Description

   The C RTL opens the new file for reading and writing, and
   returns the corresponding file descriptor.

   If the file exists:

   o  A version number one greater than any existing version is
      assigned to the newly created file.

   o  By default, the new file inherits certain attributes from
      the existing version of the file unless those attributes are
      specified in the creat call. The following attributes are
      inherited:

      -  Record format (FAB$B_RFM)

      -  Maximum record size (FAB$W_MRS)

      -  Carriage control (FAB$B_RAT)

      -  File protection

   o  When a new version of a file is created, and the named file
      already exists as a symbolic link, the file to which the
      symbolic link refers is created.

   If the file did not previously exist:

   o  It is given the file protection that results from performing
      a bitwise AND on the mode argument and the complement of the
      current protection mask.

   o  It defaults to stream format with line-feed record separator
      and implied carriage-return attributes.

   See also open, close, read, write, and lseek in this section.