# Client for the DICT protocol (RFC2229)
#
# Copyright (C) 2002 John Goerzen
#
# 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
# Retrieved from: http://gopher.quux.org:80/devel
import socket, re
version = '1.0'
def dequote(s):
"""Will remove single or double quotes from the start and end of a string
and return the result."""
quotechars = "'\""
while len(s) and s[0] in quotechars:
s = s[1:]
while len(s) and s[-1] in quotechars:
s = s[0:-1]
return s
def enquote(s):
"""This function will put a string in double quotes, properly
escaping any existing double quotes with a backslash. It will
return the result."""
return '"%s"' % s.replace('"', "\\\"")
class Connection:
"""This class is used to establish a connection to a database server.
You will usually use this as the first call into the dictclient library.
Instantiating it takes two optional arguments: a hostname (a string)
and a port (an int). The hostname defaults to localhost
and the port to 2628, the port specified in RFC."""
def __init__(self, hostname='localhost', port=2628):
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.connect((hostname, port))
self.rfile = self.sock.makefile("rt")
self.wfile = self.sock.makefile("wt", 0)
self.saveconnectioninfo()
def getresultcode(self):
"""Generic function to get a result code. It will return a list
consisting of two items: the integer result code and the text
following. You will not usually use this function directly."""
line = self.rfile.readline().strip()
code, text = line.split(' ', 1)
return [int(code), text]
def get200result(self):
"""Used when expecting a single line of text -- a 200-class
result. Returns [intcode, remaindertext]"""
code, text = self.getresultcode()
if code < 200 or code >= 300:
raise Exception, "Got '%s' when 200-class response expected" % \
line
return [code, text]
def get100block(self):
"""Used when expecting multiple lines of text -- gets the block
part only. Does not get any codes or anything! Returns a string."""
data = []
while 1:
line = self.rfile.readline().strip()
if line == '.':
break
data.append(line)
return "\n".join(data)
def get100result(self):
"""Used when expecting multiple lines of text, terminated by a period
and a 200 code. Returns: [initialcode, [bodytext_1lineperentry],
finalcode]"""
code, text = self.getresultcode()
if code < 100 or code >= 200:
raise Exception, "Got '%s' when 100-class response expected" % \
code
bodylines = self.get100block().split("\n")
code2 = self.get200result()[0]
return [code, bodylines, code2]
def get100dict(self):
"""Used when expecting a dictionary of results. Will read from
the initial 100 code, to a period and the 200 code."""
dict = {}
for line in self.get100result()[1]:
key, val = line.split(' ', 1)
dict[key] = dequote(val)
return dict
def saveconnectioninfo(self):
"""Called by __init__ to handle the initial connection. Will
save off the capabilities and messageid."""
code, string = self.get200result()
assert code == 220
m = re.search('<(.*)> (<.*>)$', string)
assert m is not None
capstr, msgid = m.groups()
self.capabilities = capstr.split('.')
self.messageid = msgid
def getcapabilities(self):
"""Returns a list of the capabilities advertised by the server."""
return self.capabilities
def getmessageid(self):
"""Returns the message id, including angle brackets."""
return self.messageid
def getdbdescs(self):
"""Gets a dict of available databases. The key is the db name
and the value is the db description. This command may generate
network traffic!"""
if hasattr(self, 'dbdescs'):
return self.dbdescs
self.sendcommand("SHOW DB")
self.dbdescs = self.get100dict()
return self.dbdescs
def getstratdescs(self):
"""Gets a dict of available strategies. The key is the strat
name and the value is the strat description. This call may
generate network traffic!"""
if hasattr(self, 'stratdescs'):
return self.stratdescs
self.sendcommand("SHOW STRAT")
self.stratdescs = self.get100dict()
return self.stratdescs
def getdbobj(self, dbname):
"""Gets a Database object corresponding to the database name passed
in. This function explicitly will *not* generate network traffic.
If you have not yet run getdbdescs(), it will fail."""
if not hasattr(self, 'dbobjs'):
self.dbobjs = {}
if self.dbobjs.has_key(dbname):
return self.dbobjs[dbname]
# We use self.dbdescs explicitly since we don't want to
# generate net traffic with this request!
if dbname != '*' and dbname != '!' and \
not dbname in self.dbdescs.keys():
raise Exception, "Invalid database name '%s'" % dbname
self.dbobjs[dbname] = Database(self, dbname)
return self.dbobjs[dbname]
def sendcommand(self, command):
"""Takes a command, without a newline character, and sends it to
the server."""
self.wfile.write(command + "\n")
def define(self, database, word):
"""Returns a list of Definition objects for each matching
definition. Parameters are the database name and the word
to look up. This is one of the main functions you will use
to interact with the server. Returns a list of Definition
objects. If there are no matches, an empty list is returned.
Note: database may be '*' which means to search all databases,
or '!' which means to return matches from the first database that
has a match."""
self.getdbdescs() # Prime the cache
if database != '*' and database != '!' and \
not database in self.getdbdescs():
raise Exception, "Invalid database '%s' specified" % database
self.sendcommand("DEFINE " + enquote(database) + " " + enquote(word))
code = self.getresultcode()[0]
retval = []
if code == 552:
# No definitions.
return []
if code != 150:
raise Exception, "Unknown code %d" % code
while 1:
code, text = self.getresultcode()
if code != 151:
break
m = re.search('^"(.+)" (\S+)', text)
assert m is not None
resultword, resultdb = m.groups()
defstr = self.get100block()
retval.append(Definition(self, self.getdbobj(resultdb),
resultword, defstr))
return retval
def match(self, database, strategy, word):
"""Gets matches for a query. Arguments are database name,
the strategy (see available ones in getstratdescs()), and the
pattern/word to look for. Returns a list of Definition objects.
If there is no match, an empty list is returned.
Note: database may be '*' which means to search all databases,
or '!' which means to return matches from the first database that
has a match."""
self.getstratdescs() # Prime the cache
self.getdbdescs() # Prime the cache
if not strategy in self.getstratdescs().keys():
raise Exception, "Invalid strategy '%s'" % strategy
if database != '*' and database != '!' and \
not database in self.getdbdescs().keys():
raise Exception, "Invalid database name '%s'" % database
self.sendcommand("MATCH %s %s %s" % (enquote(database),
enquote(strategy),
enquote(word)))
code = self.getresultcode()[0]
if code == 552:
# No Matches
return []
if code != 152:
raise Exception, "Unexpected code %d" % code
retval = []
for matchline in self.get100block().split("\n"):
matchdict, matchword = matchline.split(" ", 1)
retval.append(Definition(self, self.getdbobj(matchdict),
dequote(matchword)))
if self.getresultcode()[0] != 250:
raise Exception, "Unexpected end-of-list code %d" % code
return retval
class Database:
"""An object corresponding to a particular database in a server."""
def __init__(self, dictconn, dbname):
"""Initialize the object -- requires a Connection object and
a database name."""
self.conn = dictconn
self.name = dbname
def getname(self):
"""Returns the short name for this database."""
return self.name
def getdescription(self):
if hasattr(self, 'description'):
return self.description
if self.getname() == '*':
self.description = 'All Databases'
elif self.getname() == '!':
self.description = 'First matching database'
else:
self.description = self.conn.getdbdescs()[self.getname()]
return self.description
def getinfo(self):
"""Returns a string of info describing this database."""
if hasattr(self, 'info'):
return self.info
if self.getname() == '*':
self.info = "This special database will search all databases on the system."
elif self.getname() == '!':
self.info = "This special database will return matches from the first matching database."
else:
self.conn.sendcommand("SHOW INFO " + self.name)
self.info = "\n".join(self.conn.get100result()[1])
return self.info
def define(self, word):
"""Get a definition from within this database.
The argument, word, is the word to look up. The return value is the
same as from Connection.define()."""
return self.conn.define(self.getname(), word)
def match(self, strategy, word):
"""Get a match from within this database.
The argument, word, is the word to look up. The return value is
the same as from Connection.define()."""
return self.conn.match(self.getname(), strategy, word)
class Definition:
"""An object corresponding to a single definition."""
def __init__(self, dictconn, db, word, defstr = None):
"""Instantiate the object. Requires: a Connection object,
a Database object (NOT corresponding to '*' or '!' databases),
a word. Optional: a definition string. If not supplied,
it will be fetched if/when it is requested."""
self.conn = dictconn
self.db = db
self.word = word
self.defstr = defstr
def getdb(self):
"""Get the Database object corresponding to this definition."""
return self.db
def getdefstr(self):
"""Get the definition string (the actual content) of this
definition."""
if not self.defstr:
self.defstr = self.conn.define(self.getdb().getname(), self.word)[0].getdefstr()
return self.defstr
def getword(self):
"""Get the word this object describes."""
return self.word
