<?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;
	  
	 /*
	  *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' => $this->_filesize, 'tip' => UPLOAD_SUCCESS);
	 */
	  function ready($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;
		}
	  }
	}

$dir = 'upload/';
require("upload_class.php");
$u = new file_uploader;
$u->ready($dir, $_FILES['upload_file'], false, false, true, 0);
echo $u->do_upload();