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How to implement file upload and download in php
- 藏色散人Original
- 2020-10-29 09:28:063724browse
php method to implement file upload and download: first create a form page; then upload the client file to the server; finally move the server-side file to the specified directory.
Recommended: "PHP Video Tutorial"
PHP Implementation of File Upload and Download
1. Upload principle and configuration
1.1 Principle
Upload the client file to the server, and then upload the server-side file to the server. Just move the file (temporary file) to the specified directory.
1.2 Client configuration
Required: (Select upload file);
Specifically: The sending method is POST, add enctype="multipart/form-data" Attributes, both are indispensable (however, advantages and disadvantages coexist, here also limits the upload method and the call after the uploaded file, etc., which will be mentioned later)
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <form action="doAction.php" method="post" enctype="multipart/form-data"> 请选择您要上传的文件： <input type="file" name="myFile" /><br/> <input type="submit" value="上传"/> </form> <?php ?> </body> </html>
First is the form page (please ignore it automatically Front-end problem...), the key is the attribute of form; the other is the use of type="file" in input (reflecting the powerful expansion of PHP, etc.).
Then doAction
<?php
//$_FILES:文件上传变量
//print_r($_FILES);
$filename=$_FILES['myFile']['name'];
$type=$_FILES['myFile']['type'];
$tmp_name=$_FILES['myFile']['tmp_name'];
$size=$_FILES['myFile']['size'];
$error=$_FILES['myFile']['error'];
//将服务器上的临时文件移动到指定位置
//方法一move_upload_file($tmp_name,$destination)
//move_uploaded_file($tmp_name, "uploads/".$filename);//文件夹应提前建立好，不然报错
//方法二copy($src,$des)
//以上两个函数都是成功返回真，否则返回false
//copy($tmp_name, "copies/".$filename);
//注意，不能两个方法都对临时文件进行操作，临时文件似乎操作完就没了，我们试试反过来
copy($tmp_name, "copies/".$filename);
move_uploaded_file($tmp_name, "uploads/".$filename);
//能够实现，说明move那个函数基本上相当于剪切；copy就是copy，临时文件还在
//另外，错误信息也是不一样的，遇到错误可以查看或者直接报告给用户
if ($error==0) {
echo "上传成功！";
}else{
switch ($error){
case 1:
echo "超过了上传文件的最大值，请上传2M以下文件";
break;
case 2:
echo "上传文件过多，请一次上传20个及以下文件！";
break;
case 3:
echo "文件并未完全上传，请再次尝试！";
break;
case 4:
echo "未选择上传文件！";
break;
case 5:
echo "上传文件为0";
break;
}
}First look at the information of print_r($_FILES)
Array
(
[myFile] => Array
(
[name] => 梁博_简历.doc
[type] => application/msword
[tmp_name] => D:\wamp\tmp\php1D78.tmp
[error] => 0
[size] => 75776
)
)So what you get is a two-dimensional array. How to use it is all basic Things (actually I like to reduce dimensions and reuse them);
is basically something that can be understood at a glance, without being wordy, there are two key points: tmp_name temporary file name; error error message (code name, you can use it later);
Then let’s take a look at the last part of doAction, using error reporting information to feed back to the user. What needs to be explained is why the error reporting occurred and what the error reporting information is;
1.3 About error reporting
--Cause of error report:
Basically, it exceeds or does not meet the server's configuration for uploading files. So what are the server-side configurations?
First consider uploading what we used? POST, upload
So look for these items in php.ini:
file_upload:On
upload_tmp_dir=——Temporary file saving directory;
upload_max_filesize=2M
max_file_uploads=20——The maximum number of files allowed to be uploaded at one time (note the difference from the above one, don’t think about it if there is a size)
post_max_size=8M——post method Maximum value of sent data
Other related configuration
max_exectuion_time=-1——Maximum execution time to avoid the program from occupying server resources;
max_input_time=60
max_input_nesting_level=64——Input nesting depth;
memory_limit=128M——Maximum independent memory usage of a single thread
In short, it is all about resources configuration.
--Error number
The following (lazy) is quoted from http://blog.sina.com.cn/s/blog_3cdfaea201008utf.html
- UPLOAD_ERR_OK Value: 0; No error occurred and the file was uploaded successfully.
- UPLOAD_ERR_INI_SIZE Value: 1; The uploaded file exceeds the limit of the upload_max_filesize option in php.ini.
- UPLOAD_ERR_FORM_SIZE Value: 2; The size of the uploaded file exceeds the value specified by the MAX_FILE_SIZE option in the HTML form.
- UPLOAD_ERR_PARTIAL Value: 3; Only part of the file is uploaded.
- UPLOAD_ERR_NO_FILE Value: 4; No file was uploaded.
Note: This error message is the information uploaded in the first step, that is, uploaded to a temporary folder, not the case of move or copy.
2. Upload related restrictions
2.1 Client restrictions
<form action="doAction2.php" method="post" enctype="multipart/form-data"> <input type="hidden" name="MAX_FILE_SIZE" value="101321" />
Please select the file you want to upload:
<input type="file" name="myFile" accept="image/jpeg,image/gif,text/html"/><br/> <input type="submit" value="上传"/> </form>
Here The input attribute is used to limit the size and type of uploaded files, but my personal feeling is: first, the html code is "visible"; second, it often doesn't work (I haven't found the reason, but because of the first one I also want to give up on it) , just know it.
2.2 Server-side restrictions
Mainly limit size and type, and then the method.
<?php
header('content-type:text/html;charset=utf-8');
//接受文件，临时文件信息
$fileinfo=$_FILES["myFile"];//降维操作
$filename=$fileinfo["name"];
$tmp_name=$fileinfo["tmp_name"];
$size=$fileinfo["size"];
$error=$fileinfo["error"];
$type=$fileinfo["type"];
//服务器端设定限制
$maxsize=10485760;//10M,10*1024*1024
$allowExt=array('jpeg','jpg','png','tif');//允许上传的文件类型（拓展名
$ext=pathinfo($filename,PATHINFO_EXTENSION);//提取上传文件的拓展名
//目的信息
$path="uploads";
if (!file_exists($path)) { //当目录不存在，就创建目录
mkdir($path,0777,true);
chmod($path, 0777);
}
//$destination=$path."/".$filename;
//得到唯一的文件名！防止因为文件名相同而产生覆盖
$uniName=md5(uniqid(microtime(true),true)).$ext;//md5加密，uniqid产生唯一id，microtime做前缀
if ($error==0) {
if ($size>$maxsize) {
exit("上传文件过大！");
}
if (!in_array($ext, $allowExt)) {
exit("非法文件类型");
}
if (!is_uploaded_file($tmp_name)) {
exit("上传方式有误，请使用post方式");
}
if (@move_uploaded_file($tmp_name, $uniName)) {//@错误抑制符，不让用户看到警告
echo "文件".$filename."上传成功!";
}else{
echo "文件".$filename."上传失败!";
}
//判断是否为真实图片（防止伪装成图片的病毒一类的
if (!getimagesize($tmp_name)) {//getimagesize真实返回数组，否则返回false
exit("不是真正的图片类型");
}
}else{
switch ($error){
case 1:
echo "超过了上传文件的最大值，请上传2M以下文件";
break;
case 2:
echo "上传文件过多，请一次上传20个及以下文件！";
break;
case 3:
echo "文件并未完全上传，请再次尝试！";
break;
case 4:
echo "未选择上传文件！";
break;
case 7:
echo "没有临时文件夹";
break;
}
}
这里，具体实现都有注释，每一步其实都可以自己2.3 Encapsulation
Function
<?php
function uploadFile($fileInfo,$path,$allowExt,$maxSize){
$filename=$fileInfo["name"];
$tmp_name=$fileInfo["tmp_name"];
$size=$fileInfo["size"];
$error=$fileInfo["error"];
$type=$fileInfo["type"];
//服务器端设定限制
$ext=pathinfo($filename,PATHINFO_EXTENSION);
//目的信息
if (!file_exists($path)) {
mkdir($path,0777,true);
chmod($path, 0777);
}
$uniName=md5(uniqid(microtime(true),true)).'.'.$ext;
$destination=$path."/".$uniName;
if ($error==0) {
if ($size>$maxSize) {
exit("上传文件过大！");
}
if (!in_array($ext, $allowExt)) {
exit("非法文件类型");
}
if (!is_uploaded_file($tmp_name)) {
exit("上传方式有误，请使用post方式");
}
//判断是否为真实图片（防止伪装成图片的病毒一类的
if (!getimagesize($tmp_name)) {//getimagesize真实返回数组，否则返回false
exit("不是真正的图片类型");
}
if (@move_uploaded_file($tmp_name, $destination)) {//@错误抑制符，不让用户看到警告
echo "文件".$filename."上传成功!";
}else{
echo "文件".$filename."上传失败!";
}
}else{
switch ($error){
case 1:
echo "超过了上传文件的最大值，请上传2M以下文件";
break;
case 2:
echo "上传文件过多，请一次上传20个及以下文件！";
break;
case 3:
echo "文件并未完全上传，请再次尝试！";
break;
case 4:
echo "未选择上传文件！";
break;
case 7:
echo "没有临时文件夹";
break;
}
}
return $destination;
}Call
<?php header('content-type:text/html;charset=utf-8'); $fileInfo=$_FILES["myFile"]; $maxSize=10485760;//10M,10*1024*1024 $allowExt=array('jpeg','jpg','png','tif'); $path="uploads"; include_once 'upFunc.php'; uploadFile($fileInfo, $path, $allowExt, $maxSize);
3. Implementation of multi-file upload
3.1 Use single file encapsulation
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="doAction5.php" method="post" enctype="multipart/form-data">
请选择您要上传的文件：<input type="file" name="myFile1" /><br/>
请选择您要上传的文件：<input type="file" name="myFile2" /><br/>
请选择您要上传的文件：<input type="file" name="myFile3" /><br/>
请选择您要上传的文件：<input type="file" name="myFile4" /><br/>
<input type="submit" value="上传"/>
</form>
</body>
</html>
<?php
//print_r($_FILES);
header('content-type:text/html;charset=utf-8');
include_once 'upFunc.php';
foreach ($_FILES as $fileInfo){
$file[]=uploadFile($fileInfo);
}The idea here is from print_r ($_FILES), print it out and you will see that it is a two-dimensional array. It is very simple, just traverse it and use it!
Change the definition of the function above and give some default values
function uploadFile($fileInfo,$path="uploads",$allowExt=array('jpeg','jpg','png','tif'),$maxSize=10485760){ Like this, simple is simple, but there are some problems.
It is no problem to upload 4 pictures normally, but if the exit in the function is activated in the middle, it will stop immediately, causing other pictures It also cannot be uploaded.
3.2 Upgraded version of encapsulation
Aims to implement encapsulation for uploading multiple or single files
First write a static file like this
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <form action="doAction5.php" method="post" enctype="multipart/form-data"> 请选择您要上传的文件：<input type="file" name="myFile[]" /><br/> 请选择您要上传的文件：<input type="file" name="myFile[]" /><br/> 请选择您要上传的文件：<input type="file" name="myFile[]" /><br/> 请选择您要上传的文件：<input type="file" name="myFile[]" /><br/> <input type="submit" value="上传"/> </form> </body> </html>
Print $_FILES
Array
(
[myFile] => Array
(
[name] => Array
(
[0] => test32.png
[1] => test32.png
[2] => 333.png
[3] => test41.png
)
[type] => Array
(
[0] => image/png
[1] => image/png
[2] => image/png
[3] => image/png
)
[tmp_name] => Array
(
[0] => D:\wamp\tmp\php831C.tmp
[1] => D:\wamp\tmp\php834C.tmp
[2] => D:\wamp\tmp\php837C.tmp
[3] => D:\wamp\tmp\php83BB.tmp
)
[error] => Array
(
[0] => 0
[1] => 0
[2] => 0
[3] => 0
)
[size] => Array
(
[0] => 46174
[1] => 46174
[2] => 34196
[3] => 38514
)
)
)You can get a three-dimensional array.
It’s complicated, but it’s complicated, and the values are all together, which is very convenient for us to get values! !
So get the file information first and turn it into a single file processing information
function getFiles(){
$i=0;
foreach($_FILES as $file){
if(is_string($file['name'])){ //单文件判定
$files[$i]=$file;
$i++;
}elseif(is_array($file['name'])){
foreach($file['name'] as $key=>$val){ //我的天，这个$key用的diao
$files[$i]['name']=$file['name'][$key];
$files[$i]['type']=$file['type'][$key];
$files[$i]['tmp_name']=$file['tmp_name'][$key];
$files[$i]['error']=$file['error'][$key];
$files[$i]['size']=$file['size'][$key];
$i++;
}
}
}
return $files;
}然后之前的那种exit错误，就把exit改一下就好了，这里用res
function uploadFile($fileInfo,$path='./uploads',$flag=true,$maxSize=1048576,$allowExt=array('jpeg','jpg','png','gif')){
//$flag=true;
//$allowExt=array('jpeg','jpg','gif','png');
//$maxSize=1048576;//1M
//判断错误号
$res=array();
if($fileInfo['error']===UPLOAD_ERR_OK){
//检测上传得到小
if($fileInfo['size']>$maxSize){
$res['mes']=$fileInfo['name'].'上传文件过大';
}
$ext=getExt($fileInfo['name']);
//检测上传文件的文件类型
if(!in_array($ext,$allowExt)){
$res['mes']=$fileInfo['name'].'非法文件类型';
}
//检测是否是真实的图片类型
if($flag){
if(!getimagesize($fileInfo['tmp_name'])){
$res['mes']=$fileInfo['name'].'不是真实图片类型';
}
}
//检测文件是否是通过HTTP POST上传上来的
if(!is_uploaded_file($fileInfo['tmp_name'])){
$res['mes']=$fileInfo['name'].'文件不是通过HTTP POST方式上传上来的';
}
if($res) return $res;
//$path='./uploads';
if(!file_exists($path)){
mkdir($path,0777,true);
chmod($path,0777);
}
$uniName=getUniName();
$destination=$path.'/'.$uniName.'.'.$ext;
if(!move_uploaded_file($fileInfo['tmp_name'],$destination)){
$res['mes']=$fileInfo['name'].'文件移动失败';
}
$res['mes']=$fileInfo['name'].'上传成功';
$res['dest']=$destination;
return $res;
}else{
//匹配错误信息
switch ($fileInfo ['error']) {
case 1 :
$res['mes'] = '上传文件超过了PHP配置文件中upload_max_filesize选项的值';
break;
case 2 :
$res['mes'] = '超过了表单MAX_FILE_SIZE限制的大小';
break;
case 3 :
$res['mes'] = '文件部分被上传';
break;
case 4 :
$res['mes'] = '没有选择上传文件';
break;
case 6 :
$res['mes'] = '没有找到临时目录';
break;
case 7 :
case 8 :
$res['mes'] = '系统错误';
break;
}
return $res;
}
}里面封装了两个小的
function getExt($filename){
return strtolower(pathinfo($filename,PATHINFO_EXTENSION));
}
/**
* 产生唯一字符串
* @return string
*/
function getUniName(){
return md5(uniqid(microtime(true),true));
}然后静态中，用multiple属性实现多个文件的输入；
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="doAction6.php" method="POST" enctype="multipart/form-data">
请选择您要上传的文件：<input type="file" name="myFile[]" multiple='multiple' /><br/>
<input type="submit" value="上传"/>
</form>
</body>
</html>
doAction6
<?php
//print_r($_FILES);
header("content-type:text/html;charset=utf-8");
require_once 'upFunc2.php';
require_once 'common.func.php';
$files=getFiles();
// print_r($files);
foreach($files as $fileInfo){
$res=uploadFile($fileInfo);
echo $res['mes'],'<br/>';
$uploadFiles[]=@$res['dest'];
}
$uploadFiles=array_values(array_filter($uploadFiles));
//print_r($uploadFiles);这样子的几个文件，就实现比较强大的面向过程的上传文件的功能（学的叫一个心酸。。。）；
四、面向对象的文件上传
<?php
class upload{
protected $fileName;
protected $maxSize;
protected $allowMime;
protected $allowExt;
protected $uploadPath;
protected $imgFlag;
protected $fileInfo;
protected $error;
protected $ext;
/**
* @param string $fileName
* @param string $uploadPath
* @param string $imgFlag
* @param number $maxSize
* @param array $allowExt
* @param array $allowMime
*/
public function __construct($fileName='myFile',$uploadPath='./uploads',$imgFlag=true,$maxSize=5242880,$allowExt=array('jpeg','jpg','png','gif'),$allowMime=array('image/jpeg','image/png','image/gif')){
$this->fileName=$fileName;
$this->maxSize=$maxSize;
$this->allowMime=$allowMime;
$this->allowExt=$allowExt;
$this->uploadPath=$uploadPath;
$this->imgFlag=$imgFlag;
$this->fileInfo=$_FILES[$this->fileName];
}
/**
* 检测上传文件是否出错
* @return boolean
*/
protected function checkError(){
if(!is_null($this->fileInfo)){
if($this->fileInfo['error']>0){
switch($this->fileInfo['error']){
case 1:
$this->error='超过了PHP配置文件中upload_max_filesize选项的值';
break;
case 2:
$this->error='超过了表单中MAX_FILE_SIZE设置的值';
break;
case 3:
$this->error='文件部分被上传';
break;
case 4:
$this->error='没有选择上传文件';
break;
case 6:
$this->error='没有找到临时目录';
break;
case 7:
$this->error='文件不可写';
break;
case 8:
$this->error='由于PHP的扩展程序中断文件上传';
break;
}
return false;
}else{
return true;
}
}else{
$this->error='文件上传出错';
return false;
}
}
/**
* 检测上传文件的大小
* @return boolean
*/
protected function checkSize(){
if($this->fileInfo['size']>$this->maxSize){
$this->error='上传文件过大';
return false;
}
return true;
}
/**
* 检测扩展名
* @return boolean
*/
protected function checkExt(){
$this->ext=strtolower(pathinfo($this->fileInfo['name'],PATHINFO_EXTENSION));
if(!in_array($this->ext,$this->allowExt)){
$this->error='不允许的扩展名';
return false;
}
return true;
}
/**
* 检测文件的类型
* @return boolean
*/
protected function checkMime(){
if(!in_array($this->fileInfo['type'],$this->allowMime)){
$this->error='不允许的文件类型';
return false;
}
return true;
}
/**
* 检测是否是真实图片
* @return boolean
*/
protected function checkTrueImg(){
if($this->imgFlag){
if(!@getimagesize($this->fileInfo['tmp_name'])){
$this->error='不是真实图片';
return false;
}
return true;
}
}
/**
* 检测是否通过HTTP POST方式上传上来的
* @return boolean
*/
protected function checkHTTPPost(){
if(!is_uploaded_file($this->fileInfo['tmp_name'])){
$this->error='文件不是通过HTTP POST方式上传上来的';
return false;
}
return true;
}
/**
*显示错误
*/
protected function showError(){
exit('<span style="color:red">'.$this->error.'</span>');
}
/**
* 检测目录不存在则创建
*/
protected function checkUploadPath(){
if(!file_exists($this->uploadPath)){
mkdir($this->uploadPath,0777,true);
}
}
/**
* 产生唯一字符串
* @return string
*/
protected function getUniName(){
return md5(uniqid(microtime(true),true));
}
/**
* 上传文件
* @return string
*/
public function uploadFile(){
if($this->checkError()&&$this->checkSize()&&$this->checkExt()&&$this->checkMime()&&$this->checkTrueImg()&&$this->checkHTTPPost()){
$this->checkUploadPath();
$this->uniName=$this->getUniName();
$this->destination=$this->uploadPath.'/'.$this->uniName.'.'.$this->ext;
if(@move_uploaded_file($this->fileInfo['tmp_name'], $this->destination)){
return $this->destination;
}else{
$this->error='文件移动失败';
$this->showError();
}
}else{
$this->showError();
}
}
}
<?php
header('content-type:text/html;charset=utf-8');
require_once 'upload.class.php';
$upload=new upload('myFile1','imooc');
$dest=$upload->uploadFile();
echo $dest;四、下载
对于浏览器不识别的，可以直接下载，但对于能识别的，需要多一两步
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Insert title here</title> </head> <body> <a href="1.rar">下载1.rar</a> <br /> <a href="1.jpg">下载1.jpg</a> <br /> <a href="doDownload.php?filename=1.jpg">通过程序下载1.jpg</a> <br /> <a href="doDownload.php?filename=../upload/nv.jpg">下载nv.jpg</a> <?php ?> </body> </html> <?php $filename=$_GET['filename']; header('content-disposition:attachment;filename='.basename($filename)); header('content-length:'.filesize($filename)); readfile($filename);
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