grd2xyz(1gmt) on Linux
The text a28f7b952d52, as Debian 8 (Jessie), Debian 7 (Wheezy), Debian 6.0 (Squeeze), Debian 4.0 (Etch), Debian 3.1 (Sarge) shipped it.
Converting a grdfile to an ASCII or binary table
Flags it lists
-
-H -
-L -
-R -
-S -
-V -
-Z -
-bo