dns

#!/bin/bash
#
# dns -- A simple tool to easily add/remove from the local hostfile
# so you don't need to fire up an editor to switch a domain
# back and forth between localhost when developing a website
#
#
# Copyright 2011 Derek Gallo. All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
#    1. Redistributions of source code must retain the above copyright notice,
#       this list of conditions and the following disclaimer.
# 
#    2. Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY DEREK GALLO ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
# EVENT SHALL DEREK GALLO OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
# OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# 
# The views and conclusions contained in the software and documentation are
# those of the authors and should not be interpreted as representing official
# policies, either expressed or implied, of Derek Gallo.
#

usage()
{
cat << EOF

Modify a dns host name locally on this machine.

dns <ip-address> <domain-name>

<ip-address>    - The ip address to point the domain name to. 
                - local = localhost
                - global = use DNS (remove hostfile entry)
<domain-name>   - domain name to add/remove to host database

EOF
}

IP=$1
DOMAIN=$2

if [[ -z $IP ]] || [[ -z $DOMAIN ]]
then
     usage
     exit 1
fi

#if global given then remove the hostname from the host file
if [ $IP == "global" ]
then
     sudo bash -c "sed /$DOMAIN/d /etc/hosts > /tmp/hosts"
	 # when attempting above command to output directly to /etc/hosts
	 # I get an empty hosts file. dunno why so using a tmp file and copying over
	 sudo cp /tmp/hosts /etc/hosts
     exit 0
fi

#if local was passed transform it to 127.0.0.1
if [ $IP == "local" ]
then
    IP="127.0.0.1"
fi

sudo bash -c "echo '$IP $DOMAIN' >> /etc/hosts"