• https://www.jianshu.com/p/4d86de908721

• Mach-O文件结构 https://www.jianshu.com/p/1f22d1e667e3

• MachOView

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    //这里必须要先加载一次NSLog，如果不写NSLog，符号表里面根本就不会出现NSLog的地址
    NSLog(@"123"); 

    //定义rebinding结构体
    struct rebinding nslogBind;
    //函数的名称
    nslogBind.name = "NSLog";
    //新的函数地址
    nslogBind.replacement = myMethod;
    //保存原始函数地址变量的指针
    nslogBind.replaced = (void *)&old_nslog;
    
    //定义数组
    struct rebinding rebs[] = {nslogBind};
    
    /**
     arg1: 存放rebinding结构体的数组
     arg2: 数组的长度
     */
    rebind_symbols(rebs, 1);
}

//函数指针，用来保存原始的函数地址
static void (*old_nslog)(NSString *format, ...);

//新的NSLog
void myMethod(NSString *format, ...) {
    //再调用原来的
    old_nslog(@"勾上了！");
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    NSLog(@"点击屏幕");
}

lldb

• iOS之LLDB常用命令 https://www.jianshu.com/p/7fb43e0b956a