how to send an int over a socket

[Tom Brown]

Hi,

I have what seems to be a simple problem. But I can not for the life of me
find a way to send an integer over a socket. The send method will only accept
strings. Here is what I am trying to do:

testmessage = 'test message'
msglen = len(testmessage)
sock.send(msglen)
sock.send(testmessage)

Now, I know I can do this:

testmessage = 'test message'
sock.send('\xC') # send hard coded length of testmessage in hex in string
sock.send(testmessage)

However, in my actual program I will not know the length of testmessage in
advance. So how do I convert msglen into a suitable format for the send
method?

Thanks,
Tom

 

[Paul Rubin]

However, in my actual program I will not know the length of testmessage in
advance. So how do I convert msglen into a suitable format for the send
method?

'123'

You might also look at

http://cr.yp.to/proto/netstrings.txt

which describes some issues you should pay attention to, and suggests
a standardized format.

 

[Pierre Quentel]

Use string formatting :

msglen = '%16s' %len(testmessage)

will return a 16-byte string, beginning with spaces. Send it over your
connection and use int() to get the message length

Pierre