Hi Denis,
> The man page for 'grops' mentions "ttftot42" but this program is now
> obsolete and won't compile out of the box. (it is not in my Linux
> distribution). I did find "ttftotype42" in the distribution, part of
> package lcdf-typetools. It does not generate AFM, but there is a
> program "ttf2afm" which does.
I have no idea if these are suitable.
$ pkgfile -vr '.*ttf.*42'
extra/texlive-bin 2019.51075-2 /usr/bin/ttftotype42
extra/texlive-bin 2019.51075-2 /usr/share/man/man1/ttftotype42.1.gz
$ pkgfile -vr '.*ttf.*afm'
extra/texlive-bin 2019.51075-2 /usr/bin/ttf2afm
extra/texlive-bin 2019.51075-2 /usr/share/man/man1/ttf2afm.1.gz
$
I'm using Arch Linux, but I assume the matching package on your distro
will also have them.
--
Cheers, Ralph.