oc语言复制视频文件

 void copyFile()
 {
     NSString *home=NSHomeDirectory();
     NSString *path=[NSString stringWithFormat:@"%@/desktop/oc.mp4",home];
     NSString *path1=[NSString stringWithFormat:@"%@/desktop/oc1.mp4",home];
     NSFileHandle *handle=[NSFileHandle fileHandleForReadingAtPath:path];
     NSFileManager *fm=[NSFileManager defaultManager];
     BOOL ret=NO;
     if ([fm fileExistsAtPath:path1])
     {
         NSLog(@"存在");
     }
     else
     {
        ret= [fm createFileAtPath:path1 contents:nil attributes:nil];

     }
     NSFileHandle *writeHandle=[NSFileHandle fileHandleForWritingAtPath:path1];
     NSData *data=nil;
     if (ret==YES)
     {
         data=[handle readDataOfLength:*];
         while ([data length]==*)
         {
             [writeHandle writeData:data];
             data=[handle readDataOfLength:*];
         }
         [writeHandle writeData:data];
     }
     [handle closeFile];
     [writeHandle closeFile];

 }