Bash script to open remote erlang shell on firewalled box

remote-shell.sh

#!/bin/bash

if [ $# -ne 3 ]; then
echo "Usage: $0 hostname name cookie";
exit 1;
fi

HOST="$1"
NAME="$2"
COOKIE="$3"

CONTROL_PATH="remote-shell"
LOCAL_EPMD_PORT=$(($RANDOM + 1024))
LOCAL_SERVICE_PORT=$(($RANDOM + 1024))
REMOTE_EPMD_PORT=4369
REMOTE_SERVICE_PORT=$(ssh $HOST "epmd -names" | grep $NAME | awk '{print $5}')

ssh -M -S $CONTROL_PATH \
    -fNTL $LOCAL_EPMD_PORT:localhost:$REMOTE_EPMD_PORT \
    -fNTR $LOCAL_SERVICE_PORT:localhost:$LOCAL_SERVICE_PORT \
    -fNTL $REMOTE_SERVICE_PORT:localhost:$REMOTE_SERVICE_PORT $HOST

export ERL_EPMD_PORT=$LOCAL_EPMD_PORT

erl -name remote@127.0.0.1 \
    -kernel inet_dist_listen_min $LOCAL_SERVICE_PORT inet_dist_listen_max $LOCAL_SERVICE_PORT \
    -setcookie $COOKIE \
    -connect_all false

ssh -S $CONTROL_PATH -O exit $HOST