Re: Converting Type Characters to type string

[Adam Beneschan <adam@irvine.com>]

On Mar 31, 1:26 pm, Maciej Sobczak <see.my.homep...@gmail.com> wrote:
> On 31 Mar, 17:41, Adam Beneschan <a...@irvine.com> wrote:
>
> > I almost never use single-character input.  The only time I would want
> > to is if, for some reason, you need the program to react immediately
> > to some key that's typed in (other than Return or Enter).  E.g. I've
> > written programs that will do something interesting if the user
> > presses the up-arrow or down-arrow keys on the keyboard.
>
> How did you do this?
> Normally, the operating system (the terminal, actually), isolates the
> process from all such things and feeds the complete line of text to
> the process' input queue *after* it is committed by Enter. The program
> has no way to react to individual keystrokes.

No, any decent OS would provide a way to input immediate keystrokes.
On Linux, I think it involves a call to either ioctl() or
tcsetattr()---I don't remember---to turn off the OS's complete-line
handling.

As Georg pointed out, Get_Immediate is available in Ada to do this for
you.  Actually, I may have written this program before Ada 95 was
available, which meant that Get_Immediate wasn't available, so
something tricky had to be done.  But my program still uses
Text_IO.Get.  Of course, whatever I did is non-portable.

Anyway, I'm a bit sorry I mentioned this, because it has nothing to do
with the point I was trying to make.

                                  -- Adam