如何在swift-ios文件中使用asl.h

Question

我是ios/swift的新手。我想在swift文件中使用來自asl.h 的日誌c函數。任何人？我搜索了一下，人們似乎寫了他們自己的日誌快速課程。沒有不敬，但我想只用asl。 也就是說，SWIFT不喜歡 #include <asl.h>，它不喜歡我只是打電話asl_log(NULL, NULL, ASL_LEVEL_INFO, "Hello World!");

Answer 1

感謝，並與http://doing-it-wrong.mikeweller.com/2012/07/youre-doing-it-wrong-1-nslogdebug-ios.html幫助我做了如下修改：

增加了BRASL.h文件，其內容如下項目：

// 
// 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 

然後加入相應的.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 

當然橋接文件

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

#import "BRASL.h" 

然後在我的SWIFT代碼我可以使用，例如：

aslInfo("Initializing managed object context") 

到目前爲止好，看起來像廣告:)

Answer 2

到目前爲止，我發現最簡單的方法是以下（它可以用於任何C-庫）：

第一步：File-New-File Objective-C，例如MyBridgeToACLib.h，MyBridgeToACLib.m

步驟2：在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 

步驟3：在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 

步驟4：設置以下「MyProjectName -Bridging-Header.h」。谷歌「XCode橋接頭」的指示。

// 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

這裏有幾個開源項目的工作，可能會引起您的興趣：

•CleanroomASL - 用於從&寫入Apple系統日誌的低級別但Swiftified API日誌

•CleanroomLogger - 一個高層次的斯威夫特記錄的API，支持寫入ASL

•AppleSystemLogSwiftPackage - 迅速軟件包管​​理器（SPM）的聲明，允許你「進口翔升」從你的代碼中。 （請注意，SPM目前僅適用於Mac OS X，因此目前無法幫助您使用iOS。）

根據您撰寫的內容，我懷疑CleanroomLogger項目是最合適的你的使用。

希望對您有所幫助，

E.

全面披露：我已經給每個項目的貢獻。