My question pertains to this example:
#!/usr/bin/env python
import socket, sys, time
host = sys.argv[1]
textport = sys.argv[2]
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
try:
port = int(textport)
except ValueError:
# That didn't work. Look it up instread.
port = socket.getservbyname(textport, 'udp')
s.connect((host, port))
print "Enter data to transmit: "
data = sys.stdin.readline().strip()
s.sendall(data)
s.shutdown(1)
print "Looking for replies; press Ctrl-C or Ctrl-Break to stop."
while 1:
buf = s.recv(2048)
if not len(buf):
break
print "Received: %s" % buf
As far as I can tell, the if statement:
if not len(buf):
break
does nothing. Either recv() is going to read some data or it's going
to block. My understanding is that udp sockets do not have a
connection, so the server can't close the connection--hich would cause
a blank string to be sent to the client.
So, as far as I can tell, the only way that code would make sense is
if the server were programmed to send a blank string to the client
after it sent data to the client. Is that correct?
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