As others have commented, it's not necessary. If you wrote cp in such a way that it's a reusable C library that other programs might use, then I can understand

As others have commented, it's not necessary. If you wrote cp in such a way that it's a reusable C library that other programs might use, then I can understand why they do this. It still doesn't make much sense for the command-line version to call this. Of course, it might run on some weird platform where the OS doesn't reclaim the memory of a process on exit(?).