The fsck_hfs utility verifies and repairs HFS+ file systems. The first form of fsck_hfs quickly checks the specified file systems to determine whether they were cleanly unmounted. The second form of fsck_hfs preens the specified file systems. It is normally started by fsck run from /etc/rc.boot during automaticreboot, when a HFS file system is detected. When preening file systems, fsck_hfs will fix common inconsistencies for file systems thatwere not unmounted cleanly.