Some useful functions working with CJK processing

libcjk.php

<?php
// Flora LibCjk by LeaskH.com

/**
 * Dictionary:
 * http://plugins.svn.wordpress.org/sil-dictionary-webonary/trunk/include/dictionary-search.php
 * http://stackoverflow.com/questions/5074161/what-is-the-most-efficient-way-to-whitelist-utf-8-characters-in-php
 */
function get_CJK_unicode_ranges() {
    return array(
        '[\x{2E80}-\x{2EFF}]',   # CJK Radicals Supplement
        '[\x{2F00}-\x{2FDF}]',   # Kangxi Radicals
        '[\x{2FF0}-\x{2FFF}]',   # Ideographic Description Characters
        '[\x{3000}-\x{303F}]',   # CJK Symbols and Punctuation
        '[\x{3040}-\x{309F}]',   # Hiragana
        '[\x{30A0}-\x{30FF}]',   # Katakana
        '[\x{3100}-\x{312F}]',   # Bopomofo
        '[\x{3130}-\x{318F}]',   # Hangul Compatibility Jamo
        '[\x{3190}-\x{319F}]',   # Kanbun
        '[\x{31A0}-\x{31BF}]',   # Bopomofo Extended
        '[\x{31F0}-\x{31FF}]',   # Katakana Phonetic Extensions
        '[\x{3200}-\x{32FF}]',   # Enclosed CJK Letters and Months
        '[\x{3300}-\x{33FF}]',   # CJK Compatibility
        '[\x{3400}-\x{4DBF}]',   # CJK Unified Ideographs Extension A
        '[\x{4DC0}-\x{4DFF}]',   # Yijing Hexagram Symbols
        '[\x{4E00}-\x{9FFF}]',   # CJK Unified Ideographs
        '[\x{A000}-\x{A48F}]',   # Yi Syllables
        '[\x{A490}-\x{A4CF}]',   # Yi Radicals
        '[\x{AC00}-\x{D7AF}]',   # Hangul Syllables
        '[\x{F900}-\x{FAFF}]',   # CJK Compatibility Ideographs
        '[\x{FE30}-\x{FE4F}]',   # CJK Compatibility Forms
        '[\x{1D300}-\x{1D35F}]', # Tai Xuan Jing Symbols
        '[\x{20000}-\x{2A6DF}]', # CJK Unified Ideographs Extension B
        '[\x{2F800}-\x{2FA1F}]', # CJK Compatibility Ideographs Supplement
    );
}

function checkCjk($string) {
    return preg_match('/' . implode('|', get_CJK_unicode_ranges()) . '/u', $string);
}