CHAPTER 9 – FILES AND STREAMS

Accessing files has changed drastically. Prior to PHP 4.3.0, each type of file (local, compressed, remote) had a different implementation. However, with the introduction of streams, every interaction with a file makes use of the streams layer, a layer that abstracts access to the implementation details of a specific kind of "file." The streams layer makes it possible to create a GD image object from an HTTP source with a URL stream, work with compressed files, or copy a file from one file to another. You can apply your own conversions during the copy process by implementing a user-stream or filter.