OC9_文件操作

//
//  main.m
//  OC9_文件操作
//
//  Created by zhangxueming on 15/6/19.
//  Copyright (c) 2015年 zhangxueming. All rights reserved.
//

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //文件句柄
        //以只读的方式创建文件句柄
        //+ (instancetype)fileHandleForReadingAtPath:(NSString *)path;
        //以只写的方式创建文件句柄
        //+ (instancetype)fileHandleForWritingAtPath:(NSString *)path;
        //以可读可写的方式创建文件句柄
        NSFileHandle *fh = [NSFileHandle fileHandleForUpdatingAtPath:@"/Users/zhangxueming/Desktop/Test/1.txt"];

        //移动文件指针到文件末尾
        [fh seekToEndOfFile];
        //写文件
        NSData *data1 = [@"qianfenghulian" dataUsingEncoding:NSUTF8StringEncoding];
        [fh writeData:data1];

        NSData *data2 = [@"千锋互联" dataUsingEncoding:NSUTF8StringEncoding];
        [fh writeData:data2];
        //把文件的内容同步到磁盘中
        [fh synchronizeFile];
        [fh closeFile];//文件句柄消失的时候, 对应的文件也会关闭;

        NSFileHandle *fh1 = [NSFileHandle fileHandleForUpdatingAtPath:@"/Users/zhangxueming/Desktop/Test/2.txt"];
        //读取文件内容到文件末尾
//        NSData *data3 = [fh1 readDataToEndOfFile];
//        NSLog(@"data3 = %@", [[NSString alloc] initWithData:data3 encoding:NSUTF8StringEncoding]);
        //移动文件指针到指定位置
        [fh1 seekToFileOffset:];
        //读取文件指定长度大小
        NSData *data4 = [fh1 readDataOfLength:];
        NSLog(@"data4 = %@", data4);
        NSLog(@"data4 = %@", [[NSString alloc] initWithData:data4 encoding:NSUTF8StringEncoding]);

        //截断文件为指定大小
        [fh1 truncateFileAtOffset:];
    }
    return ;
}