NAME
sync, lsync — update disk
SYNOPSIS
#include <unistd.h>
void sync(void);
void lsync(void);
DESCRIPTION
sync()
causes all information in memory that should be on disk to be written out.
This includes modified file system meta-data and delayed block I/O.
It should be used by commands and programs
that examine a file system, such as
fsck,
df,
and so on.
It is mandatory before a shutdown.
The writing, although scheduled,
is not necessarily complete upon return from
sync().
In some HP-UX systems,
sync()
may be reduced to a no-op.
This is permissible on a system which does not cache buffers
or in a system that in some way ensures that the disks
are always in a consistent state.
lsync()
is a deprecated system call that is currently functionally
identical to
sync().
HP-UX kernel support for it remains only to aid
compatibility with very old HP-UX binaries.
AUTHOR
sync()
was developed by HP
and AT&T Bell Laboratories.
STANDARDS CONFORMANCE
sync(): SVID2, SVID3, XPG2