Summary of PHP file upload problems, _PHP tutorial-PHP Tutorial-php.cn

Summary of PHP file upload problems, _PHP tutorial

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Release： 2016-07-13 10:08:30

Original

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A summary of problems with php uploading files,

1. First make the simplest upload file

Copy code The code is as follows:

if (($_FILES["file"]["size"] < 20000)
{
if ($_FILES["file"]["error"] > 0)
{
echo "Return Code: " . $_FILES["file"]["error"] . "
";
}
else
{
echo "Upload: " . $_FILES["file"]["name"] . "
";
echo "Type: " . $_FILES["file"]["type"] . "
";
echo "Size: " . ($_FILES["file"]["size"] / 1024) . " Kb
";
echo "Temp file: " . $_FILES["file"]["tmp_name"] . "
";
If (file_exists("upload/" . $_FILES["file"]["name"]))
          {
echo $_FILES["file"]["name"] . " already exists. ";
}
      else
          {
       move_uploaded_file($_FILES["file"]["tmp_name"],
"upload/" . $_FILES["file"]["name"]);
echo "Stored in: " . "upload/" . $_FILES["file"]["name"];
}
}
}
else
{
echo "Invalid file";
}
?>

2. Then understand the value of the super global variable $_FILES

Copy code The code is as follows:

$_FILES['userfile']['name']
$_FILES['userfile']['type']
$_FILES['userfile']['size']
$_FILES['userfile']['tmp_name']
$_FILES['userfile']['error']

Among them, all values of $_FILES['userfile']['error']:

UPLOAD_ERR_OK The value is 0, no error occurs, and the file is uploaded successfully.

UPLOAD_ERR_INI_SIZE Its value is 1, and the uploaded file exceeds the value limited by the upload_max_filesize option in php.ini.

UPLOAD_ERR_FORM_SIZE With a value of 2, the size of the uploaded file exceeds the value specified by the MAX_FILE_SIZE option in the HTML form.

UPLOAD_ERR_PARTIAL Its value is 3, the file is only partially uploaded.

UPLOAD_ERR_NO_FILE Its value is 4, no file was uploaded.

UPLOAD_ERR_NO_TMP_DIR has a value of 6 and the temporary folder cannot be found. Introduced in PHP 4.3.10 and PHP 5.0.3.

UPLOAD_ERR_CANT_WRITE Its value is 7, file writing failed. Introduced in PHP 5.1.0.

3. In many cases: it is necessary to strictly judge the uploaded file type

We know that it is unwise to use $_FILES['userfile']['type'] to determine the type of uploaded file, because the judgment is based on the suffix of the file. Anyone can change the suffix of an mp3 file Change it to jpg and upload it disguised as a picture. Therefore, PHP officially recommends using the PHP extension php_fileinfo to determine the mime of the file. There are many ways to enable the extension on Baidu. Win and Linux are slightly different.

4. Scenario 1: Automatically rename the uploaded file with the same name

Copy code The code is as follows:

if (file_exists("./upload/" . $_FILES["file"]["name"]))
{
   do{
       $suffix ="";
       $suffix_length = 4;
       $str = "0123456789abcdefghijklmnopqrstuvwxyz";
       $len = strlen($str)-1;
       //文件名后追加4个随机字符
       for($i=0 ; $i<$suffix_length; $i++){
          $suffix .= $str[rand(0,$len)];
       }
       $upload_filename = $_FILES['file']['name'];
       $filename = substr($upload_filename,0,strrpos($upload_filename,".")).$suffix.".".substr($upload_filename,strrpos($_FILES["file"]["name"],".")+1);
   }while(file_exists("./upload/".$filename));
       move_uploaded_file($_FILES["file"]["tmp_name"],"./upload/" . $filename);
}else{
       move_uploaded_file($_FILES["file"]["tmp_name"], "upload/" . $_FILES["file"]["name"]);
}

5.情景二：根据日期分目录上传文件

复制代码代码如下:

$structure = './'.date("Y").'/'.date("m").'/'.date("d").'/';
if (!mkdir($structure, 0777, true)) {
die('Failed to create folders...');
}
move_uploaded_file($_FILES["file"]["tmp_name"],$structure . $_FILES["file"]["name"]);

6.情景三：多文件上传

复制代码代码如下:

foreach ($_FILES["pictures"]["error"] as $key => $error) {
     if ($error == UPLOAD_ERR_OK) {
         $tmp_name = $_FILES["pictures"]["tmp_name"][$key];
         $name = $_FILES["pictures"]["name"][$key];
         move_uploaded_file($tmp_name, "data/$name");
     }
}
?>

有的情况下多文件的这种变量结构并不好用：

复制代码代码如下:

array(1) {
    ["upload"]=>array(2) {
        ["name"]=>array(2) {
            [0]=>string(9)"file0.txt"
            [1]=>string(9)"file1.txt"
        }
        ["type"]=>array(2) {
            [0]=>string(10)"text/plain"
            [1]=>string(10)"text/html"
        }
    }
}

很多情况下我们需要的是类似这样的结构

复制代码代码如下:

array(1) {
["upload"]=>array(2) {
[0]=>array(2) {
                ["name"]=>string(9)"file0.txt"
               ["type"]=>string(10)"text/plain"
},
[1]=>array(2) {
               ["name"]=>string(9)"file1.txt"
               ["type"]=>string(10)"text/html"
}
}
}

Use the following function to easily convert the structure

Copy code The code is as follows:

function diverse_array($vector) {
$result = array();
foreach($vector as $key1 => $value1)
foreach($value1 as $key2 => $value2)
$result[$key2][$key1] = $value2;
Return $result;
}
$upload = diverse_array($_FILES["upload"]);

7. Sometimes: you need to configure the server to modify the maximum upload file size

First, on the form

Upload file size can be limited (can be bypassed).

Then you also need to adjust the configuration on the server

php.ini:

Copy code The code is as follows:

max_execution_time = 30 The maximum time for each script to run, in seconds
max_input_time = 60, the time each script can consume, the unit is also seconds
memory_limit = 128M, this is the maximum memory consumed by the script
post_max_size = 8M, the maximum data submitted by the form is 8M. This item does not limit the size of a single uploaded file, but limits the submitted data of the entire form.
upload_max_filesize = 2M, the maximum allowed size of uploaded files

nginx:

Copy code The code is as follows:

location / {
Root html;
index index.html index.htm;
Client_max_body_size 1000m;
}

Let’s summarize these for now, I hope you guys like it.