Darcy

Adds the debug menu to macOS apps

2024-04-18T00:00:00+00:00

Enables debug menu for any macOS apps:

defaults write -g _NS_4445425547 -bool true

Enables debug menu for a specific application by specifying the CFBundleIdentifier, e.g.:

defaults write com.apple.dt.XCode _NS_4445425547 -bool true

References:

iOS Private APIs(2): Observing Volume Keys' Press Events

2023-01-05T00:00:00+00:00

Observing Volume Keys’ Press Events in iOS

If you’ve used iOS devices, you might have observed that certain apps enable you to capture photos by pressing the volume buttons. This functionality mimics the experience of using a DSLR camera and improves the overall photography experience. But how is this feature actually implemented? One popular method involves monitoring changes in the audio session using AVAudioSession to detect volume button presses. However, it’s worth noting that this approach is not completely reliable and necessitates handling specific edge cases. Interestingly, iOS has had private NSNotifications available since early versions for tracking volume button presses.

Below are four events that can be utilized by NSNotificationCenter to monitor volume key press events on the iPhone. These events have been extracted from iOS header dump files:

_UIApplicationVolumeDownButtonDownNotification
_UIApplicationVolumeDownButtonUpNotification
_UIApplicationVolumeUpButtonDownNotification
_UIApplicationVolumeUpButtonUpNotification

Additionally, it is necessary to invoke the private method [UIApplication setWantsVolumeButtonEvents:YES] in order to enable the aforementioned notifications before observing them.

Here’s an example implementation:

- (void)viewDidLoad {
    [super viewDidLoad];

    [[UIApplication sharedApplication] performSelector:@selector(setWantsVolumeButtonEvents:) withObject:(@YES)];

    // Subscribe to the volumedown button press notification
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(volumeDownButtonPressed:)
                                                 name:@"_UIApplicationVolumeDownButtonDownNotification"
                                               object:nil];
}

// Method that gets called when the volume down button is pressed
- (void)volumeDownButtonPressed:(NSNotification *)notification {
    NSLog(@"Volume Down Button was pressed.");
}

Make sure to call [UIApplication setWantsVolumeButtonEvents:YES] to enable the notifications before observing them.

Please keep in mind that using private APIs can lead to your app being rejected from the App Store. Hence, it’s advised to always use public APIs that Apple has documented for developers.

-EOF-

Protecting Nginx directories with Password

2022-12-24T00:00:00+00:00

Protecting Nginx directories with Password

Add auth_basic to nginx configuration file.

location /subdirectory {
  auth_basic "Restricted";
  auth_basic_user_file /etc/nginx/htpasswd/example.com/.htpasswd;
}

Create the .htpasswd file with specified username.

htpasswd -c /etc/nginx/htpasswd/example.com/.htpasswd USERNAME

Restart Nginx.

systemctl restart nginx

-EOF-

iOS Private APIs(1): Disabling Universal Links in WKWebView

2022-09-11T00:00:00+00:00

Disabling Universal Links in WKWebView

Universal Links provide a seamless user experience by allowing your web server to relate HTTP links to your website with corresponding links for your iOS app. However, there might be situations where you would like to disable this feature in a WKWebView.

This guide will show you how to disable Universal Links from opening in-app and instead let them open in WKWebView using Objective-C.

Prerequisites

Xcode installed on your Mac.
Basic knowledge of Objective-C.
An existing iOS project with WKWebView set up.

Step-by-step Instructions

Step 1: Conform to the WKNavigationDelegate protocol

Your ViewController must conform to the WKNavigationDelegate protocol. Declare this conformance in your interface declaration.

@interface YourViewController () <WKNavigationDelegate>
//...
@end

Step 2: Set WKWebView’s navigationDelegate

Set your WKWebView instance’s navigationDelegate property to self.

webView.navigationDelegate = self;

Step 3: Implement the decidePolicyForNavigationAction method

Implement the webView:decidePolicyForNavigationAction:decisionHandler: delegate method. Here, we use WKNavigationActionPolicyAllow + 2, which is a private API that handles Universal Links as normal web links.

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    decisionHandler((WKNavigationActionPolicy)(WKNavigationActionPolicyAllow + 2));
}

That’s it! This will prevent your WKWebView from opening Universal Links in-app.

Important Note

Using private APIs like WKNavigationActionPolicyAllow + 2 can lead to your app being rejected from the App Store. They’re not documented or supported and may change or disappear without notice in future iOS versions. Use them cautiously and only when necessary. Always consider the potential risks and consequences before deciding to use private APIs in production code.

-EOF-

Shutdown ESXi host over SSH

2016-04-08T00:00:00+00:00

Shutdown ESXi host over SSH

Connect ESXi host over SSH
Get a list of running virtual machines, we will use the [World ID] later.

esxcli vm process list

Power off the virtual machines one by one from the list

esxcli vm process kill --type=[soft, hard, force] --world-id=[World ID]

Shutdown VMs and Power off ESXi Host

/sbin/shutdown.sh && /sbin/poweroff

[Alternative]Power off/on a virtual machine with command-line utilities

List VMs

vim-cmd vmsvc/getallvms

Get the power state of a VM

vim-cmd vmsvc/power.getstate <Vmid>

Power on a virtual machine

vim-cmd vmsvc/power.off <Vmid>

References

Hello World!

1970-01-01T00:00:00+00:00

Hello World!