Helper application cannot be killed and is not launching the main app

Question

I have other questions on SO about making a sandboxed app launch at login, that apparently have no solution: here and here

As you know, you have to create a helper application that will launch the main app and die.

All tutorials out there say to add this to the helper delegate:

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {

  // Get the path for the main app bundle from the helper bundle path.
  NSString *basePath = [[NSBundle mainBundle] bundlePath];
  NSString *path = [basePath stringByDeletingLastPathComponent];
  path = [path stringByDeletingLastPathComponent];
  path = [path stringByDeletingLastPathComponent];
  path = [path stringByDeletingLastPathComponent];

  [[NSWorkspace sharedWorkspace] launchApplication:path];
  [[NSApplication sharedApplication] terminate:self];
}

This code does exactly nothing because the main app is not launched (for the reasons you will see on my other questions) and as a bonus the helper is not killed.

I have tried to kill the helper using a variety of methods, like

[NSApp terminate:self];

and even this dramatic method

NSArray *runningApplications = [[NSWorkspace sharedWorkspace] runningApplications];
  NSString *theName;
  NSNumber *pid;
  for ( NSDictionary *applInfo in runningApplications ) {
    if ( (theName = [applInfo objectForKey:@"NSApplicationName"]) ) {
      if ( (pid = [applInfo objectForKey:@"NSApplicationProcessIdentifier"]) ) {
        //NSLog( @"Process %@ has pid:%@", theName, pid );  
        if( [theName isEqualToString:@"MyHelper"] ) {
          kill( [pid intValue], SIGKILL );
        }
      }
    }
  }

Nothing kills the helper.

As another bonus, when I launch the main app manually and it sits on the menu bar, I have the option to choose QUIT from the main app itself, so I can quit the app but the main app itself is not killable too, using the same programmatically methods.

What is going on?

I have followed @vadian instructions and it is not working. I have uploaded a proof of concept project to here. You will see that the helper loads but not the app.

Answer 1

Your method cannot work because it's incomplete. At least you have to add these two path components to get the path to the executable of the main app (replace MyApp with the name of the executable in the MacOS folder)

path = [path stringByAddingPathComponent:@"MacOS"];
path = [path stringByAddingPathComponent:@"MyApp"];

Nevertheless the recommended and reliable way is to check if the main application is already running and to send an LaunchConfigurationArgument to the main application to indicate that the app is launched at login (and of course to use the modern URL related API of NSBundle and NSWorkspace):

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    BOOL alreadyRunning = NO, isActive = NO;
    NSArray *running = [[NSWorkspace sharedWorkspace] runningApplications];
    for (NSRunningApplication *app in running) {
        if ([[app bundleIdentifier] isEqualToString:@"com.myCompany.MyApp"]) {
            alreadyRunning = YES;
            isActive = [app isActive];
            break;
        }
    }

    if (!alreadyRunning || !isActive) {
        NSURL *bundleURL = [[NSBundle mainBundle] bundleURL];
        NSMutableArray *pathComponents = [[bundleURL pathComponents] mutableCopy];
        NSUInteger numberOfPathcomponents = [pathComponents count];
        [pathComponents removeObjectsInRange:NSMakeRange(numberOfPathcomponents - 3, 3)];
        [pathComponents addObject:@"MacOS"];
        [pathComponents addObject:@"MyApp"];
        NSURL *newURL = [NSURL fileURLWithPathComponents:pathComponents];
        NSDictionary *dict = @{NSWorkspaceLaunchConfigurationArguments: @[@"launchedAtLogin"]};
        [[NSWorkspace sharedWorkspace] launchApplicationAtURL:newURL
                                                      options:NSWorkspaceLaunchWithoutActivation
                                                configuration:dict
                                                        error:nil];
    }
    [NSApp terminate:nil];
}

Basically you don't have to quit the helper app from somewhere else. The helper app is supposed to quit itself in any case.