BigPond usage

#!/bin/bash

# All rights to this script are hereby disclaimed and its contents released
# into the public domain by the author.

###########################################
# EDIT THE VARIABLES BELOW TO MATCH YOUR ACCOUNT AND SYSTEM
###########################################

# If you leave the username blank, you will be prompted to enter it on the command line.
USERNAME="your_username@bigpond.com"

# If you leave the password blank, you will be prompted to enter it on the command line.
PASSWORD="your_password"

# Path to a writable directory to store temporary files.
TEMP_DIR=/tmp

# Path to the curl binary. You need version 7.18.0 or later.
CURL=/usr/bin/curl

# Path to the grep binary.
GREP=/bin/grep

# Path to html2text binary.
HTML2TEXT=/usr/bin/html2text

# Path to mktemp binary.
MKTEMP=/bin/mktemp

##############################################
# END OF USER VARIABLES. YOU SHOULDN'T NEED TO EDIT BELOW THIS LINE.
##############################################

# Function to check that a binary exists and is executable.
# Exits the script if either condition is false.
check_binary()
{
    if [ ! -f $1 ]
    then
        echo "$1 does not exist. Use your package manager to install it."
        exit -1
    fi

    if [ ! -x $1 ]
    then
        echo "$1 is not executable."
        exit -1
    fi
}

# Function to check that a directory exists and is writeable.
# Exits the script if either condition is false.
check_directory()
{
if [ ! -d $1 ]
    then
        echo "$1 is not a directory."
        exit -1
    fi

    if [ ! -w $1 ]
    then
        echo "$1 is not writeable."
        exit -1
    fi
}


check_binary $CURL
check_binary $HTML2TEXT
check_binary $GREP
check_binary $MKTEMP

check_directory $TEMP_DIR

# Prompt user to enter username if not provided above.
if [ "$USERNAME" == "" ]
then
    read -p "username>" USERNAME
fi

# Prompt user to enter password if not provided above.
if [ "$PASSWORD" == "" ]
then
    read -p "password>" PASSWORD
fi

LOGIN_PAGE="https://signon.bigpond.com/login"
MYACCOUNT_PAGE="https://myaccount.bigpond.com"
SERVICE_PAGE="/MyServices.do"
TEMP_HTML_FILE=$( $MKTEMP -u -p $TEMP_DIR XXXXXXXXXXXXXXXX )
TEMP_TEXT_FILE=$( $MKTEMP -u -p $TEMP_DIR XXXXXXXXXXXXXXXX )
COOKIE_FILE=$( $MKTEMP -u -p XXXXXXXXXXXXXXXX )
USER_AGENT="Mozilla/5.0"
CURL_OPTIONS="--insecure --silent --location"

# Setup a signal handler to cleanup when the script exits.
trap "{ rm -f $TEMP_HTML_FILE; rm -f $TEMP_TEXT_FILE; exit -1; }" EXIT

# First, login and access the service page.
$CURL $CURL_OPTIONS --user-agent \"$USER_AGENT\" --cookie \"$COOKIE_FILE\" --output $TEMP_HTML_FILE --data-urlencode goto=$SERVICE_PAGE --data-urlencode username=$USERNAME --data-urlencode password=$PASSWORD $LOGIN_PAGE?goto=$MYACCOUNT_PAGE$SERVICE_PAGE
if [ $? != 0 ]
then
    exit -1
fi

# Get the link to the usage page for this account.
USAGE_PAGE=$( $GREP MyServicesViewUsage $TEMP_HTML_FILE | cut -d\" -f2 )

# Remove the downloaded page.
rm $TEMP_HTML_FILE

# Download the usage page.
$CURL $CURL_OPTIONS --user-agent \"$USER_AGENT\" --cookie \"$COOKIE_FILE\" --output $TEMP_HTML_FILE --data-urlencode goto=$USAGE_PAGE --data-urlencode username=$USERNAME --data-urlencode password=$PASSWORD $LOGIN_PAGE?goto=$MYACCOUNT_PAGE$USAGE_PAGE
if [ $? != 0 ]
then
    exit -1
fi

# Convert the page to text for easy parsing.
$HTML2TEXT $TEMP_HTML_FILE > $TEMP_TEXT_FILE

$GREP -m 1 'Current Account Usage' $TEMP_TEXT_FILE
$GREP -m 1 'Monthly Plan Allowance' $TEMP_TEXT_FILE
$GREP -m 1 'Current Bill Period' $TEMP_TEXT_FILE