A wrapper function for file_put_contents with cache invalidation.
write_file( string $file, mixed $data [, int $flags ] ) : int
$file (string) (Required) File path.
$data (mixed) (Required) The data to write.
$flags (int) (optional) Default value: null
(int) Number of written bytes.
$data = 'data...';
write_file(BASEDIR.'test.txt', $data);