php源码分析之DZX1.5字符串截断函数cutstr用法

本文实例讲述了php源码分析之DZX1.5字符串截断函数cutstr用法。分享给大家供大家参考。具体分析如下：

    <?php 
    /**
     * 函数来源DZX1.5，文件所在 /source/function/function_core.php
     */
    define('CHARSET','UTF-8');
    function cutstr($string, $length, $dot="...") {
      if(strlen($string)<=$length) {
        return $string;
      }
      if(strtolower(CHARSET) == "utf-8") {
        $n = $tn = $noc = 0;
        while($n < strlen($string)) {
          $t = ord($string[$n]);
          if($t == 9 || $t == 10 || (32 <= $t && $t <= 126)) {
            $tn = 1; $n++; $noc++;
          } elseif(194 <= $t && $t <= 223) {
            $tn = 2; $n += 2; $noc += 2;
          } elseif(224 <= $t && $t <= 239) {
            $tn = 3; $n += 3; $noc += 2;
          } elseif(240 <= $t && $t <= 247) {
            $tn = 4; $n += 4; $noc += 2;
          } elseif(248 <= $t && $t <= 251) {
            $tn = 5; $n += 5; $noc += 2;
          } elseif($t == 252 || $t == 253) {
            $tn = 6; $n += 6; $noc += 2;
          } else {
            $n++;
          }
          if($noc >= $length) {
            break;
          }
        }
        if($noc > $length) {
          $n -= $tn;
        }
        $strcut = substr($string, 0, $n);
      } else {
        for($i = 0; $i < $length; $i++) {
          $strcut .= ord($string[$i])>127 ? $string[$i].$string[++$i] : $string[$i];
        }
      }
      $pos = strrpos($strcut, chr(1));
      if($pos !== false) {
        $strcut = substr($strcut,0,$pos);
      }
      return $strcut.$dot;
    }
    $string = '测试数据库ablci102020@(#)!)!测试劳动力ddk';
    echo cutstr($string,15);
    /*End of php*/

运行结果如下：

测试数据库ablci1020...

希望本文所述对大家的php程序设计有所帮助。