by Jacek Olszewski Menu software by
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Who or what submits a web form?Web forms, eg. blogs, guest books, web mail pages, wiki sites, etc are intended to be filled out and submitted by people. They may, however, be also filled out and submitted by so-called spam-bots, web crawling robots. The latter try to use them as means to spread their load amongst the form owners and to use email capabilities of the form processing scripts to send their load elsewhere if possible.A simple way to verify if the form is submitted by a real person rather than by a spam-bot is to display an image containing some random sequence of letters/digits, and to ask the visitor to type the sequence in the field provided for that purpose. What is simple and obvious for a person filling out the form, is practically impossible for a spam-bot. To do that, the latter would have to be able to:
Image verification tools for web forms have been known and used for a long time, especially in scripts written in PHP. A quick search through www.hotscripts.com for "image verification" reveals several ready to be used tools, all in PHP. Examples: http://www.reconn.us/random_image.htmlTo find such a tool in Perl seems hard, although many form scripts have been written in Perl and they are most likely still in use. After a few unsuccessful attempts to find one, I have written VVS (Visitor Verification Script) for web forms in Perl. It provides image verification tool for web forms, written entirely in Perl, and not requiring any modifications to the actual form processing scripts (actions), except for renaming them. To see how it works, click HERE. To get it, use downloads in the menu.
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