cocoa – 是否可以使用FSEvents获取文件夹已被移动的通知？

概述我正在使用FSEvents API来获取我正在跟踪的本地目录中的更改通知. 是否可以使用FSEvents或其他任何内容获得已监视目录已移至磁盘上其他位置的通知？ 更新： 这是我到目前为止的代码,我现在正在尝试使用带有FSEventStreamCreate的kFSEventStreamCreateFlagWatchRoot标志来获取根更改通知,到目前为止还没有成功. - (void)register 我正在使用FSEvents API来获取我正在跟踪的本地目录中的更改通知.

是否可以使用FSEvents或其他任何内容获得已监视目录已移至磁盘上其他位置的通知？

更新：

这是我到目前为止的代码,我现在正在尝试使用带有FSEventStreamCreate的kFSEventStreamCreateFlagWatchRoot标志来获取根更改通知,到目前为止还没有成功.

- (voID)registerForfileSystemNotifications {    Nsstring *watchedDirectoryPath = [[NSUserDefaults standardUserDefaults] valueForKey:kMyWatchedDirectoryPathKey];    self.watchedDirectoryfileDescriptor = open([watchedDirectoryPath cStringUsingEnCoding:NSUTF8StringEnCoding],O_RDONLY);    NSArray *paths = [NSArray arrayWithObject:watchedDirectoryPath];    voID *appController = (voID *)self;    FSEventStreamContext context = {0,appController,NulL,NulL};    FSEventStreamRef streamRef = FSEventStreamCreate(NulL,&fsevents_callback,&context,(CFArrayRef) paths,kFSEventStreamEventIDSinceNow,(CFTimeInterval)2.0,kFSEventStreamCreateFlagUseCFTypes | kFSEventStreamCreateFlagWatchRoot);    FSEventStreamScheduleWithRunLoop(streamRef,CFRunLoopGetCurrent(),kcfRunLoopDefaultMode);    FSEventStreamStart(streamRef);}voID fsevents_callback(ConstFSEventStreamRef streamRef,voID *userData,size_t numumberOfEvents,voID *eventPaths,const FSEventStreamEventFlags eventFlags[],const FSEventStreamEventID eventIDs[]) {    MyAppController *appController = (MyAppController *)userData;       char *newPath = calloc(4096,sizeof(char));    int pathIntPointer = (int)newPath;    int length = fcntl(appController.watchedDirectoryfileDescriptor,F_GETPATH,pathIntPointer);    Nsstring *newPathString = [[Nsstring alloc] initWithBytes:newPath length:(NSUInteger)length enCoding:NSUTF8StringEnCoding];    NSLog(@"newPathString: %@",newPathString); // empty}

解决方法 是.将kFSEventStreamCreateFlagWatchRoot作为FSEventStreamCreate的最后一个参数传递,如果目录被移动或重命名,您将收到通知.从 docs：

Request notifications of changes along the path to the path(s) you’re watching. For example,with this flag,if you watch “/foo/bar” and it is renamed to “/foo/bar.old”,you would receive a RootChanged event. The same is true if the directory “/foo” were renamed. The event you receive is a special event: the path for the event is the original path you specifIEd,the flag kFSEventStreamEventFlagRootChanged is set and event ID is zero. RootChanged events are useful to indicate that you should rescan a particular hIErarchy because it changed completely (as opposed to the things insIDe of it changing). If you want to track the current location of a directory,it is best to open the directory before creating the stream so that you have a file descriptor for it and can issue an F_GETPATH fcntl() to find the current path.

编辑：添加fcntl示例

那个cocoadev的例子表明作者对指针有点缺乏经验. pathIntPointer不仅是不必要的,它也是你的问题的原因.从fnctl检查返回码的错误会抓住它.这是你的回调的修订版本：

voID fsevents_callback(ConstFSEventStreamRef streamRef,const FSEventStreamEventID eventIDs[]) {    MyAppController *appController = (MyAppController *)userData;       char newPath[ MAXPATHLEN ];    int rc;    rc = fcntl( appController.watchedDirectoryfileDescriptor,newPath );    if ( rc == -1 ) {        perror( "fnctl F_GETPATH" );        return;    }    Nsstring *newPathString = [[Nsstring alloc] initWithUTF8String: newPath ];    NSLog(@"newPathString: %@",newPathString);    [ newPathString release ];}

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