Improve comments, better wait for CTRL-C method.

examples/pingpong/main.go

@@ -3,6 +3,9 @@ package main
 import (
 	"flag"
 	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
 
 	"github.com/bwmarrin/discordgo"
 )
@@ -10,7 +13,6 @@ import (
 // Variables used for command line parameters
 var (
 	Token string
-	BotID string
 )
 
 func init() {
@@ -28,29 +30,24 @@ func main() {
 		return
 	}
 
-	// Get the account information.
-	u, err := dg.User("@me")
-	if err != nil {
-		fmt.Println("error obtaining account details,", err)
-	}
-
-	// Store the account ID for later use.
-	BotID = u.ID
-
-	// Register messageCreate as a callback for the messageCreate events.
+	// Register the messageCreate func as a callback for MessageCreate events.
 	dg.AddHandler(messageCreate)
 
-	// Open the websocket and begin listening.
+	// Open a websocket connection to Discord and begin listening.
 	err = dg.Open()
 	if err != nil {
 		fmt.Println("error opening connection,", err)
 		return
 	}
 
+	// Wait here until CTRL-C or other term signal is received.
 	fmt.Println("Bot is now running.  Press CTRL-C to exit.")
-	// Simple way to keep program running until CTRL-C is pressed.
-	<-make(chan struct{})
-	return
+	sc := make(chan os.Signal, 1)
+	signal.Notify(sc, syscall.SIGINT, syscall.SIGTERM, os.Interrupt, os.Kill)
+	<-sc
+
+	// Cleanly close down the Discord session.
+	dg.Close()
 }
 
 // This function will be called (due to AddHandler above) every time a new
@@ -58,17 +55,17 @@ func main() {
 func messageCreate(s *discordgo.Session, m *discordgo.MessageCreate) {
 
 	// Ignore all messages created by the bot itself
-	if m.Author.ID == BotID {
+	// This isn't required in this specific example but it's a good practice.
+	if m.Author.ID == s.State.User.ID {
 		return
 	}
-
 	// If the message is "ping" reply with "Pong!"
 	if m.Content == "ping" {
-		_, _ = s.ChannelMessageSend(m.ChannelID, "Pong!")
+		s.ChannelMessageSend(m.ChannelID, "Pong!")
 	}
 
 	// If the message is "pong" reply with "Ping!"
 	if m.Content == "pong" {
-		_, _ = s.ChannelMessageSend(m.ChannelID, "Ping!")
+		s.ChannelMessageSend(m.ChannelID, "Ping!")
 	}
 }