slimtoolkit/slim · error

unknown command: %s

Error message

unknown command: %s

What it means

runControlCommand switches on the control command parsed from os.Args[2]. If the value matches none of the known control commands (stop-target-app, wait-for-event, etc.), the default branch returns this error, aborting the sensor run with a message naming the unrecognized command.

Source

Thrown at pkg/app/sensor/app.go:325

	cmd := control.Command(os.Args[2])

	switch cmd {
	case control.StopTargetAppCommand:
		if err := control.ExecuteStopTargetAppCommand(ctx, *commandsFile); err != nil {
			return fmt.Errorf("error stopping target app: %w", err)
		}

	case control.WaitForEventCommand:
		if len(os.Args) < 4 {
			return errors.New("missing event name")
		}
		if err := control.ExecuteWaitEvenCommand(ctx, eventsFilePath(), event.Type(os.Args[3])); err != nil {
			return fmt.Errorf("error waiting for sensor event: %w", err)
		}

	default:
		return fmt.Errorf("unknown command: %s", cmd)
	}

	return nil
}

View on GitHub (pinned to 81940d17fa)

Solutions

1. Print/echo os.Args[2] and compare it exactly against the exported control command constants.
2. Fix the spelling in the calling script to match the control package constants.
3. Check the control package for the current list of valid commands after upgrading the sensor version.
4. Add argument validation with usage output before dispatching so bad commands fail early with help text.

Example fix

// before
sensor stoped-target-app   // typo
// after
sensor stop-target-app     // exact control.StopTargetAppCommand value

valid := map[control.Command]bool{
    control.StopTargetAppCommand: true,
    control.WaitForEventCommand:  true,
}
if !valid[control.Command(os.Args[2])] {
    return fmt.Errorf("usage: sensor <%s|%s>", control.StopTargetAppCommand, control.WaitForEventCommand)
}

func isKnownCommand(s string) bool {
    switch control.Command(s) {
    case control.StopTargetAppCommand, control.WaitForEventCommand:
        return true
    }
    return false
}

When it happens

Trigger: Invoking the sensor binary with an unknown or misspelled second argument, e.g. sensor stop-target (instead of the exact control.StopTargetAppCommand string) or passing an empty/garbage token in os.Args[2].

Common situations: Script/Makefile typos in the sensor invocation; version drift where an old script uses a command name removed from the control package; quoting bugs that pass the wrong argv slot as the command.

Related errors

• unknown sensor mode
• missing command
• missing event name
• error stopping target app: %w
• error waiting for sensor event: %w

AI-assisted analysis of slimtoolkit/slim@81940d17fa (2026-08-31). Data as JSON: /api/errors/a132abf4fc397e21. Report an issue: GitHub.