How to download a temporary file
<p>I'm trying to create a short PHP script that takes a JSON string, converts it to CSV format (using <code>fputcsv</code>), and makes that CSV available as a downloaded .csv file.  My thought was to use <code>tmpfile()</code> to not worry about cronjobs or running out of disk space, but I can't seem to make the magic happen.</p>

<p>Here's my attempt, which is a converted example from <a href="http://php.net/manual/en/function.readfile.php#refsect1-function.readfile-examples" rel="nofollow">the PHP docs of <code>readfile</code></a>:</p>

<pre><code>$tmp = tmpfile();
$jsonArray = json_decode( $_POST['json'] );
fputcsv($tmp, $jsonArray);

header('Content-Description: File Transfer');
header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename='.basename($tmp));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($tmp));

ob_clean();
flush();
readfile($tmp);
</code></pre>

<p>I feel like the <code>Content-Disposition</code> and <code>Content-Transfer-Encoding</code> headers are wrong, but I'm not sure how to fix them.  For example, <code>basename($tmp)</code> doesn't seem to return anything, and I'm not sure <code>text/csv</code> transfers as binary encoding. Likewise, <code>echo filesize($tmp)</code> is blank as well.  Is there a way to do what I'm attempting here?</p>

<p><strong>[Edit]</strong></p>

<p>*<em>Below is the working code I wrote as a result of the accepted answer:</em></p>

<pre><code>$jsonArray = json_decode( $_POST['json'], true );
$tmpName = tempnam(sys_get_temp_dir(), 'data');
$file = fopen($tmpName, 'w');

fputcsv($file, $jsonArray);
fclose($file);

header('Content-Description: File Transfer');
header('Content-Type: text/csv');
header('Content-Disposition: attachment; filename=data.csv');
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize($tmpName));

ob_clean();
flush();
readfile($tmpName);

unlink($tmpName);
</code></pre>
