void
     sync(void);

DESCRIPTION

     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 user process update(8) (about every 30 seconds).

     The function fsync(2) may be used to synchronize individual file descrip-
     tor attributes.

SEE ALSO

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

BUGS

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

HISTORY

     A sync() function call appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution        June 4, 1993        4th Berkeley Distribution