SYNC(2) SysV SYNC(2)
NAME
sync - update super block
SYNOPSIS
void sync ( )
DESCRIPTION
sync causes all information in memory that should be on disk to be
written out. This includes modified super blocks, modified i-nodes, and
delayed block I/O. Domain/OS requires no explicit sync operation; it
writes out the system buffers automatically at shutdown. We provide sync
in the interest of ensuring compatibility with other implementations.
Under other implementations, sync should be used by programs which
examine a file system, for example fsck, df, etc. It is mandatory before
a boot.
Under implementations that depend on sync, the writing out of system
buffers, although scheduled, is not necessarily complete upon return from
the call.