Provided by: duperemove_0.11.2-3build2_amd64 

NAME
show-shared-extents - Show extents that are shared.
SYNOPSIS
show-shared-extents files...
DESCRIPTION
Print all the extents in files that are shared. A sum of shared extents is also printed. On btrfs, an extent is reported as shared if it has more than one reference.
SEE ALSO
duperemove(8) btrfs(8) Version 0.09 December 2014 show-shared-extents(8)