<?php

function file_down($file_name){

 $file_file="./down/".$file_name;

 //echo $file_file;

 $file_name=iconv("UTF-8","GB2312",$file_name);

 if(!file_exists($file_file)){

  echo "文件不存在！";

  return;

 }else{

  $fp=fopen($file_file,"r");

  $fs=filesize($file_file);

 }

 header("Content-type: application/octet-stream");

 header("Accept-Ranges: bytes");

 header("Accept-Length:".$fs);

 header("Content-Disposition: attachment; filename=".$file_name);

 $fss=1024;

 $file_content=0;

 while($fs-$file_content>0){

  $file_data=fread($fp,$fss);

  $file_content+=$fss;

  echo $file_data;

 }

 fclose($fp);

}

file_down("456.wmv");

 ?>