如何在文件中使用asl.h

Question

我是ios/的新手。我希望在快速文件中使用asl.h中的日志c-函数。有没有人？我在googled上搜索，人们似乎编写了自己的日志快速类。没有不敬之处，但我只想用asl。也就是说，斯威夫特不喜欢#include <asl.h>，也不喜欢我只打电话给asl_log(NULL, NULL, ASL_LEVEL_INFO, "Hello World!");

Answer 1

谢谢，在http://doing-it-wrong.mikeweller.com/2012/07/youre-doing-it-wrong-1-nslogdebug-ios.html的帮助下，我做了以下修改：

向项目中添加了一个BRASL.h文件，其内容如下：

//
//  BRASL.h
//

#ifndef BRASL_h
#define BRASL_h

#import <asl.h>
#import <Foundation/Foundation.h>


// Define which loglevel is necessary for deployment and development
// =================================================================
// Used to conditionally implement the log functions. All log
// functions are defined so the compiler does not complain. But only
// those logfunctions that are used will contain code.
// =================================================================
#ifndef BRASL_LOG_LEVEL
    // DEBUG is set in the project build-settings
    #if DEBUG == 1
        // Set logging level for development
        #define BRASL_LOG_LEVEL ASL_LEVEL_DEBUG
    #else
        // Set logging level for deployment
        #define BRASL_LOG_LEVEL ASL_LEVEL_NOTICE
    #endif
#endif


// Define the log functions
// ========================
void aslEmergency(NSString *string);
void aslAlert(NSString *string);
void aslCritical(NSString *string);
void aslError(NSString *string);
void aslWarning(NSString *string);
void aslNotice(NSString *string);
void aslInfo(NSString *string);
void aslDebug(NSString *string);


#endif

然后使用以下内容添加相应的.m文件：

//
//  BRASL.h
//

#import "BRASL.h"


// We need this to set asl up to also write the information to the debugger
// ========================================================================
static void AddStderrOnce() {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        asl_add_log_file(NULL, STDERR_FILENO);
    });
}


// Implement the log functions where necessary
// ===========================================
#if BRASL_LOG_LEVEL >= ASL_LEVEL_EMERG
void aslEmergency(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_EMERG, "%s", [string UTF8String]);
}
#else
void aslEmergency(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_ALERT
void aslAlert(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_ALERT, "%s", [string UTF8String]);
}
#else
void aslAlert(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_CRIT
void aslCritical(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_CRIT, "%s", [string UTF8String]);
}
#else
void aslCritical(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_ERR
void aslError(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_ERR, "%s", [string UTF8String]);
}
#else
void aslError(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_WARNING
void aslWarning(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_WARNING, "%s", [string UTF8String]);
}
#else
void aslWarning(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_NOTICE
void aslNotice(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_NOTICE, "%s", [string UTF8String]);
}
#else
void aslNotice(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_INFO
void aslInfo(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_INFO, "%s", [string UTF8String]);
}
#else
void aslInfo(NSString *string) {}
#endif

#if BRASL_LOG_LEVEL >= ASL_LEVEL_DEBUG
void aslDebug(NSString *string) {
    AddStderrOnce();
    asl_log(NULL, NULL, ASL_LEVEL_DEBUG, "%s", [string UTF8String]);
}
#else
void aslDebug(NSString *string) {}
#endif

当然，桥接文件

//
//  Use this file to import your target's public headers that you would like to expose to Swift.
//

#import "BRASL.h"

然后，在我的快速代码中，我可以使用例如：

aslInfo("Initializing managed object context")

到目前为止，似乎像广告中所说的那样起作用:)

Answer 2

到目前为止，我发现的最简单的方法是以下方法(，它适用于任何c库)：

步骤1:文件-新-文件目标-C，例如MyBridgeToACLib.h，MyBridgeToACLib.m

步骤2: MyBridgeToACLib.h

#import <Foundation/Foundation.h>
@interface MyBridgeToACLib : NSObject    
  // here you need to declare a function for each c-function you want to call from swift, e.g. : 
  + (void) debug:(NSString*) nsStr;
  + (void) debug:(NSString*) nsStr secondValue:(NSInteger) nsInt;
@end

步骤3: MyBridgeToACLib.m

#include <asl.h>  // or any c-library you need to call from Swift
#import "MyBridgeToACLib.h"

@implementation MyBridgeToACLib

+ (void) debug:(NSString*) nsStr {
  // here you need to convert from Objective-C types to C-types, e.g. NSString to char*
  const char *cStr = [nsStr UTF8String];
  printf("%s\n", cStr);
  // call your c-functions
  asl_log(NULL, NULL, ASL_LEVEL_DEBUG, "%s", cStr);
}

+ (void) debug:(NSString*) nsStr secondValue:(NSInteger) nsInt {
  const char *cStr = [nsStr UTF8String];
  long cInt = nsInt;
  printf("%s%li\n", cStr, cInt);
  asl_log(NULL, NULL, ASL_LEVEL_DEBUG, "%s%li", cStr, cInt);
}
@end

步骤4:设置以下“MyProjectName-桥接-Header.h”。谷歌"XCode桥接-标题“的说明。

    // Swift and Objective-C in the Same Project   
//https://developer.apple.com/library/ios/documentation/swift/conceptual/buildingcocoaapps/MixandMatch.html
    //
    // Here import all of your "Bridge"-headers 
    #import "MyBridgeToACLib.h"

Answer 3

下面是一些您可能感兴趣的开源项目：

·CleanroomASL- A低级别但快速的API，用于读取和写入苹果系统日志

·支持向ASL写入的CleanroomLogger- A高级Swift日志记录API

·AppleSystemLogSwiftPackage--一个Swift (SPM)声明，允许您从代码中“导入ASL”。(请注意，SPM目前只为Mac构建，因此目前它无法帮助您使用iOS。)

基于您所写的内容，我怀疑CleanroomLogger项目最适合您使用。

希望你觉得这有帮助，

E.

充分披露:我已经为这些项目中的每一个做出了贡献。