Thank you for responding. My recollection is that one of your
folks put the spelling corrector into the shell so when I typed
the wrong letters for a directory or file, the spelling correct
would help. It was particularly noticible in the "chdir - cd" shell
command. Do you recall any such person and if so, did he (and it
was a he) use Peter's work?

There was a distance algorithm that was far better than anything I've seen
since. Yes, please send me Peter's contact information.

I am

Ed Bradford, Ph.D. Physics, retired from IBM

PS: We chatted sometime in 1980 or so about
adding database capabilities to the interactive
environment. I was interested in adding it to
the Bourne Shell at the time.

On Sun, Jan 3, 2021 at 2:23 PM M Douglas McIlroy <> wrote:
> I was a BTL person for 8 years between 1976 and 1984. During
> that time there was a spelling corrector that was better than
> anything I see today. There was a concept of "spelling distance"
> that corrected a whole bunch of stuff that even today cannot be > corrected.

> Who in that era worked on spelling correction at BTL. I was at
> Columbus BTL (1976-1979) and Whippany BTL (1979-1984).

Peter Nelson made an interface to spell(1) that showed putative errors in context. I believe it could suggest corrections. I remember the project; I installed hooks for it in spell(1). I don't remember the date, but it would probably not have been early enough for you to have used it in Columbus.

If there's a chance that Peter's program is the one you remember
and you'd like to get in touch with him, I can give you his
email address.


Advice is judged by results, not by intentions.