[TUHS] regex early discussions

Larry McVoy lm at mcvoy.com
Mon Mar 4 13:38:45 AEST 2024


Marc is right.  I'll add that I grew up in terminal rooms, a bunch of
kids connected to a VAX 780, like 40 or more.  I have no idea how the
kids ahead of me learned but I learned by looking at their terminal
and going "what did you just do?".

My real understanding of regex is from Henry Spencer's regex.

On Sun, Mar 03, 2024 at 07:03:39PM -0700, Marc Rochkind wrote:
> Will, here's my recollection, when I got to UNIX in late 1972 or
> thereabouts:
> 
> First, there was ed. grep and sed were derived from ed, so came along
> later. awk came along way later.
> 
> There were only manual pages. You typed "man ed" and there it was. The man
> pages were very accurate, very clear, and very authoritative. Many found
> them too succinct, especially as UNIX got more popular, but all of us back
> in the day found them perfect. Maybe you had to read the man page a few
> times to understand it, but at least that's all you had to read. No need to
> hunt around for more documentation!
> 
> (Well, there was more documentation: The source code, which was all online.
> But reading the ed source to understand regular expressions was impossible.
> It was in assembler, and Ken was generating code on the fly as the
> expression was compiled.)
> 
> Also, it should be noted that ed produced a single error message: a
> question mark. No wasting of teletype paper!
> 
> The motivation for learning regular expressions was that that's how you
> edited files. ed was the only game in town.
> 
> (sh used a greatly restricted form of regular expressions, which were
> documented on the sh man page.)
> 
> Marc Rochkind
> 
> On Sun, Mar 3, 2024 at 6:31???PM Will Senn <will.senn at gmail.com> wrote:
> 
> > Hi All,
> >
> > I was wondering, what were the best early sources of information for
> > regexes and why did folks need to know them to use unix? In my recent
> > explorations, I have needed to have a better understanding of them, so I'm
> > digging in... awk's my most recent thing and it's deeply associated with
> > them, so here we are. I went to the bookshelf to find something appropriate
> > and as usual, I've traced to primary sources to some extent. I started with
> > Mastering Regular Expressions by Friedl, and I won't knock it (it's one of
> > the bestsellers in our field), but it's much to long for my personal taste
> > and it's not quite as systematic as I would like (the author himself notes
> > that his interests are less technical than authors preceding him on the
> > subject). So, back to the shelves... Bourne's, The Unix Environment, and
> > Kernighan & Pike's, The Unix Programming Evironment both talk about them in
> > the context of grep, ed, sed, and awk. Going further back, the Unix
> > Programmer's Manual v7 - ed, grep, sed, awk...
> >
> > After digging around it seems like folks needed regexes for ed, grep, sed
> > and awk... and any other utility that leveraged the wonderful nature of
> > these handy expressions. Fine. Where did folks go learn them? Was there a
> > particularly good (succinct and accurate) source of information that folks
> > kept handy? I'm imagining (based on what I've seen) that someone might cut
> > out the ed discussion or the grep pages of the manual and tape them to
> > their monitors, but maybe I'm stooopid and they didn't need no stinkin'
> > memory device for regexes - surely they're intuitive enough that even a
> > simpleton could pick them up after seeing a few examples... but if that
> > were really the case, Friedl's book would have been a flop and it wasn't
> > :). So seriously, if you remember that far back - what was the definitive
> > source of your regex knowledge and what were the first motivators for
> > learning them?
> >
> > Thanks,
> >
> > Will
> >
> 
> 
> -- 
> *My new email address is mrochkind at gmail.com <mrochkind at gmail.com>*

-- 
---
Larry McVoy           Retired to fishing          http://www.mcvoy.com/lm/boat


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