sync(8)

sync8

Force completion of pending disk writes (flush cache)

Usage

sync

Overview

The sync utility can be called to ensure that all disk writes have been completed before the processor is halted in a way not suitably done by reboot(8) or halt(8). Generally, it is preferable to use reboot(8) or halt(8) to shut down the system, as they may perform additional actions such as resynchronizing the hardware clock and flushing internal caches before performing a final sync.

The sync utility utilizes the sync(2) function call.

Releases

163 releases since Mac OS X 10.0; the text changed 3 times.

  1. 10.0–10.4.11
  2. 10.5–10.5.8
  3. 10.6–12.5
  4. 13.0–26.5

History

A sync utility appeared in Version 4 AT&T UNIX.

From system_cmds 1042.120.1 in macOS 26.5. Parsed by carta from the page's mdoc source.