php源码分析之DZX1.5字符串截断函数cutstr用法

<?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*/