Perl script monitors payments and feedback in eBay sales
Watchful Seller

We show how to use a screen-scraper and an application for the official eBay API to trigger an alarm on incoming eBay customer feedback and detect errors in the monthly billing statement.
If I ever get around to writing my memoirs, I am going to include a lengthy chapter about my life's motto, which is: "Anything you don't constantly monitor is guaranteed to go belly up when you least expect it." True to this motto, I wrote a script this month to receive an email immediately when one of my eBay customers has left feedback about a transaction.
Simply Scraping
As a quick and dirty solution, and to first avoid having to register as a developer with eBay, I wrote a screen-scraper that extracts the current feedback score from the slew of HTML on the feedback page, before saving the counter and raising the alarm during subsequent runs if the value has increased.
When I click on my username on eBay.com, the browser lands on the feedback page in Figure 1. Selecting view-source
in the browser shows the HTML code from Figure 2, and a text search for the string 362
(the current feedback score) shows that this number is found in a markup tag of the mbg-l
class:
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