IOS文件常用操作 NSFileManager----不断更新中

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-------文件的创建，遍历，得到文件属性(创建日期等),删除等操作
直接从工程里面扒出来的，不过写的很清晰。
NSDateFormatter * dateFormatter = [[[NSDateFormatter alloc] init]autorelease];
[dateFormatter setDateFormat:@"yyyy_MM_dd"];
NSString* dataStr = [dateFormatter stringFromDate:[NSDate date]];

NSString *dicpath = [NSString stringWithFormat:@"%@/Documents/logs",NSHomeDirectory()];
NSString *path = [NSString stringWithFormat:@"%@/log%@.html",dicpath,dataStr];
NSFileManager *manager = [NSFileManager defaultManager];

//如果不存在当天的日志，则新建
if ([manager fileExistsAtPath:path] == NO) {
//删除max interval 以上的log
NSFileManager* fm= [[[NSFileManager alloc] init]autorelease];
NSArray *levelList = [fm contentsOfDirectoryAtPath:dicpath error:nil ] ;

for (NSString *fname in levelList) {
NSString *fpath = [NSString stringWithFormat:@"%@/%@",dicpath,fname];
NSDictionary *fileAttributes = [manager attributesOfItemAtPath:fpath error:nil];
NSDate * creationDate=nil;
if ((creationDate = [fileAttributes objectForKey:NSFileCreationDate])) {
NSTimeInterval interval = [creationDate timeIntervalSinceNow];
//printf("%s's interval is: %f\n",[fpath UTF8String ],interval);
if ((interval*-1) >MAX_INTERVAL*24*60*60) {
[manager removeItemAtPath:fpath error:nil];
//NSLog(@"delete file:%@ \n",fpath );
}
}
}

//创建新log
[manager createDirectoryAtPath:dicpath withIntermediateDirectories:YES attributes:nil error:nil];
[manager createFileAtPath:path contents:nil attributes:nil];

///Users/user/Library/Application Support/iPhone Simulator/5.1/Applications/5403DF94-1B63-4CCF-8A5B-548ED5902DBE/hello.app
NSString *stylePath = [NSString stringWithFormat:@"%@/FALog.css",[[NSBundle mainBundle] resourcePath]];
NSString *styleStr = [NSString stringWithContentsOfFile:stylePath encoding:NSUTF8StringEncoding error:nil];
// //NSLog(@"styleStr:%@",styleStr);
str = [NSString stringWithFormat:@"%@ \n%@",styleStr,str];

}

NSDictionary * attributes = [manager attributesOfItemAtPath:path error:nil];
long long fileSize = [[attributes objectForKey:NSFileSize] longLongValue];
NSFileHandle *uFile = [NSFileHandle fileHandleForWritingAtPath:path];
[uFile seekToFileOffset:fileSize];
[uFile writeData:[str dataUsingEncoding:NSUTF8StringEncoding]];


-----得到file 大小
NSDictionary *fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:URL error:&attributesError];

NSNumber *fileSizeNumber = [fileAttributes objectForKey:NSFileSize];
long long fileSize = [fileSizeNumber longLongValue];