Using the `t_name_to_handle_at` and `t_open_by_handle_at` helpers provided in the Linux manual page:
```
bash-4.2# echo "hello" > test.txt
bash-4.2# /opt/name_to_handle/t_name_to_handle_at test.txt > fh
bash-4.2# /opt/name_to_handle/t_open_by_handle_at /dev/null < fh
Read 6 bytes
bash-4.2# stat --printf="%i\n" test.txt
2731679
bash-4.2# rm test.txt
bash-4.2# echo "hello" > test.txt
bash-4.2# stat --printf="%i\n" test.txt
2731680
bash-4.2# /opt/name_to_handle/t_open_by_handle_at /dev/null < fh
open_by_handle_at: Stale file handle
```
So, that basic functionality seems to work as expected.
Note that the explicit `/dev/null` is provided to prevent `t_open_by_handle_at` from grubbing around in `/proc/self/mountinfo` for a matching mount_id, which is not something we provide in linprocfs yet. And our open_by_handle_at does not care about the `mountfd`, so any old fd works. Linux programs obviously can't rely on that property, so at some point we would need to implement `mountinfo` to better support these syscalls.