Don't fall for the "dollar mistake" here. Remember that $ doesn't match end of string: it matches "end of string or just before a newline at end of string".

This means that you could have "123423453456456756786789789a89ab\n" in your string, and it'd still match. While this may not make any difference for your application, in some cases this could be a missed crucial check for a security validation, allowing a messy character where it doesn't belong (such as in a filename).

Beware the dollar. Use \z instead: /^[0-9a-f]{32}\z/i.

-- Randal L. Schwartz, Perl hacker

In reply to Re^2: hex-only regex by merlyn
in thread hex-only regex by dwhite20899

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