Gehookter subcommand 'diff'

[zogftw@r500 ~]$ zogftw diff 2 /home/zogftw/.config/zogftw/zogftw.conf
2014-11-06 13:16:07 zogftw: Diffing '[...]ftw.conf' with its version on 'tank/home/zogftw@2014-11-06_13:03'
--- [...].zfs/snapshot/2014-11-06_13:03/.config/zogftw/zogftw.conf	2014-11-06 12:53:47.037927894 +0100
+++ /home/zogftw/.config/zogftw/zogftw.conf	2014-11-06 13:14:21.056840354 +0100
@@ -15,3 +15,4 @@
     echo "${timestamp} zogftw: "
 }
 
+. "${ZOGFTW_CONFIG_DIRECTORY}/zogftw.hooks"