sync(2) sync(2) NAME sync - update super block 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 super blocks, modified i-nodes, and delayed block I/O. It should be used by programs that examine a file system, such as fsck(1M), df(1M), etc. It is mandatory before a re-boot. The writing, although scheduled, is not necessarily completed before sync returns. The fsync system call completes the writing before it returns. SEE ALSO fsync(2) Page 1