SYNC(2)                    Linux Programmer's Manual                   SYNC(2)
NAME
       sync - commit buffer cache to disk

SYNOPSIS
       #include <unistd.h>

       void sync(void);

DESCRIPTION
       sync() first commits inodes to buffers, and then buffers to disk.

ERRORS
       This function is always successful.

CONFORMING TO
       SVr4, 4.3BSD, POSIX.1-2001.

BUGS
       According  to  the  standard specification (e.g., POSIX.1-2001), sync()
       schedules the writes, but may return before the actual writing is done.
       However,  since  version  1.3.20 Linux does actually wait.  (This still
       does not guarantee data integrity: modern disks have large caches.)

NOTES
       Since glibc 2.2.2 the Linux prototype is as listed above, following the
       various  standards.  In libc4, libc5, and glibc up to 2.2.1 it was "int
       sync(void)", and sync() always returned 0.

SEE ALSO
       bdflush(2), fdatasync(2), fsync(2), sync(8), update(8)

Linux 2.4                         2001-10-10                           SYNC(2)