bsd man page for sync

SYNC(8) 						      System Manager's Manual							   SYNC(8)

NAME
       sync - update the super block

SYNOPSIS
       sync

DESCRIPTION
       Sync  executes  the  sync  system primitive.  Sync can be called to insure that all disk writes have been completed before the processor is
       halted in a way not suitably done by reboot(8) or halt(8).  Generally, it is preferable to use reboot or halt to shut down the  system,	as
       they may perform additional actions such as resynchronizing the hardware clock and flushing internal caches before performing a final sync.

       See sync(2) for details on the system primitive.

SEE ALSO
       sync(2), fsync(2), halt(8), reboot(8), update(8)

4th Berkeley Distribution					 November 27, 1996							   SYNC(8)