Unbuffered line input and the GNU library

Unbuffered line input and the GNU library

[Steve Dondley]

I'm new to C, learning from a beginner's book.  The book mentions in passing
that unbuffered line input can be accomplished with the non-standard getch()
function.  However, I did a grep on every *.h file on my computer and wasn't
able to locate the function's declaration.  A message in this list's archive
hinted that getch() might be in the 'ncurses', 'curses', or 'termcap' header
files.  However, these don't seem to exist in my library either.  I looked
on the web for some kind of documentation for getch() and that proved
fruitless as well.  So I have some basic questions:

1)  Where are all the GNU C library functions documented?

2)  Where can I download the GNU C library functions from and how do I
install them?  I tried 'apt-get install ncurses' but I got some funky
message about ncurses being obsoleted or not available.

3)  If I'm going in the wrong direction, my question is: How do you perform
unbuffered line input with the GNU C library.

I'm running Debian/Woody, GCC version 2.95.4 (Debian prerelease).

Re: Unbuffered line input and the GNU library

[Ish Rattan]

On Mon, 19 Aug 2002, Steve Dondley wrote:

> function.  However, I did a grep on every *.h file on my computer and wasn't
It is a macro defined in /usr/include/stdio.h

-ishwar

Re: Unbuffered line input and the GNU library

[Claudio Bley]

>>>>> "Ish" == Ish Rattan <ishwar@pali.cps.cmich.edu> writes:

    Ish> On Mon, 19 Aug 2002, Steve Dondley wrote:
    >> function.  However, I did a grep on every *.h file on my
    >> computer and wasn't
    Ish> It is a macro defined in /usr/include/stdio.h

I can't find it there (glibc 2.2.5 Debian GNU/Linux). What's the
version of your C library that you're using?

Usually, in order to get unbuffered line input you need to switch the
terminal to unbufferd input mode (and properly restore it when done -
I guess this wouldn't work with a simple macro; I'd really like to see
the macro if it really is there).

Here's some code I used for this purpose:

,----
|   struct termios tio_orig;
|   struct termios tio_new;
| 
|   tcgetattr(0, &tio_orig);
| 
|   tio_new = tio_orig;
|   tio_new.c_lflag &= ~(ICANON|ECHO); /* Clear ICANON and ECHO. */
|   tcsetattr(0,TCSANOW,&tio_new);
|   
|   /* ... */
| 
|   tcsetattr(0,TCSANOW,&tio_orig);
`----

Cheers.

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