I'd do it with an allow list and substitution: 
$my_var =~ s/[^a-zA-Z0-9_@#$%]//g;
print "Bad length!" unless (length $my_var >= 8) && (length $my_var <=
+ 12);

[download]
This will remove all illegal characters, then complain if what's left is outside of the desired size range.

In reply to Re: pattern matching with specified length by dsheroh
in thread pattern matching with specified length by tariqahsan

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