sergio_ag at terra dot com dot br (2012-09-05 20:09:33)

A nice trick to reorder the $_FILES array when you use a input name as array is:

<?php
function diverse_array($vector) {
    $result = array();
    foreach($vector as $key1 => $value1)
        foreach($value1 as $key2 => $value2)
            $result[$key2][$key1] = $value2;
    return $result;
}
?>

will transform this:

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"
        }
    }
}

into:

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"
        }
    }
}

just do:

<?php $upload = diverse_array($_FILES["upload"]); ?>

sparticvs at popebp dot com (2012-09-01 20:59:21)

A note of security: Don't ever trust $_FILES["image"]["type"]. It takes whatever is sent from the browser, so don't trust this for the image type. I recommend using finfo_open (http://www.php.net/manual/en/function.finfo-open.php) to verify the MIME type of a file. It will parse the MAGIC in the file and return it's type...this can be trusted (you can also use the "file" program on Unix, but I would refrain from ever making a System call with your PHP code...that's just asking for problems).

tjbp (2012-08-04 21:46:11)

For quick debugging (eg. var_dump($_FILES);), these are the values of the error constants. Obviously don't use these for comparison in real code.
UPLOAD_ERR_OK: 0
UPLOAD_ERR_INI_SIZE: 1
UPLOAD_ERR_FORM_SIZE: 2
UPLOAD_ERR_NO_TMP_DIR: 6
UPLOAD_ERR_CANT_WRITE: 7
UPLOAD_ERR_EXTENSION: 8
UPLOAD_ERR_PARTIAL: 3

seifert at alesak dot net (2012-07-02 14:02:31)

I just spent long time debugging strange behavior of one of our application on new webhosting. We have 30 file inputs on one page for upload to server. Problem was that only 20 was actually uploaded.
Now I found there is an option max_file_uploads in php.ini limiting maximum size of $_FILES to 20 by default.
When you have suhosin extension installed it has own option limiting same thing to 25 (suhosin.upload.max_uploads in php.ini)

Alexandre Teles (2012-05-20 04:31:17)

You can check error index this way:

<?php

$errorIndex = $_FILES["file"]["error"];

if ($errorIndex > 0) {
    die('We have a error. Try Again.');
}

processFile();

?>

codycoder at me dot com (2012-03-28 01:51:59)

I find that using sizeof() works ok.
EG:
if(sizeof($_FILES)!=0){
handleFiles();
}

yuriy dot nayda at gmail dot com (2012-03-15 16:49:14)

THis is an solution to convert Cyrillic and umlaut characters as file name when uplaoding files into needed encoding. Was searching for it but could not find. Thus posting this. Just like this:
$value = mb_convert_encoding($value, "UTF-8");

BigShark666 at gmail dot com (2011-11-21 22:51:50)

Nontypicall array comes in php after the submission.I wrote a small function to restate it to the familiar look.
<?php
function multiple(array $_files, $top = TRUE)
{
    $files = array();
    foreach($_files as $name=>$file){
        if($top) $sub_name = $file['name'];
        else    $sub_name = $name;
        
        if(is_array($sub_name)){
            foreach(array_keys($sub_name) as $key){
                $files[$name][$key] = array(
                    'name'     => $file['name'][$key],
                    'type'     => $file['type'][$key],
                    'tmp_name' => $file['tmp_name'][$key],
                    'error'    => $file['error'][$key],
                    'size'     => $file['size'][$key],
                );
                $files[$name] = multiple($files[$name], FALSE);
            }
        }else{
            $files[$name] = $file;
        }
    }
    return $files;
}

print_r($_FILES);
/*
Array
(
    [image] => Array
        (
            [name] => Array
                (
                    [0] => 400.png
                )
            [type] => Array
                (
                    [0] => image/png
                )
            [tmp_name] => Array
                (
                    [0] => /tmp/php5Wx0aJ
                )
            [error] => Array
                (
                    [0] => 0
                )
            [size] => Array
                (
                    [0] => 15726
                )
        )
)
*/
$files = multiple($_FILES);
print_r($files);
/*
Array
(
    [image] => Array
        (
            [0] => Array
                (
                    [name] => 400.png
                    [type] => image/png
                    [tmp_name] => /tmp/php5Wx0aJ
                    [error] => 0
                    [size] => 15726
                )
        )
)
*/
?>

kbolyshev at gmail dot com (2011-11-18 04:39:53)

For situation download[file1], download[file2], ..., download[fileN], try it:

<?php

/**
 *
 * @param array     $arrayForFill
 * @param string    $currentKey
 * @param mixed     $currentMixedValue
 * @param string    $fileDescriptionParam (name, type, tmp_name, error или size)
 * @return void
 */
function rRestructuringFilesArray(&$arrayForFill, $currentKey, $currentMixedValue, $fileDescriptionParam)
{
    if (is_array($currentMixedValue)) {
        foreach ($currentMixedValue as $nameKey => $mixedValue) {
            rRestructuringFilesArray($arrayForFill[$currentKey],
                                     $nameKey,
                                     $mixedValue,
                                     $fileDescriptionParam);
        }
    } else {
        $arrayForFill[$currentKey][$fileDescriptionParam] = $currentMixedValue;
    }
}

$arrayForFill = array();
foreach ($_FILES as $firstNameKey => $arFileDescriptions) {
    foreach ($arFileDescriptions as $fileDescriptionParam => $mixedValue) {
        rRestructuringFilesArray($arrayForFill,
                                 $firstNameKey,
                                 $_FILES[$firstNameKey][$fileDescriptionParam],
                                 $fileDescriptionParam);
    }
}
$_FILES = $arrayForFill;
?>

unca dot alby at gmail dot com (2011-09-02 13:31:26)

In checking the error code, you probably ought to check for code 4. I believe Code 4 means no file was uploaded, and there are many instances where that's perfectly OK.
Such as when you have a form with multiple data items, including file and image uploads, plus whatever else. The user might not be adding a new upload for whatever reason, such as there may already be a file in the system from an earlier update, and the user is satisfied with that.

Sbastien (2011-06-13 07:36:52)

If you're uploading multiple files and you name your file inputs "upload[]" the $_FILES array will look different than the var_dump posted below. I figured I'd post what it looks like since it caused me (and still causes me) headaches!
array(1) {
["upload"]=>array(5) {
["name"]=>array(3) {
[0]=>string(9)"file0.txt"
[1]=>string(9)"file1.txt"
[2]=>string(9)"file2.txt"
}
["type"]=>array(3) {
[0]=>string(10)"text/plain"
[1]=>string(10)"text/plain"
[2]=>string(10)"text/plain"
}
["tmp_name"]=>array(3) {
[0]=>string(14)"/tmp/blablabla"
[1]=>string(14)"/tmp/phpyzZxta"
[2]=>string(14)"/tmp/phpn3nopO"
}
["error"]=>array(3) {
[0]=>int(0)
[1]=>int(0)
[2]=>int(0)
}
["size"]=>array(3) {
[0]=>int(0)
[1]=>int(0)
[2]=>int(0)
}
}
}
(I thought the array would have looked like upload[index][name] which is not the case.)

Anonymous (2011-04-26 14:48:45)

Having url rewrite patterns in .htaccess file which modify your urls can affect $_FILES sometimes. Even though the php page loads and works fine, this variable may not work because of it. Therefore if you rewrite 'www.example.com' to 'example.com', make sure you use the latter one when sending POST to the php page. I'm still not sure why this happens, but its worth noting here so others don't spend time chasing ghosts.

Anonymous (2011-04-18 06:23:17)

As mentioned , you should check the error index of the upload.

Example below suggests you have a file field named 'image'.

<?php

        if($_FILES['image']['error'] == 0){
            // success - move uploaded file and process stuff here

        }else{
            // 'there was an error uploading file' stuff here....    
        }
?>

John (2011-02-03 18:14:13)

In the past you could unconditionally call $_FILES['profile_pic'] without ever having to worry about PHP spitting an "Undefined index: profile_pic" error (so long as the page posting had a file input on it (e.g. <input type="file" name="profile_pic" />)). This was the case regardless of whether or not the end user actually uploaded a file. These days, with so many people browsing the web via iPads, you have to explicitly check to see if the input isset($_FILES['profile_pic']) before calling into it, else you'll get the aforementioned error message. This is because iOS devices running Safari disable file inputs thereby causing them to be treated as if they don't exist. Time to update your scripts!
-john

mwgamera at gmail dot com (2009-08-13 05:40:55)

To determine whether upload was successful you should check for error being UPLOAD_ERR_OK instead of checking the file size. When nothing is chosen to be uploaded, the key in $_FILES will still be there, but it should have error equal UPLOAD_ERR_NO_FILE.

calurion at gmail dot com (2009-06-29 16:51:37)

For some reason when I tried to check if $_FILES['myVarName'] was empty() or !isset() or array_key_exists(), it always came back that the file was indeed in the superglobal, even when nothing was uploaded.
I wonder if this is a result of enctype="multipart/form-data".
Anyways, I solved my issue by checking to make sure that $_FILES['myVarName']['size'] > 0

Sam (2009-05-21 19:08:16)

This is REQUIRED by the xhtml specs.

dewi at dewimorgan dot com (2009-03-18 10:35:46)

The format of this array is (assuming your form has two input type=file fields named "file1", "file2", etc):
Array
(
[file1] => Array
(
[name] => MyFile.txt (comes from the browser, so treat as tainted)
[type] => text/plain (not sure where it gets this from - assume the browser, so treat as tainted)
[tmp_name] => /tmp/php/php1h4j1o (could be anywhere on your system, depending on your config settings, but the user has no control, so this isn't tainted)
[error] => UPLOAD_ERR_OK (= 0)
[size] => 123 (the size in bytes)
)
[file2] => Array
(
[name] => MyFile.jpg
[type] => image/jpeg
[tmp_name] => /tmp/php/php6hst32
[error] => UPLOAD_ERR_OK
[size] => 98174
)
)
Last I checked (a while ago now admittedly), if you use array parameters in your forms (that is, form names ending in square brackets, like several file fields called "download[file1]", "download[file2]" etc), then the array format becomes... interesting.
Array
(
[download] => Array
(
[name] => Array
(
[file1] => MyFile.txt
[file2] => MyFile.jpg
)
[type] => Array
(
[file1] => text/plain
[file2] => image/jpeg
)
[tmp_name] => Array
(
[file1] => /tmp/php/php1h4j1o
[file2] => /tmp/php/php6hst32
)
[error] => Array
(
[file1] => UPLOAD_ERR_OK
[file2] => UPLOAD_ERR_OK
)
[size] => Array
(
[file1] => 123
[file2] => 98174
)
)
)
So you'd need to access the error param of file1 as, eg $_Files['download']['error']['file1']

andrewpunch at bigfoot dot com (2009-01-17 00:16:26)

If $_FILES is empty, even when uploading, try adding enctype="multipart/form-data" to the form tag and make sure you have file uploads turned on.