Library import 16 (#2433)

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1 files changed, 966 insertions, 0 deletions

diff --git a/contrib/tools/python3/Lib/ftplib.py b/contrib/tools/python3/Lib/ftplib.py
new file mode 100644
index 0000000000..10c5d1ea08
--- /dev/null
+++ b/contrib/tools/python3/Lib/ftplib.py
@@ -0,0 +1,966 @@
+"""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, source_address, encoding
+
+    The first four arguments are all strings, and have default value ''.
+    The parameter ´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.
+    The last parameter is the encoding of filenames, which defaults to utf-8.
+
+    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 = True
+    # Disables https://bugs.python.org/issue43285 security if set to True.
+    trust_server_pasv_ipv4_address = False
+
+    def __init__(self, host='', user='', passwd='', acct='',
+                 timeout=_GLOBAL_DEFAULT_TIMEOUT, source_address=None, *,
+                 encoding='utf-8'):
+        """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()).
+        """
+        self.encoding = encoding
+        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 self.timeout is not None and not self.timeout:
+            raise ValueError('Non-blocking socket (timeout=0) is not supported')
+        if source_address is not None:
+            self.source_address = source_address
+        sys.audit("ftplib.connect", self, self.host, self.port)
+        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')
+        sys.audit("ftplib.sendcmd", self, line)
+        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.'''
+        sock = socket.create_server(("", 0), family=self.af, backlog=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):
+        """Internal: Does the PASV or EPSV handshake -> (address, port)"""
+        if self.af == socket.AF_INET:
+            untrusted_host, port = parse227(self.sendcmd('PASV'))
+            if self.trust_server_pasv_ipv4_address:
+                host = untrusted_host
+            else:
+                host = self.sock.getpeername()[0]
+        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 data := conn.recv(blocksize):
+                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 buf := fp.read(blocksize):
+                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 not isinstance(args[-1], str):
+            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.'
+        >>>
+        '''
+
+        def __init__(self, host='', user='', passwd='', acct='',
+                     *, context=None, timeout=_GLOBAL_DEFAULT_TIMEOUT,
+                     source_address=None, encoding='utf-8'):
+            if context is None:
+                context = ssl._create_stdlib_context()
+            self.context = context
+            self._prot_p = False
+            super().__init__(host, user, passwd, acct,
+                             timeout, source_address, encoding=encoding)
+
+        def login(self, user='', passwd='', acct='', secure=True):
+            if secure and not isinstance(self.sock, ssl.SSLSocket):
+                self.auth()
+            return super().login(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.context.protocol >= 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 = super().ntransfercmd(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: ftplib [-d] [-r[file]] host [-l[dir]] [-d[dir]] [-p] [file] ...
+
+    Options:
+      -d        increase debugging level
+      -r[file]  set alternate ~/.netrc file
+
+    Commands:
+      -l[dir]   list directory
+      -d[dir]   change the current directory
+      -p        toggle passive and active mode
+      file      retrieve the file and write it to stdout
+    '''
+
+    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:
+            print("Could not open account file -- using anonymous login.",
+                  file=sys.stderr)
+    else:
+        try:
+            userid, acct, passwd = netrcobj.authenticators(host)
+        except (KeyError, TypeError):
+            # no account for host
+            print("No account -- using anonymous login.", file=sys.stderr)
+    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.buffer.write, 1024)
+            sys.stdout.buffer.flush()
+        sys.stdout.flush()
+    ftp.quit()
+
+
+if __name__ == '__main__':
+    test()