Description

   The close function tries to write buffered data by using an
   implicit call to fflush. If the write fails (because the disk
   is full or the user's quota was exceeded, for example), close
   continues executing. It closes the OpenVMS channel, deallocates
   any buffers, and releases the memory associated with the file
   descriptor (or FILE pointer). Any buffered data is lost, and the
   file descriptor (or FILE pointer) no longer refers to the file.

   If your program needs to recover from errors when flushing
   buffered data, it should make an explicit call to fsync (or
   fflush) before calling close.