php实现文件上传的代码

来源：互联网发布：网络协议的三要素定义编辑：程序博客网时间：2024/05/16 09:43

<form method="post" action="upload.php" enctype="multipart/form-data">
      <table border=0 cellspacing=0 cellpadding=0 align=center width="100%">
       <tr>
         <td width=55 height=20 align="center"><input type="hidden" name="MAX_FILE_SIZE" value="2000000">文件: </TD>
         <td height="16">
         <input name="file" type="file"  value="浏览" >
         <input type="submit" value="上传" name="B1">
         </td>
       </tr>
      </table>
      </form>

表单提交upload.php

<?php

    $uploaddir = "./files/";//设置文件保存目录注意包含/
   $type=array("jpg","gif","bmp","jpeg","png");//设置允许上传文件的类型
   $patch="http://127.0.0.1/test/files";//程序所在路径

    //获取文件后缀名函数
      function fileext($filename)
     {
         return substr(strrchr($filename, '.'), 1);
     }
   //生成随机文件名函数
    function random($length)
     {
        $hash = 'CR-';
        $chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz';
        $max = strlen($chars) - 1;
        mt_srand((double)microtime() * 1000000);
             for($i = 0; $i < $length; $i++)
             {
                $hash .= $chars[mt_rand(0, $max)];
             }
         return $hash;
     }

   $a=strtolower(fileext($_FILES['file']['name']));
   //判断文件类型
   if(!in_array(strtolower(fileext($_FILES['file']['name'])),$type))
      {
        $text=implode(",",$type);
         echo "您只能上传以下类型文件: ",$text,"<br>";
      }
   //生成目标文件的文件名
   else{
    $filename=explode(".",$_FILES['file']['name']);
         do
         {
            $filename[0]=random(10); //设置随机数长度
            $name=implode(".",$filename);
            //$name1=$name.".Mcncc";
            $uploadfile=$uploaddir.$name;
         }

    while(file_exists($uploadfile));

         if (move_uploaded_file($_FILES['file']['tmp_name'],$uploadfile)){

             if(is_uploaded_file($_FILES['file']['tmp_name'])){
                //输出图片预览
                echo "<center>您的文件已经上传完毕上传图片预览: </center><br><center><img src='$uploadfile'></center>";
                 echo"<br><center><a href='javascript:history.go(-1)'>继续上传</a></center>";
               }
               else{
                 echo "上传失败！";
               }
         }
    }

?>