simonitor

<a href="http://www.simon.com/giftcard/">
  <img class="right" src="simon_giftcard.jpg" /></a>

For privacy reasons, I use
[prepaid debit cards](privacy_through_prepaid_credit_cards) instead of
credit cards. Right now, I mostly use
[Simon gift cards](http://www.simon.com/giftcard/).

Like most prepaid card web sites,
[Simon's](http://www.simon.com/giftcard/card_balance.aspx) can show your
card's balance and transaction history in real time. However, it's a little
tedious to navigate the site and enter the card number and CCV each time.
So, I automated it.

[simonitor.sh](simonitor.sh) is a shell script that fetches the available
balance, expiration date, and address (if registered) for one or more
[Simon gift cards](http://www.simon.com/giftcard/). It uses
[curl](http://curl.haxx.se/) to POST each card number and CCV to
[Simon's web site](http://www.simon.com/), then handles the cookies, follows
links, and screen scrapes the resulting HTML.

Here's an example run:

    $ simonitor.sh 9999012345789/123 8888012345789/456#uber
    Enter the captcha string: ABC123
    99990123456789/123: $232.67, expires 08/2008
                        Joe Bob  Mountain View, CA 94043 650-123-4567
    88880123456789/456#uber: $39.91, expires 12/2008
                        Jimmy J  Mountain View, CA 94043 650-321-7654

Simon uses a [CAPTCHA](http://www.google.com/search?q=define%3Acaptcha) to
discourage bots. This script displays the CAPTCHA image to the user, asks them
for its text, and passes that text back to the site.

It also supports comments, e.g. the `#uber` after the second card. I store my
active cards in a file and use a command line like
<nobr><code>simonitor.sh &#96;cat my_cards&#96;</code></nobr>,
so I use comments to remind myself of cards set up with specific services.

Naturally, Simon tweaks their web site every now and then, which breaks this
script. When they do, I've found the
[Live HTTP Headers](http://livehttpheaders.mozdev.org/) Firefox plugin
indispensable for capturing the actual requests and POST data sent over the
wire.

I briefly considered writing a [Greasemonkey](http://greasemonkey.mozdev.org/)
script, but I have a small brain, and the shell script was simpler and didn't
need a browser.

`simonitor.sh` is in the public domain.