What do PHP stream contexts do in relation to file operations?

Question

In the PHP manual, the file operations reference an optional context (e.g. for copy). How do these contexts affect basic file operations?

Answer 1

As it turns out, stream contexts can contain both options and parameters. At the current time, parameters are simply callback functions so that you can be notified at various points of the file operation. Options are wrapper-specific, and filesystem operations don't have any options. Some examples of options for the HTTP wrapper are method, proxy, etc.