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How to implement file upload and download in PHP
- 墨辰丷Original
- 2018-05-31 15:05:116177browse
This article mainly introduces examples of file upload and download in PHP. This article explains in detail and comprehensively the demand analysis and function implementation related to file upload, and also provides the usage code. Friends who need it can refer to it. PHP implements file upload and download
1. Upload principle and configuration
1.1 Principle
Upload client files to the server. Then move the server-side files (temporary files) to the specified directory.
1.2 Client configuration
Required: form page (select upload file);
Specifically: the sending method is POST, add enctype="multipart/form- data" attribute, both are indispensable (however, both advantages and disadvantages coexist, and the upload method and subsequent calling of the uploaded file are also limited here, which will be discussed later)
<!DOCTYPE html> <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>
The first is the form page (please ignore the front-end issues automatically...), the key is the attribute of form; the other is the use of type="file" in input (reflecting the power of PHP expansion, 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 (in fact, I like to reduce the dimension and then use it); It’s basically a glance Just understand things, not verbose, 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, and use the error message to give feedback to Users, what needs to be explained is why the error is reported and what the error message is;1.3 About error reporting
--The reason for the error reporting:
Basically They all exceed or do not comply with the server's configuration for uploading files. So what are the server-side configurations? First consider uploading what we used? POST, uploadSo look for these items in php.ini:file_upload:Onupload_tmp_dir=——Temporary file saving directory; upload_max_filesize=2Mmax_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 dataOther related configuration
max_exectuion_time=-1——Maximum execution time to avoid the program from occupying server resources; max_input_time=60max_input_nesting_level=64——Input nesting depth;memory_limit=128M——Maximum independent memory usage of a single threadIn 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 was uploaded.
- UPLOAD_ERR_NO_FILE Value: 4; No file was uploaded.
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>The input attributes are used here to limit the size and type of uploaded files, but my personal feeling is: , the html code is "visible"; second, it often doesn't work (I didn't find the reason, but because of the first one I also want to give up on it, just know it. 2.2 Server-side restrictionsMainly limit the 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 ($error){
case 1:
echo "超过了上传文件的最大值，请上传2M以下文件";
break;
case 2:
echo "上传文件过多，请一次上传20个及以下文件！";
break;
case 3:
echo "文件并未完全上传，请再次尝试！";
break;
case 4:
echo "未选择上传文件！";
break;
case 7:
echo "没有临时文件夹";
break;
}
}
这里，具体实现都有注释，每一步其实都可以自己
2.3 EncapsulationFunction<?php
function uploadFile($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, $maxSize);
3. Implementation of uploading multiple files
3.1 Use single file encapsulation<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="doAction5.php" method="post" enctype="multipart/form-data">
请选择您要上传的文件：<input type="file" name="myFile1" /><br/>
请选择您要上传的文件：<input type="file" name="myFile2" /><br/>
请选择您要上传的文件：<input type="file" name="myFile3" /><br/>
请选择您要上传的文件：<input type="file" name="myFile4" /><br/>
<input type="submit" value="上传"/>
</form>
</body>
</html>
<?php
//print_r($_FILES);
header('content-type:text/html;charset=utf-8');
include_once 'upFunc.php';
foreach ($_FILES as $fileInfo){
$file[]=uploadFile($fileInfo);
}
The idea here is found in print_r($_FILES) and printed out Seeing that it is a two-dimensional array, it is very simple, just traverse it and use it!Change the definition of the function above and give some default valuesfunction uploadFile($fileInfo,$path="uploads",$allowExt=array('jpeg','jpg','png','tif'),$maxSize=10485760){
This way, 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 immediately Stop, causing other pictures to be unable to be uploaded. 3.2 Upgraded version of packagingAims to implement packaging for uploading multiple or single filesFirst 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
)
)
)
可以得到一个三维数组。
复杂是复杂了，但复杂的有规律，各项数值都在一起了，很方便我们取值！！
所以先得到文件信息，变成单文件处理那种信息
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);
总结：以上就是本篇文的全部内容，希望能对大家的学习有所帮助。
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