NAME    [Toc]    [Back]

     sync - synchronize disk block in-core status  with  that  on
disk

SYNOPSIS    [Toc]    [Back]

     #include <unistd.h>

     void
     sync(void);

DESCRIPTION    [Toc]    [Back]

     The  sync()  function  forces  a  write  of dirty (modified)
buffers in the
     block buffer cache out to disk.  The kernel keeps  this  information in
     core  to reduce the number of disk I/O transfers required by
the system.
     As information in the cache is lost after a system  crash  a
sync() call is
     issued  frequently by the in-kernel process update(8) (about
every 30 seconds).


     The function fsync(2) may be used to synchronize  individual
file descriptor
 attributes.

SEE ALSO    [Toc]    [Back]

     fsync(2), sync(8), update(8)

HISTORY    [Toc]    [Back]

     A sync() function call appeared in Version 2 AT&T UNIX.

BUGS    [Toc]    [Back]

     sync() may return before the buffers are completely flushed.

OpenBSD      3.6                           June      4,      1993