【非凡程序员】 OC第十七节课 文件操做一 (NSFileManager和NSFileHandle)

文件操做

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        NSLog(@"Hello, World!");
       
        //------－－－-- NSFileManager---------//
       
        //实例化一个对象
        NSFileManager * f=[NSFileManager defaultManager];
       
        //根据aaa.txt的路径读取内容
        NSData *data1=[f contentsAtPath:@"/Users/feifanchengxuyuan/Desktop/aaa.txt"];
        NSString *str1=[[NSString alloc]initWithData:data1 encoding:NSUTF8StringEncoding];
        NSLog(@"%@",str);
        
        //从一个文件中直接获取数据（不须要转换）
        NSLog(@"%@", [NSString stringWithContentsOfFile:@"/Users/feifanchengxuyuan/Desktop/aaa.txt" encoding:NSUTF8StringEncoding error:nil]);

        //建立一个b.txt  内容为空
        //建立一个bbb.txt 而且把aaa.txt的文件复制到bbb.txt中
        [f createFileAtPath:@"/Users/feifanchengxuyuan/Desktop/b.txt" contents:nil attributes:nil];
        [f createFileAtPath:@"/Users/feifanchengxuyuan/Desktop/bbb.txt" contents:data1 attributes:nil];
        
        //把str转化为文件流，写入到bbb.txt （若是是已经存在该文件，则会覆盖以前的内容）
        NSString *str2=@"zhang";
        NSData *data2=[str2 dataUsingEncoding:NSUTF8StringEncoding]；
        [f createFileAtPath:@"/Users/feifanchengxuyuan/Desktop/bbb.txt" contents:data2 attributes:nil];
   
        //获取路径
        NSString *str3= [f currentDirectoryPath];
        NSLog(@"%@",str3);

          // 更改当前路径
        [f changeCurrentDirectoryPath:@"/Users/feifanchengxuyuan/Desktop/"];
        NSLog(@"%@",[f  currentDirectoryPath]);
       
        //路径相同就是更名，路径不一样就是移动
        [f moveItemAtPath:@"/Users/feifanchengxuyuan/Desktop/b.txt"  toPath:@"/Users/feifanchengxuyuan/Desktop/ccc.txt"  error:nil];
        [f copyItemAtPath:@"/Users/feifanchengxuyuan/Desktop/b.txt" toPath:@"/Users/feifanchengxuyuan/Desktop/ccc" error:nil];

        //遍历当前路径
        NSArray *array=  [f contentsOfDirectoryAtPath:@"/Users/feifanchengxuyuan/Desktop" error:nil];
        NSLog(@"%@,array);
        
         // 枚举遍历
        NSLog(@"%@:[f enumeratorAtPath:@"/Users/feifanchengxuyuan/Desktop"]);
        NSEnumerator *ee=[f enumeratorAtPath:@"/Users/feifanchengxuyuan/Desktop"];
        NSArray *array1=[ee allObjects];
        NSLog(@"%@,array1);              

        //深度遍历当前路径
        NSArray * array1=[f subpathsAtPath:@"/Users/feifanchengxuyuan/Desktop"];
        NSLog(@"%@",array1);

        
        
       // 建立文件夹  withIntermediateDirectories:YES若是没有该文件，就建立,     NO，若是不存就会报错
        NSError *error = nil;
        [f createDirectoryAtPath:@"/Users/feifanchengxuyuan/Desktop3/aaa1" withIntermediateDirectories:YES attributes:nil error:&error];
        if( error )
        {
            NSLog( @"%@", error );
        }
       
   
  //--------－－－－--- NSFileHandle-----－(重点)－－---//

        //1 文件必须建立
      //2文件必须给出足够的权限 如 chmod 777文件名＋文件类型
       
        //1.获取用户主目录
        NSString *homepath = NSHomeDirectory();
        NSLog( @"homepath: %@", homepath);
        //2.根据参数链接目录
        NSString *sourcepath = [homepath stringByAppendingPathComponent:@"/Desktop/ssss.txt"];
        //只能写@"/Desktop/ssss.txt" 不能写@"/Users/feifanchengxuyuan/Desktop/ssss.txt"由于这是链接目录，自动链接根目录/Users/feifanchengxuyuan

（－－－－－－－－－－－－－－－－注意－－－－－－－－－－－－－－）
        NSLog( @"sourcepath: %@", sourcepath );
       
       //3.建立NSFileHandle对象类型fileHandleForUpdatingAtPath 为可更新的类型
        //fileHandleForReadingAtPath //读取
        NSFileHandle *filhandle = [NSFileHandle fileHandleForUpdatingAtPath:sourcepath];
       
        //4.定位偏移量到文件内容尾部
        [filhandle seekToEndOfFile];
       
        //5.定义要追加的字符串
        NSString *string = @"hello xiaohe   sacnkwanc;w\n";
       
       //6.转化成文件流
        NSData *nsdate = [string dataUsingEncoding:NSUTF8StringEncoding];
       
        //7写数据
        [filhandle writeData:nsdate];

        //8.关闭文件
        [filhandle closeFile];

        
           //将字典直接写入到@"/Users/feifanchengxuyuan/Desktop/Friday.plist"路径下，不须要转换
        NSDictionary *dict=@{
                             @"1":@"a",
                             @"2":@"b",
                             @"3":@"c"
                             };
        [dict writeToFile:@"/Users/feifanchengxuyuan/Desktop/Friday.plist" atomically:YES];

 

          //echo jjjjjj>>aaa.txt  在终端中给aaa.txt添加jjjjjj文本
          cat 文件名是读取内容     

         chmod 777 文件名－－－改最大权限  　　chmod 000 文件名－－－最小权限
   

   }    return 0;}