Write errors to Stderr and remove a few fatal calls

deck.go

@@ -141,7 +141,7 @@ func emulateKeyPresses(keys string) {
 // emulates a (multi-)key press.
 func emulateKeyPress(keys string) {
 	if keyboard == nil {
-		fmt.Println("Keyboard emulation is disabled!")
+		fmt.Fprintln(os.Stderr, "Keyboard emulation is disabled!")
 		return
 	}
 
@@ -150,7 +150,7 @@ func emulateKeyPress(keys string) {
 		k = formatKeycodes(strings.TrimSpace(k))
 		kc, err := strconv.Atoi(k)
 		if err != nil {
-			fatalf("%s is not a valid keycode: %s\n", k, err)
+			fmt.Fprintf(os.Stderr, "%s is not a valid keycode: %s\n", k, err)
 		}
 
 		if i+1 < len(kk) {
@@ -166,7 +166,7 @@ func emulateKeyPress(keys string) {
 func emulateClipboard(text string) {
 	err := clipboard.WriteAll(text)
 	if err != nil {
-		fatalf("Pasting to clipboard failed: %s\n", err)
+		fmt.Fprintf(os.Stderr, "Pasting to clipboard failed: %s\n", err)
 	}
 
 	// paste the string
@@ -177,7 +177,7 @@ func emulateClipboard(text string) {
 func executeDBusMethod(object, path, method, args string) {
 	call := dbusConn.Object(object, dbus.ObjectPath(path)).Call(method, 0, args)
 	if call.Err != nil {
-		fmt.Printf("dbus call failed: %s\n", call.Err)
+		fmt.Fprintf(os.Stderr, "dbus call failed: %s\n", call.Err)
 	}
 }
 
@@ -190,12 +190,12 @@ func executeCommand(cmd string) {
 	args := strings.Split(cmd, " ")
 	c := exec.Command(args[0], args[1:]...) //nolint:gosec
 	if err := c.Start(); err != nil {
-		fmt.Printf("command failed: %s\n", err)
+		fmt.Fprintf(os.Stderr, "Command failed: %s\n", err)
 		return
 	}
 
 	if err := c.Wait(); err != nil {
-		fmt.Printf("command failed: %s\n", err)
+		fmt.Fprintf(os.Stderr, "Command failed: %s\n", err)
 	}
 }
 
@@ -215,11 +215,12 @@ func (d *Deck) triggerAction(dev *streamdeck.Device, index uint8, hold bool) {
 				if a.Deck != "" {
 					d, err := LoadDeck(dev, filepath.Dir(d.File), a.Deck)
 					if err != nil {
-						fatal(err)
+						fmt.Fprintln(os.Stderr, "Can't load deck:", err)
+						return
 					}
-					err = dev.Clear()
-					if err != nil {
+					if err := dev.Clear(); err != nil {
 						fatal(err)
+						return
 					}
 
 					deck = d

desktop_unix.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"image"
+	"os"
 	"time"
 
 	"github.com/jezek/xgb"
@@ -198,7 +199,7 @@ func (x Xorg) name(w xproto.Window) (string, error) {
 func (x Xorg) icon(w xproto.Window) (image.Image, error) {
 	icon, err := xgraphics.FindIcon(x.util, w, 128, 128)
 	if err != nil {
-		fmt.Printf("Could not find icon for window %d\n", w)
+		fmt.Fprintf(os.Stderr, "Could not find icon for window %d\n", w)
 		return nil, err
 	}
 

main.go

@@ -134,10 +134,10 @@ func eventLoop(dev *streamdeck.Device, tch chan interface{}) error {
 
 func closeDevice(dev *streamdeck.Device) {
 	if err := dev.Reset(); err != nil {
-		fmt.Fprintln(os.Stderr, "unable to reset Stream Deck")
+		fmt.Fprintln(os.Stderr, "Unable to reset Stream Deck")
 	}
 	if err := dev.Close(); err != nil {
-		fmt.Fprintln(os.Stderr, "unable to close Stream Deck")
+		fmt.Fprintln(os.Stderr, "Unable to close Stream Deck")
 	}
 }
 
@@ -216,15 +216,15 @@ func run() error {
 		defer xorg.Close()
 		xorg.TrackWindows(tch, time.Second)
 	} else {
-		fmt.Printf("Could not connect to X server: %s\n", err)
-		fmt.Println("Tracking window manager will be disabled!")
+		fmt.Fprintf(os.Stderr, "Could not connect to X server: %s\n", err)
+		fmt.Fprintln(os.Stderr, "Tracking window manager will be disabled!")
 	}
 
 	// initialize virtual keyboard
 	keyboard, err = uinput.CreateKeyboard("/dev/uinput", []byte("Deckmaster"))
 	if err != nil {
-		fmt.Printf("Could not create virtual input device (/dev/uinput): %s\n", err)
-		fmt.Println("Emulating keyboard events will be disabled!")
+		fmt.Fprintf(os.Stderr, "Could not create virtual input device (/dev/uinput): %s\n", err)
+		fmt.Fprintln(os.Stderr, "Emulating keyboard events will be disabled!")
 	} else {
 		defer keyboard.Close() //nolint:errcheck
 	}

widget.go

@@ -239,6 +239,7 @@ func drawString(img *image.RGBA, bounds image.Rectangle, ttf *truetype.Font, tex
 
 	c.SetSrc(image.NewUniform(color))
 	if _, err := c.DrawString(text, freetype.Pt(pt.X, pt.Y)); err != nil {
-		fatal(err)
+		fmt.Fprintf(os.Stderr, "Can't render string: %s\n", err)
+		return
 	}
 }

widget_top.go

@@ -50,7 +50,7 @@ func (w *TopWidget) Update() error {
 	case "cpu":
 		cpuUsage, err := cpu.Percent(0, false)
 		if err != nil {
-			fatal(err)
+			return fmt.Errorf("can't retrieve CPU usage: %s", err)
 		}
 
 		value = cpuUsage[0]
@@ -59,7 +59,7 @@ func (w *TopWidget) Update() error {
 	case "memory":
 		memory, err := mem.VirtualMemory()
 		if err != nil {
-			fatal(err)
+			return fmt.Errorf("can't retrieve memory usage: %s", err)
 		}
 		value = memory.UsedPercent
 		label = "MEM"