From:	"Fred" <see AT body DOT of DOT mess>
Newsgroups:	comp.os.msdos.djgpp
Subject:	getch() problems please help
Date:	Thu, 20 Nov 1997 13:28:34 +1100
Organization:	ANS Communications Pty Ltd
Lines:	65
Message-ID:	<879992901.96859@gigi.ans.com.au>
NNTP-Posting-Host:	gigi.ans.com.au
Cache-Post-Path:	gigi.ans.com.au!unknown AT 203 DOT 56 DOT 162 DOT 33
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Hi,

I'm using DJGPP in a win95 dos box.


/* getchar input routine */
#include <stdio.h>
#include <CONIO.h>

main()
{
char input[20];
int i = 0;
cprintf ("You:");
        while (input[i - 1] != 13)
        {
             if (input[i - 1] == 8)
             {
             i--;
             }
             if (i == 19)
             {
              cprintf("\b");
              i = 18;
             }
         input[i] = getch();
         cprintf("%c", input[i]);
         i++;
        }
        input[i] = 0;
        printf ("\n%s", input);
}


Okay, what I'm 'trying' to accomplish here is get a string from the user.
I'm having trouble with the backspace part:
                if (input[i - 1] == 8)
                 {
                 i--;
                 }
It is a little hard to explain what happens when I run it, so if you could
compile and run it yourself, you will get a better idea of what the problem
is.

Basically, if you type in a few chars, backspace a few, type more,
eventually it will stop allowing you to type more chars, as it should with
the:

                    if (i == 19)
                     {
                      cprintf("\b");
                      i = 18;
                     }

which just makes the character overwrite itself when you have reached the
limit of the input[] array. However if you use backspaces in the dos box, it
might start doing this after only about 5 characters have been displayed.
However the output shows that it has been taking in what you have been
typing as the input[] array contains the 19 chars as it should.

Any ideas?

- Raw text -