This link will describe to you how to switch between ASCII characters and their corresponding numerical value.

Perl Cookbook Recipe 1.4. Converting Between ASCII Characters and Values

You can then step through the unpack'd string with a foreach loop to compare that numerical value with the values for alphabetic characters, A-Z(65-90) and a-z(97-122).
amt

Steve_p - Removed link to copyrighted material

In reply to Re: Challenge - Creative Way To Detect Alpha Characters by amt
in thread Challenge - Creative Way To Detect Alpha Characters by Limbic~Region

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