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



PPRROOLLOOGG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.


NNAAMMEE
       fdatasync -- synchronize the data of a file (RREEAALLTTIIMMEE)

SSYYNNOOPPSSIISS
       #include <unistd.h>

       int fdatasync(int _f_i_l_d_e_s);

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

       The functionality shall be equivalent to _f_s_y_n_c() 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.

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

EERRRROORRSS
       The _f_d_a_t_a_s_y_n_c() function shall fail if:

       EEBBAADDFF  The _f_i_l_d_e_s argument is not a valid file descriptor open for
              writing.

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

       In the event that any of the queued I/O operations fail, _f_d_a_t_a_s_y_n_c()
       shall return the error conditions defined for _r_e_a_d() and _w_r_i_t_e().

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       None.

RRAATTIIOONNAALLEE
       None.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       None.

SSEEEE AALLSSOO
       _a_i_o___f_s_y_n_c(), _f_c_n_t_l(), _f_s_y_n_c(), _o_p_e_n(), _r_e_a_d(), _w_r_i_t_e()

       The Base Definitions volume of POSIX.1-2008, <<uunniissttdd..hh>>

CCOOPPYYRRIIGGHHTT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is
       POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2013                         FDATASYNC(3)
