Can you delete a FILE object created from fopen?

Question

During the accident investigation, I came across this code:

FILE * RejectFile = fopen("filename", "a+"); // other code happens delete RejectFile; 

I understand that you only call delete on objects created by new . Of course, some of this old code is really bad, so it's probably wrong, but I'm not sure. Is this a valid code?

Answer 1

No, this is not true. Use delete only pointers obtained with new . This is where undefined behavior occurs; it can work, it can fall, it can take out the trash, it can start playing music ...

You need to use fclose() to destroy the file descriptor.

Answer 2

If you really need to use delete, you can use some wrappers around these constructs. How,

 class MyFILE { public: MyFILE(/*file params*/); virtual ~MyFILE(){fclose(_fileptr); private: FILE * _fileptr; } 

Using an example will

 MyFILE * f = new MyFILE(/*file params*/); delete f; 

Personally, I prefer this shell solution, as it provides an exhaustive way to manage resources. For example, when we are on a code segment where exceptions can be thrown at any time on any part of it. If we allocate resources, such as open files, this mechanism opens the way to “automatically” delete the object when the shell goes out of scope.