Google says http://www.cgi101.com/class/ch4/text.html
Next is a rather complicated regular expression that substitutes every %HH hex pair back to its equivalent ASCII character, using the pack() function. We'll learn exactly how this works in Chapter 14, but for now we'll just use it to parse the form data: 

    $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;

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In reply to Re: A regexp from paypal by Anonymous Monk
in thread A regexp from paypal by davidov0009

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