NAME

       sync — schedule file system updates

LIBRARY

       Standard C Library (libc, -lc)

SYNOPSIS

       #include <unistd.h>

       void
       sync(void);

DESCRIPTION

       The  sync() system call forces a write of dirty (modified) buffers in the block buffer cache out to disk.
       The kernel keeps this information in core to reduce the number of disk  I/O  transfers  required  by  the
       system.   As  information  in  the  cache  is  lost  after a system crash, a sync() system call is issued
       frequently by the kernel process syncer(4) (about every 30 seconds).

       The fsync(2) system call may be used to synchronize individual file descriptor attributes.

SEE ALSO

       fsync(2), syncer(4), sync(8)

HISTORY

       The sync() function appeared in Version 3 AT&T UNIX.

BUGS

       The sync() system call may return before the buffers are completely flushed.

Debian                                          December 1, 2017                                         SYNC(2)