Add option to flush after each line of input (#244)

config.go

@@ -20,6 +20,7 @@ type Config struct {
 	LocalAddress       string          `long:"source-ip" description:"Local source IP address to use for making connections"`
 	Senders            int             `short:"s" long:"senders" default:"1000" description:"Number of send goroutines to use"`
 	Debug              bool            `long:"debug" description:"Include debug fields in the output."`
+	Flush              bool            `long:"flush" description:"Flush after each line of output."`
 	GOMAXPROCS         int             `long:"gomaxprocs" default:"0" description:"Set GOMAXPROCS"`
 	ConnectionsPerHost int             `long:"connections-per-host" default:"1" description:"Number of times to connect to each host (results in more output)"`
 	ReadLimitPerHost   int             `long:"read-limit-per-host" default:"96" description:"Maximum total kilobytes to read for a single host (default 96kb)"`

output.go

@@ -153,6 +153,9 @@ func OutputResults(w *bufio.Writer, results <-chan []byte) error {
 		if err := w.WriteByte('\n'); err != nil {
 			return err
 		}
+		if config.Flush {
+			out.Flush()
+		}
 	}
 	return nil
 }