capture stdout in golang

capture_stdout.go

import (
  "bytes"
  "io"
  "os"
)

// not thread safe
func captureStdout(f func()) string {
  old := os.Stdout
  r, w, _ := os.Pipe()
  os.Stdout = w

  f()

  w.Close()
  os.Stdout = old

  var buf bytes.Buffer
  io.Copy(&buf, r)
  return buf.String()
}

http://craigwickesser.com/post/capture-stdout-in-go/

Terrible: will simply block f() when it has reached the buffering capacity of the OS pipe.

Terrible: will simply block f() when it has reached the buffering capacity of the OS pipe.

Suggestions on how to fix it?

https://stackoverflow.com/a/10476304 demonstrates using io.Copy in a Go routine to keep the pipe flowing. Also does a clean shutdown and value return via channel.