1

class MyStubService : public DbusServer<MyStubService> {};

1
2
3
4
5
6
7
8

template <typename Derived>
class Base {
    // 基类定义
};

class Derived : public Base<Derived> {  // 关键：派生类将自己作为模板参数传递给基类
    // 派生类定义
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

template <typename Derived>
class Animal {
public:
    void speak() {
        static_cast<Derived*>(this)->speakImpl();  // 编译时绑定
    }
    
    void run() {
        static_cast<Derived*>(this)->runImpl();
    }
};

class Dog : public Animal<Dog> {
public:
    void speakImpl() {
        std::cout << "Woof!" << std::endl;
    }
    
    void runImpl() {
        std::cout << "Running on four legs" << std::endl;
    }
};

class Cat : public Animal<Cat> {
public:
    void speakImpl() {
        std::cout << "Meow!" << std::endl;
    }
    
    void runImpl() {
        std::cout << "Running gracefully" << std::endl;
    }
};

// 使用
template <typename T>
void makeAnimalSpeak(Animal<T>& animal) {
    animal.speak();  // 编译时确定调用哪个实现
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24

template <typename T>
class Counter {
private:
    static int count;
protected:
    Counter() { ++count; }
    Counter(const Counter&) { ++count; }
    ~Counter() { --count; }
public:
    static int getCount() { return count; }
};

// 静态成员初始化
template <typename T>
int Counter<T>::count = 0;

// 使用
class MyClass : public Counter<MyClass> {
    // 自动获得计数功能
};

class AnotherClass : public Counter<AnotherClass> {
    // 独立的计数
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

template <typename Derived>
class Chainable {
public:
    Derived& self() { return static_cast<Derived&>(*this); }
    
    Derived& setX(int x) {
        // 具体实现由派生类提供
        self().setXImpl(x);
        return self();  // 返回派生类引用，支持链式调用
    }
    
    Derived& setY(int y) {
        self().setYImpl(y);
        return self();
    }
};

class Point : public Chainable<Point> {
private:
    int x, y;
public:
    Point& setXImpl(int x_) { x = x_; return *this; }
    Point& setYImpl(int y_) { y = y_; return *this; }
    
    void print() const {
        std::cout << "Point(" << x << ", " << y << ")" << std::endl;
    }
};

// 使用：链式调用
Point p;
p.setX(10).setY(20).print();

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23

template <typename Derived>
class Comparable {
public:
    bool operator==(const Derived& other) const {
        return static_cast<const Derived*>(this)->equals(other);
    }
    
    bool operator!=(const Derived& other) const {
        return !static_cast<const Derived*>(this)->equals(other);
    }
};

class Person : public Comparable<Person> {
private:
    std::string name;
    int age;
public:
    Person(const std::string& n, int a) : name(n), age(a) {}
    
    bool equals(const Person& other) const {
        return name == other.name && age == other.age;
    }
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14

template <typename Derived>
class MustHaveFoo {
public:
    void callFoo() {
        static_assert(std::is_same_v<decltype(&Derived::foo), void(Derived::*)()>,
                      "Derived must define void foo() member");
        static_cast<Derived*>(this)->foo();
    }
};

class OK : public MustHaveFoo<OK> {
public:
    void foo() {}
};

1
2
3
4
5

template <typename T>
concept HasFoo = requires(T t) { t.foo(); };

template <HasFoo Derived>
class MustHaveFoo2 { /* ... */ };

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14

template <typename Derived>
class Orderable {
public:
    friend bool operator<(const Derived& a, const Derived& b) {
        return a.less(b);
    }
};

class Node : public Orderable<Node> {
public:
    bool less(const Node& other) const { return key < other.key; }
private:
    int key{0};
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73

name: Deploy to Tencent Cloud

on:
  push:
    branches: [ public ]  # 当推送到主分支时触发

jobs:
  deploy:
    runs-on: ubuntu-latest
    
    steps:
    - name: Checkout code
      uses: actions/checkout@v3
      with:
        submodules: true  # 初始化submodules，包括你的主题
        fetch-depth: 0

    - name: Setup Hugo v0.135.0
      uses: peaceiris/actions-hugo@v2
      with:
        hugo-version: '0.135.0'  # 指定与你本地相同的版本
        extended: true
        
    - name: Setup Node.js
      uses: actions/setup-node@v3
      with:
        node-version: '16'
        
    - name: Install dependencies
      run: npm install
        
    - name: Build Hugo site
      run: |
        hugo --minify --baseURL https://amclock.online/
        
    - name: Deploy to server
      uses: appleboy/ssh-action@v0.1.5
      with:
        host: ${{ secrets.HOST }}
        username: ${{ secrets.USERNAME }}
        key: ${{ secrets.KEY }}
        port: ${{ secrets.PORT }}
        script: |
          # 备份当前版本
          if [ -d "/var/www/myconfig/amclock.online.public" ]; then
            sudo cp -r /var/www/myconfig/amclock.online.public /var/www/myconfig/amclock.online.public.backup.$(date +%Y%m%d_%H%M%S)
          fi
          
          # 清理目标目录
          sudo rm -rf /var/www/myconfig/amclock.online.public/*
          
    - name: Upload files
      uses: appleboy/scp-action@v0.1.4
      with:
        host: ${{ secrets.HOST }}
        username: ${{ secrets.USERNAME }}
        key: ${{ secrets.KEY }}
        port: ${{ secrets.PORT }}
        source: "public/*"
        target: "/var/www/myconfig/amclock.online.public"
        strip_components: 1
        
    - name: Set permissions and reload nginx
      uses: appleboy/ssh-action@v0.1.5
      with:
        host: ${{ secrets.HOST }}
        username: ${{ secrets.USERNAME }}
        key: ${{ secrets.KEY }}
        port: ${{ secrets.PORT }}
        script: |
          sudo chmod -R 755 /var/www/myconfig/amclock.online.public
          sudo systemctl reload nginx
          echo "部署完成！网站已更新到 https://amclock.online" 

1
2

ssh: connect to host github.com port 22: Operation timed out
fatal: Could not read from remote repository.

1

nc -vz github.com 22

1

vi ~/.ssh/config

1

ssh -T git@github.com

1

git config --global url."https://github.com/".insteadOf git@github.com:

1

sudo -E apt update

1

sudo visudo

1
2
3
4
5
6

sudo apt-get update
sudo apt-get install apt-transport-https ca-certificates curl software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt-get update
sudo apt-get install docker-ce

1

sudo systemctl status docker

1

sudo usermod -aG docker ${USER}

1
2

sudo mkdir -p /etc/systemd/system/docker.service.d
sudo touch /etc/systemd/system/docker.service.d/proxy.conf

1
2
3
4

[Service]
Environment="HTTP_PROXY=http://proxy.example.com:8080/"
Environment="HTTPS_PROXY=http://proxy.example.com:8080/"
Environment="NO_PROXY=localhost,127.0.0.1,.example.com"

1
2
3
4
5
6
7
8
9

{
 "proxies": {
   "default": {
     "httpProxy": "http://proxy.example.com:8080",
     "httpsProxy": "http://proxy.example.com:8080",
     "noProxy": "localhost,127.0.0.1,.example.com"
   }
 }
}

1
2
3
4
5

docker build . \
    --build-arg "HTTP_PROXY=http://proxy.example.com:8080/" \
    --build-arg "HTTPS_PROXY=http://proxy.example.com:8080/" \
    --build-arg "NO_PROXY=localhost,127.0.0.1,.example.com" \
    -t your/image:tag

1
2

sudo systemctl daemon-reload
sudo systemctl restart docker

1
2
3
4
5
6
7
8

Err:5 https://download.docker.com/linux/ubuntu focal Release                                            
  Could not handshake: The TLS connection was non-properly terminated. [IP: <xx.xxx.xx.xxx> 3128]
Hit:6 http://security.ubuntu.com/ubuntu focal-security InRelease                                        
Hit:7 http://us.archive.ubuntu.com/ubuntu focal-security InRelease
Reading package lists... Done
E: The repository 'https://download.docker.com/linux/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

extension String {
    var localized: String {
        // TalkingNumCalUserDefaults.voiceLang has value like 'en-US', 'fr-FR', 'de-DE' etc.
        if let lang = Locale(identifier: TalkingNumCalUserDefaults.voiceLang).languageCode { // e.g. en, jp, zh ...
            if let path = Bundle.main.path(forResource: lang, ofType: "lproj"), let bundle = Bundle(path: path) {
                let string = bundle.localizedString(forKey: self, value: nil, table: nil)
                return string
            }
        }
        return NSLocalizedString(self, comment: "")
    }
}

1
2
3
4
5
6
7
8
9

extension String {
    var localized: String {
        // TalkingNumCalUserDefaults.voiceLang has value like 'en-US', 'fr-FR', 'de-DE' etc.
        if let lang = Locale(identifier: TalkingNumCalUserDefaults.voiceLang).languageCode { // e.g. en, jp, zh ...
            Bundle.setLanguage(lang)
        }
        return NSLocalizedString(self, tableName: nil, bundle: Bundle.main, value: "", comment: "")
    }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32

template<typename T>
struct DataStruct {
    DataStruct(int i, T n): index(i), value(n) {}

    int index;
    T value;
};

template<typename T>
auto func1(string prefix, int i, T n) {
    cout << __FUNCTION__ << "(" << prefix << ", " << i << ", " << n << ")" << endl;
}

template<typename... T> // mark 1
auto func2(string p, const DataStruct<T>&&... s) { // mark 2
    (func1(p, s.index, s.value), ...);  // mark 3
}


int main() {

    func2<string>("hi ", DataStruct<string>(12, "Tom"), DataStruct<string>(29, "Mason"), DataStruct<int>(100, 999));
    cout << "done\n";
}

// execute result
/*
func1(hi , 12, Tom)
func1(hi , 29, Mason)
func1(hi , 100, 999)
done
*/

1
2
3
4
5
6
7

void coutX() {} // 终止条件

template<typename T, typename... Types>
void coutX(const T& t, const Types&... args) {
    cout << t << endl; // cout 1st argument
    coutX(args...); // 对可变参数递归调用 coutX
}

1
2
3
4

template<typename... T> // variadic template
auto func2(string p, const DataStruct<T>&&... s) { // variadic template
    (func1(p, s.index, s.value), ...); // fold expression
}

1
2
3
4
5

template<typename... Values>
auto sum(Values const&... values) {
    return (0 + ... + values);
}
sum(1, 2, 3, 4); // same as (0 + 1 + 2 + 3 + 4)

1
2
3

void coutX(const Types&... args) {
    cout << ... << args << endl;
}

1

mount -o remount,rw /

1

fsck -f /dev/sda1

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21

class SubscriptionSheetPresenter: NSObject {
    static let instance = SubscriptionSheetPresenter()

    func presentBottomSheetForSubscription(from vc: UIViewController) {
        // storyboard 中定义了定制页面的布局
        let dashboard = UIStoryboard.init(name: "Main", bundle: nil)
        guard let subscriptionVC = dashboard.instantiateViewController(withIdentifier: "subscriptionViewController") as? SubscriptionViewController else {
            return
        }
        subscriptionVC.modalPresentationStyle = .custom
        subscriptionVC.transitioningDelegate = self
        vc.present(subscriptionVC, animated: true, completion: nil)
    }
}

// MARK: - Bottom Sheet for Subscription
extension SubscriptionSheetPresenter: UIViewControllerTransitioningDelegate {
    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
        return SubscriptionSheetPresentationController(presentedViewController: presented, presenting: presenting)
    }
}

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18

class SubscriptionViewController: UIViewController {
    @IBOutlet weak var monthlyBuy: UIButton!
    @IBOutlet weak var yearlyBuy: UIButton!

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        updateUI()
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        updateUI()
    }

    private func updateUI() {
        // update layour for diff device (iPhone/iPad) and view (Landscape/Protraint)
        // ...
    }

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46

class SubscriptionSheetPresentationController: UIPresentationController {
    override var frameOfPresentedViewInContainerView: CGRect {
        let screenWidth = UIScreen.main.bounds.width
        let screenHeight = UIScreen.main.bounds.height

         // default is iPhone+portrait for non-SE
        var width: CGFloat = screenWidth
        var height: CGFloat = screenHeight * 2/3
        var x: CGFloat = 0
        var yOffset = 1.0

        if UIDevice.current.userInterfaceIdiom == .phone {
            if UIDevice.current.orientation.isLandscape {
                width = screenWidth / 2
                height = screenHeight * 0.95
            } else {
                if screenHeight < 700 {
                    height = screenHeight * 2.5/3
                }
            }
        } else { // iPad or Mac
            if UIDevice.current.orientation.isLandscape {
                width = screenWidth / 2.5
                height = screenHeight * 0.65
            } else {
                width = screenWidth / 1.8
                height = screenHeight * 0.5
            }
            yOffset = 0.5
        }

        x = (screenWidth - width)/2

        return CGRect(x: x,
                      y: (containerView.bounds.height - height) * yOffset,
                      width: width,
                      height: height)
    }

    override func containerViewWillLayoutSubviews() {
        super.containerViewWillLayoutSubviews()
        if let presentedView = presentedView {
            presentedView.frame = frameOfPresentedViewInContainerView
        }
    }
}

1
2
3
4
5

class <Any>ViewController: <XXX>ViewController {
    func showSubscription() {
        SubscriptionSheetPresenter.instance.presentBottomSheetForSubscription(from: self)
    }
}

1
2
3
4
5

class <Anyother>ViewController: <YYY>ViewController {
    func goPremium() {
        SubscriptionSheetPresenter.instance.presentBottomSheetForSubscription(from: self)
    }
}

1

ssh-keygen -R github.com

1
2

$ ping github.com
PIING github.com(127.0.0.1): 56 data bytes

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17

// template<class>
template<class T>
class MyClass1 {
    // ...
};

// template<typename>
template<typename T>
class MyContainer {
public:
    // internal usage
    using value_type = T;
    // nested type
    typename MyContainer<T>::value_type getValue() {
        // ...
    }
};

1
2
3
4
5
6
7
8
9

extends CharacterBody2D

@onready var _animated_sprite = $AnimatedSprite2D

func _process(_delta):
    if Input.is_action_pressed("ui_right"):
        _animated_sprite.play("run")
    else:
        _animated_sprite.stop()

1
2
3
4
5
6
7
8
9

extends CharacterBody2D

@onready var _animation_player = $AnimationPlayer

func _process(_delta):
    if Input.is_action_pressed("ui_right"):
        _animation_player.play("walk")
    else:
        _animation_player.stop()

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

class A {
public:
  A() {}
  ~A() {}

  int getVal() const { return val; }
  void setVal(int i) { val = i; }

private:
  int val;
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21

#include <iostream>
#include <map>
#include <set>
using namespace std;

int main() {
  A a1, a2;

  a1.setVal(100);
  a2.setVal(-200);

  map<A, string> mapOfA;
  mapOfA[a1] = "hello";
  mapOfA[a2] = "world";

  set<A> setOfA;
  setOfA.insert(a1);
  setOfA.insert(a2);

  return 0;
}

1
2
3
4
5
6

/usr/include/c++/9/bits/stl_function.h: In instantiation of ‘constexpr bool std::less<_Tp>::operator()(const _Tp&, const _Tp&) const [with _Tp = A]’:
/usr/include/c++/9/bits/stl_map.h:497:32:   required from ‘std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type& std::map<_Key, _Tp, _Compare, _Alloc>::operator[](const key_type&) [with _Key = A; _Tp = std::__cxx11::basic_string<char>; _Compare = std::less<A>; _Alloc = std::allocator<std::pair<const A, std::__cxx11::basic_string<char> > >; std::map<_Key, _Tp, _Compare, _Alloc>::mapped_type = std::__cxx11::basic_string<char>; std::map<_Key, _Tp, _Compare, _Alloc>::key_type = A]’
/home/rduis/Workspace/github/notesnotes/swift/src/custom-class-in-std-map.cpp:25:12:   required from here
/usr/include/c++/9/bits/stl_function.h:386:20: error: no match for ‘operator<’ (operand types are ‘const A’ and ‘const A’)
  386 |       { return __x < __y; }
      |                ~~~~^~~~~

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14

class A {
public:
  A() {}
  ~A() {}

  int getVal() const { return val; }
  void setVal(int i) { val = i; }

  // solution 1: operator <
  bool operator<(const A &rhs) const { return val < rhs.getVal(); }

private:
  int val;
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20

class A {
public:
  A() {}
  ~A() {}

  int getVal() const { return val; }
  void setVal(int i) { val = i; }

private:
  int val;
};

// solution 2: delcare comparator
class comparator
{
    public:
    bool operator()(const A& lhs, const A& rhs) const {
        return lhs.getVal() < rhs.getVal();
    }
};

1
2
3

cd <folder of your project>

find . -type f \( -iname "*.swift" -o -iname "*.h" -o -iname "*.m" \) -exec sed -i -e "s/^\( \{1,99\}\)*$//g" {} \;

1
2
3
4
5
6
7
8

enum Week        {Mon   ,Tue   ,Wed  ,Thu  };
enum Season      {Sprint,Summer,Fall ,Winter};

Week w = Tue;
Season s = Summer;

bool isEqual = (w == s); // isEqual is true
}

1
2
3

warning: comparison between ‘enum Week’ and ‘enum Season’ [-Wenum-compare]
      |   bool isEqual = (w == s);
      |                        ^

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60

#include <iostream>

using namespace std;

namespace EnumOnly {
enum Week { Mon, Tue, Wed, Thu };
enum Season { Sprint, Summer, Fall, Winter };
} // namespace EnumOnly

namespace EnumClass {
enum class Month { Jan, Feb, Mar, Apr };
enum class Num { One=1, Two, Three, Four };

} // namespace EnumClass

int main() {
  cout << "EnumOnly::Week::Mon = " << EnumOnly::Week::Mon << endl;
  cout << "EnumClass::Month::Jan = " << static_cast<int>(EnumClass::Month::Jan) << endl;

  cout << "Is EnumOnly::Week a class : " << std::is_class<EnumOnly::Week>::value << endl;
  cout << "Is EnumOnly::Week a enum : " << std::is_enum<EnumOnly::Week>::value << endl;

  cout << "Is EnumClass::Month a class : " << std::is_class<EnumClass::Month>::value << endl;
  cout << "Is EnumClass::Month a enum : " << std::is_enum<EnumClass::Month>::value << endl;


  EnumOnly::Week w = EnumOnly::Tue;
  EnumOnly::Season s = EnumOnly::Summer;

  EnumClass::Month m = EnumClass::Month::Feb;
  EnumClass::Num n = EnumClass::Num::Two;
  EnumClass::Num n2 = static_cast<EnumClass::Num>(2);
  EnumClass::Num n3 = EnumClass::Num::Three;

  if (w == s) {
    cout << "w == s, ohh!" << endl;  // unmeaningful
  } else {
    cout << "w != s" << endl;
  }
  
  if (n == n2) {
    cout << "n == n2, yes" << endl;
  } else {
    cout << "n != n2, why" << endl;
  }

  if (n == n3) {
    cout << "n == n3" << endl;
  } else {
    cout << "n != n3, yes" << endl;
  }
/*
  if (w == m) {
    cout << "w == m";
  } else {
    cout << "w != m";
  }
*/
  return 0;
}

1
2
3
4
5
6
7
8
9

EnumOnly::Week::Mon = 0
EnumClass::Month::Jan = 0
Is EnumOnly::Week a class : 0
Is EnumOnly::Week a enum : 1
Is EnumClass::Month a class : 0
Is EnumClass::Month a enum : 1
w == s, ohh!
n == n2, yes
n != n3, yes

1
2
3
4
5
6

error: no match for ‘operator==’ (operand types are ‘EnumOnly::Week’ and ‘EnumClass::Month’)
      |   if (w == m) {
      |       ~ ^~ ~
      |       |    |
      |       |    EnumClass::Month
      |       EnumOnly::Week

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
SHA256:xxxxxxx.
Please contact your system administrator.
Add correct host key in /Users/xxx/.ssh/known_hosts to get rid of this message.
Offending RSA key in /Users/xxx/.ssh/known_hosts:1
Host key for github.com has changed and you have requested strict checking.
Host key verification failed.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

1

ssh-keygen -lf ~/.ssh/known_hosts

1

256 SHA256:xxxxxxxxxxxxxxxx github.com,13.250.177.223

1

>>>> $ ssh-keygen -R 13.250.177.223

1
2
3

# Host 13.250.177.223 found: line 1
/Users/xxx/.ssh/known_hosts updated.
Original contents retained as /Users/xxx/.ssh/known_hosts.old

1

Are you sure you want to continue connecting (yes/no)? 

1
2

bash '/Library/Application Support/org.pqrs/Karabiner-DriverKit-VirtualHIDDevice/scripts/uninstall/deactivate_driver.sh'
sudo '/Library/Application Support/org.pqrs/Karabiner-Elements/uninstall.sh'

1
2

$ bash '/Library/Application Support/org.pqrs/Karabiner-DriverKit-VirtualHIDDevice/scripts/uninstall/deactivate_driver.sh'
bash: /Library/Application Support/org.pqrs/Karabiner-DriverKit-VirtualHIDDevice/scripts/uninstall/deactivate_driver.sh: No such file or directory

1
2
3
4
5
6
7
8

cd <your_repo>

# 备份 .git
cp -r .git .git-bak

cd .git
find . -type f -empty -delete -print
git fsck --full

1
2

![替换文本](图片路径 "图片标题")
![alt text](image_path "image title")

1
2

![substring is deprecated](/images/xcode-while-editing.png "XCode屏幕截图")
*Tips: 可以在图片下面用一行斜体的说明文本。图片标题不保证一定会显示*

1

<image src="https://picsum.photos/400/200" alt="网络图片400*200">

1

<image src="https://picsum.photos/400/200" alt="网络图片400*200" width="100" height="200">

1

![alt text](image path "image title"){ width=80%,height=120px }

1
2
3

<a href="https://apps.apple.com/cn/app/id1528477391">
  <img src="https://mzstatic.com/image/AppIcon.png"/>
</a>

1

Bad owner or permissions on <user>/.ssh/config

1
2
3
4
5
6

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@         WARNING: UNPROTECTED PRIVATE KEY FILE!          @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Permissions 0640 for '<user>/.ssh/id_rsa' are too open.
It is required that your private key files are NOT accessible by others.
This private key will be ignored.

1
2
3
4
5
6

cd ~/.ssh

sudo chmod 700 .      # .ssh dir
sudo chmod 700 *.pub  # PUBLIC key file
sudo chmod 600 id_rsa # PRIVATE key file
sudo chmod 600 config # config file

1
2
3
4
5

if let firstFive = str.firstIndex(of: "5") {
    let substr = str[str.startIndex..<firstFive] // substr = 01234
    // 或者可以省略开始的index
    let substr2 = str[..<firstFive] // substr2 = 01234
}

1

let substr = str[...firstFive] // substr = 012345

1

let substr = str[firstFive...] // 56789

1

let strstr = str[str.startIndex..<str.index(str.startIndex, offsetBy: 7)] // 0123456

1
2
3

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

1
2
3
4
5
6

// Observer.h 

class Observer {
public:
  virtual void update(string msg) = 0; // abstract virtual
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

// Subject.h

class Subject {
public:
  virtual void addObserver(Observer * observer);
  virtual void removeObserver(Observer * observer);
  virtual void notify(string msg);

private:
  std::set<Observer*> observers;
};

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15