Use /dev/null as a log writer by default (#15)

* Use /dev/null as a log writer by default

* Update

README.md

@@ -20,14 +20,14 @@ brew install nakabonne/gosivy/gosivy
 #### RHEL/CentOS
 
 ```
-rpm -ivh https://github.com/nakabonne/gosivy/releases/download/v0.1.1/gosivy_0.1.1_linux_amd64.rpm
+rpm -ivh https://github.com/nakabonne/gosivy/releases/download/v0.2.0/gosivy_0.2.0_linux_amd64.rpm
 ```
 
 #### Debian/Ubuntu
 
 ```
-wget https://github.com/nakabonne/gosivy/releases/download/v0.1.1/gosivy_0.1.1_linux_amd64.deb
-apt install ./gosivy_0.1.1_linux_amd64.deb
+wget https://github.com/nakabonne/gosivy/releases/download/v0.2.0/gosivy_0.2.0_linux_amd64.deb
+apt install ./gosivy_0.2.0_linux_amd64.deb
 ```
 
 #### Go

agent/agent.go

@@ -40,7 +40,7 @@ type Options struct {
 	// By default "127.0.0.1:0" is populated.
 	Addr string
 
-	// Where to emit the log to. By default os.Stderr is used.
+	// Where to emit the log to. By default ioutil.Discard is used.
 	LogWriter io.Writer
 }
 
@@ -55,7 +55,7 @@ func Listen(opts Options) error {
 	defer mu.Unlock()
 	logWriter = opts.LogWriter
 	if logWriter == nil {
-		logWriter = os.Stderr
+		logWriter = ioutil.Discard
 	}
 
 	if pidFile != "" {
@@ -149,7 +149,6 @@ func listen() {
 // handle keeps using the given connection until an issue occurred.
 func handle(conn net.Conn) error {
 	defer conn.Close()
-
 	for {
 		conn.SetReadDeadline(time.Now().Add(5 * time.Second))
 		sig := make([]byte, 1)

diagnoser/diagnoser.go

@@ -1,4 +1,4 @@
-// Package diagnoser mainly provides two components, scraper and TUI
+// Package diagnoser mainly provides two components, scraper and GUI
 // for the process diagnosis.
 package diagnoser
 

examples/local/main.go

@@ -3,13 +3,17 @@ package main
 import (
 	"fmt"
 	"log"
+	"os"
 	"time"
 
 	"github.com/nakabonne/gosivy/agent"
 )
 
 func main() {
-	if err := agent.Listen(agent.Options{}); err != nil {
+	err := agent.Listen(agent.Options{
+		LogWriter: os.Stdout,
+	})
+	if err != nil {
 		log.Fatal(err)
 	}
 	defer agent.Close()