CaptainHook

Common hooking/monkey patching headers for Objective-C on Mac OS X and iPhone OS. MIT licensed

Introduction to CaptainHook

CaptainHook is a generic hooking framework for the Objective-C 2.0 runtime designed to make hooking methods simple.

Basic Setup

#import

Initializes CaptainHook so the fun can begin.

Declaring Classes

Classes must be declared and loaded before they can be used with CaptainHook. CHConstructor blocks denote code that will be run as soon as the binary is loaded.

#import 
CHDeclareClass(NSString);
CHConstructor {
  CHLoadLateClass(NSString);
}

Method Hooking

Standard Method

Methods are hooked by first declaring a method using CHMethod, and then registering it in a constructor using CHHook:

#import 
CHDeclareClass(NSString);
CHMethod(2, void, NSString, writeToFile, NSString *, path, atomically, BOOL, flag)
{
    NSLog(@"Writing string to %@: %@", path, self);
    CHSuper(2, NSString, writeToFile, path, atomically, flag);
}

CHConstructor
{
    CHLoadClass(NSString);
    CHHook(2, NSString, writeToFile, atomically);
}

Simpler Method

A simpler syntax may be used, but it is slightly less efficient and offers no control over when the hooks get registered:

#import 
CHDeclareClass(NSString);
CHDeclareMethod(2, void, NSString, writeToFile, NSString *, path, atomically, BOOL, flag)
{
    NSLog(@"Writing string to %@: %@", path, self);
    CHSuper(2, NSString, writeToFile, path, atomically, flag);
}

New Classes at Runtime

New Classes may be created at runtime by using the CHRegisterClass macro:

#import 
CHDeclareClass(NSObject);
CHDeclareClass(MyNewClass);
CHMethod(0, id, MyNewClass, init)
{
    if ((self = CHSuper(0, MyNewClass, init))) {
        NSLog(@"Initted MyNewClass");
    }
    return self;
}

CHConstructor
{
    CHAutoreleasePoolForScope();
    CHLoadClass(NSObject);
    CHRegisterClass(MyNewClass, NSObject) {
        CHHook(0, MyNewClass, init);
    }
    [CHAlloc(MyNewClass) autorelease];
}

This works even for classes that can't be linked

https://blog.csdn.net/Airths/article/details/121379091

Hook 对象方法（CHMethod + CHHook）
Hook 对象方法（CHDeclareMethod）
CHMethod 与 CHDeclareMethod 的区别
Hook 类方法（CHClassMethod + CHClassHook）
Hook 类方法（CHDeclareClassMethod）
CHClassMethod 与 CHDeclareClassMethod 的区别

skfly007/CaptainHook