NAME    [Toc]    [Back]

       fdatasync  -  Writes  data  changes in a file to permanent
       storage

SYNOPSIS    [Toc]    [Back]

       #include <unistd.h>

       int fdatasync (
            int fildes );

PARAMETERS    [Toc]    [Back]

       Specifies a valid open file descriptor.

DESCRIPTION    [Toc]    [Back]

       The fdatasync function causes system buffers containing  a
       file's  modified  data to be written to permanent storage.
       The fdatasync function does not return until the operation
       has  been completed.  The fdatasync function provides data
       integrity, ensuring that  data  in  permanent  storage  is
       identical to data in the buffer. However, use of fdatasync
       does not guarantee that file control information  such  as
       owner  and modification time has been updated to permanent
       storage (see the fsync function).

NOTES    [Toc]    [Back]

       The file identified by the fildes parameter must  be  open
       for  writing  when the fdatasync function is issued or the
       call will fail.

RETURN VALUES    [Toc]    [Back]

       Upon successful completion, the fdatasync function returns
       a  value  of  0 (zero). If the fdatasync function fails, a
       value of -1 is returned and errno is set to  indicate  the
       error.  If fdatasync fails, outstanding I/O operations are
       not guaranteed to have been completed.

ERRORS    [Toc]    [Back]

       If the fdatasync function fails, errno may be set  to  one
       of  the  following  values:  The fildes parameter is not a
       valid file descriptor.   The  fildes  parameter  does  not
       refer to a file on which this operation is possible.

       If  any queued I/O operations fail, the fdatasync function
       returns error conditions defined for the  read  and  write
       functions.

SEE ALSO    [Toc]    [Back]

       Functions:  fcntl(2), fsync(2), open(2), read(2), sync(2),
       write(2)



                                                     fdatasync(2)