Anonymous (2013-03-04 18:05:37)

Normalizing $_FILES structure:

<?php
    $files = [];
    $fix = function (&$files, $values, $prop) use (&$fix) {
        foreach ($values as $key => $value) {
            if (is_array($value)) {
                $fix($files[$key], $value, $prop);
            } else {
                $files[$key][$prop] = $value;
            }
        }
    };
    foreach ($_FILES as $name => $props) {
        foreach ($props as $prop => $value) {
            if (is_array($value)) {
                $fix($files[$name], $value, $prop);
            } else {
                $files[$name][$prop] = $value;
            }
        }
    }
?>

gustavo at roskus dot com (2011-08-08 12:21:03)

Some hosting does not have permission to use the move_uploaded_file function should replace the copy function

Age Bosma (2011-06-10 02:49:38)

"If no file is selected for upload in your form, PHP will return $_FILES['userfile']['size'] as 0, and $_FILES['userfile']['tmp_name'] as none."
Note that the situation above is the same when a file exceeding the MAX_FILE_SIZE hidden field is being uploaded. In this case $_FILES['userfile']['size'] is also set to 0, and $_FILES['userfile']['tmp_name'] is also empty. The difference would only be the error code.
Simply checking for these two conditions and assuming no file upload has been attempted is incorrect.
Instead, check if $_FILES['userfile']['name'] is set or not. If it is, a file upload has at least been attempted (a failed attempt or not). If it is not set, no attempt has been made.

zingaburga at hotmail dot com (2011-02-02 19:09:43)

The documentation is a little unclear about the MAX_FILE_SIZE value sent in the form with multiple file input fields. The following is what I have found through testing - hopefully it may clarify it for others.
The MAX_FILE_SIZE is applied to each file (not the total size of all files) and to all file inputs which appear after it. This means that it can be overridden for different file fields. You can also disable it by sending no number, or sending 0 (probably anything that == '0' if you think about it).
Example:
<form enctype="multipart/form-data" action="." method="POST">
<!-- no maximum size for userfile0 -->
<input name="userfile0" type="file" />
<input type="hidden" name="MAX_FILE_SIZE" value="1000" />
<!-- maximum size for userfile1 is 1000 bytes -->
<input name="userfile1" type="file" />
<!-- maximum size for userfile2 is 1000 bytes -->
<input name="userfile2" type="file" />
<input type="hidden" name="MAX_FILE_SIZE" value="2000" />
<!-- maximum size for userfile3 is 2000 bytes -->
<input name="userfile3" type="file" />
<input type="hidden" name="MAX_FILE_SIZE" value="0" />
<!-- no maximum size for userfile4 -->
<input name="userfile4" type="file" />
</form>

mail at markuszeller dot com (2011-01-10 00:34:30)

If you want to increase the upload size, it could make sense to allow it only to a specified directory and not in the php.ini for the whole domain or server. In my case it worked very well placing that into the .htaccess file like this:
php_value upload_max_filesize 100M
php_value post_max_size 101M
Remember, post_max_size must be bigger than the upload_max_filesize.

Mark (2010-09-29 16:12:18)

$_FILES will be empty if a user attempts to upload a file greater than post_max_size in your php.ini
post_max_size should be >= upload_max_filesize in your php.ini.

michael (2009-12-05 09:19:50)

Just a little note, when I was trying to get this to work on my webserver I got error telling me the permissions were wrong, I checked and couldn't see anything wrong then I thought to try "./" for my upload directory instead of the full address which was something like "home/username/public_html/uploaddir". This will save it in the same directory as your script for the program above thats something like

<?php
// In PHP versions earlier than 4.1.0, $HTTP_POST_FILES should be used instead
// of $_FILES.

$uploaddir = './';//<----This is all I changed
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);

echo '<pre>';
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) {
    echo "File is valid, and was successfully uploaded.\n";
} else {
    echo "Possible file upload attack!\n";
}

echo 'Here is some more debugging info:';
print_r($_FILES);

print "</pre>";

?>

I know something trivial but when your new to this, those kind of things elude you.

daevid at daevid dot com (2009-06-11 14:35:44)

I think the way an array of attachments works is kind of cumbersome. Usually the PHP guys are right on the money, but this is just counter-intuitive. It should have been more like:

Array
(
    [0] => Array
        (
            [name] => facepalm.jpg
            [type] => image/jpeg
            [tmp_name] => /tmp/phpn3FmFr
            [error] => 0
            [size] => 15476
        )

    [1] => Array
        (
            [name] => 
            [type] => 
            [tmp_name] => 
            [error] => 4
            [size] => 
        )
)

and not this
Array
(
    [name] => Array
        (
            [0] => facepalm.jpg
            [1] => 
        )

    [type] => Array
        (
            [0] => image/jpeg
            [1] => 
        )

    [tmp_name] => Array
        (
            [0] => /tmp/phpn3FmFr
            [1] => 
        )

    [error] => Array
        (
            [0] => 0
            [1] => 4
        )

    [size] => Array
        (
            [0] => 15476
            [1] => 0
        )
)

Anyways, here is a fuller example than the sparce one in the documentation above:

<?php
foreach ($_FILES["attachment"]["error"] as $key => $error)
{
       $tmp_name = $_FILES["attachment"]["tmp_name"][$key];
       if (!$tmp_name) continue;

       $name = basename($_FILES["attachment"]["name"][$key]);

    if ($error == UPLOAD_ERR_OK)
    {
        if ( move_uploaded_file($tmp_name, "/tmp/".$name) )
            $uploaded_array[] .= "Uploaded file '".$name."'.<br/>\n";
        else
            $errormsg .= "Could not move uploaded file '".$tmp_name."' to '".$name."'<br/>\n";
    }
    else $errormsg .= "Upload error. [".$error."] on file '".$name."'<br/>\n";
}
?>

eslindsey at gmail dot com (2009-03-29 23:09:00)

Also note that since MAX_FILE_SIZE hidden field is supplied by the browser doing the submitting, it is easily overridden from the clients' side. You should always perform your own examination and error checking of the file after it reaches you, instead of relying on information submitted by the client. This includes checks for file size (always check the length of the actual data versus the reported file size) as well as file type (the MIME type submitted by the browser can be inaccurate at best, and intentionally set to an incorrect value at worst).

claude dot pache at gmail dot com (2009-03-19 09:26:04)

Note that the MAX_FILE_SIZE hidden field is only used by the PHP script which receives the request, as an instruction to reject files larger than the given bound. This field has no significance for the browser, it does not provide a client-side check of the file-size, and it has nothing to do with web standards or browser features.