That was done by Tom Duff, I believe before he came to Bell Labs. I might have brought the idea with me from Toronto. The code, or at least a simple version of it, is in The Unix Programming Environment starting around page 208. We credit Tom in the endnotes for the chapter. -rob On Mon, Jan 4, 2021 at 8:00 PM Ed Bradford &lt;egbegb2(a)gmail.com&gt; wrote: > 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 > Pflugerville,TX > egbegb2(a)gmail.com > > 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 < > m.douglas.mcilroy(a)dartmouth.edu&gt; 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. >> >> Doug >> > > > -- > Advice is judged by results, not by intentions. > Cicero > >

I also remember a program that was kicking around WH and MH called grope(1) that IIRC used the algorithms in the code for the 411 operators. Was that related? I do remember is that had a separate dictionary from spell and ispell that was stored in /usr/lib/grope/[a-z]/mumble ᐧ On Mon, Jan 4, 2021 at 4:08 AM Rob Pike &lt;robpike(a)gmail.com&gt; wrote: > That was done by Tom Duff, I believe before he came to Bell Labs. I might > have brought the idea with me from Toronto. The code, or at least a simple > version of it, is in The Unix Programming Environment starting around page > 208. We credit Tom in the endnotes for the chapter. > > -rob > > > On Mon, Jan 4, 2021 at 8:00 PM Ed Bradford &lt;egbegb2(a)gmail.com&gt; wrote: > >> 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 >> Pflugerville,TX >> egbegb2(a)gmail.com >> >> 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 < >> m.douglas.mcilroy(a)dartmouth.edu&gt; 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. >>> >>> Doug >>> >> >> >> -- >> Advice is judged by results, not by intentions. >> Cicero >> >>