PHP not moving files from /tmp to target dir

Trying to create a simple file depository on a LAMP stack, but whenever I upload files they won’t move from /tmp to target dir.

I can’t workout where I’m going wrong, I’m using the example code from the PHP docs:

<?php

    $uploaddir='/var/www/example.com/public_html/uploads/';
    $uploadfile=$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>";

?>

<!-- The data encoding type, enctype, MUST be specified as below -->

<form enctype="multipart/form-data" action="index.php" method="POST">

    <!-- MAX_FILE_SIZE must precede the file input field -->
    <input type="hidden" name="MAX_FILE_SIZE" value="30000" />

    <!-- Name of input element determines name in $_FILES array -->
    Send this file: <input name="userfile" type="file" />

    <input type="submit" value="Send File" />
</form>

Browser output is:

Possible file upload attack!
Here is some more debugging info:Array
(
    [userfile] => Array
        (
            [name] => Test_File.txt
            [full_path] => Test_File.txt
            [type] => text/plain
            [tmp_name] => /tmp/php1hAD8G
            [error] => 0
            [size] => 19
        )

)

and the apache error log gives the following warning:

PHP Warning:  move_uploaded_file(/var/www/example.com/public_html/uploads/Test_File.txt): Failed to open stream: Permission denied

Which I assume means that the system doesn’t believe it has permission to create the file in teh target dir. when I set up the site I used:

sudo chown -R $USER:$USER /var/www/example.com/public_html/uploads
sudo chmod -R 755 /var/www/

and I can see that the files are owned by whatever account I’m logged into on the SSH as.

I’m pretty new to this, but I assume I’ve done everything right here but I’ve made a mistakes with the permissions?