Function SetOutput

log/log.go:55–59

SetOutput sets the log output to w. If SetOutput hasn't been called, the default behavior is to write to stdout.

(w io.Writer)

// If SetOutput hasn't been called,
// the default behavior is to write to stdout.
func SetOutput(w io.Writer) {
	logWriterMu.Lock()
	logWriter = w
	logWriterMu.Unlock()
}

func appendPrefix(b []byte, keyval ...interface{}) []byte {
	// Invariant: len(keyval) is always even.