/**
 * 
 * 中英混合字符串長度判斷 
 * @param unknown_type $str
 * @param unknown_type $charset
 */
function strLength($str, $charset = 'utf-8') {
  if ($charset == 'utf-8')
    $str = iconv ( 'utf-8', 'gb2312', $str );
  $num = strlen ( $str );
  $cnNum = 0;
  for($i = 0; $i < $num; $i ++) {
    if (ord ( substr ( $str, $i + 1, 1 ) ) > 127) {
      $cnNum ++;
      $i ++;
    }
  }
  $enNum = $num - ($cnNum * 2);
  $number = ($enNum / 2) + $cnNum;
  return ceil ( $number );
}

/**
 * 
 * 中英混合的字符串截取
 * @param unknown_type $sourcestr
 * @param unknown_type $cutlength
 */
function cut_str($sourcestr, $cutlength) {
  $returnstr = '';
  $i = 0;
  $n = 0;
  $str_length = strlen ( $sourcestr ); //字符串的字節(jié)數(shù) 
  while ( ($n < $cutlength) and ($i <= $str_length) ) {
    $temp_str = substr ( $sourcestr, $i, 1 );
    $ascnum = Ord ( $temp_str ); //得到字符串中第$i位字符的ascii碼 
    if ($ascnum >= 224) //如果ASCII位高與224，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 3 ); //根據(jù)UTF-8編碼規(guī)范，將3個連續(xù)的字符計(jì)為單個字符   
      $i = $i + 3; //實(shí)際Byte計(jì)為3
      $n ++; //字串長度計(jì)1
    } elseif ($ascnum >= 192) //如果ASCII位高與192，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 2 ); //根據(jù)UTF-8編碼規(guī)范，將2個連續(xù)的字符計(jì)為單個字符 
      $i = $i + 2; //實(shí)際Byte計(jì)為2
      $n ++; //字串長度計(jì)1
    } elseif ($ascnum >= 65 && $ascnum <= 90) //如果是大寫字母，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
      $i = $i + 1; //實(shí)際的Byte數(shù)仍計(jì)1個
      $n ++; //但考慮整體美觀，大寫字母計(jì)成一個高位字符
    } else //其他情況下，包括小寫字母和半角標(biāo)點(diǎn)符號，
    {
      $returnstr = $returnstr . substr ( $sourcestr, $i, 1 );
      $i = $i + 1; //實(shí)際的Byte數(shù)計(jì)1個
      $n = $n + 0.5; //小寫字母和半角標(biāo)點(diǎn)等與半個高位字符寬...
    }
  }
  if ($str_length > $cutlength) {
    $returnstr = $returnstr . "..."; //超過長度時在尾處加上省略號
  }
  return $returnstr;
}