The 'from' and 'to' points are entered by mouse into the map displayed in the GRASS monitor, or if the coordinates option is used they can be specified non-interactively. The actions bound to the mouse buttons are described in the terminal window when running the command.
To calculate shortest path non-interactively and save the path to a new vector map, use the v.net.path module.
g.region vector=roadsmajor -p d.vect roadsmajor d.path roadsmajor coordinates=668646.15,224447.16,668348.83,235894.02
Non-interactive shortest path routing on road network (North Carolina sample dataset):
d.path -b roadsmajor coordinates=668646.15,224447.16,668348.83,235894.02
Last changed: $Date$