msghack(1) on Linux
The text b1ce24d32f05, as Debian 9 (Stretch), Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 5.0 (Lenny) shipped it.
Alter .po files in ways no sane mind would think about
Flags it lists
-
--append -
--empty -
--invert -
--master -
-o