log to /tmp/waybar-mpris.log

automatically removes the socket after 5 seconds of no input so that its
functions headlessly.

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"log"
 	"net"
@@ -44,6 +45,7 @@ const (
 	// PropertiesChanged
 	MATCH_PC = "type='signal',path='/org/mpris/MediaPlayer2',interface='org.freedesktop.DBus.Properties'"
 	SOCK     = "/tmp/waybar-mpris.sock"
+	LOGFILE  = "/tmp/waybar-mpris.log"
 )
 
 var (
@@ -64,21 +66,21 @@ func NewPlayer(conn *dbus.Conn, name string) (p *Player) {
 	for key, val := range knownPlayers {
 		if strings.Contains(name, key) {
 			playerName = val
-			if val == "Browser" {
+			break
+		}
+	}
+	if playerName == "Browser" {
 		file, err := ioutil.ReadFile(fmt.Sprintf("/proc/%d/cmdline", pid))
 		if err == nil {
 			cmd := string(file)
-					for k, v := range knownBrowsers {
-						if strings.Contains(cmd, k) {
-							playerName = v
+			for key, val := range knownBrowsers {
+				if strings.Contains(cmd, key) {
+					playerName = val
 					break
 				}
 			}
 		}
 	}
-			break
-		}
-	}
 	p = &Player{
 		player:   conn.Object(name, PATH),
 		conn:     conn,
@@ -352,6 +354,13 @@ func (pl *PlayerList) Toggle() {
 }
 
 func main() {
+	logfile, err := os.OpenFile(LOGFILE, os.O_CREATE|os.O_APPEND|os.O_RDWR, 0666)
+	if err != nil {
+		log.Fatalf("Couldn't open %s for writing: %s", LOGFILE, err)
+	}
+	mw := io.MultiWriter(logfile, os.Stdout)
+	log.SetOutput(mw)
+	os.Stderr = logfile
 	flag.StringVar(&PLAY, "play", PLAY, "Play symbol/text to use.")
 	flag.StringVar(&PAUSE, "pause", PAUSE, "Pause symbol/text to use.")
 	flag.StringVar(&SEP, "separator", SEP, "Separator string to use between artist, album, and title.")
@@ -382,10 +391,11 @@ func main() {
 			fmt.Println("Response:")
 			fmt.Printf(response)
 		}
-	} else {
+		os.Exit(0)
+	}
 	conn, err := dbus.SessionBus()
 	if err != nil {
-			panic(err)
+		log.Fatalln("Error connecting to DBus:", err)
 	}
 	players := &PlayerList{
 		conn: conn,
@@ -397,13 +407,34 @@ func main() {
 	lastLine := ""
 	// fmt.Println("New array", players)
 	// Start command listener
+	if _, err := os.Stat(SOCK); err == nil {
+		fmt.Printf("Socket %s already exists, this could mean waybar-mpris is already running.\nStarting this instance will overwrite the file, possibly stopping other instances from accepting commands.\n", SOCK)
+		var input string
+		ignoreChoice := false
+		fmt.Printf("Continue? [y/n]: ")
 		go func() {
+			fmt.Scanln(&input)
+			if strings.Contains(input, "y") && !ignoreChoice {
 				os.Remove(SOCK)
+			}
+		}()
+		time.Sleep(5 * time.Second)
+		if input == "" {
+			fmt.Printf("\nRemoving due to lack of input.\n")
+			ignoreChoice = true
+			os.Remove(SOCK)
+		}
+
+	}
+	go func() {
 		listener, err := net.Listen("unix", SOCK)
 		if err != nil {
 			log.Fatalln("Couldn't establish socket connection at", SOCK)
 		}
-			defer listener.Close()
+		defer func() {
+			listener.Close()
+			os.Remove(SOCK)
+		}()
 		for {
 			con, err := listener.Accept()
 			if err != nil {
@@ -418,21 +449,27 @@ func main() {
 			}
 			command := string(buf[0:nr])
 			if command == "player-next" {
-					if players.current < uint(len(players.list)-1) {
+				length := len(players.list)
+				if length != 1 {
+					if players.current < uint(length-1) {
 						players.current += 1
 					} else {
 						players.current = 0
 					}
 					players.Refresh()
 					fmt.Println(players.JSON())
+				}
 			} else if command == "player-prev" {
+				length := len(players.list)
+				if length != 1 {
 					if players.current != 0 {
 						players.current -= 1
 					} else {
-						players.current = uint(len(players.list) - 1)
+						players.current = uint(length - 1)
 					}
 					players.Refresh()
 					fmt.Println(players.JSON())
+				}
 			} else if command == "next" {
 				players.Next()
 			} else if command == "prev" {
@@ -504,5 +541,4 @@ func main() {
 			}
 		}
 	}
-	}
 }