SYNC

sync ? commit buffer cache to disk.

#include <unistd.h>

int sync(void);

sync first commits inodes to buffers, and then buffers to disk.

sync always returns 0.

SVr4, SVID, X/OPEN, BSD 4.3

According to the standard specification (e.g., SVID), 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.)

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