FDATASYNC(3P)                                       POSIX Programmer's Manual                                      FDATASYNC(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       fdatasync - synchronize the data of a file (REALTIME)

SYNOPSIS
       #include <unistd.h>

       int fdatasync(int fildes);


DESCRIPTION
       The  fdatasync()  function  shall  force  all  currently queued I/O operations associated with the file indicated by file
       descriptor fildes to the synchronized I/O completion state.

       The functionality shall be equivalent to fsync() with the symbol _POSIX_SYNCHRONIZED_IO defined, with the exception  that
       all I/O operations shall be completed as defined for synchronized I/O data integrity completion.

RETURN VALUE
       If  successful,  the fdatasync() function shall return the value 0; otherwise, the function shall return the value -1 and
       set errno to indicate the error. If the fdatasync() function fails, outstanding I/O operations are not guaranteed to have
       been completed.

ERRORS
       The fdatasync() function shall fail if:

       EBADF  The fildes argument is not a valid file descriptor open for writing.

       EINVAL This implementation does not support synchronized I/O for this file.


       In the event that any of the queued I/O operations fail, fdatasync() shall return the error conditions defined for read()
       and write().

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       aio_fsync(), fcntl(), fsync(), open(), read(), write(), the Base Definitions volume of IEEE Std 1003.1-2001, <unistd.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003  Edition,  Standard  for
       Information  Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy  between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group
       Standard  is  the  referee   document.   The   original   Standard   can   be   obtained   online   at   http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                 FDATASYNC(3P)