bcast-ip

#!/usr/bin/env python3

import argparse
import socket
import sys

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('-l', action='store_true', help='listen to IP broadcast')
    parser.add_argument('name', help='broadcast name')
    args = parser.parse_args()

    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    if args.l:
        s.bind(('0.0.0.0', 9999))
        print('Waiting for IP broadcast (' + args.name + ')...', file=sys.stderr)
        while True:
            packet = s.recvfrom(1024)
            if packet[0].decode('utf-8') == 'bcast-ip ' + args.name:
                print('Accepting IP broadcast from ' + packet[1][0] + '.', file=sys.stderr)
                print(packet[1][0])
                break
    else:
        print('Broadcasting IP (' + args.name + ').', file=sys.stderr)
        s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
        s.sendto(('bcast-ip ' + args.name).encode('utf-8'), ('255.255.255.255', 9999))

if __name__ == '__main__':
    try: main()
    except KeyboardInterrupt: pass