NAME

sync − update disk

SYNOPSIS

#include <unistd.h>

void sync(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, etc.  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. 

AUTHOR

sync() was developed by HP and AT&T Bell Laboratories. 

SEE ALSO

sync(1M), fdatasync(2), fsync(2). 

STANDARDS CONFORMANCE

sync(): SVID2, SVID3, XPG2

Hewlett-Packard Company  —  HP-UX Release 10.20:  July 1996