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CAPTCHA for PERL Uer
Notes and Fixes
Thousands of perl developers
have downloaded the captcha for perl program and added it to
their current programs. Here are a few useful ideas from some
webmasters that may be handy in your application of the script.
Windows CAPTCHA Fix
- I was clear in the description that I knew nothing about
windows and did not know if it would work on that o/s. Apparently,
it does work, but according to Jeff, you need a binmode statement
added to the captcha.cgi to keep the image from being distorted.
Here is what he says:
I came across your captcha.cgi
PERL script and noticed that on Windows it generated a garbled
verification image sometimes when the form loads. If you add:
binmode STDOUT;
to the captcha.cgi script directly above where you print out the
headers
(print "Content-type: image/jpeg\n";) it solves this
problem.
Image Reload Problems
- Many people have had issues with users backing up and trying to
submit the form after a captcha failure, since the old image is
cached and there is no file to verify against since there was
already a failure, it fails again and again. People don't know
what reload or refresh means, so you almost have to do it for
them.
Knut from Norway found the
answer with a simple java script link to reload the image
automatically. Here is what he offers:
<script language="javaScript">
function reloadCAPTCHA() {
document.getElementById('CAPTCHA').src='captcha.cgi?randomnumber?'+Date();
}
</script>
<a href="javascript:reloadCAPTCHA();">Load
New Code</a>
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