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# ftp.py - handle urls with a ftp scheme
#
# Copyright (C) 1998, 1999 Albert Hopkins (marduk)
# Copyright (C) 2002 Mike W. Meyer
# Copyright (C) 2005 Arthur de Jong
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
"""This module defines the functions needed for creating Link objects for urls
using the ftp scheme."""
import urllib
import mimetypes
import ftplib
import urlparse
import string
import debugio
# FIXME: honor ftp proxy settings
# TODO: figure out a nicer way to close the connections with something like:
#try:
# debugio.debug("FTP: "+ftp.quit())
#except:
# debugio.debug("FTP: "+ftp.close())
# a map of netlocs to ftp connections
_ftpconnections = {}
def _getconnection(netloc):
"""Return a FTP connection object to the specified server."""
# NOTE: this method is not thread safe
if _ftpconnections.has_key(netloc):
return _ftpconnections[netloc]
# split url into useful parts
(userpass, host) = urllib.splituser(netloc)
if userpass is not None:
(user, passwd) = urllib.splitpasswd(userpass)
else:
(user, passwd) = ('anonymous', '')
(host, port) = urllib.splitnport(host,ftplib.FTP_PORT)
# initialize a new connection
ftp = ftplib.FTP()
debugio.debug('schemes.ftp._getconnection(): CONNECT: '+ftp.connect(host, port))
debugio.debug('schemes.ftp._getconnection(): LOGIN: '+ftp.login(user, passwd))
_ftpconnections[netloc] = ftp
return ftp
def _cwd(ftp, path):
"""Go down the path on the ftp server returning the part that cannot be
changed into."""
# split the path into directories
dirs = path.split('/')
try:
# decend down the tree
while len(dirs) > 0:
d = dirs[0]
if d != '':
debugio.debug('schemes.ftp._cwd(): CWD '+d+': '+ftp.cwd(d))
dirs.pop(0)
return None
except ftplib.error_perm, e:
debugio.debug('schemes.ftp._cwd(): CWD '+d+' : '+str(e))
return string.join(dirs,'/')
def fetch(link, acceptedtypes):
"""Fetch the specified link."""
# try to fetch the document
content = None
try:
ftp = _getconnection(link.netloc)
debugio.debug('schemes.ftp.fetch(): FTP: CWD / : '+ftp.cwd('/'))
# descend down the directory tree as far as we can go
path=urllib.unquote(link.path)
path=_cwd(ftp, path)
# check if we are dealing with an (exising) directory
if path is None:
# check that the url ends with a slash
if link.path[-1:] != '/':
debugio.debug('schemes.ftp.fetch(): directory referenced without trailing slash')
link.redirectdepth = 1
link.add_child(urlparse.urljoin(link.url,link.path+'/'))
else:
# add children
debugio.debug('schemes.ftp.fetch(): add files as children of this page')
link.ispage = True
debugio.debug('schemes.ftp.fetch(): TYPE A: '+ftp.voidcmd('TYPE A'))
# FIXME: this raises an exception for empty directories
for f in ftp.nlst():
link.add_child(urlparse.urljoin(link.url,urllib.quote(f)))
else:
# figure out the size of the document
link.size = ftp.size(path)
debugio.debug('schemes.ftp.fetch(): size='+str(link.size))
# guess the mimetype of the document
if link.mimetype is None:
link.mimetype = mimetypes.guess_type(path)[0]
# try to fetch file
if link.mimetype in acceptedtypes:
debugio.debug('schemes.ftp.fetch(): TYPE I: '+ftp.voidcmd('TYPE I'))
(conn, size) = ftp.ntransfercmd('RETR ' + path)
if size:
content = conn.makefile().read(size)
else:
content = conn.makefile().read()
debugio.debug('schemes.ftp.fetch(): fetched, size=%d' % len(content))
except ftplib.all_errors, e:
debugio.debug('schemes.ftp.fetch(): CAUGHT '+str(e))
link.add_problem(str(e))
# we're done
return content
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