Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!adm!Shekar_Narayanan.SV@Xerox.COM
From: Shekar_Narayanan.SV@Xerox.COM
Newsgroups: comp.lang.c
Subject: Quick C Strange Problems
Message-ID: <12170@brl-adm.ARPA>
Date: 7 Mar 88 22:11:27 GMT
Sender: news@brl-adm.ARPA
Lines: 78

Hello there,

	I am using QuickC for some development at my leisure at home. I am having the
strange problems as described below:

1) With character pointers. The code reads like this.

char *getstring(col, row, len)
int col, row, len;
{
	char *temp, *s;
	char ch;
	int count;

	gotoxy(col, row);
	clearxy(col, row);	/* clear upto end of row */
	gotoxy(col, row):
	temp = s;
	count = 0;
	for (;;)
	{
		if (count > len) return temp;
		ch = getkey(); /* get a key from user */
		if (ch == ESC) return NULL;
		switch (ch)
		{
			case CR:
				*s = ch;
				return temp;
				break;
			case BS:
				if (count > 0)
				{
				*(s --) = '\0';
				col --;
				count --;
				}
				break;
			default:
				*s = ch;
				s++;
				col++;
				count ++;
				break;
		}
		gotoxy(col, row);
		putchar(ch);
	}
}

In this code what I expect to see is that the return in "temp" should contain
the char array that "s" accumulated in the process. Instead, while debugging I
found that "temp" was pointing only to the last character in the array. Also the
char pointers temp and s are pointing to garbage string of characters from
nowhere at the first line of the program. I am not sure what is wrong here. Do I
need to forcefully do strcpy(temp, ""); to initialise the char pointers
everytime.

2) If I use the C library functions int86 to manipulate cursor and other goodies
via dos interrupt and somewhere else in the program I use direct video ram
access to write to screen then things go crazy. Is there any limitation that is
not documentated in QuickC.

3) Finally, I somehow got my program running and compiling in memory in QC
environment and when I create and exe image from QC and try to run it from dos
command line the screen just freezes and I have to reboot. I had only the stack
checking and language extensions options turned on in compiling the program. I
am not sure what is wrong.

4) I am also interested in some more information on QC library calls for Memory
resident programs  using the calls _setvec _getvec  etc . There are absolutely
no examples in the run time library documentation. 

	Would appreciate any input.

	Thanks in advance,

	Shekar