Date: Wed, 30 Apr 1997 02:17:19 -0400 (EDT)
From: Michael Phelps <morphine AT hops DOT cs DOT jhu DOT edu>
To: maf01028 AT acan DOT net
cc: djgpp AT delorie DOT com
Subject: Re: VERY basic question
In-Reply-To: <5k688j$2vp$1@newserve.gulftel.com>
Message-ID: <Pine.GSO.3.95.970430020942.13642A-100000@hops.cs.jhu.edu>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
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On 30 Apr 1997 Robert DOT L DOT Mackey AT delorie DOT com wrote:

> I am using DJGPP V2.01and RHIDE. I have been using them for 3 days. 
> I have tried to teach myself c and c++. I wrote a standard "Hello, World"
> program, and it chrashed. I was running under a DOS box in W3.1 so I 
> wouldn't have to fool with DPMI. The program is as follows.

Windows provides _only_ DPMI for DOS boxes.  In DJGPP V2, you have no
choice but to use DPMI.  

> #include "include/stdio.h"
> void main() {

suggest:  int main() { /* operating system wants an int returned */

>       printf("Hello World", %s);

oops...you're passing "%s" where:
	a)  no variable "s" has been declared
	b)  the function is expecting the address of a string

Instead, try something like:
	char	s[] = "Hello world";
	printf("%s\n", s); /* "%s\n" means "print a string, then newline*/
	/* s is the address of the array called "s" */

	return 0; /* if you declared int main(), need to return an int */ 
> }
> First it complained about a file, include/sys/djtypes.h, which it said
> was missing. (It wasn't.) I played around with <>s and "" and finally 
> got that fixed.  Then it said somthing about a parse error before the %.
> Finally, it compiled. I ran the program and got shot back to windows,
> where it said HELLO.EXE had violated system integrity. HOW DOES 
> "HELLO, WORLD" VIOLATE SYSTEM INTEGRITY. Any thoughts?
> 
> Also, I downloaded the C++ compiler and library files. The library files
> say I have to run a makefile or something like that. How do I do that?

Huh?  Just unpack the .zip files, call the setdjgpp program, and compile
with gxx for C++ programs (just append ".cc" or ".C" (uppercase) or ".cpp"
for C++ programs).

> 
> Also, I learned the syntax and rules and all that.. Now what do I do
> with this? I can't think of any programs to write. I don't know 

Get a good C programming book.

> any graphics or anything like that Any tips for a beginner?
> 
> PLEASE REPLY TO maf01028 AT acan DOT net. DON'T HIT REPLY! Thanks a lot for the help.
> 
> David Mackey.
>