/*      real_escape_string(string)   */
static VALUE real_escape_string(VALUE obj, VALUE str)
{
    MYSQL* m = GetHandler(obj);
    VALUE ret;
    Check_Type(str, T_STRING);
    ret = rb_str_new(0, (RSTRING(str)->len)*2+1);
    RSTRING(ret)->len = mysql_real_escape_string(m, RSTRING(ret)->ptr, RSTRING(str)->ptr, RSTRING(str)->len);
    return ret;
}