gmtdigitize(1gmt) on Linux
The text af20c05519d0, as Debian 7 (Wheezy) shipped it.
Digitizing and Inverse map transformation of map x/y coordinates
Flags it lists
-
-A -
-C -
-D -
-F -
-H -
-J -
-L -
-N -
-R -
-S -
-V -
-Z -
-bo -
-m