@Immutable
    public static int strncasecmp(String value1, String value2, int len) {
        int len1 = value1.length();
        int len2 = value2.length();
        String _value1 = len1 <= len ? value1 : value1.substring(0, len);
        String _value2 = len2 <= len ? value2 : value2.substring(0, len);

        return _value1.compareToIgnoreCase(_value2);
    }
Parses the cslashes bitmap returning an actual bitmap.

@param charset the bitmap string

@return the actual bitmap
exts/jphp-zend-ext/src/main/java/org/develnext/jphp/zend/ext/standard/StringFunctions.java