Re: socket send help
Gabriel Genellina wrote: James Mills escribió: Bryan Olson wrote: I thought a firewall would block an attempt to bind to any routeable address, but not to localhost. So using INADDR_ANY would be rejected. No. My understanding is that firewalls block network traffic, not system calls. This is correct. Firewalls (real firewalls) can only act on incoming and outgoing traffic on the IP level. That's true for hardware firewalls (those found in a router, by example). They can at most analyze traffic at the application layer but have no idea of the applications (processes) behind. A software firewall may react not just to traffic but to *who* is doing that; it may block *processes* when they try to bind/listen to any port, even before any packet is sent or received. See http://www.securityfocus.com/infocus/1839 (One may argue whether those are *real* firewalls or not, but that's their common name...) Even if one's 'firewall' product is one of the rather useless ones that merely hook socket calls (in the words of the linked article), I still don't see failing a bind() to INADDR_ANY while allowing a bind() to 127.0.0.1. INADDR_ANY means all available adapters. If some physical network adapter should be unavailable while the loopback is allowed, fine; passing INADDR_ANY should work and bind to the loopback adapter. (Also note that I'm far for being an expert on these topics) Sure. I was mostly just making a couple points because at one time they confused me. Python's socket.bind() treats the empty string as INADDR_ANY, which means all available adapters. It's a fine address parameter for bind(), and ought to work at least as well as any. The time to bind() to localhost is when we specifically do not want to be available on an external network adapter. Now don't get me started on the vagaries of passing INADDR_ANY to connect(). -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
En Mon, 05 Jan 2009 22:59:46 -0200, James Mills prolo...@shortcircuit.net.au escribió: On Tue, Jan 6, 2009 at 10:49 AM, Bryan Olson fakeaddr...@nowhere.org wrote: I thought a firewall would block an attempt to bind to any routeable address, but not to localhost. So using INADDR_ANY would be rejected. No. My understanding is that firewalls block network traffic, not system calls. This is correct. Firewalls (real firewalls) can only act on incoming and outgoing traffic on the IP level. That's true for hardware firewalls (those found in a router, by example). They can at most analyze traffic at the application layer but have no idea of the applications (processes) behind. A software firewall may react not just to traffic but to *who* is doing that; it may block *processes* when they try to bind/listen to any port, even before any packet is sent or received. See http://www.securityfocus.com/infocus/1839 (One may argue whether those are *real* firewalls or not, but that's their common name...) (Also note that I'm far for being an expert on these topics) -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
En Sat, 03 Jan 2009 21:44:34 -0200, Bryan Olson fakeaddr...@nowhere.org escribió: Gabriel Genellina wrote: greyw...@gmail.com escribió: [...] A simple server: from socket import * myHost = '' Try with myHost = '127.0.0.1' instead - a firewall might be blocking your server. Just a nit: I'd say the reason to use '127.0.0.1' instead of the empty string is that a firewall might *not* be blocking your server. The Python sockets module interprets the empty string as INADDR_ANY, which means to bind to all available adapters including the loopback, A.K.A localhost, A.K.A '127.0.0.1'. I thought a firewall would block an attempt to bind to any routeable address, but not to localhost. So using INADDR_ANY would be rejected. -- Gabriel Genellina -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
Gabriel Genellina wrote: Bryan Olson escribió: Gabriel Genellina wrote: greyw...@gmail.com escribió: [...] A simple server: from socket import * myHost = '' Try with myHost = '127.0.0.1' instead - a firewall might be blocking your server. Just a nit: I'd say the reason to use '127.0.0.1' instead of the empty string is that a firewall might *not* be blocking your server. The Python sockets module interprets the empty string as INADDR_ANY, which means to bind to all available adapters including the loopback, A.K.A localhost, A.K.A '127.0.0.1'. I thought a firewall would block an attempt to bind to any routeable address, but not to localhost. So using INADDR_ANY would be rejected. So you thought this would fail at bind()? My understanding is that firewalls block network traffic, not system calls. -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
On Tue, Jan 6, 2009 at 10:49 AM, Bryan Olson fakeaddr...@nowhere.org wrote: I thought a firewall would block an attempt to bind to any routeable address, but not to localhost. So using INADDR_ANY would be rejected. No. My understanding is that firewalls block network traffic, not system calls. This is correct. Firewalls (real firewalls) can only act on incoming and outgoing traffic on the IP level. cheers James -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
On Wed, Dec 24, 2008 at 3:59 PM, greyw...@gmail.com greyw...@gmail.com wrote:
(snip)
If I run testserver.py via the cmd prompt in Windows XP and then the
testclient.py program, I get the following error:
Traceback (most recent call last):
File C:\Python30\testclient.py, line 12, in module
s.send('Hello world') # send the data
TypeError: send() argument 1 must be string or buffer, not str
This happens in 2.6 or 3.0 and with different example client server
programs from the web. What am I missing?
I'm sorry I should have answered sooner :)
Python 3.x (and probably 2.6+) required that you use
bytes to send your data through sockets rather than
strings. This was part of the revamp for better unicode
support irrc.
cheers
James
--
http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
Gabriel Genellina wrote: greyw...@gmail.com escribió: [...] A simple server: from socket import * myHost = '' Try with myHost = '127.0.0.1' instead - a firewall might be blocking your server. Just a nit: I'd say the reason to use '127.0.0.1' instead of the empty string is that a firewall might *not* be blocking your server. The Python sockets module interprets the empty string as INADDR_ANY, which means to bind to all available adapters including the loopback, A.K.A localhost, A.K.A '127.0.0.1'. -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
Hi again,
I've done some more playing around with socket and socketserver and
have discovered I can send strings or lists with socket.send() by
converting to bytes. But lists with strings in them or dicts can't be
converted by bytes(). How can I send those?
One idea I initially tried was to set up a server (host,port) for
receiving data and another one (host, different port) for strings, but
that didn't work so I was thinking of throwing everything into a list
or a dictionary and sending that but that's not working either.
Any ideas?
Thanks,
John.
On Dec 24, 12:03 am, Gabriel Genellina gagsl-...@yahoo.com.ar
wrote:
En Wed, 24 Dec 2008 03:59:42 -0200, greyw...@gmail.com
greyw...@gmail.com escribió:
New guy here. I'm trying to figure out sockets in order to one day do
a multiplayer game. Here's my problem: even the simplest examples
don't work on my computer:
A simple server:
fromsocketimport *
myHost = ''
Try with myHost = '127.0.0.1' instead - a firewall might be blocking your
server.
s.listen(5) # allow 5 simultaneous connections
Not exactly: your server program only handles a single connection at a
time. The 5 above specifies how many connections may exist on hold
waiting for you to accept() them.
connection.send('echo - ' + data)
That's fine for Python 2.6, but you must use b'echo - ' with 3.0
And a simple client:
s.send('Hello world') # send the data
Same as above, should be b'Hello world' with Python 3.0
If I run testserver.py via the cmd prompt in Windows XP and then the
testclient.py program, I get the following error:
Traceback (most recent call last):
File C:\Python30\testclient.py, line 12, in module
s.send('Hello world') # send the data
TypeError: send() argument 1 must be string or buffer, not str
The above error message is wrong (and I think it was corrected on the 3.0
final release; if you got it with 3.0 final, file a bug report at
http://bugs.python.org/)
This happens in 2.6 or 3.0 and with different example client server
programs from the web. What am I missing?
The error above surely comes from 3.0; with 2.6 you should get a different
error (if it fails at all). Try again with 2.6.1. I didn't run the code
but it looks fine -- if you got it from a book or article, unless it
explicitely says Python 3.0, assume it was written for the 2.x series.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
On Thu, Dec 25, 2008 at 10:08 PM, greyw...@gmail.com greyw...@gmail.com wrote: Hi again, I've done some more playing around with socket and socketserver and have discovered I can send strings or lists with socket.send() by converting to bytes. But lists with strings in them or dicts can't be converted by bytes(). How can I send those? If you're sending structured data rather than just bytestrings, you should use proper serialization. Use the `json`, `pickle`, or `marshal` modules to convert your data to an external representation in bytes, send the bytes thru the socket, then deserialize the bytes back into data structures using the same module again. The Python std lib docs are your friend. Merry Christmas, Chris -- Follow the path of the Iguana... http://rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
Chris Gabriel,
Thank you so much. My simple example now works. It was very
frustrating that even the simple example didn't work, so your help is
most appreciated.
b'hello world' was the key. As for the error, I do still get it with
3.0 final so I'll go ahead and report it.
John.
On Dec 24, 12:03 am, Gabriel Genellina gagsl-...@yahoo.com.ar
wrote:
En Wed, 24 Dec 2008 03:59:42 -0200, greyw...@gmail.com
greyw...@gmail.com escribió:
New guy here. I'm trying to figure out sockets in order to one day do
a multiplayer game. Here's my problem: even the simplest examples
don't work on my computer:
A simple server:
fromsocketimport *
myHost = ''
Try with myHost = '127.0.0.1' instead - a firewall might be blocking your
server.
s.listen(5) # allow 5 simultaneous connections
Not exactly: your server program only handles a single connection at a
time. The 5 above specifies how many connections may exist on hold
waiting for you to accept() them.
connection.send('echo - ' + data)
That's fine for Python 2.6, but you must use b'echo - ' with 3.0
And a simple client:
s.send('Hello world') # send the data
Same as above, should be b'Hello world' with Python 3.0
If I run testserver.py via the cmd prompt in Windows XP and then the
testclient.py program, I get the following error:
Traceback (most recent call last):
File C:\Python30\testclient.py, line 12, in module
s.send('Hello world') # send the data
TypeError: send() argument 1 must be string or buffer, not str
The above error message is wrong (and I think it was corrected on the 3.0
final release; if you got it with 3.0 final, file a bug report at
http://bugs.python.org/)
This happens in 2.6 or 3.0 and with different example client server
programs from the web. What am I missing?
The error above surely comes from 3.0; with 2.6 you should get a different
error (if it fails at all). Try again with 2.6.1. I didn't run the code
but it looks fine -- if you got it from a book or article, unless it
explicitely says Python 3.0, assume it was written for the 2.x series.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
socket send help
Hi everyone,
New guy here. I'm trying to figure out sockets in order to one day do
a multiplayer game. Here's my problem: even the simplest examples
don't work on my computer:
A simple server:
from socket import *
myHost = ''
myPort = 21500
s = socket(AF_INET, SOCK_STREAM)# create a TCP socket
s.bind((myHost, myPort))# bind it to the server port
s.listen(5) # allow 5 simultaneous connections
while True:
connection, address = s.accept()
while True:
data = connection.recv(1024)
if data:
connection.send('echo - ' + data)
else:
break
connection.close() # close socket
And a simple client:
import sys
from socket import *
serverHost = 'localhost'# servername is localhost
serverPort = 21500 # use arbitrary port 1024
s = socket(AF_INET, SOCK_STREAM)# create a TCP socket
s.connect((serverHost, serverPort)) # connect to server on the port
s.send('Hello world') # send the data
data = s.recv(1024) # receive up to 1K bytes
print(data)
If I run testserver.py via the cmd prompt in Windows XP and then the
testclient.py program, I get the following error:
Traceback (most recent call last):
File C:\Python30\testclient.py, line 12, in module
s.send('Hello world') # send the data
TypeError: send() argument 1 must be string or buffer, not str
This happens in 2.6 or 3.0 and with different example client server
programs from the web. What am I missing?
Thanks,
John R.
--
http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
On Tue, Dec 23, 2008 at 9:59 PM, greyw...@gmail.com greyw...@gmail.com wrote:
Hi everyone,
New guy here. I'm trying to figure out sockets in order to one day do
a multiplayer game. Here's my problem: even the simplest examples
don't work on my computer:
A simple server:
from socket import *
myHost = ''
myPort = 21500
s = socket(AF_INET, SOCK_STREAM)# create a TCP socket
s.bind((myHost, myPort))# bind it to the server port
s.listen(5) # allow 5 simultaneous connections
while True:
connection, address = s.accept()
while True:
data = connection.recv(1024)
if data:
connection.send('echo - ' + data)
else:
break
connection.close() # close socket
And a simple client:
import sys
from socket import *
serverHost = 'localhost'# servername is localhost
serverPort = 21500 # use arbitrary port 1024
s = socket(AF_INET, SOCK_STREAM)# create a TCP socket
s.connect((serverHost, serverPort)) # connect to server on the port
s.send('Hello world') # send the data
data = s.recv(1024) # receive up to 1K bytes
print(data)
If I run testserver.py via the cmd prompt in Windows XP and then the
testclient.py program, I get the following error:
Traceback (most recent call last):
File C:\Python30\testclient.py, line 12, in module
s.send('Hello world') # send the data
TypeError: send() argument 1 must be string or buffer, not str
This happens in 2.6 or 3.0 and with different example client server
programs from the web. What am I missing?
The text of the error message seems outdated (it should probably say
bytes or bytearray instead of string or buffer), but what it's
trying to say is that you can only send() bytes, not unicode strings.
For a byte literal, you need to add a 'b' prefix, e.g. b'Hello World'
Alternatively, you can encode the unicode into bytes using .encode(),
e.g. Hello World.encode('utf8')
Cheers,
Chris
--
Follow the path of the Iguana...
http://rebertia.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: socket send help
En Wed, 24 Dec 2008 03:59:42 -0200, greyw...@gmail.com
greyw...@gmail.com escribió:
New guy here. I'm trying to figure out sockets in order to one day do
a multiplayer game. Here's my problem: even the simplest examples
don't work on my computer:
A simple server:
from socket import *
myHost = ''
Try with myHost = '127.0.0.1' instead - a firewall might be blocking your
server.
s.listen(5) # allow 5 simultaneous connections
Not exactly: your server program only handles a single connection at a
time. The 5 above specifies how many connections may exist on hold
waiting for you to accept() them.
connection.send('echo - ' + data)
That's fine for Python 2.6, but you must use b'echo - ' with 3.0
And a simple client:
s.send('Hello world') # send the data
Same as above, should be b'Hello world' with Python 3.0
If I run testserver.py via the cmd prompt in Windows XP and then the
testclient.py program, I get the following error:
Traceback (most recent call last):
File C:\Python30\testclient.py, line 12, in module
s.send('Hello world') # send the data
TypeError: send() argument 1 must be string or buffer, not str
The above error message is wrong (and I think it was corrected on the 3.0
final release; if you got it with 3.0 final, file a bug report at
http://bugs.python.org/ )
This happens in 2.6 or 3.0 and with different example client server
programs from the web. What am I missing?
The error above surely comes from 3.0; with 2.6 you should get a different
error (if it fails at all). Try again with 2.6.1. I didn't run the code
but it looks fine -- if you got it from a book or article, unless it
explicitely says Python 3.0, assume it was written for the 2.x series.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
