file_desc

    A file descriptor.

 buffer

    A pointer to a character string that is large enough to hold the
    file specification.

  . . .

    An optional argument that can be either 1 or 0. If you specify
    1, the getname function returns the file specification in OpenVMS
    format. If you specify 0, the getname function returns the file
    specification in UNIX style format. If you omit this argument,
    the getname function returns the filename according to your
    current command-language interpreter (CLI).