Re: Control code problems (was: Re: need 1 stripper

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On Wed, 17 Dec 2003, Lee Maschmeyer wrote:

> >I think I could make a filter with sed if I knew the
> >structure of control codes.
> 
> There ain't none! Each escape sequence has its own
> syntax which might be as simple as (not guaranteed to
> be accurate but for example purposes only) escA to
> esc[A to esc27M to whatever. You'd have to emulate a
> whole ANSI console.

There are utilities that come with ncurses that can show
these (man infocmp).  The output, for, say, one of the
more brain damaged ansi emulations, would be quite
limited -- not at all difficult for a smallish sed
script.
 
But this is only necessary for utilities that use
(n)curses.  Better yet, learn the hundreds of line
oriented text utilities that are a permanent part of
linux; well, ok, you probably won't need all of them.
And you'd certainly want to take a look at edbrowse and
Karl Dahlke's other line oriented utilities.  Karl
makes a fairly convincing case that the idea of full
screen utilities for blind users is... uh, broken.  See
http://www.eklhad.net/linux/app for his stuff.

> What's your TERM variable?
 
As intimated above, the choice of TERM variable should
be somewhat arbitrary, choosing a simple one to make
ascii conversion easy.

> I'm not on Linux right now so can't verify the
> location, but look in the terminfo directory (I don't
> think it's directly under /etc but could be wrong).
> Some file in there that specifies no capability is
> what you need; maybe /etc/terminfo/t/tty? Make sure

/usr/share/terminfo, and for the older curses,
/etc/termcap (which is human readable ascii).

> the case is right. The value of $TERM must match one
> of these files.
 
> Of course, whether Linux will fully honor such specs

Terminfo and termcap descriptions are control files,
not specs, and will always be honored, barring bugs
(and current ncurses libs are rock solid mature).
 
> is an open question since, shrill protests to the
> contrary notwithstanding, the world really is going
> GUI and those kids don't hardly know what a dumb
> terminal is, let alone condescend to use one.

While the fear that the GUI will edge out text stuff is
understandable, that's all it is, just a worry,
entertained by relative newbies.  Such comments, and
discussion threads they spawn come up so often that
someone probably needs to dig some of the real info
out of the archives, and submit it to Hans for
inclusion in the Blinux FAQ.  But for now, the archives
will have to be the answer to this one: the simple
truth is that text mode stuff is growing at an amazing
pace, not going away -- such a thing is not even
possible or likely, and any shrill suggestions
otherwise are based on pure ignorance.  If you doubt
this, browse the coreutils, and the starting menu of
"info", then follow the announcements on freshmeat.net
for a few weeks.

LCR

-- 
L. C. Robinson
reply to no_spam+munged_lcr@xxxxxxxxxxxxxxxxxxx

People buy MicroShaft for compatibility, but get
incompatibility and instability instead.  This is
award winning "innovation".  Find out how MS holds
your data hostage with "The *Lens*"; see
"CyberSnare" at
http://www.netaction.org/msoft/cybersnare.html


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