Chapter 13: Using Unnamed and Named Pipes

Overview of Pipes

A pipe is a channel of communication between two processes. A process with a handle to one end can communicate with another process that has a handle to the other end. This means that you can use a specialized Windows application to provide information to your SAS session or vice versa.

Pipes can be one-way or two-way. With a one-way pipe, one application can only write data to the pipe while the other application reads from it. With a two-way pipe, both applications can read and write data. There are two types of pipes:

unnamed pipe

• handles one way communication. Also called an anonymous pipe (or simply pipe), it is typically used to communicate between a parent process and a child process. Within SAS, SAS is the parent process that invokes (and reads data from) a child process.

named pipe

• handles one-way or two-way communication between two unrelated processes. That is, one process is not started by the other. In fact, it is possible to have two applications communicating over a pipe on a network. You can use named pipes within SAS to communicate with other applications or even with another SAS session.