Q:

How to match Cyrillic characters with a regular expression

How do I match French and Russian Cyrillic alphabet characters with a regular expression?  I only want to do the alpha characters, no numbers or special characters.  Right now I have
[A-Za-z]

A:

If your regex flavor supports Unicode blocks ([\p{IsCyrillic}]), you can match Cyrillic characters with:
[\p{IsCyrillic}] or [\p{Cyrillic}]

Otherwise try using:
[U+0400–U+04FF]

For PHP use:
[\x{0400}-\x{04FF}]

Explanation:
[\p{IsCyrillic}]

Match a character from the Unicode block “Cyrillic” (U+0400–U+04FF) «[\p{IsCyrillic}]»

Note:
Unicode Characters list and Numeric HTML Entities of [U+0400–U+04FF] .

A:

It depends on your regex flavor. If it supports Unicode character classes (like .NET, for instance), \p{L} matches a letter character (in any character set).

A:

If you use modern PHP version - just:
preg_match("/^[\p{L}]+$/u");

Don't forget the u flag for unicode support!

