Where Goeth the Line-editing? (was Re: Strangeness in shell)

[Jim Webb]

In article <13303 at bloom-beacon.MIT.EDU>, jik at athena.mit.edu (Jonathan I. Kamens) writes:
>   In multics, it was possible to install a driver that lived at the
> gateway between the actual terminal and user processes.  This driver
> would intercept and process *all* input before sending it to the
> process.  Therefore, if you wrote a line-editing driver and installed
> it, it would work for *every* program on the system, without fail.
> There were, of course, ways to turn off the line-editing features for
> programs that needed character-by-character input.


This is *exactly* what a streams module does in SVR3 and beyond. 
For example, when you are talking over a streams based tty line,
you are talking thru a streams module that handles backspaces, and
kill characters, and tabs, and the like.  It then sends the data
to the process when it gets the end of line character.  So, it would
be fairly trivial to code up a streams driver to do the line editting
we all like in ksh, provided you wanted to keep your history in kernel
space at least :-)


-- 
Jim Webb                "Out of Phase -- Get Help"               att!mtune!jrw
#include <std/disclaimer.h>                                  jrw at mtune.att.com