How to Stop Digital Thieves with CGIWritten by Steve Humphrey
I'm going to assume you're serious about your business. If you're not, I can't help you anyway. You've gone as far as getting a real merchant account to accept credit card payments online.
You know that this was neither easy or cheap. So does everyone else! So, a merchant account shows that you've made a serious commitment to your business. That's good for customer confidence, which is good for business. So far so good...
Now there's issue of selling stuff to people online. Your order form leads them to feed their credit card info to a secure gateway, using software you bought or leased from (or through) your merchant account provider. Finally, transaction is approved or denied.
If approved, software generates a receipt and emails you and customer each a copy. At this point, customer is returned to a page you specified. In case of downloadable products, this is often page where they download your product. So, you've got entire process fully automated.
For a product or service with a fairly low price point and a potential for many thousands of sales, this seems ideal. You can quite literally make sales and earn income 24 hours a day. So, what's problem?
The form code on your order page is problem. If someone uses ViewSource function of their browser, they can see all your code. If they have even a tiny bit of initiative and skill, they can locate URL of your download page. After all, it's right there in your form code!
CGI provides two ways of fixing this problem. One involves using a script that makes it impossible to view source code. You can find a source for such a script by searching web. Expect to pay a lot for this technology.
Another way is to make return path a script instead of actual download location. The script would be used to create and display download page. It would not be visible to surfer, since it's not an HTML document. The script can also record details of transaction for book-keeping purposes.
Quick Intro to PHP DevelopmentWritten by Alan Grissett
Chances are that if you’ve been around Internet long enough, you’ve heard of server-side scripting languages such as PERL, ASP and ColdFusion. These are all popular languages that are used to add interactivity to Web sites, but one stands out from crowd in terms of usability, power, and, yes, price: PHP scripting language. Initially developed in 1995 by North Carolina programmer Rasmus Lerdorf, PHP has since blossomed into one of leading open-source, cross-platform scripting languages available. This is due, in large part, to worldwide community of coders that contributes to its development. Unlike proprietary scripting languages like ASP and ColdFusion, PHP’s source code is freely available for peer review and contributions. This is, of course, essence of open-source software development, but why is it that PHP in particular has gained such popularity among Web developers when there are other open-source alternatives, such as good old-fashioned PERL CGI scripts?
One very strong reason is that PHP, unlike PERL CGI scripts, is scalable and fast. Instead of requiring server to start a new process in operating system’s kernel for each new request, which uses both CPU time and memory, PHP can run as a part of Web server itself, which saves a considerable amount of processing time when dealing with multiple requests. This decreased processing time means that PHP can be used for high-traffic sites that cannot afford to have their performance hampered by relatively slow CGI scripts.
In addition to its scalability and speed, another usability factor that sets PHP apart is its ease of use. The PHP language is considered to be a mix between C and PERL, and it draws from best features of each parent language, while adding unique features of its own. For example, PHP code can be embedded within standard HTML documents without using additional print statements or calling separate scripts to perform processing tasks. In practice, this allows for very flexible programming practices. Although a working knowledge of HTML is a prerequisite for PHP development, PHP’s basic functions can be learned quickly and applied to a wide range of common Webmaster-related projects, such as order forms, e-mail responses, and interactive Web pages.