Add and delete global login items for Mac 10.6+. ARC code. C routines.

gistfile1.m

#import <ApplicationServices/ApplicationServices.h>

void addLoginItem(NSURL *appURL)
{
    AuthorizationItem right[1] = {{"system.global-login-items.", 0, NULL, 0}};
    AuthorizationRights setOfRights = {1, right};
    AuthorizationRef auth = NULL;
    AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &auth);


    if (auth != NULL)
    {
        AuthorizationCopyRights(auth, &setOfRights, kAuthorizationEmptyEnvironment,
                                (kAuthorizationFlagDefaults
                                 | kAuthorizationFlagInteractionAllowed
                                 | kAuthorizationFlagExtendRights), NULL);

        LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL, kLSSharedFileListGlobalLoginItems, NULL); // or kLSSharedFileListSessionLoginItems
        LSSharedFileListSetAuthorization(loginItems, auth);

        if (loginItems != NULL)
        {
            LSSharedFileListItemRef item = LSSharedFileListInsertItemURL(loginItems, kLSSharedFileListItemLast,
                                                                         NULL, NULL, (__bridge CFURLRef)(appURL), NULL, NULL);
            if (item)
                CFRelease(item);

            CFRelease(loginItems);
        }
        AuthorizationFree(auth, kAuthorizationFlagDefaults);
    }
    
}

void deleteLoginItem(NSURL *forURL)
{
    AuthorizationItem right[1] = {{"system.global-login-items.", 0, NULL, 0}};
    AuthorizationRights setOfRights = {1, right};
    AuthorizationRef auth = NULL;
    AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &auth);

    if (auth != NULL)
    {
        AuthorizationCopyRights(auth, &setOfRights, kAuthorizationEmptyEnvironment,
                                (kAuthorizationFlagDefaults
                                 | kAuthorizationFlagInteractionAllowed
                                 | kAuthorizationFlagExtendRights), NULL);


        LSSharedFileListRef loginItems = LSSharedFileListCreate(NULL, kLSSharedFileListGlobalLoginItems, NULL); // or kLSSharedFileListSessionLoginItems
        LSSharedFileListSetAuthorization(loginItems, auth);

        if (loginItems)
        {
            UInt32 seedValue;

            NSArray *loginItemsArray = (NSArray *)CFBridgingRelease(LSSharedFileListCopySnapshot(loginItems, &seedValue));

            NSUInteger count = [loginItemsArray count];
            NSUInteger i;
            for (i = 0; i < count; i++)
            {
                LSSharedFileListItemRef itemRef = (__bridge LSSharedFileListItemRef)([loginItemsArray objectAtIndex:i]);
                CFURLRef url = NULL;;
                UInt32 resolutionFlags = kLSSharedFileListNoUserInteraction | kLSSharedFileListDoNotMountVolumes;
                if (LSSharedFileListItemResolve(itemRef, resolutionFlags, &url, NULL) == noErr)
                {
                    NSString *urlPath = CFBridgingRelease(CFURLCopyPath(url));
                    if ([[forURL path] isEqualToString:urlPath])
                        LSSharedFileListItemRemove(loginItems, itemRef);
                    
                    CFRelease(url);
                }
            }
            CFRelease(loginItems);
        }
        AuthorizationFree(auth, kAuthorizationFlagDefaults);
    }
}