Upload error - file is not writable - php

Question

I want to upload multiple files to the server.
As far as I can see files are not writable.
What can I do so my code can actually work and upload files.
PHP:
if(isset($_FILES ['uploaded_files']))
{
foreach($_FILES['uploaded_files']['name'] as $key=>$value)
{
if(is_uploaded_file($_FILES['uploaded_files']['tmp_name'][$key]) && $_FILES['uploaded_files']['error'][$key] == 0)
{
$filename = $_FILES['uploaded_files']['name'][$key];
if (is_writable($filename)) {
echo 'The file is writable';
} else {
echo 'The file is not writable';
}
if(move_uploaded_file($_FILES['uploaded_files']['tmp_name'][$key], '../images/gallery'. $filename))
{
//code
}
else
{
die ('There was a problem uploading the pictures.');
}
}
else
{
die ('There is a problem with the uploading system.');
}
}
}
HTML:
<form enctype="multipart/form-data" action="upload.php" method="POST">
<input type="hidden" id="input_clone_id" name="input_clone_id" value="'.$row['id'].'"/>
<input type="hidden" id="input_clone_var" name="input_clone_var" value="V"/>
<input type="file" name="uploaded_files[]" id="input_clone" multiple="multiple" /><br />
<input type="submit" style="margin-left:0" value="Upload Files" />
</form>

Answer 1

I see two problems with this. The first is a security issue and the second is probably what is causing your problem
You have a security problem here:
$filename = $_FILES['uploaded_files']['name'][$key];
...
if(move_uploaded_file($_FILES['uploaded_files']['tmp_name'][$key], '../images/gallery'. $filename))
...
Problem a: Since $filename comes from the $_FILES array, it CANNOT be trusted. The user told your site what the name of their file was and put it there. They could feed you some bogus filename that could cause your script to fail in interesting ways. You need to sanitize that filename before using it in any way.
Problem b: By allowing the user to specify the filename, they could potentially overwrite other files in your "images/gallery" directory simply by specifying a conflicting filename. The way to avoid this is to use a database, generate a unique identifier for the uploaded file, store the file under that unique name, and in the database keep a record of the original filename and other information. That way you always know what the original filename was and you don't have the chance of someone trying to overwrite files in that directory.
Writing problem:*
Your "check for writable" statement is wrong. The filename that comes back is the one that the user used when submitting. This will not point to any point on your filesystem...it points to a spot on theirs (sometimes) which you cannot see. What you need to check is that your "../images/gallery" directory is writable rather than $filename. If that fails, you need to do either "chmod -R 777 gallery" while in the images folder if you have command line access or give it world write access through whatever FTP client you are using if you are using FTP to talk to your server.
So, what you should have instead for that check is:
if (is_writable("../images/gallery")) {
echo 'The file is writable';
} else {
echo 'The file is not writable';
}
After doing that, if your script comes back and says "the file is writable", it should have been able to copy the file into your images/gallery folder (remember to not use the name of the file the user gave you). If not, perhaps you don't have permissions to move uploaded files.
As for the location of uploaded files, I think sometimes they are deleted after the script execution ends sometimes, but if not, you can echo the 'tmp_name' of the file and if you go to that directory you should find it sitting there. That would be just a verification test to make sure the file was actually getting to your server. So long as you have write permissions (that what chmod 777 does) on the directory you are moving the uploaded file to, you should be able to copy it there.

Answer 2

You are checking to see if a file that you recently uploaded, but not yet saved is writable, I don't think such a file will ever be writable.
Better remove that if, or just check if the folder you are uploading to is writable.
Other than that, I checked your code and it works.