gdal_proximity(1) on Linux
The text dfca3a323c18, as Debian 9 (Stretch) shipped it.
produces a raster proximity map
Flags it lists
-
-co -
-distunits -
-dstband -
-fixed-buf-val -
-maxdist -
-nodata -
-of -
-ot -
-srcband -
-use_input_nodata -
-values