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SAS Companion for the Microsoft Windows Environment

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. With the SAS System and Windows NT, this means that you can use a specialized Windows application to provide information to your SAS session or vice versa.

Note:    Pipes and named pipes are supported in SAS only under Windows NT. Windows 95 can support named pipes, but only as a client.  [cautend]

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, the SAS System 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.


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