Sender: nate AT cartsys DOT com
Message-ID: <37053889.962F1C17@cartsys.com>
Date: Fri, 02 Apr 1999 13:37:13 -0800
From: Nate Eldredge <nate AT cartsys DOT com>
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To: djgpp AT delorie DOT com
Subject: Re: Runtime error for compiled c program
References: <Pine DOT GSO DOT 3 DOT 96 DOT 990402143715 DOT 19475C-100000 AT morgan>
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Reply-To: djgpp AT delorie DOT com

Derek Gordon wrote:
> 
> Dear djgpp guru:
> 
> Hello - my name is Derek Gordon, and I have been using the djgpp compiler
> for some time now. A few days ago, a colleague asked me to recompile a
> c program using some new ( and larger) program constants. I did so - the
> name of the program is makeped.c, and so I typed
> 
> gcc makeped.c -o makeped.exe
> 
> The program compiled ok. The executable "makeped" has a command line flag,
> "n" which refers to loops in a pedigree. When I run the program with "n"
> flag, I get no errors - the program runs fine. When I run without the
> flag, I receive the following error (even though the desired output file
> is produced):
> 
> General Protection Fault at eip=00004f4c
> eax=00000000 ebx=00069200 ecx=00088000 etc.
> 
> What is the source of this error? How may I correct it?

It's almost surely a bug in your program.  See FAQ section 9.2 for how
to interpret this dump.

At a guess, I would suspect your code assumes an argument on the command
line as argv[1].  When it isn't given, argv[1] will be NULL, and trying
to dereference that pointer will crash.  But it could also be something
else entirely.
-- 

Nate Eldredge
nate AT cartsys DOT com