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
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