I've got this regex that I'm trying to make work. Maybe I don't properly understand how negative look-behinds function. From what I understand in the docs, the following code (w/ regex):

$file = '_error' unless ($file =~ /\A(?<!compiled)a-zA-Z0-9]+\z/);

should do the same thing as this:

$file = '_error' if ( substr($file, 0, 8) eq 'compiled' or $file !~ /\Aa-zA-Z0-9]+\z/);

The code should set $file to '_error' if the variable is not all 'a-zA-Z0-9', or if the variable begins with the word 'compiled'. The second example works fine, but my regex doesn't. Any help?

Edited by planetscape - added code tags

In reply to Failed regex: negative look-behinds by loikiolki

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