[TUHS] Remember the ed thread?

John Cowan cowan at ccil.org
Tue Mar 30 10:11:21 AEST 2021

On Mon, Mar 29, 2021 at 11:59 AM Norman Wilson <norman at oclsc.org> wrote:

> The b command (stands for browse) came from late-1970s
> U of T; rob probably brought it to 1127.

It's little things like this that make me use ex rather than ed, though it
is spelled z there.  Linux ed has z as an extension.

> There were a
> handful of other syntactic conveniences, like being
> allowed to leave off the final delimeter of an s command,
> and declaring that a missing address means 1 before the
> comma or semicolon and $ after, so
>         3,s/fish/&head
> works over all lines from 3 to the last, and , standing
> alone addresses the whole buffer.

Those things are in Posix now.  Linux ed is a superset of Posix; *BSD ed is
rather lacking, being based on an old SVID.

> Also the idea that s followed by a digit N means start
> with the Nth instance of the pattern:
>         s3/fish/&head/
> affects only the third fish, and
>         s3/fish/&head/g
> every fish after the second.

That's neither Posix ed nor ex, and very annoying it is to lack it.

> b.  The > < | commands, [...] make qed into a kind of workbench,
> both for massaging data and for constructing a list
> of commands to send to the shell.
> I gather current Linux/BSD eds have > and <, spelled
> r ! and w !, but without | it just ain't the same,
> rather like the way | revolutionized the shell.

Ex extends the ! command to accept numeric arguments and has the same
semantics.  Unfortunately, although "r !" and "w !" are in both Posix ed
and ex, in ex "w !foo" means "output to the foo command" whereas "w! foo"
means "write to foo, ignoring the internal 'don't overwrite' bit that you
can set."

I wrote two specs that may be of interest to someone:

<https://github.com/johnwcowan/exx/blob/master/exx/exx-features.txt> was my
attempt to describe "ex extended" that could still be a lightweight editor
by not needing the vi bag on the side.

<https://github.com/johnwcowan/exx/blob/master/sam/sam-extensions.txt> is a
list of things that make me not want to use sam -d editing until they are
provided in some form.

John Cowan          http://vrici.lojban.org/~cowan        cowan at ccil.org
On the Semantic Web, it's too hard to prove you're not a dog.
        --Bill de hOra
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