moddeps.erl

-module(moddeps).
-compile(export_all).


write_to(Filename) ->
    xref:start(s),
    xref:add_directory(s, "ebin"),
    {ok, Calls} = xref:q(s, "XC"),
    Mods = [{From, To} || {{From,_,_}, {To,_,_}} <- Calls],

    A2L = fun atom_to_list/1,
    file:write_file(Filename,
        ["graph G { \n"
        , [[$\t, A2L(From), " -- ", A2L(To), " ; ", $\n]
            || {From, To} <- Mods]
        , " }\n"]).

Since second argument of write_file is iodata(), this should work as well.