.NET Regular Expression to match any kind of letter from any language

Question

Which regular expression can I use to match (allow) any kind of letter from any language?

I need to match any letter including any diacritics (e.g., á, ü, ñ) and exclude any kind of symbol (math symbols, currency signs, dingbats, box-drawing characters, etc.) and punctuation characters.

I'm using ASP.NET MVC 2 with .NET 4. I’ve tried this annotation in my view model

[RegularExpression(@"\p{L}*", ...

and this one

[RegularExpression(@"\p{L}\p{M}*", ...

but client-side validation rejects accented characters.

UPDATE: Thank you for all your answers. Your suggestions work but only for .NET, and the problem here is that it also uses the regex for client-side validation with JavaScript.

I had to go with

[^0-9_\|°¬!#\$%/\\\(\)\?¡¿\+\{\}\[\]:\.\,;@ª^\*<>=&]

which is very ugly and does not cover all scenarios but is the closest thing to what I need.

Answer 1

\p{L}* should match "any kind of letter from any language". It should work, I used it in a i18n-proof uppercase/lowercase recognition regex in .NET.

Answer 2

Your problem is more likely to the fact that you will only have to have one alpha-char, because the regex will match anything that has at least one char.

By adding ^ as prefix and $ as postfix, the whole sentence should comply to your regex. So this prob works:

^\p{L}*$

Regexbuddy explains:

1. ^ Assert position at beginning of the string
2. \p{L} A character with the Unicode property 'letter' (any kind of letter from any kind of language) 2a. Between zero and unlimited times, as many as possible (greedy)
3. $ Assert position at the end of the string