xfs_spaceman(8) on Linux
The text 461ef2e4ea30, as Debian 10 (Buster) shipped it.
show free space information about an XFS filesystem
Flags it lists
-
-a -
-b -
-d -
-e -
-f -
-g -
-h -
-m -
-p -
-r -
-s -
-u