Improve versatility of getClipCommands()

clip/clipClearProcess.go

@@ -13,7 +13,10 @@ import (
 // ClearProcess clears the clipboard after 30 seconds if the clipboard contents have not changed.
 // assignedContents can be omitted to clear the clipboard immediately and unconditionally.
 func ClearProcess(assignedContents string) error {
-	cmdPaste, cmdClear := getClipCommands()
+	cmdPaste, cmdClear, err := getClipCommands()
+	if err != nil {
+		return errors.New("unable to determine clipboard platform: " + err.Error())
+	}
 
 	clearClipboard := func() error {
 		err := cmdClear.Run()

clip/copy_UNIX.go

@@ -13,32 +13,48 @@ import (
 // CopyString copies a string to the clipboard.
 func CopyString(clearClipboardAutomatically bool, copySubject string) error {
 	// determine whether to use wl-copy (Wayland) or xclip (X11)
-	var envSet, isWayland bool // track whether environment variables are set
+	sessionIsWayland, err := isWayland()
+	if err != nil {
+		return err
+	}
 	var cmdCopy *exec.Cmd
-	if _, envSet = os.LookupEnv("WAYLAND_DISPLAY"); envSet {
+	if sessionIsWayland {
 		cmdCopy = exec.Command("wl-copy", "-t", "text/plain")
-		isWayland = true
-	} else if _, envSet = os.LookupEnv("DISPLAY"); envSet {
-		cmdCopy = exec.Command("xclip", "-sel", "c", "-t", "text/plain")
 	} else {
-		return errors.New("clipboard platform could not be determined")
+		cmdCopy = exec.Command("xclip", "-sel", "c", "-t", "text/plain")
 	}
 
 	_ = back.WriteToStdin(cmdCopy, copySubject)
-	err := cmdCopy.Run()
+	err = cmdCopy.Run()
 	if err != nil {
 		return errors.New("unable to copy to clipboard: " + err.Error())
 	}
 	if clearClipboardAutomatically {
-		LaunchClipClearProcess(copySubject, isWayland)
+		LaunchClipClearProcess(copySubject, sessionIsWayland)
 	}
 	return nil
 }
 
 // getClipCommands returns the commands for pasting and clearing the clipboard contents.
-func getClipCommands() (*exec.Cmd, *exec.Cmd) {
+func getClipCommands() (*exec.Cmd, *exec.Cmd, error) {
-	if os.Args[2] == "true" { // wayland
+	sessionIsWayland, err := isWayland()
-		return exec.Command("wl-paste"), exec.Command("wl-copy", "-c")
+	if err != nil {
+		return nil, nil, err
+	}
+	if sessionIsWayland {
+		return exec.Command("wl-paste"), exec.Command("wl-copy", "-c"), nil
+	}
+	return exec.Command("xclip", "-o", "-sel", "c"), exec.Command("xclip", "-i", "/dev/null", "-sel", "c"), nil
+}
+
+// isWayland returns a boolean indicating whether the current session is Wayland.
+func isWayland() (bool, error) {
+	var envSet bool // track whether environment variables are set
+	if _, envSet = os.LookupEnv("WAYLAND_DISPLAY"); envSet {
+		return true, nil
+	} else if _, envSet = os.LookupEnv("DISPLAY"); envSet {
+		return false, nil
+	} else {
+		return false, errors.New("unable to detect Wayland or X11 session")
 	}
-	return exec.Command("xclip", "-o", "-sel", "c"), exec.Command("xclip", "-i", "/dev/null", "-sel", "c")
 }