Is there an API to read file content?

Question

Most references seem to read files using PHP functions like file_get_contents(), fgets(), fread(), or readfile().

Is there is any Drupal API that allows to read uploaded files independent of underlying storage?

We are using AWS S3 as our file field storage. Our ec2 instance is in a private subnet with an interface to S3 services. Say the URI is s3://bucketname/object.csv. I need a Drupal API that does an s3 getObject() SDK call under the hood that way I don't get blocked on network level instead request goes through the S3 network interface.

Answer 1

Drupal implements access to managed files through stream wrappers. So you can access files using native PHP functions as follows.

file_get_contents('public://some/public/file.txt');
file_get_contents('private://some/private/file.txt');
file_get_contents('temporary://some/temporary/file.txt');