NAME
fdatasync —
synchronize the data of a file (REALTIME)
SYNOPSIS
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(3) 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(3) and write(3).
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
aio_fsync(3), fcntl(3), fsync(3), open(3), read(3), write(3)
XBD <unistd.h>
CHANGE HISTORY
First released in Issue 5. Included for alignment with the POSIX Realtime Extension.
Issue 6
The [ENOSYS] error condition has been removed as stubs need not be provided if an implementation does not support the Synchronized Input and Output option.
The fdatasync () function is marked as
part of the Synchronized Input and Output option.