Checking for diacritics with a regular expression

Question

Simple problem: an existing project allows me to add additional fields (with additional checks on those fields as regular expressions) to support custom input forms. And I

Answer 1

You can use the specific Unicode escape for letters - \p{L} (this will include the A-Za-z ranges):

^[.\p{L}]*$

See on regularexpressions.info:

\p{L} or \p{Letter}

Matches a single Unicode code point that has the property "letter". See Unicode Character Properties in the tutorial for a complete list of properties. Each Unicode code point has exactly one property. Can be used inside character classes.