Under MacOS file reading problem

• Use Xcode to write C ++ programs can be used directly fstream read and write files, as follows:

const char* path1 = [path UTF8String];
string filename = path1;
ifstream in(filename,ifstream::in);
if(in){
　　string buf;
　　while(getline(in,buf)){
　　　　cout<<buf<<endl;
   }
}else{
　　cerr<<"cannot open this file: "<<filename<<endl;
}

• If you write App, the absolute path to the file can not be used, you must use relative paths, as follows:

NSString *path = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"question.txt"];
NSString *fileContent = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

• If the one-time reading of the file size is too large, use NSString save the contents of the file will lose some out of memory, while C ++ is not read by line.