blocks|key|577490|text|这是我使用的，并且效果很好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|577491|http://parmanoir.com/Redirecting_NSLog_to_a_file|offset|length|577492|希望能有所帮助。|577493|为了内容的缘故，我只是把它贴在这里|577494|-+(BOOL)redirectNSLog+{+
+++++//+Create+log+file+
+++++[@""+writeToFile:@"/NSLog.txt"+atomically:YES+encoding:NSUTF8StringEncoding+error:nil];+
+++++id+fileHandle+=+[NSFileHandle+fileHandleForWritingAtPath:@"/NSLog.txt"];+
+++++if+(!fileHandle)+return+NSLog(@"Opening+log+failed"),+NO;+
+++++[fileHandle+retain];++

+++++//+Redirect+stderr+
+++++int+err+=+dup2([fileHandle+fileDescriptor],+STDERR_FILENO);+
+++++if+(!err)+return+NSLog(@"Couldn't+redirect+stderr"),+NO;++return+YES;+
}|code-block|syntax|javascript|577495|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1C|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|W|8|@]|9|@$D|X|E|Y|1|Z]]|A|$]]|$1|F|3|G|5|6|7|10|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|11|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|12|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|13|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|C]]]]

This is what I use and works well:

<a href="http://parmanoir.com/Redirecting_NSLog_to_a_file" rel="nofollow">http://parmanoir.com/Redirecting_NSLog_to_a_file</a>

Hope it helps.

I'll just post it here for the sake of the content

<pre><code>- (BOOL)redirectNSLog { 
 // Create log file 
 [@"" writeToFile:@"/NSLog.txt" atomically:YES encoding:NSUTF8StringEncoding error:nil]; 
 id fileHandle = [NSFileHandle fileHandleForWritingAtPath:@"/NSLog.txt"]; 
 if (!fileHandle) return NSLog(@"Opening log failed"), NO; 
 [fileHandle retain]; 

 // Redirect stderr 
 int err = dup2([fileHandle fileDescriptor], STDERR_FILENO); 
 if (!err) return NSLog(@"Couldn't redirect stderr"), NO; return YES; 
}
</code></pre>

blocks|key|793780|text|选项1:使用ASL|type|unstyled|depth|inlineStyleRanges|entityRanges|data|793781|NSLog输出日志到ASL+(苹果版本的syslog)和控制台，这意味着当你使用iPhone模拟器时，它已经在你的Mac中写入一个文件。如果您想阅读它，请打开应用程序Console.app，然后在filter字段中键入应用程序的名称。要在iPhone设备中执行相同的操作，您需要使用API并进行一些编码。|793782|选项2:写入文件|793783|假设您正在模拟器上运行，并且不想使用Console.app。您可以使用freopen将错误流重定向到您喜欢的文件：|793784|freopen([path+cStringUsingEncoding:NSASCIIStringEncoding],+"a%2B",+stderr);|offset|length|style|CODE|793785|有关详细信息，请参阅此explanation+and+sample+project。|793786|或者，您可以使用宏用自定义函数覆盖NSLog。例如，将此类添加到您的项目中：|793787|//+file+Log.h
#define+NSLog(args...)+_Log(@"DEBUG+",+__FILE__,__LINE__,__PRETTY_FUNCTION__,args);
@interface+Log+:+NSObject
void+_Log(NSString+*prefix,+const+char+*file,+int+lineNumber,+const+char+*funcName,+NSString+*format,...);
@end

//+file+Log.m
#import+"Log.h"
@implementation+Log
void+_Log(NSString+*prefix,+const+char+*file,+int+lineNumber,+const+char+*funcName,+NSString+*format,...)+{
++++va_list+ap;
++++va_start+(ap,+format);
++++format+=+[format+stringByAppendingString:@"\n"];
++++NSString+*msg+=+[[NSString+alloc]+initWithFormat:[NSString+stringWithFormat:@"%25@",format]+arguments:ap];+++
++++va_end+(ap);
++++fprintf(stderr,"%25s%2550s:%253d+-+%25s",[prefix+UTF8String],+funcName,+lineNumber,+[msg+UTF8String]);
++++[msg+release];
}
@end|code-block|syntax|javascript|793788|并将其导入项目范围，并将以下内容添加到您的<application>-Prefix.pch中：|793789|#import+"Log.h"|793790|现在，每次对NSLog的调用都将被替换为您的自定义函数，而无需触及现有的代码。但是，上面的功能只是打印到控制台。要添加文件输出，请将此函数添加到_Log之上：|793791|void+append(NSString+*msg){
++++//+get+path+to+Documents/somefile.txt
++++NSArray+*paths+=+NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,+NSUserDomainMask,+YES);
++++NSString+*documentsDirectory+=+[paths+objectAtIndex:0];
++++NSString+*path+=+[documentsDirectory+stringByAppendingPathComponent:@"logfile.txt"];
++++//+create+if+needed
++++if+(![[NSFileManager+defaultManager]+fileExistsAtPath:path]){
++++++++fprintf(stderr,"Creating+file+at+%25s",[path+UTF8String]);
++++++++[[NSData+data]+writeToFile:path+atomically:YES];
++++}+
++++//+append
++++NSFileHandle+*handle+=+[NSFileHandle+fileHandleForWritingAtPath:path];
++++[handle+truncateFileAtOffset:[handle+seekToEndOfFile]];
++++[handle+writeData:[msg+dataUsingEncoding:NSUTF8StringEncoding]];
++++[handle+closeFile];
}|793792|并在_Log函数中的fprintf下面添加以下行：|793793|append(msg);|793794|文件写入也适用于你的iPhone设备，但文件将被创建在其中的一个目录中，除非你添加代码将其发送回mac，或者在应用程序内的视图上显示，或者使用iTunes添加文档目录，否则你将无法访问。|793795|entityMap|0|LINK|mutability|MUTABLE|url|http://azizuysal.wordpress.com/2011/01/02/redirecting-nslog-output-to-a-file-on-demand-for-iphone-debugging/^0|0|0|0|0|0|21|0|B|U|0|0|0|0|L|O|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1I|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1J|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|1K|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|1L|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|1M|8|@$J|1N|K|1O|L|M]]|9|@]|A|$]]|$1|N|3|O|5|6|7|1P|8|@]|9|@$J|1Q|K|1R|1|1S]]|A|$]]|$1|P|3|Q|5|6|7|1T|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1U|8|@]|9|@]|A|$U|V]]|$1|W|3|X|5|6|7|1V|8|@$J|1W|K|1X|L|M]]|9|@]|A|$]]|$1|Y|3|Z|5|T|7|1Y|8|@]|9|@]|A|$U|V]]|$1|10|3|11|5|6|7|1Z|8|@]|9|@]|A|$]]|$1|12|3|13|5|T|7|20|8|@]|9|@]|A|$U|V]]|$1|14|3|15|5|6|7|21|8|@]|9|@]|A|$]]|$1|16|3|17|5|T|7|22|8|@]|9|@]|A|$U|V]]|$1|18|3|19|5|6|7|23|8|@]|9|@]|A|$]]|$1|1A|3|-4|5|6|7|24|8|@]|9|@]|A|$]]]|1B|$1C|$5|1D|1E|1F|A|$1G|1H]]]]

<h3>Option 1: Use ASL</h3>

NSLog outputs log to ASL (Apple's version of syslog) and console, meaning it is already writing to a file in your Mac when you use the iPhone simulator. If you want to read it open the application Console.app, and type the name of your application in the filter field. To do the same in your iPhone device, you would need to use the ASL API and do some coding.

<h3>Option 2: write to a file</h3>

Let's say you are running on the simulator and you don't want to use the Console.app. You can redirect the error stream to a file of your liking using freopen: 
<code>freopen([path cStringUsingEncoding:NSASCIIStringEncoding], "a+", stderr);</code> 
See this <a href="http://azizuysal.wordpress.com/2011/01/02/redirecting-nslog-output-to-a-file-on-demand-for-iphone-debugging/" rel="noreferrer">explanation and sample project</a> for details.

Or you can override NSLog with a custom function using a macro. Example, add this class to your project:

<pre><code>// file Log.h
#define NSLog(args...) _Log(@"DEBUG ", __FILE__,__LINE__,__PRETTY_FUNCTION__,args);
@interface Log : NSObject
void _Log(NSString *prefix, const char *file, int lineNumber, const char *funcName, NSString *format,...);
@end

// file Log.m
#import "Log.h"
@implementation Log
void _Log(NSString *prefix, const char *file, int lineNumber, const char *funcName, NSString *format,...) {
 va_list ap;
 va_start (ap, format);
 format = [format stringByAppendingString:@"\n"];
 NSString *msg = [[NSString alloc] initWithFormat:[NSString stringWithFormat:@"%@",format] arguments:ap]; 
 va_end (ap);
 fprintf(stderr,"%s%50s:%3d - %s",[prefix UTF8String], funcName, lineNumber, [msg UTF8String]);
 [msg release];
}
@end
</code></pre>

And import it project wide adding the following to your <code>&lt;application&gt;-Prefix.pch</code>: 

<pre><code>#import "Log.h"
</code></pre>

Now every call to NSLog will be replaced with your custom function without the need to touch your existing code. However, the function above is only printing to console. To add file output, add this function above _Log:

<pre><code>void append(NSString *msg){
 // get path to Documents/somefile.txt
 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentsDirectory = [paths objectAtIndex:0];
 NSString *path = [documentsDirectory stringByAppendingPathComponent:@"logfile.txt"];
 // create if needed
 if (![[NSFileManager defaultManager] fileExistsAtPath:path]){
 fprintf(stderr,"Creating file at %s",[path UTF8String]);
 [[NSData data] writeToFile:path atomically:YES];
 } 
 // append
 NSFileHandle *handle = [NSFileHandle fileHandleForWritingAtPath:path];
 [handle truncateFileAtOffset:[handle seekToEndOfFile]];
 [handle writeData:[msg dataUsingEncoding:NSUTF8StringEncoding]];
 [handle closeFile];
}
</code></pre>

and add this line below fprintf in the _Log function:

<pre><code>append(msg);
</code></pre>

File writing also works in your iPhone device, but the file will be created in a directory inside it, and you won't be able to access unless you add code to send it back to your mac, or show it on a view inside your app, or use iTunes to add the documents directory.

blocks|key|793860|text|我找到了这个问题的最简单的解决方案：Logging+to+a+file+on+the+iPhone。不需要更改任何NSLog代码或日志记录器本身，只需将这4行代码添加到您的didFinishLaunchingWithOptions中，并确保在您的构建设置中实时发布不会激活它(我为此添加了LOG2FILE标志)。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|793861|#ifdef+LOG2FILE
+#if+TARGET_IPHONE_SIMULATOR+==+0
++++NSArray+*paths+=+NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,+NSUserDomainMask,+YES);
++++NSString+*documentsDirectory+=+[paths+objectAtIndex:0];
++++NSString+*logPath+=+[documentsDirectory+stringByAppendingPathComponent:@"console.log"];
++++freopen([logPath+cStringUsingEncoding:NSASCIIStringEncoding],"a%2B",stderr);
+#endif
#endif|code-block|syntax|javascript|793862|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/202299/logging-to-a-file-on-the-iphone/2103091#2103091^0|I|V|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

I found the simplest solution to the problem: <a href="https://stackoverflow.com/questions/202299/logging-to-a-file-on-the-iphone/2103091#2103091">Logging to a file on the iPhone</a> . No need to change any NSLog code or change logger itself, just add these 4 lines to your didFinishLaunchingWithOptions and make sure in your build settings that live release will not have this activated (I added LOG2FILE flag for this).

<pre><code>#ifdef LOG2FILE
 #if TARGET_IPHONE_SIMULATOR == 0
 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentsDirectory = [paths objectAtIndex:0];
 NSString *logPath = [documentsDirectory stringByAppendingPathComponent:@"console.log"];
 freopen([logPath cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
 #endif
#endif
</code></pre>

blocks|key|577811|text|我根据阿尔文·乔治的回答做了一点工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|577812|为了控制日志文件的大小，我实现了一个"10代日志文件“的解决方案，并添加了一个函数来在以后删除它们|577813|每次应用程序启动时，它都会生成一个索引为"0“的新日志文件。正在退出的文件将使用比以前更高的索引重命名。索引"10“将被删除。|577814|因此，每次启动都会给出一个新的日志文件，最多生成10代|577815|这可能不是最优雅的方式，但在过去的几周里对我来说效果非常好，因为我需要一些长时间的日志“离开mac”。|577816|++//+-----------------------------------------------------------------------------------------------------------
++//+redirectConsoleToFile()
++//
++//+does+two+things++
++//+1)+redirects+"stderr",+"stdin"+and+"stdout"+to+a+logfile
++//+2)+deals+with+old/existing+files+to+keep+up+to+10+generations+of+the+logfiles
++//+tested+with+IOS+9.4+and+Swift+2.2
++func+redirectConsoleToFile()+{

++++//+Instance+of+a+private+filemanager
++++let+myFileManger+=+NSFileManager.defaultManager()

++++//+the+path+of+the+documnts+directory+of+the+app
++++let+documentDirectory:+String+=+NSSearchPathForDirectoriesInDomains(.DocumentDirectory,+.UserDomainMask,+true).first!

++++//+maximum+number+of+logfiles
++++let+maxNumberOfLogFiles:+Int+=+10

++++//+look+if+the+max+number+of+files+already+exist
++++var+logFilePath+:+String+=+documentDirectory.stringByAppendingString("/Console\(maxNumberOfLogFiles).log")
++++var+FlagOldFileNoProblem:+Bool+=+true
++++if+myFileManger.fileExistsAtPath(logFilePath)+==+true+{

++++++++//+yes,+max+number+of+files+reached,+so+delete+the+oldest+one
++++++++do+{
++++++++++++try+myFileManger.removeItemAtPath(logFilePath)

++++++++}+catch+let+error+as+NSError+{

++++++++++++//+something+went+wrong
++++++++++++print("ERROR+deleting+old+logFile+\(maxNumberOfLogFiles):+\(error.description)")
++++++++++++FlagOldFileNoProblem+=+false
++++++++}
++++}

++++//+test,+if+there+was+a+problem+with+the+old+file
++++if+FlagOldFileNoProblem+==+true+{

++++++++//+loop+over+all+possible+filenames
++++++++for+i+in+0+..<+maxNumberOfLogFiles+{

++++++++++++//+look,+if+an+old+file+exists,+if+so,+rename+it+with+an+index+higher+than+before
++++++++++++logFilePath+=+documentDirectory.stringByAppendingString("/Console\((maxNumberOfLogFiles+-+1)+-+i).log")
++++++++++++if+myFileManger.fileExistsAtPath(logFilePath)+==+true+{

++++++++++++++++//+there+is+an+old+file
++++++++++++++++let+logFilePathNew+=+documentDirectory.stringByAppendingString("/WayAndSeeConsole\(maxNumberOfLogFiles+-+i).log")
++++++++++++++++do+{

++++++++++++++++++++//+rename+it
++++++++++++++++++++try+myFileManger.moveItemAtPath(logFilePath,+toPath:+logFilePathNew)

++++++++++++++++}+catch+let+error+as+NSError+{

++++++++++++++++++++//+something+went+wrong
++++++++++++++++++++print("ERROR+renaming+logFile:+(i+=+\(i)),+\(error.description)")
++++++++++++++++++++FlagOldFileNoProblem+=+false
++++++++++++++++}
++++++++++++}
++++++++}
++++}

++++//+test,+if+there+was+a+problem+with+the+old+files
++++if+FlagOldFileNoProblem+==+true+{

++++++++//+No+problem+so+far,+so+try+to+delete+the+old+file
++++++++logFilePath+=+documentDirectory.stringByAppendingString("/Console0.log")
++++++++if+myFileManger.fileExistsAtPath(logFilePath)+==+true+{

++++++++++++//+yes,+it+exists,+so+delete+it
++++++++++++do+{
++++++++++++++++try+myFileManger.removeItemAtPath(logFilePath)

++++++++++++}+catch+let+error+as+NSError+{

++++++++++++++++//+something+went+wrong
++++++++++++++++print("ERROR+deleting+old+logFile+0:+\(error.description)")
++++++++++++}
++++++++}
++++}

++++//+even+if+there+was+a+problem+with+the+files+so+far,+we+redirect
++++logFilePath+=+documentDirectory.stringByAppendingString("/Console0.log")

++++if+(isatty(STDIN_FILENO)+==+0)+{
++++++++freopen(logFilePath,+"a%2B",+stderr)
++++++++freopen(logFilePath,+"a%2B",+stdin)
++++++++freopen(logFilePath,+"a%2B",+stdout)
++++++++displayDebugString(DEBUG_Others,+StringToAdd:+"stderr,+stdin,+stdout+redirected+to+\"\(logFilePath)\"")
++++}+else+{
++++++++displayDebugString(DEBUG_Others,+StringToAdd:+"stderr,+stdin,+stdout+NOT+redirected,+STDIN_FILENO+=+\(STDIN_FILENO)")
++++}
}

//+-----------------------------------------------------------------------------------------------------------
//+cleanupOldConsoleFiles()
//
//+delete+all+old+consolfiles
func+cleanupOldConsoleFiles()+{

++++//+Instance+of+a+private+filemanager
++++let+myFileManger+=+NSFileManager.defaultManager()

++++//+the+path+of+the+documnts+directory+of+the+app
++++let+documentDirectory:+String+=+NSSearchPathForDirectoriesInDomains(.DocumentDirectory,+.UserDomainMask,+true).first!

++++//+maximum+number+of+logfiles
++++let+maxNumberOfLogFiles:+Int+=+10

++++//+working+string
++++var+logFilePath:+String+=+""

++++//+loop+over+all+possible+filenames
++++for+i+in+0+...+maxNumberOfLogFiles+{

++++++++//+look,+if+an+old+file+exists,+if+so,+rename+it+with+an+index+higher+than+before
++++++++logFilePath+=+documentDirectory.stringByAppendingString("/Console\(i).log")
++++++++if+myFileManger.fileExistsAtPath(logFilePath)+==+true+{

++++++++++++//+Yes,+file+exist,+so+delete+it
++++++++++++do+{
++++++++++++++++try+myFileManger.removeItemAtPath(logFilePath)
++++++++++++}+catch+let+error+as+NSError+{

++++++++++++++++//+something+went+wrong
++++++++++++++++print("ERROR+deleting+old+logFile+\"\(i)\":+\(error.description)")
++++++++++++}
++++++++}
++++}
}|code-block|syntax|javascript|577817|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|U|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|V|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

I worked a little bit with the answer of Alvin George.

To keep the log file sizes under control I implemented (quick and dirty) a "10 generations of log files" solution and add a func to delete them later on

Every time the app starts, it will generate a new log file with an index "0". The exiting file(s) will be renamed with an index higher than before. Index "10" will be deleted.

So, each start gives you a new log file, maximum 10 generations

Might not be the most elegant way to do it, but works for me during the last weeks very good, as I need some longtime logging "off the mac"

<pre><code> // -----------------------------------------------------------------------------------------------------------
 // redirectConsoleToFile()
 //
 // does two things 
 // 1) redirects "stderr", "stdin" and "stdout" to a logfile
 // 2) deals with old/existing files to keep up to 10 generations of the logfiles
 // tested with IOS 9.4 and Swift 2.2
 func redirectConsoleToFile() {

 // Instance of a private filemanager
 let myFileManger = NSFileManager.defaultManager()

 // the path of the documnts directory of the app
 let documentDirectory: String = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first!

 // maximum number of logfiles
 let maxNumberOfLogFiles: Int = 10

 // look if the max number of files already exist
 var logFilePath : String = documentDirectory.stringByAppendingString("/Console\(maxNumberOfLogFiles).log")
 var FlagOldFileNoProblem: Bool = true
 if myFileManger.fileExistsAtPath(logFilePath) == true {

 // yes, max number of files reached, so delete the oldest one
 do {
 try myFileManger.removeItemAtPath(logFilePath)

 } catch let error as NSError {

 // something went wrong
 print("ERROR deleting old logFile \(maxNumberOfLogFiles): \(error.description)")
 FlagOldFileNoProblem = false
 }
 }

 // test, if there was a problem with the old file
 if FlagOldFileNoProblem == true {

 // loop over all possible filenames
 for i in 0 ..&lt; maxNumberOfLogFiles {

 // look, if an old file exists, if so, rename it with an index higher than before
 logFilePath = documentDirectory.stringByAppendingString("/Console\((maxNumberOfLogFiles - 1) - i).log")
 if myFileManger.fileExistsAtPath(logFilePath) == true {

 // there is an old file
 let logFilePathNew = documentDirectory.stringByAppendingString("/WayAndSeeConsole\(maxNumberOfLogFiles - i).log")
 do {

 // rename it
 try myFileManger.moveItemAtPath(logFilePath, toPath: logFilePathNew)

 } catch let error as NSError {

 // something went wrong
 print("ERROR renaming logFile: (i = \(i)), \(error.description)")
 FlagOldFileNoProblem = false
 }
 }
 }
 }

 // test, if there was a problem with the old files
 if FlagOldFileNoProblem == true {

 // No problem so far, so try to delete the old file
 logFilePath = documentDirectory.stringByAppendingString("/Console0.log")
 if myFileManger.fileExistsAtPath(logFilePath) == true {

 // yes, it exists, so delete it
 do {
 try myFileManger.removeItemAtPath(logFilePath)

 } catch let error as NSError {

 // something went wrong
 print("ERROR deleting old logFile 0: \(error.description)")
 }
 }
 }

 // even if there was a problem with the files so far, we redirect
 logFilePath = documentDirectory.stringByAppendingString("/Console0.log")

 if (isatty(STDIN_FILENO) == 0) {
 freopen(logFilePath, "a+", stderr)
 freopen(logFilePath, "a+", stdin)
 freopen(logFilePath, "a+", stdout)
 displayDebugString(DEBUG_Others, StringToAdd: "stderr, stdin, stdout redirected to \"\(logFilePath)\"")
 } else {
 displayDebugString(DEBUG_Others, StringToAdd: "stderr, stdin, stdout NOT redirected, STDIN_FILENO = \(STDIN_FILENO)")
 }
}

// -----------------------------------------------------------------------------------------------------------
// cleanupOldConsoleFiles()
//
// delete all old consolfiles
func cleanupOldConsoleFiles() {

 // Instance of a private filemanager
 let myFileManger = NSFileManager.defaultManager()

 // the path of the documnts directory of the app
 let documentDirectory: String = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first!

 // maximum number of logfiles
 let maxNumberOfLogFiles: Int = 10

 // working string
 var logFilePath: String = ""

 // loop over all possible filenames
 for i in 0 ... maxNumberOfLogFiles {

 // look, if an old file exists, if so, rename it with an index higher than before
 logFilePath = documentDirectory.stringByAppendingString("/Console\(i).log")
 if myFileManger.fileExistsAtPath(logFilePath) == true {

 // Yes, file exist, so delete it
 do {
 try myFileManger.removeItemAtPath(logFilePath)
 } catch let error as NSError {

 // something went wrong
 print("ERROR deleting old logFile \"\(i)\": \(error.description)")
 }
 }
 }
}
</code></pre>

Is it possible to write every <code>NSLog</code> not only into console, but into a file too? I want to prepare this without replacing <code>NSLog</code> into <code>someExternalFunctionForLogging</code>.

It will be real problem to replace all <code>NSLog</code>. Maybe there is possibility for parsing data from console or catching messages?

How to NSLog into a file

有没有可能将每个NSLog不仅写入控制台，还写入一个文件？我想在不将NSLog替换为someExternalFunctionForLogging的情况下对此进行准备。替换所有NSLog将是一个真正的问题。也许有可能从控制台解析数据或捕获消息？

问如何NSLog到文件中
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问如何NSLog到文件中
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