sync - flush file system buffers
sync [OPTION]
Force changed blocks to disk, update the super block.
Written by Jim Meyering.
Report bugs to <bug-coreutils@gnu.org>.
Copyright (C) 2006 Free Software Foundation, Inc. This is free software. You may redistribute copies of it under the terms of the GNU General Public License <http://www.gnu.org/licenses/gpl.html>. There is NO WARRANTY, to the extent permitted by law.
The full documentation for sync is maintained as a Texinfo manual. If the info and sync programs are properly installed at your site, the command
info sync
should give you access to the complete manual.