Manual Pages for UNIX Operating System command usage for man fsync

Standard C Library Functions                            fsync(3C)



NAME
     fsync - synchronize changes to a file

SYNOPSIS
     #include 

     int fsync(int fildes);


DESCRIPTION
     The fsync() function moves all modified data and  attributes
     of  the  file  descriptor  fildes  to a storage device. When
     fsync() returns, all in-memory modified  copies  of  buffers
     associated  with  fildes  have  been written to the physical
     medium. The fsync() function is different from sync(), which
     schedules disk I/O for all files  but returns before the I/O
     completes. The fsync() function forces all outstanding  data
     operations  to  synchronized  file integrity completion (see
     fcntl.h(3HEAD) definition of O_SYNC.)


     The fsync() function forces all currently queued I/O  opera-
     tions  associated  with  the  file  indicated  by  the  file
     descriptor fildes to the synchronized I/O completion  state.
     All I/O operations are completed as defined for synchronized
     I/O file integrity completion.

RETURN VALUES
     Upon successful completion, 0 is returned. Otherwise, -1  is
     returned  and  errno  is  set  to indicate the error. If the
     fsync() function fails, outstanding I/O operations  are  not
     guaranteed to have been completed.

ERRORS
     The fsync() function will fail if:

     EBADF        The  fildes  argument  is  not  a  valid   file
                  descriptor.


     EINTR        A signal was caught  during  execution  of  the
                  fsync() function.


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


     ENOSPC       There was no free space remaining on the device
                  containing the file.





SunOS 5.11           Last change: 5 Feb 2008                    1






Standard C Library Functions                            fsync(3C)



     ETIMEDOUT    Remote connection timed out. This  occurs  when
                  the file is on an  NFS file system mounted with
                  the  soft option. See  mount_nfs(1M).



     In the event that any of the  queued  I/O  operations  fail,
     fsync() returns the error conditions defined for read(2) and
     write(2).

USAGE
     The fsync() function should be  used  by  applications  that
     require  that  a  file  be in a known state. For example, an
     application that  contains  a  simple  transaction  facility
     might  use   fsync() to ensure that all changes to a file or
     files caused by a  given  transaction  were  recorded  on  a
     storage medium.


     The manner in which  the  data  reach  the  physical  medium
     depends  on  both  implementation and hardware.  The fsync()
     function returns when notified by the device driver that the
     write has taken place.

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | Async-Signal-Safe           |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     mount_nfs(1M), read(2), sync(2),  write(2),  fcntl.h(3HEAD),
     fdatasync(3C), attributes(5), standards(5)











SunOS 5.11           Last change: 5 Feb 2008                    2