Unable to create a temporary file while uploading

Question

While trying to upload a file using a form and PHP/IIS 7, I get this message:

PHP Warning:  File upload error - unable to create a temporary file in Unknown on line 0

My form:

<form action="acciones.php" id="form3" method="POST" enctype="multipart/form-data">
    <input type="hidden" value="3" name="accion">
    <input type="text" name="nombre" placeholder="Nombre">
        <input type="file" name="imagen" accept="image/x-png, image/gif, image/jpeg" />
    <input type="button" id="envio" class="button azul" value="Agregar" onclick="envios()">
</form>

My PHP code and reference:

$target = "/images/";
$target = $target . basename( $_FILES['imagen']['name']);
//This gets all the other information from the form
$name=$_POST['nombre'];
$pic=($_FILES['imagen']['name']);

//Writes the information to the database
$query = "INSERT INTO Playeras (Nombre, Ruta) VALUES ('$name', $pic')";
mysql_query($query, $conexion -> conn) or die("Error: ".mysql_error()) ;

//Writes the photo to the server
if(move_uploaded_file($_FILES['imagen']['tmp_name'], $target))
{
    //Tells you if its all ok
    echo "The file ". basename( $_FILES['uploadedfile']['name']). " has been uploaded, and your information has been added to the directory";
}
else 
{
 //Gives and error if its not
 echo "Sorry, there was a problem uploading your file.";
}

I've set the path for the temp files:

upload_tmp_dir = "C:/Users/server/Pictures/tmp"

And gave permissions for IIS_IUSRS and IUSRS with total control. But every time, I get the error. I don't know what I'm doing wrong. If someone can help me, it would be great.

Answer 1

Made it work.

Changed

upload_tmp_dir = "C:/Users/server/Pictures/tmp" to "C:\TEMP".

Create the folder TEMP in C and gave the permissions. Seems like it only works when connecting to C: directly.

Answer 2

I finaly found out, why this error actually happens:

The IUSR Account (or the account the php process impersonates, depending on your authentication settings) needs to be able to enumerate the Parent Folder of the upload_tmp_dir folder.

This behaviour is odd, because this right is not needed for the log or sessions folders.

My Solution is the following (using the paths from above post):

1. Create the folder "C:/Users/server/Pictures/tmp"
2. Grant modify rights to IUSR (or other user) on that folder
3. Create the folder "C:/Users/server/Pictures/tmp/uploads"
4. Edit php.ini: upload_tmp_dir = "C:/Users/server/Pictures/tmp/uploads"

Alternatively you can grant read only rights on "this folder only" on the parent folder "C:/Users/server/Pictures/tmp". In that case you dont need another subfolder.