Add DNS to O2 wireless box

#!/bin/bash
# Add or list DNS entries in an 02 wireless box
# To compensate for O2's unreliable DNS provision

# h/u/p for standard O2 wireless box
host=192.168.1.254
user=SuperUser
pass=O2Br0ad64nd

# OpenDNS server to add
# Can be overridden on command prompt
dns=4.2.2.2
metric=5

# First argument either:
if [ "$1" != "" ]; then
  # -h to list usage
  if [ "$1" == "-h" ]; then
    echo "Usage: $0 [x.x.x.x|list] [weight]"
    exit
  fi
  # DNS entry
  dns="$1"
  # Or "list" command: see below
fi

# Second argument is the metric for the DNS entry
if [ "$2" != "" ]; then
  metric="$2"
fi

# Standard command to send over telnet
cmd="dns server route add dns=$dns intf=O2_ADSL2plus metric=$metric"
# Replace with completely different command if we want to list all routes
if [ "$1" == "list" ]; then
  cmd="dns server route list"
fi

# Pipe session into telnet command
( echo open $host
echo ^]set echo ^
sleep 1
echo -e "${user}\r"
sleep 1
echo -e "${pass}\r"
sleep 1
echo -e "$cmd\r"
sleep 1
echo -e "quit\r" ) | telnet