[Nauty] generate graphs containing a fixed subgraph

[horsthochmut at gmx-topmail.de]

Dear Nauty users, 

I want to generate all graphs with n vertices containing a fixed subgraph of n-1 vertices. A modified version of "geng", which accepts the subgraph in g6 format as an additional input parameter and outputs all graphs containing this subgraph, would be most convenient for me. 

Did anyone already implement such a modification and would provide the code to me? 

If not I want to do it by myself, but don't know where to start. What parts of naught would I have to modify? 

Kind regards, 

Chris