[TUHS] V9 shell [was Re: Warner's Early Unix Presentation]

Doug McIlroy doug at cs.dartmouth.edu
Tue Feb 11 13:32:58 AEST 2020

> What i like is the autocorrect feature in v8:
> $ cd /usr/blot
> /usr/blit
> $ pwd
> /usr/blit

Here I am, editor of the v8 manual and unaware of the feature.
We now know that silent correction is a terrible idea.

Postel's principle: "be conservative in what you do, be liberal
in what you accept from others" was doctrine in early HTML
specs, and led to disastrous disagreement among browsers'
interpretation of web pages. Sadly, the "principle" lives on 
despite its having been expunged from the HTML spec.

Today's "langsec" movement grew out of bitter experience
with malicious inputs exploiting "liberal" interpretation of
nonconforming data.

Today's NYT has an article about fake knockoffs of George Orwell
for sale on Amazon.  It cites an edition of "Animal Farm"
apparently pirated by lowgrade OCR autocorrected and never
proofread. One of the many gaffes is that every instance of
"iv" beame ChapterIV, as in "prChapterIVacy".

I didn't like some Lisp systems' DWIM (do what I mean) when I
first heard about the feature, and I like it even less 40-some
years on. I would probably have remonstrated with Rob had I
realized the shell was doing it.


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