def _parse_PASS(self):
self._parse_command_space("PASS")
try:
self._cur_command = PASSCommand(self._parse_string())
except ParsingError as err:
err.error_desc = "password"
raise
def _parse_USER(self):
self._parse_command_space("USER")
try:
self._cur_command = USERCommand(self._parse_string())
except ParsingError as err:
err.error_desc = "username"
raise
def _parse_TYPE(self):
self._parse_command_space("TYPE")
m = re.match(grammar["type-code"], self._cur_sub_string())
if m is None:
raise ParsingError("type-code")
else:
self._cur_pos += m.end(0)
self._cur_command = TYPECommand(m.group("typecode"))
def _parse_PORT(self):
self._parse_command_space("PORT")
m = re.match(grammar["host-port"], self._cur_sub_string())
if m is None:
raise ParsingError("host-port")
else:
self._cur_pos += m.end(m.lastindex)
self._cur_command = PORTCommand(m.group("hostaddress"),
m.group("portnumber"))
def _parse_RETR(self):
self._parse_command_space("RETR")
try:
s = self._parse_string()
if s[0] == "\\" or s[0] == "/":
s = s[1:]
self._cur_command = RETRCommand(s)
except ParsingError as err:
err.error_desc = "pathname"
raise
class Parser:
def __init__(self, target_string=""):
self._str = target_string
self._cur_pos = 0
self._len = len(self._str)
self._parse_method_list = \
[self._parse_USER,self._parse_PASS,self._parse_TYPE,
self._parse_SYST,self._parse_NOOP,self._parse_QUIT,
self._parse_RETR,self._parse_PORT]
self._cur_err = None
self._cur_command = None
self._server = None
# _cur_pos is the position to be read
def connect_server(self, server):
self._server = server
@property
def string_to_parse(self):
return self._str
@string_to_parse.setter
def string_to_parse(self, string_to_parse):
self._str = string_to_parse
def parse_command(self, callback=None):
self._cur_pos = 0
self._cur_command = None
self._cur_err = None
#sys.stdout.write(self._str)
pos = self._cur_pos
suc = False
for par in self._parse_method_list:
self._cur_pos = pos
try:
par()
self._parse_CRLF()
suc = True
break
except FirstWordError as er:
self._cur_err = er
continue
except ParsingError as er:
self._cur_err = er
break
if suc:
self._do_success(callback)
return self._cur_command
else:
self._do_error(callback)
def _parse_USER(self):
self._parse_command_space("USER")
try:
self._cur_command = USERCommand(self._parse_string())
except ParsingError as err:
err.error_desc = "username"
raise
def _parse_PASS(self):
self._parse_command_space("PASS")
try:
self._cur_command = PASSCommand(self._parse_string())
except ParsingError as err:
err.error_desc = "password"
raise
def _parse_RETR(self):
self._parse_command_space("RETR")
try:
s = self._parse_string()
if s[0] == "\\" or s[0] == "/":
s = s[1:]
self._cur_command = RETRCommand(s)
except ParsingError as err:
err.error_desc = "pathname"
raise
def _parse_PORT(self):
self._parse_command_space("PORT")
m = re.match(grammar["host-port"], self._cur_sub_string())
if m is None:
raise ParsingError("host-port")
else:
self._cur_pos += m.end(m.lastindex)
self._cur_command = PORTCommand(m.group("hostaddress"),
m.group("portnumber"))
def _parse_TYPE(self):
self._parse_command_space("TYPE")
m = re.match(grammar["type-code"], self._cur_sub_string())
if m is None:
raise ParsingError("type-code")
else:
self._cur_pos += m.end(0)
self._cur_command = TYPECommand(m.group("typecode"))
def _parse_SYST(self):
self._parse_single_command("SYST")
self._cur_command = SYSTCommand()
def _parse_NOOP(self):
self._parse_single_command("NOOP")
self._cur_command = NOOPCommand()
def _parse_QUIT(self):
self._parse_single_command("QUIT")
self._cur_command = QUITCommand()
def _parse_single_command(self, command_string):
m = re.match(r"(?i)" + command_string, self._cur_sub_string())
if m is None:
raise FirstWordError()
else:
self._cur_pos += m.end(0)
def _parse_command_space(self, command_string):
self._parse_single_command(command_string)
m = re.match(grammar["spaces"], self._cur_sub_string())
if m is None:
raise FirstWordError()
else:
self._cur_pos += m.end(0)
def _parse_string(self):
r = re.compile(grammar["string"])
m = r.match(self._cur_sub_string())
## Check for ascii-ness
if m is None or len(m.group(0)) != len(m.group(0).encode()):
raise ParsingError("string")
else:
self._cur_pos += m.end(0)
return m.group(0)
def _parse_CRLF(self):
r = re.compile(grammar["CRLF"])
m = r.match(self._cur_sub_string())
if m is None:
raise ParsingError("CRLF")
else:
self._cur_pos += m.end(0)
def _cur_sub_string(self):
return self.string_to_parse[self._cur_pos:]
def _do_error(self, callback=None):
if callback is not None:
callback(self._cur_err)
else:
sys.stdout.write(self._cur_err.error_message())
def _do_success(self, callback=None):
if callback is not None:
callback(self._cur_command)
else:
self._cur_command.reply()
def _parse_QUIT(self):
self._parse_single_command("QUIT")
self._cur_command = QUITCommand()
def _parse_NOOP(self):
self._parse_single_command("NOOP")
self._cur_command = NOOPCommand()
def _parse_SYST(self):
self._parse_single_command("SYST")
self._cur_command = SYSTCommand()