UDP broadcast error

[lilzz]

Code: Select all

import socket, time, os
from socket import gethostname

host = ''                               # Bind to all interfaces
port = 51423

#gw=[default, via, 10.0.0.1, dev, wlan0]

gw=os.popen("ip -4 route show default").read().split()
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)                
s.connect((gw[2],0))
myip=s.getsockname()[0]
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)   #broadcasr

#gethostname=raspberrypi
#myip = socket.gethostbyaddr(socket.gethostname())
print 'My IP',myip

# XX: assumes /24 address
broadcastip = socket.inet_ntoa(socket.inet_aton(myip)[:3] + b'\xff' )
print 'LAN broadcast', broadcastip


addr=(broadcastip, port)

data='Pi IP@'+myip
print 'send string is', data

s.bind((' ', port))                  #socket binding to any host

while True:
	s.sendto(data, addr)
	time.sleep(3)				#sleep 3 seconds

s.bind((' ', port)) causes an error, it said No address associate with hostname. how do i fix it.

[Douglas6]

I'm guessing the "any server" should be a null string. You've got one space in there. I think it wants to be

Code: Select all

s.bind(('', port)) 

[DougieLawson]

I'm guessing the "any server" should be a null string. You've got one space in there. I think it wants to be

Code: Select all

s.bind(('', port)) 

INADDR_ANY for IPv4 is 0.0.0.0

So if a null string doesn't work try

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s.bind(('0.0.0.0', port))

[lilzz]

Hi, Both approaches still give me errors.

only way works is if I comment it out

#s.bind(('', port))

is bind function necessary for board casting ?