Working with pipes

If you have a piece of code that expects a reader and another piece of code that expects a writer, you can connect the two using io.Pipe.

Connecting code expecting a reader with code expecting a writer

A good example of this use case is preparing an HTTP POST request, which requires a reader. If you have all of the data available, or if you already have a reader (such as os.File), you can use that. However, if the data is produced by a function that takes a writer, use a pipe.

How to do it...

A pipe is a synchronously connected reader and writer. That is, if you write to a pipe, there must be a reader consuming from it concurrently. So make sure you put the data-producing side (where you use the writer) in a different goroutine than the data-consuming side (where you use the reader).

• Create a pipe reader and pipe writer using io.Pipe:

  pipeReader, pipeWriter := io.Pipe()

  pipeReader will read everything written to pipeWriter.

• Use pipeWriter to...