NSFileManager和NSFileHandle文件操作

一.NSFileManager文件外操作

1.文件和目录的创建

(1).步骤

//1.创建一个单例类的对象
NSFileManager *fileManage = [NSFileManager defaultManager];

//2.创建普通文件,如果两个文件的文件名相同,会用新文件覆盖旧文件
- (BOOL)createFileAtPath:(NSString *)path contents:(NSData *)data attributes:(NSDictionary *)attr;

//3. 创建文件夹/目录
- (BOOL)createDirectoryAtPath:(NSString *)path withIntermediateDirectories:(BOOL)createIntermediates attributes:(NSDictionary *)attributes error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

(2)程序举例

NSString *pathDesktop = @"/Users/Story5/Desktop";//桌面路径
NSString *string = @"fileContent";
NSData *dataFromString = [string dataUsingEncoding:NSUTF8StringEncoding];

NSFileManager *fileManage = [NSFileManager defaultManager];//创建一个单例类的对象

[fileManage createFileAtPath:[pathDesktop stringByAppendingString:@"/file.txt"] contents:dataFromString attributes:nil];

NSError *error = nil;
[fileManage createDirectoryAtPath:[pathDesktop stringByAppendingString:@"/dir/dir1"] withIntermediateDirectories:YES attributes:nil error:&error];
    if (error != nil) {//函数调用失败
        NSLog(@"createDirectoryAtPath error: %@", [error localizedFailureReason]);
    }

2.文件和目录的复制

- (BOOL)copyItemAtPath:(NSString *)srcPath toPath:(NSString *)dstPath error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

3.文件和目录的剪切

- (BOOL)moveItemAtPath:(NSString *)srcPath toPath:(NSString *)dstPath error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

4.文件和目录的删除

- (BOOL)removeItemAtPath:(NSString *)path error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

5.目录的遍历

(1)浅度遍历

- (nullable NSArray<NSString *> *)contentsOfDirectoryAtPath:(NSString *)path error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

(2)深度遍历

- (nullable NSArray<NSString *> *)subpathsOfDirectoryAtPath:(NSString *)path error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

6.获取文件属性

- (nullable NSDictionary<NSString *, id> *)attributesOfItemAtPath:(NSString *)path error:(NSError **)error NS_AVAILABLE(10_5, 2_0);

二.NSFileHandle文件操作

1.文件的打开

(1)以只读方式打开

+ (nullable instancetype)fileHandleForReadingAtPath:(NSString *)path;

(2)以只写方式打开

+ (nullable instancetype)fileHandleForWritingAtPath:(NSString *)path;

(3)以读写方式打开

+ (nullable instancetype)fileHandleForUpdatingAtPath:(NSString *)path;

2.文件内容的读取

//读
- (NSData *)readDataOfLength:(NSUInteger)length; - (NSData *)readDataToEndOfFile; //写 - (void)writeData:(NSData *)data;

3.文件偏移量设置

- (unsigned long long)seekToEndOfFile;
- (void)seekToFileOffset:(unsigned long long)offset;