#!/bin/bash

# Copyright (C) 2014 Multi-Tech Systems

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

if [[ $# != 1 ]]; then
	echo "Usage: $(basename $0) APN"
	exit 1
fi

apn=$1
chat_file=/etc/ppp/peers/gsm_chat

sed -r -i "s/^OK\s+'AT\+CGDCONT=1,\"IP\",\"[^\"]*\"'$/OK 'AT\+CGDCONT=1,\"IP\",\"${apn}\"'/" $chat_file

if [[ $? != 0 ]]; then
	echo "Failed to change APN"
	exit 1
else
	echo "Set APN to \"${apn}\" in $chat_file"
fi

exit 0