\directlua0{
function open_font (calledname, size)
    texio.write_nl(' ')
    texio.write_nl(calledname)
    texio.write_nl(' ')
    texio.write_nl(' ')
    return font.read_tfm("cmr10", size)
end

callback.register('define_font', open_font)
}

\font\foo="first strage/B:ehaviour" \foo

\font\bar="[second-strange]/B:ehaviour"\bar 

\bye
