4.2BSD/usr/man/man2/sync.2

Compare this file to the similar file:
Show the results in this format:

.TH SYNC 2 "12 February 1983"
.UC 4
.SH NAME
sync \- update super-block
.SH SYNOPSIS
.B sync()
.SH DESCRIPTION
.I Sync
causes all information in core
memory that should be on disk to be written out.
This includes modified super blocks,
modified i-nodes, and delayed block I/O.
.PP
.I Sync
should be used by programs which examine a file system,
for example
.I "fsck, df,"
etc.
.I Sync
is mandatory before a boot.
.SH "SEE ALSO"
fsync(2), sync(8), update(8)
.SH BUGS
The writing, although scheduled, is not necessarily
complete upon return from 
.IR sync .