Grasshopper external launch

Grasshopper Developer
5

in case you won’t do this fully with a rhinoscript as provided in link, you could also create a custom command or you invoke it from outside with this (its c# but should be identical to c++ )

Grasshopper.Plugin.GH_RhinoScriptInterface gh;
gh = (Grasshopper.Plugin.GH_RhinoScriptInterface) Rhino.RhinoApp.GetPlugInObject("Grasshopper");

//Print(gh.GetType().ToString());

gh.DisableBanner();
gh.ShowEditor();
gh.OpenDocument("C:\\somewhere\\somefile.gh");
gh.DisableBanner();