These questions

        1.  Aren't germane to the C and C++ languages.
        2.  Are in direct violation of the comp.lang.c and comp.lang.c++
                charters.
        3.  Should be covered in any Unix programming FAQ (try
                ftp://rtfm.mit.edu under usenet-by-groups for comp.unix.*)

curses is the easiest, although you could match the strings given
by termcap/terminfo.

A lot of shells run the tty in "cooked" mode.  Among other things, this
results in input being fed to you a line at a time, and the tty
driver allowing basic line-editing using user-specified characters
(in this case, it's the erase character).

In some cases, the back-space key is mapped to the delete character.  If
erase is set to ^H,  the delete will be passed through to the application.

You use the GNU readline library.

Use "raw" mode and do your own handling of erase/kill/etc.

--
If a President of the United States ever lied to the American people he
should resign," --- William Clinton, 1974 while running for the US House of
Representatives responding to a question about President Nixon.

Hi,

I'm trying to develop a small application that is interactive in the
same way as, say, gnuplot.The user types commands at a command prompt.
The only thing I know how to use is scanf. So I would like to learn
answers to the following questions.
(I understand that answers to some of these questions maybe quite
involved so please feel free to direct me to a source rather than answer
the question!)

1) How to read "arrow" keys.
2) I notice that in certain shells backspace works, in others doesn't.
What parameter or variable is responsible for that?
3) How do I enable emacs bindings?
4) I don't know if this is a tcsh feature (which is the shell that I
prefer), but my shell stops taking input either after 1024 or 2048
characters. How do I change that?

I know it's quite obnoxious to ask 4 questions in the same message, so
sorry and thanks a lot in advance!

Pavel

Don't use scanf().  Ever.  If you must do something similar, use
fgets() and sscanf().  This prevents scanf() reading right over the
newline in order to satisfy an input and confusing the poor person
typing at it.

Use the "readline" library.

All of them should understand the setting used in your stty(1)
settings, but some of them are set up to understand both ASCII 8
(backspace) and ASCII 127 (delete) as "delete the last character".

Use the GNU "readline" library.

But your program has nothing whatsoever to do with the shell.  The
shell's limitations will not be the limitations of your program.
There is no need to worry about that issue.

I wouldn't say it's obnoxious.   It's certainly bandwidth-efficient.
At least the 4 questions were related...

--

I wont (but could :)  get into too much detail...just check out the CURSES
library on your unix box.  All of this not defined by Standard C++.

--
<<<<<<<<<<  Blue Skies  >>>>>>>>>>>
<        Michael J. Tobler        >

< remove "no-spam-" when replying >
<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>

Curses is overkill and will drive you mad for such a simple task.
The GNU readline library is exactly what you need.

Steve.