Type-ahead in unix

[Alex Martelli]

torek at elf.ee.lbl.gov (Chris Torek) writes:
	...
:True ... but deferred echo is not the way to do this.  Deferred echo
:is even more broken than immediate echo.  The *only* right thing is
:immediate-echo-unless-it-would-not-be-echoed-when-read followed by
:drag-user-echo-along-in-front-of-output.  That is, if you type
	...
:Now, if I had a GNOT, I would get `sliding echo-ahead' `for free',
:which solves most of the problem---password typeahead is very rare and
:`do not echo if future events would cause this not to be echoed' is an
:unreasonable demand.  Or I could use Emacs, which almost gets it right

An IBM 3270 under VM/CMS almost "gets it right", too, most of the time:
the bottom two lines are used as an 'input pad' where you can (locally,
in the terminal/controller) edit one logical-line worth of "future
input" (with echo) - however, when you "Enter" this input, it goes to
the system, which 'stacks' it (without re-echoing it until it is 
asked for - and the application can choose to explicitly 'flush' and
reject typed-ahead lines).  The editing capability of the terminal and
controller is really too limited, one line is far too little, etc, but
I believe the "separate input pad" approach was later adopted and
generalized in Apollo workstations.  I wouldn't mind, for many apps,
a variation of xterm that would give me a separate "input preparation"
text-editing widget (I know, I know, I can almost fake it with
xclipboard or whatever, and using selections, but...).
Yup, I know, GNOTs are far more elegant, but I surmise there are more
Apollos, X servers, and 3270s around (probably in increasing order of
abundance?) than GNOTs...

-- 
Alex Martelli - (home snailmail:) v. Barontini 27, 40138 Bologna, ITALIA
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