromname, toname):
          '''Rename a file.'''
          resp = self.sendcmd('RNFR ' + fromname)
          if resp[0] != '3':
              raise error_reply(resp)
          return self.voidcmd('RNTO ' + toname)
  
      def delete(self, filename):
          '''Delete a file.'''
          resp = self.sendcmd('DELE ' + filename)
          if resp[:3] in {'250', '200'}:
              return resp
          else:
              raise error_reply(resp)
  
      def cwd(self, dirname):
          '''Change to a directory.'''
          if dirname == '..':
              try:
                  return self.voidcmd('CDUP')
              except error_perm as msg:
                  if msg.args[0][:3] != '500':
                      raise
          elif dirname == '':
              dirname = '.'  # does nothing, but could return error
          cmd = 'CWD ' + dirname
          return self.voidcmd(cmd)
  
      def size(self, filename):
          '''Retrieve the size of a file.'''
          # The SIZE command is defined in RFC-3659
          resp = self.sendcmd('SIZE ' + filename)
          if resp[:3] == '213':
              s = resp[3:].strip()
              return int(s)
  
      def mkd(self, dirname):
          '''Make a directory, return its full pathname.'''
          resp = self.voidcmd('MKD ' + dirname)
          # fix around non-compliant implementations such as IIS shipped
          # with Windows server 2003
          if not resp.startswith('257'):
              return ''
          return parse257(resp)
  
      def rmd(self, dirname):
          '''Remove a directory.'''
          return self.voidcmd('RMD ' + dirname)
  
      def pwd(self):
          '''Return current working directory.'''
          resp = self.voidcmd('PWD')
          # fix around non-compliant implementations such as IIS shipped
          # with Windows server 2003
          if not resp.startswith('257'):
              return ''
          return parse257(resp)
  
      def quit(self):
          '''Quit, and close the connection.'''
          resp = self.voidcmd('QUIT')
          self.close()
          return resp
  
      def close(self):
          '''Close the connection without assuming anything about it.'''
          try:
              file = self.file
              self.file = None
              if file is not None:
                  file.close()
          finally:
              sock = self.sock
              self.sock = None
              if sock is not None:
                  sock.close()
  
  try:
      import ssl
  except ImportError:
      _SSLSocket = None
  else:
      _SSLSocket = ssl.SSLSocket
  
      class FTP_TLS(FTP):
          '''A FTP subclass which adds TLS support to FTP as described
          in RFC-4217.
  
          Connect as usual to port 21 implicitly securing the FTP control
          connection before authenticating.
  
          Securing the data connection requires user to explicitly ask
          for it by calling prot_p() method.
  
          Usage example:
          >>> from ftplib import FTP_TLS
          >>> ftps = FTP_TLS('ftp.python.org')
          >>> ftps.login()  # login anonymously previously securing control channel
          '230 Guest login ok, access restrictions apply.'
          >>> ftps.prot_p()  # switch to secure data connection
          '200 Protection level set to P'
          >>> ftps.retrlines('LIST')  # list directory content securely
          total 9
          drwxr-xr-x   8 root     wheel        1024 Jan  3  1994 .
          drwxr-xr-x   8 root     wheel        1024 Jan  3  1994 ..
          drwxr-xr-x   2 root     wheel        1024 Jan  3  1994 bin
          drwxr-xr-x   2 root     wheel        1024 Jan  3  1994 etc
          d-wxrwxr-x   2 ftp      wheel        1024 Sep  5 13:43 incoming
          drwxr-xr-x   2 root     wheel        1024 Nov 17  1993 lib
          drwxr-xr-x   6 1094     wheel        1024 Sep 13 19:07 pub
          drwxr-xr-x   3 root     wheel        1024 Jan  3  1994 usr
          -rw-r--r--   1 root     root          312 Aug  1  1994 welcome.msg
          '226 Transfer complete.'
          >>> ftps.quit()
          '221 Goodbye.'
          >>>
          '''
          ssl_version = ssl.PROTOCOL_TLS_CLIENT
  
          def __init__(self, host='', user='', passwd='', acct='', keyfile=None,
                       certfile=None, context=None,
                       timeout=_GLOBAL_DEFAULT_TIMEOUT, source_address=None):
              if context is not None and keyfile is not None:
                  raise ValueError("context and keyfile arguments are mutually "
                                   "exclusive")
              if context is not None and certfile is not None:
                  raise ValueError("context and certfile arguments are mutually "
                                   "exclusive")
              if keyfile is not None or certfile is not None:
                  import warnings
                  warnings.warn("keyfile and certfile are deprecated, use a "
                                "custom context instead", DeprecationWarning, 2)
              self.keyfile = keyfile
              self.certfile = certfile
              if context is None:
                  context = ssl._create_stdlib_context(self.ssl_version,
                                                       certfile=certfile,
                                                       keyfile=keyfile)
              self.context = context
              self._prot_p = False
              FTP.__init__(self, host, user, passwd, acct, timeout, source_address)
  
          def login(self, user='', passwd='', acct='', secure=True):
              if secure and not isinstance(self.sock, ssl.SSLSocket):
                  self.auth()
              return FTP.login(self, user, passwd, acct)
  
          def auth(self):
              '''Set up secure control connection by using TLS/SSL.'''
              if isinstance(self.sock, ssl.SSLSocket):
                  raise ValueError("Already using TLS")
              if self.ssl_version >= ssl.PROTOCOL_TLS:
                  resp = self.voidcmd('AUTH TLS')
              else:
                  resp = self.voidcmd('AUTH SSL')
              self.sock = self.context.wrap_socket(self.sock,
                                                   server_hostname=self.host)
              self.file = self.sock.makefile(mode='r', encoding=self.encoding)
              return resp
  
          def ccc(self):
              '''Switch back to a clear-text control connection.'''
              if not isinstance(self.sock, ssl.SSLSocket):
                  raise ValueError("not using TLS")
              resp = self.voidcmd('CCC')
              self.sock = self.sock.unwrap()
              return resp
  
          def prot_p(self):
              '''Set up secure data connection.'''
              # PROT defines whether or not the data channel is to be protected.
              # Though RFC-2228 defines four possible protection levels,
              # RFC-4217 only recommends two, Clear and Private.
              # Clear (PROT C) means that no security is to be used on the
              # data-channel, Private (PROT P) means that the data-channel
              # should be protected by TLS.
              # PBSZ command MUST still be issued, but must have a parameter of
              # '0' to indicate that no buffering is taking place and the data
              # connection should not be encapsulated.
              self.voidcmd('PBSZ 0')
              resp = self.voidcmd('PROT P')
              self._prot_p = True
              return resp
  
          def prot_c(self):
              '''Set up clear text data connection.'''
              resp = self.voidcmd('PROT C')
              self._prot_p = False
              return resp
  
          # --- Overridden FTP methods
  
          def ntransfercmd(self, cmd, rest=None):
              conn, size = FTP.ntransfercmd(self, cmd, rest)
              if self._prot_p:
                  conn = self.context.wrap_socket(conn,
                                                  server_hostname=self.host)
              return conn, size
  
          def abort(self):
              # overridden as we can't pass MSG_OOB flag to sendall()
              line = b'ABOR' + B_CRLF
              self.sock.sendall(line)
              resp = self.getmultiline()
              if resp[:3] not in {'426', '225', '226'}:
                  raise error_proto(resp)
              return resp
  
      __all__.append('FTP_TLS')
      all_errors = (Error, OSError, EOFError, ssl.SSLError)
  
  
  _150_re = None
  
  def parse150(resp):
      '''Parse the '150' response for a RETR request.
      Returns the expected transfer size or None; size is not guaranteed to
      be present in the 150 message.
      '''
      if resp[:3] != '150':
          raise error_reply(resp)
      global _150_re
      if _150_re is None:
          import re
          _150_re = re.compile(
              r"150 .* \((\d+) bytes\)", re.IGNORECASE | re.ASCII)
      m = _150_re.match(resp)
      if not m:
          return None
      return int(m.group(1))
  
  
  _227_re = None
  
  def parse227(resp):
      '''Parse the '227' response for a PASV request.
      Raises error_proto if it does not contain '(h1,h2,h3,h4,p1,p2)'
      Return ('host.addr.as.numbers', port#) tuple.'''
  
      if resp[:3] != '227':
          raise error_reply(resp)
      global _227_re
      if _227_re is None:
          import re
          _227_re = re.compile(r'(\d+),(\d+),(\d+),(\d+),(\d+),(\d+)', re.ASCII)
      m = _227_re.search(resp)
      if not m:
          raise error_proto(resp)
      numbers = m.groups()
      host = '.'.join(numbers[:4])
      port = (int(numbers[4]) << 8) + int(numbers[5])
      return host, port
  
  
  def parse229(resp, peer):
      '''Parse the '229' response for an EPSV request.
      Raises error_proto if it does not contain '(|||port|)'
      Return ('host.addr.as.numbers', port#) tuple.'''
  
      if resp[:3] != '229':
          raise error_reply(resp)
      left = resp.find('(')
      if left < 0: raise error_proto(resp)
      right = resp.find(')', left + 1)
      if right < 0:
          raise error_proto(resp) # should contain '(|||port|)'
      if resp[left + 1] != resp[right - 1]:
          raise error_proto(resp)
      parts = resp[left + 1:right].split(resp[left+1])
      if len(parts) != 5:
          raise error_proto(resp)
      host = peer[0]
      port = int(parts[3])
      return host, port
  
  
  def parse257(resp):
      '''Parse the '257' response for a MKD or PWD request.
      This is a response to a MKD or PWD request: a directory name.
      Returns the directoryname in the 257 reply.'''
  
      if resp[:3] != '257':
          raise error_reply(resp)
      if resp[3:5] != ' "':
          return '' # Not compliant to RFC 959, but UNIX ftpd does this
      dirname = ''
      i = 5
      n = len(resp)
      while i < n:
          c = resp[i]
          i = i+1
          if c == '"':
              if i >= n or resp[i] != '"':
                  break
              i = i+1
          dirname = dirname + c
      return dirname
  
  
  def print_line(line):
      '''Default retrlines callback to print a line.'''
      print(line)
  
  
  def ftpcp(source, sourcename, target, targetname = '', type = 'I'):
      '''Copy file from one FTP-instance to another.'''
      if not targetname:
          targetname = sourcename
      type = 'TYPE ' + type
      source.voidcmd(type)
      target.voidcmd(type)
      sourcehost, sourceport = parse227(source.sendcmd('PASV'))
      target.sendport(sourcehost, sourceport)
      # RFC 959: the user must "listen" [...] BEFORE sending the
      # transfer request.
      # So: STOR before RETR, because here the target is a "user".
      treply = target.sendcmd('STOR ' + targetname)
      if treply[:3] not in {'125', '150'}:
          raise error_proto  # RFC 959
      sreply = source.sendcmd('RETR ' + sourcename)
      if sreply[:3] not in {'125', '150'}:
          raise error_proto  # RFC 959
      source.voidresp()
      target.voidresp()
  
  
  def test():
      '''Test program.
      Usage: ftp [-d] [-r[file]] host [-l[dir]] [-d[dir]] [-p] [file] ...
  
      -d dir
      -l list
      -p password
      '''
  
      if len(sys.argv) < 2:
          print(test.__doc__)
          sys.exit(0)
  
      import netrc
  
      debugging = 0
      rcfile = None
      while sys.argv[1] == '-d':
          debugging = debugging+1
          del sys.argv[1]
      if sys.argv[1][:2] == '-r':
          # get name of alternate ~/.netrc file:
          rcfile = sys.argv[1][2:]
          del sys.argv[1]
      host = sys.argv[1]
      ftp = FTP(host)
      ftp.set_debuglevel(debugging)
      userid = passwd = acct = ''
      try:
          netrcobj = netrc.netrc(rcfile)
      except OSError:
          if rcfile is not None:
              sys.stderr.write("Could not open account file"
                               " -- using anonymous login.")
      else:
          try:
              userid, acct, passwd = netrcobj.authenticators(host)
          except KeyError:
              # no account for host
              sys.stderr.write(
                      "No account -- using anonymous login.")
      ftp.login(userid, passwd, acct)
      for file in sys.argv[2:]:
          if file[:2] == '-l':
              ftp.dir(file[2:])
          elif file[:2] == '-d':
              cmd = 'CWD'
              if file[2:]: cmd = cmd + ' ' + file[2:]
              resp = ftp.sendcmd(cmd)
          elif file == '-p':
              ftp.set_pasv(not ftp.passiveserver)
          else:
              ftp.retrbinary('RETR ' + file, \
                             sys.stdout.write, 1024)
      ftp.quit()
  
  
  if __name__ == '__main__':
      test()
  