UDP listener using socat

listen_udp.sh

#!/bin/bash

# listen_feed.sh 224.0.31.130 14382 ens6d1 out_file
# Runs: socat udp-datagram:224.0.31.130:14382,bind=:14382,ip-add-membership=224.0.31.130:ens6d1 /dev/null > out_file

UDP_ADDRESS="224.0.31.130"
UDP_PORT="14382"
INTERFACE="ens6d1"

if [ $# -ne 3 ] && [ $# -ne 4 ]; then
    echo "Example usage: $0 224.0.31.130 14382 ens6d1 <out_file>"
    echo "<out_file> is optional. Default is to pipe to console using hexdump"
    exit 255
fi
UDP_ADDRESS="$1"
UDP_PORT="$2"
INTERFACE="$3"
OUTFILE="$4"

## Alternate command, blocks other apps: socat udp-datagram:$UDP_ADDRESS:$UDP_PORT,bind=:$UDP_PORT,ip-add-membership=$UDP_ADDRESS:$INTERFACE - |
socat udp-recvfrom:$UDP_PORT,ip-add-membership=$UDP_ADDRESS:$INTERFACE,fork,reuseaddr - |
if [ "$OUTFILE" == "" ]; then
    tee /dev/null | hexdump -C
else
    tee /dev/null > $OUTFILE
fi