I am following Mike Bostock's D3 Lets make a map to create GeoJSON for states and provinces of a country. I got a shapefile for states and provinces from Natural Earth. I am trying to extract info for India with this command:
ogr2ogr -f GeoJSON -where "ADM1_A3 IN ('IND')" subunits.json ne_10m_admin_1_states_provinces.shp
Here is the error:
GeoJSON driver failed to create subunits.json
Is there any ISO country code for Admin-1 level?