cpython/Lib/ftplib.py

408 lines
11 KiB
Python

# An FTP client class. Based on RFC 959: File Transfer Protocol
# (FTP), by J. Postel and J. Reynolds
# Example:
#
# >>> from ftplib import FTP
# >>> ftp = FTP().init('ftp.cwi.nl') # connect to host, default port
# >>> ftp.login() # default, i.e.: user anonymous, passwd user@hostname
# >>> def handle_one_line(line): # callback for ftp.retrlines
# ... print line
# ...
# >>> ftp.retrlines('LIST', handle_one_line) # list directory contents
# total 43
# d--x--x--x 2 root root 512 Jul 1 16:50 bin
# d--x--x--x 2 root root 512 Sep 16 1991 etc
# drwxr-xr-x 2 root ftp 10752 Sep 16 1991 lost+found
# drwxr-srwt 15 root ftp 10240 Nov 5 20:43 pub
# >>> ftp.quit()
#
# To download a file, use ftp.retrlines('RETR ' + filename, handle_one_line),
# or ftp.retrbinary() with slightly different arguments.
# To upload a file, use ftp.storlines() or ftp.storbinary(), which have
# an open file as argument.
# The download/upload functions first issue appropriate TYPE and PORT
# commands.
import os
import sys
import socket
import string
# Magic number from <socket.h>
MSG_OOB = 0x1 # Process data out of band
# The standard FTP server control port
FTP_PORT = 21
# Exception raised when an error or invalid response is received
error_reply = 'ftplib.error_reply' # unexpected [123]xx reply
error_temp = 'ftplib.error_temp' # 4xx errors
error_perm = 'ftplib.error_perm' # 5xx errors
error_proto = 'ftplib.error_proto' # 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_reply, error_temp, error_perm, error_proto, \
socket.error, IOError)
# Line terminators (we always output CRLF, but accept any of CRLF, CR, LF)
CRLF = '\r\n'
# Next port to be used by makeport(), with PORT_OFFSET added
# (This is now only used when the python interpreter doesn't support
# the getsockname() method yet)
nextport = 0
PORT_OFFSET = 40000
PORT_CYCLE = 1000
# The class itself
class FTP:
# Initialize an instance. Arguments:
# - host: hostname to connect to
# - port: port to connect to (default the standard FTP port)
def init(self, host, *args):
if len(args) > 1: raise TypeError, 'too many args'
if args: port = args[0]
else: port = FTP_PORT
self.host = host
self.port = port
self.debugging = 0
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.connect(self.host, self.port)
self.file = self.sock.makefile('r')
self.welcome = self.getresp()
return self
# Get the welcome message from the server
# (this is read and squirreled away by init())
def getwelcome(self):
if self.debugging: print '*welcome*', `self.welcome`
return self.welcome
# Set the debugging level. 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
def debug(self, level):
self.debugging = level
# Internal: send one line to the server, appending CRLF
def putline(self, line):
line = line + CRLF
if self.debugging > 1: print '*put*', `line`
self.sock.send(line)
# Internal: send one command to the server (through putline())
def putcmd(self, line):
if self.debugging: print '*cmd*', `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()
if self.debugging > 1:
print '*get*', `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*', `resp`
self.lastresp = resp[:3]
c = resp[:1]
if c == '4':
raise error_temp, resp
if c == '5':
raise error_perm, resp
if c not in '123':
raise error_proto, resp
return resp
# Expect a response beginning with '2'
def voidresp(self):
resp = self.getresp()
if resp[0] <> '2':
raise error_reply, resp
# 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.
def abort(self):
line = 'ABOR' + CRLF
if self.debugging > 1: print '*put urgent*', `line`
self.sock.send(line, MSG_OOB)
resp = self.getmultiline()
if resp[:3] not in ('426', '226'):
raise error_proto, resp
# Send a command and return the response
def sendcmd(self, cmd):
self.putcmd(cmd)
return self.getresp()
# Send a command and expect a response beginning with '2'
def voidcmd(self, cmd):
self.putcmd(cmd)
self.voidresp()
# Send a PORT command with the current host and the given port number
def sendport(self, port):
hostname = socket.gethostname()
hostaddr = socket.gethostbyname(hostname)
hbytes = string.splitfields(hostaddr, '.')
pbytes = [`port/256`, `port%256`]
bytes = hbytes + pbytes
cmd = 'PORT ' + string.joinfields(bytes, ',')
self.voidcmd(cmd)
# Create a new socket and send a PORT command for it
def makeport(self):
global nextport
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
getsockname = sock.getsockname
except AttributeError:
if self.debugging > 1:
print '*** getsockname not supported',
print '-- using manual port assignment ***'
port = nextport + PORT_OFFSET
nextport = (nextport + 1) % PORT_CYCLE
sock.bind('', port)
getsockname = None
sock.listen(0) # Assigns the port if not explicitly bound
if getsockname:
host, port = getsockname()
resp = self.sendport(port)
return sock
# Send a port command and a transfer command, accept the connection
# and return the socket for the connection
def transfercmd(self, cmd):
sock = self.makeport()
resp = self.sendcmd(cmd)
if resp[0] <> '1':
raise error_reply, resp
conn, sockaddr = sock.accept()
return conn
# Login, default anonymous
def login(self, *args):
user = passwd = acct = ''
n = len(args)
if n > 3: raise TypeError, 'too many arguments'
if n > 0: user = args[0]
if n > 1: passwd = args[1]
if n > 2: acct = args[2]
if not user: user = 'anonymous'
if user == 'anonymous' and passwd in ('', '-'):
thishost = socket.gethostname()
if os.environ.has_key('LOGNAME'):
realuser = os.environ['LOGNAME']
elif os.environ.has_key('USER'):
realuser = os.environ['USER']
else:
realuser = 'anonymous'
passwd = passwd + realuser + '@' + thishost
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
# Retrieve data in binary mode.
# The argument is a RETR command.
# The callback function is called for each block.
# This creates a new port for you
def retrbinary(self, cmd, callback, blocksize):
self.voidcmd('TYPE I')
conn = self.transfercmd(cmd)
while 1:
data = conn.recv(blocksize)
if not data:
break
callback(data)
conn.close()
self.voidresp()
# Retrieve data in line mode.
# The argument is a RETR or LIST command.
# The callback function is called for each line, with trailing
# CRLF stripped. This creates a new port for you
def retrlines(self, cmd, callback):
resp = self.sendcmd('TYPE A')
conn = self.transfercmd(cmd)
fp = conn.makefile('r')
while 1:
line = fp.readline()
if not line:
break
if line[-2:] == CRLF:
line = line[:-2]
elif line[:-1] == '\n':
line = line[:-1]
callback(line)
fp.close()
conn.close()
self.voidresp()
# Store a file in binary mode
def storbinary(self, cmd, fp, blocksize):
self.voidcmd('TYPE I')
conn = self.transfercmd(cmd)
while 1:
buf = fp.read(blocksize)
if not buf: break
conn.send(buf)
conn.close()
self.voidresp()
# Store a file in line mode
def storlines(self, cmd, fp):
self.voidcmd('TYPE A')
conn = self.transfercmd(cmd)
while 1:
buf = fp.readline()
if not buf: break
if buf[-2:] <> CRLF:
if buf[-1] in CRLF: buf = buf[:-1]
buf = buf + CRLF
conn.send(buf)
conn.close()
self.voidresp()
# Return a list of files in a given directory (default the current)
def nlst(self, *args):
cmd = 'NLST'
for arg in args:
cmd = cmd + (' ' + arg)
files = []
self.retrlines(cmd, files.append)
return files
# Rename a file
def rename(self, fromname, toname):
resp = self.sendcmd('RNFR ' + fromname)
if resp[0] <> '3':
raise error_reply, resp
self.voidcmd('RNTO ' + toname)
# Change to a directory
def cwd(self, dirname):
self.voidcmd('CWD ' + dirname)
# Retrieve the size of a file
def size(self, filename):
resp = self.sendcmd('SIZE ' + filename)
if resp[:3] == '213':
return string.atoi(string.strip(resp[3:]))
# Make a directory, return its full pathname
def mkd(self, dirname):
resp = self.sendcmd('MKD ' + dirname)
return parse257(resp)
# Return current wording directory
def pwd(self):
resp = self.sendcmd('PWD')
return parse257(resp)
# Quit, and close the connection
def quit(self):
self.voidcmd('QUIT')
self.close()
# Close the connection without assuming anything about it
def close(self):
self.file.close()
self.sock.close()
del self.file, self.sock
# Parse a response type 257
def parse257(resp):
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
# Test program.
# Usage: ftp [-d] host [-l[dir]] [-d[dir]] [file] ...
def test():
import marshal
global nextport
try:
nextport = marshal.load(open('.@nextport', 'r'))
except IOError:
pass
try:
debugging = 0
while sys.argv[1] == '-d':
debugging = debugging+1
del sys.argv[1]
host = sys.argv[1]
ftp = FTP().init(host)
ftp.debug(debugging)
ftp.login()
def writeln(line): print line
for file in sys.argv[2:]:
if file[:2] == '-l':
cmd = 'LIST'
if file[2:]: cmd = cmd + ' ' + file[2:]
ftp.retrlines(cmd, writeln)
elif file[:2] == '-d':
cmd = 'CWD'
if file[2:]: cmd = cmd + ' ' + file[2:]
resp = ftp.sendcmd(cmd)
else:
ftp.retrbinary('RETR ' + file, \
sys.stdout.write, 1024)
ftp.quit()
finally:
marshal.dump(nextport, open('.@nextport', 'w'))