keyNotFound(CodingKeys(stringValue: "name", intValue: nil), 
Swift.DecodingError.Context(codingPath: 
[CodingKeys(stringValue: "examples", intValue: nil), _JSONKey(stringValue: "Index 0", intValue: 0)],
debugDescription: "No value associated with key CodingKeys(stringValue: \"name\", intValue: nil) (\"name\").", 
underlyingError: nil))

void HandleException(NSException *exception) {
    NSArray *stackArray = [exception callStackSymbols];
    NSString *reason = [exception reason];
    NSString *name = [exception name];
    NSString *exceptionInfo = [NSString stringWithFormat:@"Exception reason：%@\nException name：%@\nException stack：%@",name, reason, stackArray];
    
    NSLog(@"%@", exceptionInfo);
}
void InstallUncaughtExceptionHandler(void) {
    NSSetUncaughtExceptionHandler(&HandleException);
}

void SignalExceptionHandler(int signal) {
    NSMutableString *crashInfo = [[NSMutableString alloc] init];
    [crashInfo appendString:@"Stack:\n"];
    void *callstack[128];
    int i, frames = backtrace(callstack, 128);
    char **strs = backtrace_symbols(callstack, frames);
    for (i = 0; i < frames; ++i) {
        [crashInfo appendFormat:@"%s\n", strs[i]];
    }
}
void InstallSignalHandler(void) {
    signal(SIGHUP, SignalExceptionHandler);
    signal(SIGINT, SignalExceptionHandler);
    signal(SIGQUIT, SignalExceptionHandler);
    signal(SIGABRT, SignalExceptionHandler);
    signal(SIGILL, SignalExceptionHandler);
    signal(SIGSEGV, SignalExceptionHandler);
    signal(SIGFPE, SignalExceptionHandler);
    signal(SIGBUS, SignalExceptionHandler);
    signal(SIGPIPE, SignalExceptionHandler);
}

[cat mew];

objc_msgSend(cat, @selector(mew));

#import <objc/message.h>
@interface Cat : NSObject
@property (nonatomic, copy) NSString *name;
- (void)mew;
@end
@implementation Cat
- (void)mew {
    NSLog(@"喵~");
}
@end
int main(int argc, const char * argv[]) {
    @autoreleasepool {
       Cat *cat = Cat.new;
       [cat mew];
       objc_msgSend(cat, @selector(mew));
    }
    return 0;
}

喵~
喵~

id objc_msgSend(id self, SEL _cmd, ...)

typedef struct objc_class *Class;
typedef struct objc_object *id;
struct objc_object {
    Class _Nonnull isa  OBJC_ISA_AVAILABILITY;
};
struct objc_class : objc_object  {
    Class superclass;
    cache_t cache;             // 方法缓存
    class_data_bits_t bits;    // 类具体的信息
    class_rw_t *data() { 
        return bits.data();
    }
}
struct class_rw_t {
    // Be warned that Symbolication knows the layout of this structure.
    uint32_t flags;
    uint32_t version;
    const class_ro_t *ro;
    method_array_t methods; // 方法列表
    property_array_t properties; // 属性列表
    protocol_array_t protocols; // 协议列表
    ...
};
struct class_ro_t {
    uint32_t flags;
    uint32_t instanceStart;
    uint32_t instanceSize; // 对象占用空间
#ifdef __LP64__
    uint32_t reserved;
#endif
    const uint8_t * ivarLayout;
    
    const char * name; // 类名
    method_list_t * baseMethodList;
    protocol_list_t * baseProtocols;
    const ivar_list_t * ivars; // 成员变量列表
    const uint8_t * weakIvarLayout;
    property_list_t *baseProperties;
    method_list_t *baseMethods() const {
        return baseMethodList;
    }
};
typedef struct objc_selector *SEL;
typedef id _Nullable (*IMP)(id _Nonnull, SEL _Nonnull, ...);

id objc_msgSend(id self, SEL op, ...) {
    if (!self) return nil;
	IMP imp = class_getMethodImplementation(self->isa, SEL op);
	imp(self, op, ...); //调用这个函数，伪代码...
}

.macro MethodTableLookup
	...
	bl	__class_lookupMethodAndLoadCache3

IMP _class_lookupMethodAndLoadCache3(id obj, SEL sel, Class cls)
{
    return lookUpImpOrForward(cls, sel, obj, 
                              YES/*initialize*/, NO/*cache*/, YES/*resolver*/);
}
IMP lookUpImpOrForward(Class cls, SEL sel, id inst, 
                       bool initialize, bool cache, bool resolver)
{
    ...
    
    // Try this class's cache.
    imp = cache_getImp(cls, sel);
    if (imp) goto done;
    // Try this class's method lists.
    {
        Method meth = getMethodNoSuper_nolock(cls, sel);
        if (meth) {
            log_and_fill_cache(cls, meth->imp, sel, inst, cls);
            imp = meth->imp;
            goto done;
        }
    }
    // Try superclass caches and method lists.
    {
        unsigned attempts = unreasonableClassCount();
        for (Class curClass = cls->superclass;
             curClass != nil;
             curClass = curClass->superclass)
        {
            // Halt if there is a cycle in the superclass chain.
            if (--attempts == 0) {
                _objc_fatal("Memory corruption in class list.");
            }
            
            // Superclass cache.
            imp = cache_getImp(curClass, sel);
            if (imp) {
                if (imp != (IMP)_objc_msgForward_impcache) {
                    // Found the method in a superclass. Cache it in this class.
                    log_and_fill_cache(cls, imp, sel, inst, curClass);
                    goto done;
                }
                else {
                    // Found a forward:: entry in a superclass.
                    // Stop searching, but don't cache yet; call method 
                    // resolver for this class first.
                    break;
                }
            }
            
            // Superclass method list.
            Method meth = getMethodNoSuper_nolock(curClass, sel);
            if (meth) {
                log_and_fill_cache(cls, meth->imp, sel, inst, curClass);
                imp = meth->imp;
                goto done;
            }
        }
    }
    // No implementation found. Try method resolver once.
    if (resolver  &&  !triedResolver) {
        runtimeLock.unlockRead();
        _class_resolveMethod(cls, sel, inst);
        runtimeLock.read();
        // Don't cache the result; we don't hold the lock so it may have 
        // changed already. Re-do the search from scratch instead.
        triedResolver = YES;
        goto retry;
    }
    // No implementation found, and method resolver didn't help. 
    // Use forwarding.
    imp = (IMP)_objc_msgForward_impcache;
    cache_fill(cls, sel, imp, inst);
}

@interface NSObject (Sark)
+ (void)foo;
@end
@implementation NSObject (Sark)
- (void)foo {
    NSLog(@"IMP: - [NSObject (sark) foo]");
}
@end
[NSObject foo]; // 打印 IMP: - [NSObject (sark) foo]

Cat *cat = Cat.new;
[cat performSelector:@selector(lalala)];

2018-03-01 17:37:05.671634+0800 msg_send[18226:862391] -[Cat lalala]: unrecognized selector sent to instance 0x10054d9e0
2018-03-01 17:37:05.676829+0800 msg_send[18226:862391] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Cat lalala]: unrecognized selector sent to instance 0x10054d9e0'
*** First throw call stack:
(
	0   CoreFoundation                      0x00007fff4eabc54b __exceptionPreprocess + 171
	1   libobjc.A.dylib                     0x00007fff7658bc76 objc_exception_throw + 48
	2   CoreFoundation                      0x00007fff4eb55024 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
	3   CoreFoundation                      0x00007fff4ea32a90 ___forwarding___ + 1456
	4   CoreFoundation                      0x00007fff4ea32458 _CF_forwarding_prep_0 + 120
	5   msg_send                            0x0000000100001c76 main + 86
	6   libdyld.dylib                       0x00007fff771a5015 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

open /private/tmp

- Cat NSObject performSelector:
+ Cat NSObject resolveInstanceMethod:
+ Cat NSObject resolveInstanceMethod:
- Cat NSObject forwardingTargetForSelector:
- Cat NSObject forwardingTargetForSelector:
- Cat NSObject methodSignatureForSelector:
- Cat NSObject methodSignatureForSelector:
- Cat NSObject class
- Cat NSObject doesNotRecognizeSelector:
- Cat NSObject doesNotRecognizeSelector:
- Cat NSObject class

@interface Dog : NSObject
@property (nonatomic, copy) NSString *name;
@end
@implementation Dog {
    NSString *_name;
}
@dynamic name;
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        Dog *dog = [Dog new];
        dog.name = @"Kiki";
        NSLog(@"%@", dog.name);
    }
    return 0;
}

@implementation Dog {
    NSString *_name;
}
@dynamic name;
void mySetName(id self, SEL _cmd, NSString *newValue) {
//    Ivar ivar = class_getInstanceVariable(Dog.class, "_name");
//    object_setIvar(self, ivar, [newValue copy]);
    if (((Dog *)self)->_name != newValue) {
        ((Dog *)self)->_name = [newValue copy];
    }
}
NSString * myGetName(id self, SEL _cmd) {
//    Ivar ivar = class_getInstanceVariable(Dog.class, "_name");
//    return object_getIvar(self, ivar);
    return ((Dog *)self)->_name;
}
+ (BOOL)resolveInstanceMethod:(SEL)sel {
    NSLog(@"%s", __func__);
    if ([NSStringFromSelector(sel) isEqualToString:@"setName:"]) {
        class_addMethod(self, sel, (IMP)mySetName, "v@:@");
    }
    else {
        class_addMethod(self, sel, (IMP)myGetName, "@@:");
    }
    return YES;
}
@end

@implementation Dog {
    NSString *_name;
}
@dynamic name;
- (id)forwardingTargetForSelector:(SEL)aSelector {
    NSLog(@"%s", __func__);
    return Cat.new;
}
@end

@implementation Dog {
    NSString *_name;
}
@dynamic name;
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector {
    NSLog(@"%s", __func__);
    NSString *selStr = NSStringFromSelector(aSelector);
    if([selStr isEqualToString:@"name"]) {
        NSMethodSignature *sig = [NSMethodSignature signatureWithObjCTypes:"@@:"];
        return sig;
    }
    else {
        NSMethodSignature *sig = [NSMethodSignature signatureWithObjCTypes:"v@:@"];
        return sig;
    }
}
- (void)forwardInvocation:(NSInvocation *)anInvocation {
    NSLog(@"%s", __func__);
    
    SEL sel = [anInvocation selector];
    Cat *cat = [[Cat alloc] init];
    if([cat respondsToSelector:sel]) {
        [anInvocation invokeWithTarget:cat];
    }
    else {
        [self doesNotRecognizeSelector:sel];
    } 
}
@end

exiting2: 22Phoenix
exiting
exiting3

$ pip install fabric

$ fab hello
hello world

$ fab -f test.py hello
hello world

$ fab set_ips:'192.168.0.3','192.168.0.22' prepare update

$ pip install pymysql

$ fab all_ip update

cd ~/asura19.github.io

hexo new "一个标题"

在路径 ~/asura19.github.io/source/_posts/ 下打开相应文章

hexo generate  (可简写为 hexo g)

hexo server  (可简写为 hexo s)

hexo deploy  (可简写为 hexo d)

@protocol Cute
@optional
- (void)isCute;
@end
@protocol Movable
@optional
- (void)run;
@end
@interface Cat : NSObject<Movable>
@property (nonatomic, copy) NSString *name;
- (void)mew;
@end

@implementation Cat {
    NSColor *_color;
}
+ (void)mews {
    NSLog(@"+++++喵+++++");
}
- (instancetype)init {
    self = [super init];
    if (self) {
        _color = [NSColor blackColor];
    }
    return self;
}
- (void)mew {
    NSLog(@"-----喵-----");
}
- (void)run {
    NSLog(@"~~run~~");
}
- (NSArray *)method0:(NSArray *)agu0
                agu1:(CGFloat)agu1
                agu2:(NSObject *)agu2
                agu3:(NSString *)agu3
                agu4:(CGRect)agu4 {
    
    NSLog(@"test method");
    return @[];
}
- (void)method0 {
    NSLog(@">>>>>>>>0:%s", __func__);
}
- (void)method1 {
    NSLog(@">>>>>>>>1:%s", __func__);
}
- (void)method2 {
    NSLog(@">>>>>>>>2:%s", __func__);
}
+ (void)catClassMethod {
    NSLog(@"~~cat class method~~");
}
@end

@interface Cat (YYAdd)
@property (nonatomic, assign) float weight;
- (void)jump;
@end

@implementation Cat (YYAdd)
- (void)setWeight:(float)weight {
    objc_setAssociatedObject(self, @selector(weight), @(weight), OBJC_ASSOCIATION_ASSIGN);
}
- (float)weight {
    return [objc_getAssociatedObject(self, _cmd) floatValue];
}
- (void)jump {
    NSLog(@"~~Cat jump~~");
}
@end

// 获取类名
const char *className = class_getName(Cat.class);
NSLog(@"%@", [NSString stringWithUTF8String:className]);
// 结果: Cat
// 获取父类
Class superClass = class_getSuperclass(Cat.class);
NSLog(@"%@", superClass);
// 结果: NSObject
// 该函数的作用是获取类的实例所占用内存的大小
size_t instanceSizeOfClass = class_getInstanceSize(Cat.class);
NSLog(@"%zu", instanceSizeOfClass);
// 结果: 24
// 获取实例变量
Ivar ivar = class_getInstanceVariable(Cat.class, "_color");
NSLog(@"%@", [NSString stringWithUTF8String:ivar_getName(ivar)]);
// 结果: _color
    
// 获取属性
objc_property_t prop = class_getProperty(Cat.class, "name");
NSLog(@"%@", [NSString stringWithUTF8String:property_getName(prop)]);
// 结果: name
// 获取实例方法的实现, 并执行
IMP mewImp = class_getMethodImplementation(Cat.class, @selector(mew));
mewImp();
// 结果: -----喵-----
// 获取类的所有实例
unsigned int ivarListCount = 0;
Ivar *ivars = class_copyIvarList(Cat.class, &ivarListCount);
for (NSInteger i = 0; i < ivarListCount; i++) {
   Ivar ivar = ivars[i];
   const char *name = ivar_getName(ivar);
   NSLog(@"ivarList: %@", [NSString stringWithUTF8String:name]);
}
free(ivars);
// 结果: 
ivarList: _color
ivarList: _name
// 获取类的所有属性
unsigned int propertyListCount = 0;
objc_property_t *props = class_copyPropertyList(Cat.class, &propertyListCount);
for (NSInteger i = 0; i < propertyListCount; i++) {
   objc_property_t property = props[i];
   const char *name = property_getName(property);
   NSLog(@"propertyList: %@", [NSString stringWithUTF8String:name]);
}
free(props);
// 结果: 
propertyList: weight
propertyList: name
// 由此可见, 运行时添加的关联属性, 没有生成实例
// 获取类的所有实例方法
unsigned int methodListCount = 0;
Method *methods = class_copyMethodList(Cat.class, &methodListCount);
for (NSInteger i = 0; i < methodListCount; i++) {
   Method method = methods[i];
   SEL name = method_getName(method);
   NSLog(@"methodList: %@", NSStringFromSelector(name));
}
free(methods);
// 结果: 
methodList: mew
methodList: method0:agu1:agu2:agu3:agu4:
methodList: method0
methodList: method1
methodList: method2
methodList: init
methodList: .cxx_destruct
methodList: name
methodList: setName:
methodList: run
methodList: jump
methodList: setWeight:
methodList: weight
// 获取类所遵守的协议
unsigned int protocolListCount = 0;
Protocol * __unsafe_unretained *protocols = class_copyProtocolList(Cat.class, &protocolListCount);
for (NSInteger i = 0; i < protocolListCount; i++) {
   Protocol *protocal = protocols[i];
   const char *name = protocol_getName(protocal);
   NSLog(@"protocolList: %@", [NSString stringWithUTF8String:name]);
}
free(protocols);
// 结果: protocolList: Movable
    
// 获取类的某个类方法
Method classMethod = class_getClassMethod(Cat.class, NSSelectorFromString(@"catClassMethod"));
SEL classMethodName = method_getName(classMethod);
NSLog(@"clasMethod: %@", NSStringFromSelector(classMethodName));
IMP classMethodNameIMP = method_getImplementation(classMethod);
classMethodNameIMP();
// 结果: clasMethod: catClassMethod
// 获取类的元类
Class metaClass = objc_getMetaClass("Cat");
NSLog(@"meta class: %@", metaClass);
// 结果: meta class: Cat
    
// 从元类中获取所有类方法
unsigned int metaMethodListCount = 0;
Method *metaMethods = class_copyMethodList(metaClass, &metaMethodListCount);
for (NSInteger i = 0; i < metaMethodListCount; i++) {
   Method method = metaMethods[i];
   SEL name = method_getName(method);
   NSLog(@"metaMethodList: %@", NSStringFromSelector(name));
}
free(metaMethods);
// 结果: 
metaMethodList: mews
metaMethodList: catClassMethod
// 证明类方法的确存放在元类中

Cat *cat = Cat.new;
cat.name = @"小麻烦";
cat.weight = 5.0;
    
NSLog(@"cat weight: %@", @(cat.weight)); // cat weight: 5
objc_removeAssociatedObjects(cat);
NSLog(@"cat weight after remove: %@", @(cat.weight)); // cat weight after remove: 0
    
Ivar ivar = class_getInstanceVariable(Cat.class, "_color");
NSLog(@"internal instance old value: %@", object_getIvar(cat, ivar)); // internal instance old value: Generic Gray Gamma 2.2 Profile colorspace 0 1
object_setIvar(cat, ivar, [NSColor orangeColor]);
NSLog(@"internal instance new value: %@", object_getIvar(cat, ivar)); // internal instance new value: sRGB IEC61966-2.1 colorspace 1 0.5 0 1

// C语言实现得getter
NSString *personNameGetter(id classInstance, SEL _cmd) {
    Ivar ivar = class_getInstanceVariable([classInstance class], "_name");
    return object_getIvar(classInstance, ivar);
}
// C语言实现得setter
void personNameSetter(id classInstance, SEL _cmd, NSString *newName) {
    Ivar ivar = class_getInstanceVariable([classInstance class], "_name");
    id oldName = object_getIvar(classInstance, ivar);
    if (oldName != newName) object_setIvar(classInstance, ivar, [newName copy]);
}
//下面对应的编码值可以在官方文档里面找到
    //编码值     含意
    //c     代表char类型
    //i     代表int类型
    //s     代表short类型
    //l     代表long类型，在64位处理器上也是按照32位处理
    //q     代表long long类型
    //C     代表unsigned char类型
    //I     代表unsigned int类型
    //S     代表unsigned short类型
    //L     代表unsigned long类型
    //Q     代表unsigned long long类型
    //f     代表float类型
    //d     代表double类型
    //B     代表C++中的bool或者C99中的_Bool
    //v     代表void类型
    //*     代表char *类型
    //@     代表对象类型
    //#     代表类对象 (Class)
    //:     代表方法selector (SEL)
    //[array type]     代表array
    //{name=type…}     代表结构体
    //(name=type…)     代表union
    //bnum     A bit field of num bits
    //^type     A pointer to type
    //?     An unknown type (among other things, this code is used for function pointers)
    
    Class PersonClass = objc_allocateClassPair(NSObject.class, "Person", 0);
    // 添加属性必须在objc_allocateClassPair和objc_registerClassPair之间
    BOOL result = class_addIvar(PersonClass,
                                "_gender",
                                sizeof(NSString *),
                                log2(sizeof(NSString *)),
                                "@");
    
    BOOL result2 = class_addIvar(PersonClass,
                                "_name",
                                sizeof(NSString *),
                                log2(sizeof(NSString *)),
                                "@");
    // 也可以将 "@" 用@encode(NSString)表示
    
    if (result && result2) {
        objc_registerClassPair(PersonClass);
    }
    else {
        objc_disposeClassPair(PersonClass);
    }
    
    // https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/ObjCRuntimeGuide/Articles/ocrtPropertyIntrospection.html
    // 结合文档, 添加属性需以T开头, V结尾
    objc_property_attribute_t type = {"T", "@\"NSString\""};
    objc_property_attribute_t ownership = {"C", ""};
    objc_property_attribute_t nonatomic = {"N", ""};
    objc_property_attribute_t backingIvar = {"V", "_name"};
    objc_property_attribute_t attrs[] = {type, ownership, nonatomic, backingIvar};
    class_addProperty(PersonClass, "name", attrs, 4);
    
    SEL getter = NSSelectorFromString(@"name");
    SEL setter = NSSelectorFromString(@"setName:");
    // 添加方法
    class_addMethod(PersonClass, getter, (IMP)personNameGetter, "@@:"); // or use method_getTypeEncoding for last argument
    class_addMethod(PersonClass, setter, (IMP)personNameSetter, "v@:@");
    
// 以下为测试该类
    Ivar ivar = class_getInstanceVariable(PersonClass, "_gender");
    NSLog(@"Person ivar:%@",[NSString stringWithUTF8String:ivar_getName(ivar)]);
    // 结果: Person ivar:_gender
    
    
    objc_property_t prop = class_getProperty(PersonClass, "name");
    NSLog(@"Person property:%@",[NSString stringWithUTF8String:property_getName(prop)]);
    // 结果: Person property:name
    
    
    Method method = class_getInstanceMethod(PersonClass, NSSelectorFromString(@"setName:"));
    NSLog(@"%@", NSStringFromSelector(method_getName(method)));
    // 结果: setName:
    
    id person = [PersonClass new];
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Warc-performSelector-leaks"
    [person performSelector:setter withObject:@"Phoenix"];
    NSLog(@"person name get:%@", [person performSelector:getter withObject:nil]);
#pragma clang diagnostic pop
// 结果: person name get:Phoenix

void newCatMethod() {
    NSLog(@"~~汪~~");
}
void replaceMethod() {
    class_replaceMethod(Cat.class, @selector(mew), (IMP)newCatMethod, NULL);
    IMP mew = class_getMethodImplementation(Cat.class, @selector(mew));
    mew();
    // 结果: ~~汪~~
}

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"
    Method method = class_getInstanceMethod(Cat.class, @selector(method0:agu1:agu2:agu3:agu4:));
#pragma clang diagnostic pop
    
    SEL methodName = method_getName(method);
    NSLog(@"%@", NSStringFromSelector(methodName));
    // 结果: method0:agu1:agu2:agu3:agu4:
    
    IMP methodIMP = method_getImplementation(method);
#pragma unused(methodIMP)
    
    const char *attrs = method_getTypeEncoding(method);
    NSLog(@"%@", [NSString stringWithUTF8String:attrs]);
    // 结果: @80@0:8@16d24@32@40{CGRect={CGPoint=dd}{CGSize=dd}}48
    
    unsigned int count = method_getNumberOfArguments(method);
    NSLog(@"%u", count);
    // 结果: 7 因为还有self 和 _cmd
    
    for (unsigned int i =0 ; i < count; i++) {
        char result[1024] = {};
        method_getArgumentType(method, i, result, 1024);
        NSLog(@"类型是 %s", result);
    }
    
    char returnType[1024] = {};
    method_getReturnType(method, returnType, 1024);
    NSLog(@"return type:%s",returnType);
    
    struct objc_method_description result7 = *method_getDescription(method);
    NSLog(@"description ~%@ ~%@",NSStringFromSelector(result7.name),[NSString stringWithUTF8String:result7.types]);

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"
    Method result0 = class_getInstanceMethod(Cat.class, @selector(method0));
    Method result1 = class_getInstanceMethod(Cat.class, @selector(method1));
    Method result2 = class_getInstanceMethod(Cat.class, @selector(method2));
    method_setImplementation(result0, method_getImplementation(result1));
    
    method_getImplementation(result0)();
    
    method_exchangeImplementations(result0, result2);
    
    method_getImplementation(result0)();
    method_getImplementation(result2)();
#pragma clang diagnostic pop
// 结果:  
>>>>>>>>1:-[Cat method1]
>>>>>>>>2:-[Cat method2]
>>>>>>>>1:-[Cat method1]