Date: Sat, 27 Apr 1996 22:28:13 -0400 (EDT)
From: "Y. Lazarovitch" <yitzg AT haven DOT ios DOT com>
To: djgpp AT delorie DOT com
Subject: more cgets() problems...
Message-ID: <Pine.BSD.3.91.960427221413.9616A-100000@haven.ios.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

I had a program that sits in a loop  and gets and prints input using the 
cgets/cprintf functions. When I would hit an arrow key, it would seem as 
if cgets stops taking input, and after a few seconds I would get a 
"general protection" error and the program would crash. This small 
program, although it doesn't cause a GPF (it was probably some other 
part of my program that caused it) does show that cgets(), once it gets 
an arrow key, continues "getting" some kind of input, and stops when it 
reaches the maximum characters specified, and when cgets() is called 
again, it still gets the same garbage, and so on.

==begin==

#include <conio.h>
#include <stdio.h>

int main()
{
    char input[10];
    
    input[2] = 'a'; /* to fool while first time around */
    input[0] = 5;  /* cgets() uses this to know max chars to read */
 
    cprintf("Enter a max of 4 characters, 0 to stop.\r\n");
    cprintf("\r\n(Push the up arrow to see bug (?))\r\n");    

    while(input[2] != '0') {    /* first char input is in third element */
      cgets(input);
      cprintf("\r\nYou entered: %s\r\n", input + 2);  
    }                                            
    return 0;
}

==end==

Run this and you'll see the problem. 

Good day,

YL