Re^2: Strangeness in shell (really shell history discussion)

[Guido van Rossum]

Doug Gwyn writes:

>The terminal shouldn't know what a "command line" is.  Therefore it
>shouldn't be making this distinction.  I snarf&barf text freely between
>editor displays, command lines, and other text sources/sinks all the time.

I thought we were talking about command line history here, not about
general cut&paste (I assume that's what you call "snarf&barf").
Of course, there should be a way to copy&paste anything on the screen
(or from the scrollback buffer, for that matter).

But command line history is a more specialized feature, which recognized
that you are much more likely to type commands that are similar to ones
you typed earlier.  It therefore remembers previous commands even when
they have long disappeared from the screen or scrollback buffers, and
offers a specialized interface to access them quickly. 

The ideal history mechanism sits somewhere between the terminal and the
application; it should see lines exactly as they are input by the
application.  If the application is not reading text on a line-by-line
basis, the history mechanism should be clever enough not to store those
bits of input; in Unix, cbreak or raw mode would be a reasonable hint. 

Unfortunately, the best history mechanisms I've seen get their leading
edge from knowing the input syntax of the application (usually a shell)
and are thus less easily generalized.  Come to think about it, the only
other type of program for which I still use a command line interface (as
opposed to a vi-, Emacs- or X11-style interface) are debuggers.  Are
command line interfaces going out of style?

--
Guido van Rossum, Centre for Mathematics and Computer Science (CWI), Amsterdam
guido at cwi.nl or mcvax!guido or guido%cwi.nl at uunet.uu.net
"You're so *digital*, girl!" -- Neneh Cherry