[置顶] IOS高级开发～底层实现资源收集

注意：dlopen（）一个路径时候要以你本机的路径为准，我的路径为（首先右键你的XCode，然后查看Content）：

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation

1、NSArray & NSAutoreleasePool 实现

#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main() {
 
  void *sdl_library = dlopen("/System/Library/Frameworks/Foundation.framework/Versions/Current/Foundation", RTLD_LAZY);
  if (sdl_library == NULL) {
    printf("Got dlopen error!\n");
  } else {
    printf("dlopen successful!\n");
 
    // Set up an NSAutoreleasePool
    Class nsautoreleasepool = objc_getClass("NSAutoreleasePool");
    id pool = class_createInstance(nsautoreleasepool, 0);
    SEL initSel = sel_registerName("init");
    id poolAfterInit = objc_msgSend(pool, initSel);
 
    // Create an NSMutableArray
    Class nsmutablearray = objc_getClass("NSMutableArray");
 
    // Regular way to create an NSMutableArray,
    // equivalent to [[NSMutableArray alloc] initWithCapacity: 10]
    id array = objc_msgSend(nsmutablearray, sel_registerName("alloc"));
    id arrayAfterInit = objc_msgSend(array, sel_registerName("initWithCapacity:"), 10);
 
    // Alternative, shorthand way of creating an NSMutableArray,
    // equivalent to [NSMutableArray arrayWithCapacity: 10]
    //id arrayAfterInit = objc_msgSend(nsmutablearray, sel_registerName("arrayWithCapacity:"), 10);
 
    // Add an NSString and the nsma class reference to the array
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"test");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), nsmutablearray);
 
    // Print out the length and debug printout
    NSLog(@"%d", objc_msgSend(arrayAfterInit, sel_registerName("count")));
    NSLog(@"%@", arrayAfterInit);
  }
 
  return 0;
}

2、Block

（一）

  
  
  
  

   
   
   
   
#import <Foundation/Foundation.h>
#include <objc/runtime.h>
#include <Block.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main() {
 
  void *sdl_library = dlopen("/System/Library/Frameworks/Foundation.framework/Versions/Current/Foundation", RTLD_LAZY);
  if (sdl_library == NULL) {
    printf("Got dlopen error!\n");
  } else {
    printf("dlopen successful!\n");
 
    // Set up an NSAutoreleasePool
    Class nsautoreleasepool = objc_getClass("NSAutoreleasePool");
    id pool = class_createInstance(nsautoreleasepool, 0);
    SEL initSel = sel_registerName("init");
    id poolAfterInit = objc_msgSend(pool, initSel);
 
    // Create an NSMutableArray
    Class nsmutablearray = objc_getClass("NSMutableArray");
 
    // Regular way to create an NSMutableArray,
    // equivalent to [[NSMutableArray alloc] initWithCapacity: 10]
    id array = objc_msgSend(nsmutablearray, sel_registerName("alloc"));
    id arrayAfterInit = objc_msgSend(array, sel_registerName("initWithCapacity:"), 10);
 
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"a");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"b");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"c");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"d");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"e");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"f");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"g");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"h");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"i");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"j");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"k");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"l");
 
    id b = ^(id x, NSUInteger index, BOOL *stop){
      NSLog(@"%@", x);
    };
 
    NSLog(@"%@", b);
 
    objc_msgSend(arrayAfterInit, sel_registerName("enumerateObjectsUsingBlock:"), b);
  }
 
  return 0;
}
  
  
  
  

（二）

  
  
  
  

   
   
   
   
#import <Foundation/Foundation.h>
#include <objc/runtime.h>
#include <Block.h>
#include <dlfcn.h>
#include <stdio.h>
 
struct __block_literal_1 {
  void *isa;
  int flags;
  int reserved; 
  void (*invoke)(struct __block_literal_1 *, id obj, NSUInteger idx, BOOL *stop);
  struct __block_descriptor_1 *descriptor;
};
 
// This is the regular C function we are turning into a Block.
void __block_invoke_1(struct __block_literal_1 *_block, id obj, NSUInteger idx, BOOL *stop) {
  NSLog(@"%d: %@", idx, obj);
}
 
static struct __block_descriptor_1 {
  unsigned long int reserved;
  unsigned long int Block_size;
} __block_descriptor_1 = { 0, sizeof(struct __block_literal_1) };
 
 
int main() {
 
  printf("sizeof(int): %lu\n", sizeof(int));
  printf("sizeof(void *): %lu\n", sizeof(void *));
  printf("sizeof(void (*)()): %lu\n", sizeof(void (*)()));
  printf("sizeof(struct __block_descriptor *): %lu\n", sizeof(struct __block_descriptor *));
  printf("sizeof(__block_literal_1): %lu\n", sizeof(struct __block_literal_1));
  printf("sizeof(__block_descriptor_1): %lu\n", sizeof(struct __block_descriptor_1));
 
  printf(" calculated: %lu\n", sizeof(void*)+sizeof(int)+sizeof(int)+sizeof(void (*)())+sizeof(struct __block_descriptor_1 *));
 
 
  void *sdl_library = dlopen("/System/Library/Frameworks/Foundation.framework/Versions/Current/Foundation", RTLD_LAZY);
  if (sdl_library == NULL) {
    printf("Got dlopen error!\n");
  } else {
    printf("dlopen successful!\n");
 
    // Set up an NSAutoreleasePool
    Class nsautoreleasepool = objc_getClass("NSAutoreleasePool");
    id pool = class_createInstance(nsautoreleasepool, 0);
    SEL initSel = sel_registerName("init");
    id poolAfterInit = objc_msgSend(pool, initSel);
 
    // Create an NSMutableArray
    Class nsmutablearray = objc_getClass("NSMutableArray");
 
    // Regular way to create an NSMutableArray,
    // equivalent to [[NSMutableArray alloc] initWithCapacity: 10]
    id array = objc_msgSend(nsmutablearray, sel_registerName("alloc"));
    id arrayAfterInit = objc_msgSend(array, sel_registerName("initWithCapacity:"), 10);
 
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"a");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"b");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"c");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"d");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"e");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"f");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"g");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"h");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"i");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"j");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"k");
    objc_msgSend(arrayAfterInit, sel_registerName("addObject:"), @"l");
 
    struct __block_literal_1 _block_literal = {
      &_NSConcreteStackBlock,
      //&_NSConcreteGlobalBlock,
      (1<<29),
      0,
      __block_invoke_1,
      &__block_descriptor_1
    };
 
    id b = (id)&_block_literal;
 
    NSLog(@"%@", b);
 
    objc_msgSend(arrayAfterInit, sel_registerName("enumerateObjectsUsingBlock:"), b);
  }
 
  return 0;
}
  
  
  
  

3、打印Class详情

#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main(int argc, char **argv) {
 
  dlopen("/System/Library/Frameworks/Foundation.framework/Foundation", RTLD_LAZY);
  dlopen("/System/Library/Frameworks/AppKit.framework/AppKit", RTLD_LAZY);
  dlopen("/System/Library/Frameworks/Cocoa.framework/Cocoa", RTLD_LAZY);
 
  char * className = argc == 2 ? argv[1] : "NSMutableArray";
  Class NSMA = objc_getClass(className);
 
  if (!NSMA) {
    printf("Could not load Class: %s\n", className);
    return 1;
  }
 
  const char *name = class_getName(NSMA);
  printf("class_getName: %s\n", name);
 
  int version = class_getVersion(NSMA);
  printf("class_getVersion: %d\n", version);
 
  const char *weakIvarLayout = class_getWeakIvarLayout(NSMA);
  printf("class_getWeakIvarLayout: %s\n", weakIvarLayout);
 
  BOOL isMetaClass = class_isMetaClass(NSMA);
  printf("class_isMetaClass: %s\n", isMetaClass ? "yes" : "no");
 
  // get the metaclass
  id metaclass = NSMA->isa;
  isMetaClass = class_isMetaClass(metaclass);
  printf("class_isMetaClass(isa): %s\n", isMetaClass ? "yes" : "no");
 
 
  // Look up the Ivars
  unsigned int i = 0;
  unsigned int numIvars = 999999;
  Ivar *ivars = NULL;
  ivars = class_copyIvarList(NSMA, &numIvars);
  printf("\nNum ivars: %d\n", numIvars);
  for (; i<numIvars; i++) {
    Ivar ivar = ivars[i];
    const char *ivarName = ivar_getName(ivar);
    printf("  %s (%s)\n", ivarName, ivar_getTypeEncoding(ivar));
  }
  free(ivars);
 
 
  // Copy the Property List
  unsigned int numProps = 999999;
  objc_property_t *props = NULL;
  props = class_copyPropertyList(NSMA, &numProps);
  printf("\nNum props: %d\n", numProps);
  for (i=0; i<numProps; i++) {
  }
  free(props);
 
 
  // Copy Protocol List
  unsigned int numProtocols = 9999999;
  Protocol **ps = class_copyProtocolList(NSMA, &numProtocols);
  printf("\nNum Protocols: %d\n", numProtocols);
  for (i=0; i<numProtocols; i++) {
    Protocol *p = ps[i];
    printf("  %s\n", protocol_getName(p));
  }
  free(ps);
 
  // Copy Method List (instance methods)
  unsigned int numMethods = 99999999;
  Method * methods = NULL;
  methods = class_copyMethodList(NSMA, &numMethods);
  printf("\nNum Instance Methods: %d\n", numMethods);
  for (i=0; i<numMethods; i++) {
    Method m = methods[i];
    SEL name = method_getName(m);
    printf("  %s (%s)\n", sel_getName(name), method_getTypeEncoding(m));
  }
  free(methods);
 
 
  // Copy Method List (class methods)
  numMethods = 0;
  methods = NULL;
  methods = class_copyMethodList(metaclass, &numMethods);
  printf("\nNum Class Methods: %d\n", numMethods);
  for (i=0; i<numMethods; i++) {
    Method m = methods[i];
    SEL name = method_getName(m);
    printf("  %s (%s)\n", sel_getName(name), method_getTypeEncoding(m));
  }
  free(methods);
 
  // get superclass
  Class superclass = NSMA;
  printf("\nWalking inheritance chain:\n");
  printf("  %s\n", name);
  unsigned int numClasses = 0;
  do {
    printf("  ");
    numClasses++;
    superclass = class_getSuperclass(superclass);
    for (i=0; i<numClasses; i++) {
      printf("  ");
    }
    printf("↳ %s\n", class_getName(superclass));
  } while(superclass);
 
 
  return 0;
}

4、打印所有协议

#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main(int argc, char **argv) {
 
  dlopen("/System/Library/Frameworks/Foundation.framework/Versions/Current/Foundation", RTLD_LAZY);
 
  unsigned int i, n;
  Protocol **ps = NULL;
 
  ps = objc_copyProtocolList(&n);
  printf("Num Protocols: %d\n", n);
 
 
  // Do stuff with `classes`
  for (i=0; i<n; i++) {
    Protocol *p = ps[i];
    printf("%s\n", protocol_getName(p));
  }
 
  free(ps);
 
  return 0;
}

5、获取某个framework的所有class

#import <Foundation/Foundation.h>
#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main(int argc, char **argv) {
 
  dlopen("/System/Library/Frameworks/Foundation.framework/Foundation", RTLD_LAZY);
  dlopen("/System/Library/Frameworks/AppKit.framework/AppKit", RTLD_LAZY);
 
  int i = 0;
  int numClasses;
  Class * classes = NULL;
 
  numClasses = objc_getClassList(NULL, 0);
  printf("Num classes: %d\n", numClasses);
 
  if (numClasses > 0 ) {
    classes = malloc(sizeof(Class) * numClasses);
    numClasses = objc_getClassList(classes, numClasses);
 
    // Do stuff with `classes`
    for (i=0; i<numClasses; i++) {
      Class c = classes[i];
      printf("%s\n", class_getName(c));
    }
 
    free(classes);
  }
 
  return 0;
}

6、HelloWorld

  
  
  
  

   
   
   
   
#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main() {
 
  void *sdl_library = dlopen("/System/Library/Frameworks/Foundation.framework/Versions/Current/Foundation", RTLD_LAZY);
  if (sdl_library == NULL) {
    printf("Got dlopen error!\n");
  } else {
    printf("dlopen successful!\n");
 
    // Set up an NSAutoreleasePool
    Class nsautoreleasepool = objc_getClass("NSAutoreleasePool");
    id pool = class_createInstance(nsautoreleasepool, 0);
    SEL initSel = sel_registerName("init");
    id poolAfterInit = objc_msgSend(pool, initSel);
 
    // Set up a NSString with the contents "Hello World" from a C string
    Class nsstring = objc_getClass("NSString");
    SEL stringUTF8sel = sel_registerName("stringWithUTF8String:");
    id hello = objc_msgSend(nsstring, stringUTF8sel, "Hello World\n");
 
    // Print it back out as a C string
    printf("%s", (char *)objc_msgSend(hello, sel_registerName("UTF8String")));
  }
 
  return 0;
}
   
   
   
   

   
   
   
   

  
  
  
  

7、获取size

#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>
 
int main(int argc, char **argv) {
 
  dlopen("/System/Library/Frameworks/Foundation.framework/Foundation", RTLD_LAZY);
  dlopen("/System/Library/Frameworks/AppKit.framework/AppKit", RTLD_LAZY);
  dlopen("/System/Library/Frameworks/Cocoa.framework/Cocoa", RTLD_LAZY);
 
  char * className = argc == 2 ? argv[1] : "NSMutableArray";
  Class NSMA = objc_getClass(className);
 
  if (!NSMA) {
    printf("Could not load Class: %s\n", className);
    return 1;
  }
 
  const char *name = class_getName(NSMA);
  printf("class_getName: %s\n", name);
 
  int version = class_getVersion(NSMA);
  printf("class_getVersion: %d\n", version);
 
  const char *weakIvarLayout = class_getWeakIvarLayout(NSMA);
  printf("class_getWeakIvarLayout: %s\n", weakIvarLayout);
 
  BOOL isMetaClass = class_isMetaClass(NSMA);
  printf("class_isMetaClass: %s\n", isMetaClass ? "yes" : "no");
 
  // get the metaclass
  id metaclass = NSMA->isa;
  isMetaClass = class_isMetaClass(metaclass);
  printf("class_isMetaClass(isa): %s\n", isMetaClass ? "yes" : "no");
 
 
  // Look up the Ivars
  unsigned int i = 0;
  unsigned int numIvars = 999999;
  Ivar *ivars = NULL;
  ivars = class_copyIvarList(NSMA, &numIvars);
  printf("\nNum ivars: %d\n", numIvars);
  for (; i<numIvars; i++) {
    Ivar ivar = ivars[i];
    const char *ivarName = ivar_getName(ivar);
    printf("  %s (%s)\n", ivarName, ivar_getTypeEncoding(ivar));
  }
  free(ivars);
 
 
  // Copy the Property List
  unsigned int numProps = 999999;
  objc_property_t *props = NULL;
  props = class_copyPropertyList(NSMA, &numProps);
  printf("\nNum props: %d\n", numProps);
  for (i=0; i<numProps; i++) {
  }
  free(props);
 
 
  // Copy Protocol List
  unsigned int numProtocols = 9999999;
  Protocol **ps = class_copyProtocolList(NSMA, &numProtocols);
  printf("\nNum Protocols: %d\n", numProtocols);
  for (i=0; i<numProtocols; i++) {
    Protocol *p = ps[i];
    printf("  %s\n", protocol_getName(p));
  }
  free(ps);
 
  // Copy Method List (instance methods)
  unsigned int numMethods = 99999999;
  Method * methods = NULL;
  methods = class_copyMethodList(NSMA, &numMethods);
  printf("\nNum Instance Methods: %d\n", numMethods);
  for (i=0; i<numMethods; i++) {
    Method m = methods[i];
    SEL name = method_getName(m);
    printf("  %s (%s)\n", sel_getName(name), method_getTypeEncoding(m));
  }
  free(methods);
 
 
  // Copy Method List (class methods)
  numMethods = 0;
  methods = NULL;
  methods = class_copyMethodList(metaclass, &numMethods);
  printf("\nNum Class Methods: %d\n", numMethods);
  for (i=0; i<numMethods; i++) {
    Method m = methods[i];
    SEL name = method_getName(m);
    printf("  %s (%s)\n", sel_getName(name), method_getTypeEncoding(m));
  }
  free(methods);
 
  // get superclass
  Class superclass = NSMA;
  printf("\nWalking inheritance chain:\n");
  printf("  %s\n", name);
  unsigned int numClasses = 0;
  do {
    printf("  ");
    numClasses++;
    superclass = class_getSuperclass(superclass);
    for (i=0; i<numClasses; i++) {
      printf("  ");
    }
    printf("↳ %s\n", class_getName(superclass));
  } while(superclass);
 
 
  return 0;
}

#import <Foundation/Foundation.h>
#include <objc/runtime.h>
#include <dlfcn.h>
#include <stdio.h>

int main() {
    
    void *sdl_library = dlopen("/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation", RTLD_LAZY);
    if (sdl_library == NULL) {
        printf("Got dlopen error!\n");
    } else {
        printf("dlopen successful!\n");
    }
    
    printf("sizeof(Class): %lu\n", sizeof(Class));
    printf("sizeof(Method): %lu\n", sizeof(Method));
    printf("sizeof(unsigned long int): %lu\n", sizeof(unsigned long int));
    printf("sizeof(struct int, void*): %lu\n", sizeof(struct test { int test; void * ptr; }));
    printf("sizeof(struct int, int, void*): %lu\n", sizeof(struct test2 { int test; int test2; void * ptr; }));
    printf("sizeof(struct void*, int, int, void*): %lu\n", sizeof(struct test3 { void *ptr2; int test2; void * ptr; }));
    
    return 0;
}

8、捕获异常

#include <objc/runtime.h>
#include <objc/objc-exception.h>
#include <dlfcn.h>
#include <stdio.h>
 
void uncaughtExceptionHandler (id exception) {
  fprintf(stderr, "Inside uncaughtException handler!!!!\n");
  fprintf(stderr, "Exception Type: %s\n", (const char *)objc_msgSend(objc_msgSend(exception, sel_registerName("name")), sel_registerName("UTF8String")));
  fprintf(stderr, "Exception Reason: %s\n", (const char *)objc_msgSend(objc_msgSend(exception, sel_registerName("reason")), sel_registerName("UTF8String")));
}
 
 
int main() {
 
  void *sdl_library = dlopen("/System/Library/Frameworks/Foundation.framework/Versions/Current/Foundation", RTLD_LAZY);
  if (sdl_library == NULL) {
    printf("Got dlopen error!\n");
  } else {
    printf("dlopen successful!\n");
 
    // Set up an NSAutoreleasePool
    Class nsautoreleasepool = objc_getClass("NSAutoreleasePool");
    id pool = class_createInstance(nsautoreleasepool, 0);
    SEL initSel = sel_registerName("init");
    id poolAfterInit = objc_msgSend(pool, initSel);
 
 
    // Set up an uncaughtException handler
    objc_setUncaughtExceptionHandler((objc_uncaught_exception_handler)uncaughtExceptionHandler);
 
 
    // Intentionally throw an exception, by sending a bad selector to an object
    Class nsobject = objc_getClass("NSObject");
    SEL badSel = sel_registerName("badSelector");
    objc_msgSend(nsobject, badSel);
  }
 
  return 0;
}

9、设备当前运行的进程

- (NSArray *)runningProcesses {
    
    int mib[4] = {CTL_KERN,KERN_PROC, KERN_PROC_ALL, 0};
    size_t miblen = 4;
    
    size_t size;
    int st = sysctl(mib, miblen,NULL, &size, NULL, 0);
    
    struct kinfo_proc * process =NULL;
    struct kinfo_proc * newprocess =NULL;
    
    do {
        
        size += size / 10;
        newprocess = realloc(process, size);
        
        if (!newprocess){
            
            if (process){
                free(process);
            }
            
            return nil;
        }
        
        process = newprocess;
        st = sysctl(mib, miblen, process, &size,NULL, 0);
        
    } while (st == -1 &&errno == ENOMEM);
    
    if (st == 0){
        
        if (size % sizeof(structkinfo_proc) == 0){
            int nprocess = size / sizeof(struct kinfo_proc);
            
            if (nprocess){
                
                NSMutableArray * array = [[NSMutableArrayalloc] init];
                
                for (int i = nprocess -1; i >= 0; i--){
                    
                    NSString * processID = [[NSStringalloc] initWithFormat:@"%d", process[i].kp_proc.p_pid];
                    NSString * processName = [[NSStringalloc] initWithFormat:@"%s", process[i].kp_proc.p_comm];
                    
                    NSDictionary * dict = [[NSDictionaryalloc] initWithObjects:[NSArrayarrayWithObjects:processID, processName, nil]
                                                                       forKeys:[NSArray arrayWithObjects:@"ProcessID", @"ProcessName",nil]];
                    [processID release];
                    [processName release];
                    [array addObject:dict];
                    [dict release];
                }
                
                free(process);
                return [array autorelease];
            }
        }
    }
    
    return nil;
}
// 当前运行的进程
    NSArray * processes = [selfrunningProcesses];
    for (NSDictionary * dictin processes){
        NSLog(@"%@ - %@", [dictobjectForKey:@"ProcessID"], [dictobjectForKey:@"ProcessName"]);
    }