PHP file upload class example

<?php

define('NO_FILE', '不存在上传文件');

define('NOT_ALLOW_EXT', '文件类型不在允许范围内');

define('NOT_ALLOW_SIZE', '文件大小不在允许范围内');

define('HAS_THE_FILE', '该文件已经存在');

define('UPLOAD_FAILED', '上传失败');

define('UPLOAD_SUCCESS', '上传成功');

class file_uploader

{

  var $_file;

  var $_filesize;

  var $_fileext;

  var $_filedir;

  var $_filename;

  var $_filetmpname;

  var $allowsize;

  var $allowext;

  var $neednewname;

  var $newname;

  var $syslang;

  var $report;

  function ready($filedir = '', $file, $allowsize = '', $allowext = '', $neednewname = false, $report = 0){

    $this->_filedir = is_dir($filedir) ? $filedir : '';

    if(empty($file) || !isset($file['size']) || $file['size'] == 0) $this->error(NO_FILE);

    $this->_filesize = $file['size'];

    $this->_filename = $file['name'];

    $this->_filetmpname = $file['tmp_name'];

    $this->allowsize = $allowsize;

    $this->allowext = $allowext;

    $this->neednewname = ($neednewname) ? true : false;

    $this->newname = '';

    $this->report = $report;

  }

  function do_upload(){

    if(!is_uploaded_file($this->_filetmpname)) $this->error(NO_FILE);

    if($this->chk_ext()){

      $this->error(NOT_ALLOW_EXT);

      return '';

    }

    if($this->chk_size()){

      $this->error(NOT_ALLOW_SIZE);

      return '';

    }

    if($this->neednewname) $this->newname = $this->generate_name().".".$this->get_fileext();

    if($this->chk_hasfile()){

      $this->error(HAS_THE_FILE);

      return '';

    }

    $filename = empty($this->newname) ? @iconv('utf-8','gb2312',$this->_filename) : $this->newname;

    @chmod($this->_filedir.$filename, 0777);

    if(move_uploaded_file($this->_filetmpname, $this->_filedir.$filename)){

      return $this->result();

    }else{

      $this->error(UPLOAD_FAILED);

      return '';

    }

  }

  function chk_ext(){

    if(empty($this->allowext) || in_array($this->get_fileext(), explode("|",$this->allowext))) return false;

    return true;

  }

  function chk_size(){

    if(empty($this->allowsize) || get_filesize <= $this->allowsize*1024*1024) return false;

    return true;

  }

  function get_filesize(){

    return $this->_filesize;

  }

  function get_fileext(){

    return substr($this->_filename,strrpos($this->_filename,".")+1);

  }

  function generate_name(){

    return substr(md5(time()),26);

  }

  function chk_hasfile(){

    return is_file($this->_filedir.$this->_filename);

  }

  function error($tip){

    echo $tip;

  }

  function result(){

    if($this->report){

      $filename = empty($this->newname) ? $this->_filename : $this->newname;

      $arr = array('filename' => $filename, 'filesize' => $this->_filesize, 'tip' => UPLOAD_SUCCESS);

      return $arr;

    }else{

      return UPLOAD_SUCCESS;

    }

  }

}

/***使用方法与参数说明***/

/***

  第一个参数$dir 为上传文件存放的路径

   第二个参数为$_FILES 为你那个上传文件变量

   第三个参数允许文件大小 单位为MB

  第四个参数允许的文件类型 格式为jpg|png|gif

  第五个参数是否需要生成新的文件名

   第六个参数为返回的提示格式 0为直接提示上传正确 1则返回一个数组array('filename' => $filename, 'filesize' => $this->_filesize, 'tip' => UPLOAD_SUCCESS);

***/

//require("类文件");

//$u = new file_uploader;

//$u->ready($dir, $_FILES['upload_file'], false, false, true, 0);

//echo $u->do_upload();

?>

$dir = 'upload/';

  require("upload_class.php");

  $u = new file_uploader;

  $u->ready($dir, $_FILES['upload_file'], false, false, true, 0);

  echo $u->do_upload();