grdrotater(1gmt) on Linux
The text 3c3b5ffc69d0, as Debian 8 (Jessie) shipped it.
Rotate a grid using a finite rotation
Flags it lists
-
-: -
-F -
-G -
-H -
-N -
-Q -
-R -
-S -
-T -
-V -
-bi -
-bo -
-m