Putting created file to date folder - php

Question

I made some file name.
First I need to create folder with year and month and then in that folder to put my new created csv file.
Everything seems to be working except the part where I need to put that csv file in new created folder.
File is created and folder is created.
Can someone help with the trick.
It puts it outside the folder.
My code:
// get directory path to save csv files
$rootDir = $this->container->get('kernel')->getRootDir();
$dir = $rootDir . '/../web/uploads/files/';
// makeing new directory by date
if(!is_dir($dir . date('Y-m'))) {
mkdir($dir . date('Y-m'), 0777, true);
}
// generating csv file name
$fileName = 'export-'.date('Y-m-d').'.csv';
$fp = fopen($dir .$fileName, 'w');

Answer 1

You create a folder with the year and month, but you never add the new folder to your $dir-variable.
Try this:
$rootDir = $this->container->get('kernel')->getRootDir();
// Let's add the full destination here (including the month-dir)
$dir = $rootDir . '/../web/uploads/files/' . date('Y-m');
// Now we don't need to append the date since it's already included
if(!is_dir($dir)) {
mkdir($dir, 0777, true);
}
// generating csv file name
$fileName = 'export-'.date('Y-m-d').'.csv';
// Just add a / and the filename and it should be the correct path
$fp = fopen($dir . '/' . $fileName, 'w');