PHP implements upload restrictions on file upload and download
Client restrictions
The code is as follows:
<!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no"> <meta name="format-detection" content="telephone=no" /> <title>文件上傳(客戶(hù)端限制)</title> <meta charset="utf-8" /> </head> <body> <form action="upload2.php" method="post" enctype="multipart/form-data"> <input type="hidden" name="MAX_FILE_SIZE" value="101321" /> 請(qǐng)選擇您要上傳的文件： <input type="file" name="myFile" accept="image/jpeg,image/gif,text/html"/><br/> <input type="submit" value="上傳"/> </form> </body> </html>
The input attributes are used here to limit the size and type of uploaded files. But I personally feel that
1.html code is "visible"
2. 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.
##Server Side Limitations
<?php
header('content-type:text/html;charset=utf-8');
//接受文件，臨時(shí)文件信息
$fileinfo=$_FILES["myFile"];//降維操作
$filename=$fileinfo["name"];
$tmp_name=$fileinfo["tmp_name"];
$size=$fileinfo["size"];
$error=$fileinfo["error"];
$type=$fileinfo["type"];
//服務(wù)器端設(shè)定限制
$maxsize=10485760;//10M,10*1024*1024
$allowExt=array('jpeg','jpg','png','tif');//允許上傳的文件類(lèi)型（拓展名
$ext=pathinfo($filename,PATHINFO_EXTENSION);//提取上傳文件的拓展名
//目標(biāo)存放文件夾
$path="uploads";
if (!file_exists($path)) { //當(dāng)目錄不存在，就創(chuàng)建目錄
mkdir($path,0777,true);//創(chuàng)建目錄
chmod($path, 0777);//改變文件模式,所有人都有執(zhí)行權(quán)限、寫(xiě)權(quán)限、度權(quán)限
}
//得到唯一的文件名！防止因?yàn)槲募嗤a(chǎn)生覆蓋
$uniName=md5(uniqid(microtime(true),true)).".$ext";//md5加密，uniqid產(chǎn)生唯一id，microtime做前綴
//目標(biāo)存放文件地址
$destination=$path."/".$uniName;
//當(dāng)文件上傳成功，存入臨時(shí)文件夾，服務(wù)器端開(kāi)始判斷
if ($error===0) {
if ($size>$maxsize) {
exit("上傳文件過(guò)大！");
}
if (!in_array($ext, $allowExt)) {
exit("非法文件類(lèi)型");
}
if (!is_uploaded_file($tmp_name)) {
exit("上傳方式有誤，請(qǐng)使用post方式");
}
//判斷是否為真實(shí)圖片（防止偽裝成圖片的病毒一類(lèi)的
if (!getimagesize($tmp_name)) {//getimagesize真實(shí)返回?cái)?shù)組，否則返回false
exit("不是真正的圖片類(lèi)型");
}
//move_uploaded_file($tmp_name, "uploads/".$filename);
if (@move_uploaded_file($tmp_name, $destination)) {//@錯(cuò)誤抑制符，不讓用戶(hù)看到警告
echo "文件".$filename."上傳成功!";
}else{
echo "文件".$filename."上傳失敗!";
}
}else{
switch ($error){
case 1:
echo "超過(guò)了上傳文件的最大值，請(qǐng)上傳2M以下文件";
break;
case 2:
echo "上傳文件過(guò)多，請(qǐng)一次上傳20個(gè)及以下文件！";
break;
case 3:
echo "文件并未完全上傳，請(qǐng)?jiān)俅螄L試！";
break;
case 4:
echo "未選擇上傳文件！";
break;
case 7:
echo "沒(méi)有臨時(shí)文件夾";
break;
}
}Here, the specific implementation is commented, and you can actually try it yourself, which is very interesting .
