How to truncate a file from the end? (cross platform)

Question

I am trying to find a cross-platform method to delete X bytes from the end of a file.

Currently I have found:

• Platform specific solutio

Answer 1

The Boost.Filesystem library (version 1.44 and above) provides a resize_file function.

Answer 2

How do you think cross platform functions work? Just make your own function like this:

int truncate(int fd, long size)
{
#ifdef _WIN32 || _WIN64 
    return _chsize(fd, size);
#else
  #ifdef POSIX
    return ftruncate(fd, size);
  #else
    // code for other OSes
  #endif
#endif
}

Answer 3

There is no such thing in the Standard library. They support streams- but streams don't have ends, files happen to have ends- at the current time.

All you can do is write a cross-platform wrapper on the function.