fsck(8) on macOS
The text 1bc1bf37f500, as Mac OS X 10.5.8, Mac OS X 10.5.7, Mac OS X 10.5.6, Mac OS X 10.5.5, Mac OS X 10.5.4, Mac OS X 10.5.3, Mac OS X 10.5.2, Mac OS X 10.5.1, Mac OS X 10.5 shipped it.
filesystem consistency check and interactive repair
Flags it lists
-
-b -
-f -
-l -
-m -
-n -
-q -
-y