4.3BSD - /usr/man/cat2/fsync.0

FSYNC(2)                                                              FSYNC(2)


NAME
       fsync - synchronize a file’s in-core state with that on disk

SYNOPSIS
       fsync(fd)
       int fd;

DESCRIPTION
       Fsync  causes  all  modified data and attributes of fd to be moved to a
       permanent storage device.  This normally results in all  in-core  modi‐
       fied copies of buffers for the associated file to be written to a disk.

       Fsync should be used by programs that require a file to be in  a  known
       state, for example, in building a simple transaction facility.

RETURN VALUE
       A 0 value is returned on success.  A -1 value indicates an error.

ERRORS
       The fsync fails if:

       [EBADF]        Fd is not a valid descriptor.

       [EINVAL]       Fd refers to a socket, not to a file.

       [EIO]          An  I/O  error occurred while reading from or writing to
                      the file system.

SEE ALSO
       sync(2), sync(8), update(8)


4.2 Berkeley Distribution        May 22, 1986                         FSYNC(2)