return static error on unimplemented manager actions

README.md

@@ -72,7 +72,7 @@ Option | Description
 `-s`  | select initial container sort field
 `-scale-cpu`	| show cpu as % of system total
 `-v`	| output version information and exit
-`-shell` | specify shell (default: sh)
+`-shell` | exec shell to use (default: sh)
 
 ### Keybindings
 

connector/manager/main.go

@@ -1,5 +1,9 @@
 package manager
 
+import "errors"
+
+var ActionNotImplErr = errors.New("action not implemented")
+
 type Manager interface {
 	Start() error
 	Stop() error

connector/manager/mock.go

@@ -7,29 +7,29 @@ func NewMock() *Mock {
 }
 
 func (m *Mock) Start() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (m *Mock) Stop() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (m *Mock) Remove() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (m *Mock) Pause() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (m *Mock) Unpause() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (m *Mock) Restart() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (m *Mock) Exec(cmd []string) error {
-	return nil
+	return ActionNotImplErr
 }

connector/manager/runc.go

@@ -7,29 +7,29 @@ func NewRunc() *Runc {
 }
 
 func (rc *Runc) Start() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (rc *Runc) Stop() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (rc *Runc) Remove() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (rc *Runc) Pause() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (rc *Runc) Unpause() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (rc *Runc) Restart() error {
-	return nil
+	return ActionNotImplErr
 }
 
 func (rc *Runc) Exec(cmd []string) error {
-	return nil
+	return ActionNotImplErr
 }

main.go

@@ -46,7 +46,7 @@ func main() {
 		invertFlag      = flag.Bool("i", false, "invert default colors")
 		scaleCpu        = flag.Bool("scale-cpu", false, "show cpu as % of system total")
 		connectorFlag   = flag.String("connector", "docker", "container connector to use")
-		defaultShell    = flag.String("shell", "", "default shell")
+		defaultShell    = flag.String("shell", "sh", "exec shell to use")
 	)
 	flag.Parse()