File is not creating on heroku using cakephp - cakephp

Question

I tried to make a file on heroku using PHP code:
$fh = fopen("../DownloadFiles/".$filename,'a');
fwrite($fh,$s);
but the file has not been created and it is not showing any error. Please help.

Answer 1

This should work just fine, but are you aware that if you're running multiple dynos, that file will exist only on the dyno that served that one request, and not on all the others?
Also, Dynos restart every 24 hours, and their state is reset every time you push a change to Heroku, so you cannot store persistent information on them; that's called an ephemeral filesystem.
You could, for instance, store uploaded files on Amazon S3, like described in the docs: https://devcenter.heroku.com/articles/s3-upload-php
Two remarks about your original issue:
you're probably running an old version of CakePHP which mangles all internal PHP error handling and writes it out to a log file (if you're lucky), so you can't see anything in heroku logs, and it's not possible to configure it otherwise; upgrade to a more recent version that lets you log to streams and then use php://stderr as the destination
in general, if you want to write to a file in PHP, you can just do file_put_contents($filename, $contents)...

Answer 2

Does the DownloadFiles folder exist in the deployment? Node fs gives error if the directory is not found. You can add a snippet to check if dir exists and if not then create. You can use fs.exists and fs.mkdir.
For more info http://nodejs.org/api/fs.html