问如何使用Objective-C在IOS中读取和存储系统日志消息

EN

NSDate *currentDate = [[NSDate alloc] init];

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:[NSString stringWithFormat: @"dd-MM-yyyy-HHmmss"]];

NSString *logFileName = [[formatter stringFromDate:currentDate] stringByAppendingString:@".log"];

NSError *error;
NSMutableString *content = [[NSMutableString alloc] init];


 aslmsg q, m;
 int i;
 const char *key, *val;

 q = asl_new(ASL_TYPE_QUERY);

 aslresponse r = asl_search(NULL, q);

 while (NULL != (m = asl_next(r)))
 {
     NSMutableDictionary *tmpDict = [NSMutableDictionary dictionary];

     for (i = 0; (NULL != (key = asl_key(m, i))); i++)
     {
         NSString *keyString = [NSString stringWithUTF8String:(char *)key];

         val = asl_get(m, key);

         NSString *string = [NSString stringWithUTF8String:val];
         [tmpDict setObject:string forKey:keyString];
     }

     [content appendString:[NSString stringWithFormat:@"%@",tmpDict]];
 }

asl_release(r);

NSString *filePath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject] stringByAppendingPathComponent:logFileName];

[[NSString stringWithString:content] writeToFile:filePath atomically:YES encoding:NSUTF8StringEncoding error:&error];