NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part1/321

Text File | 1996-08-05 | 5.5 KB | 215 lines

Newsgroups: comp.lang.c
Path: news.kei.com!wang!news
From: [e-mail] (Kohn Emil Dan)
Subject: Re: EMM386 Problem - main.c (0/1)
Organization: Technion, Israel Institute of Technology
Date: Thu, 4 Jan 1996 12:00:16 GMT
Message-ID: <[e-mail]>
Sender: [e-mail]



On Wed, 3 Jan 1996, Paul Anderson wrote:

> "Ian G. Crozier" <[e-mail]> wrote:
>
> >[e-mail] (Paul Anderson) wrote:
> >>I'm writing a menu program, I don't have much of it done yet, but on
> >>running the exec of what I have done I get EMM386 Exception error #12
> >>or #06.  I use Watcom's compiler.  I've attached the source.
> >>
>
> >I'm not surprised that you're having problems with your program.
>
> >You've posted NINE messages, none of which give any useful information
> >about your code!!
>
> Uh-ohhhh.......  Sorry, mail reader hickup...  Some of them where
> supposed to have the source attached, but, I can't change the
> encoding!!!  I can just import the source, and here goes:
>
> /*
>       A menu prog, I am bored, so, why not put in *MY* bid to take
>       the place of MM?  Oooohhhh....  Let's see,
>       We want lots of configurability.  Igor!  Bring the config
> files!
> */
>
> #include <stdio.h>
> #include <stdlib.h>

 #include <string.h>
             ^-------------if you want to follow my advice, then you'll
                           have to include this, too

> #include "menu.h"
>
> main(int argc, char *argv[])
> {
>       int i=1;

>       /* Engage command-line parser! */
>
>       if (argc == 1) {
>               printf("\a\nUuuuhhhhh... Yer supposed to tell me the
> config file name.");
>               exit(0);
>               }
>       /* Okey-dokey, got that down, let's plop up the for loop.*/
>       while(0==0)  /* Index=2(i.e. second param, first is: menu.exe)
> Up Mr. Index. */
>       {
>              /* printf("%s", argv[i]);*/
>              /* Bug test... */
>              /*i=i + 1;*/
>              /* We only need the config file name, nothing else. */
>              /* Remember, include config file var def in h file. */
>              config=fopen(argv[i], "r" );
>              if (config == NULL)
>                       {
>                       /* Uh-oh...  *BIG* problem... */
>                       printf("\a\nError: Unable to open config file
> %s!", argv[i]);
>                       printf("\nRead docs for help.");
>                       exit(1);
>                       }
>              /* Now, let us test the error. */
>
>              i=loadcnf(config);
>              exit(0); /* Exit prog...*/
>
>       }
>        /*Let's roast this sucker....*/
> }
>
> atexit()
> {
>       fclose(config);
>       return 0;
> }
>
> /* Config file data loader. */
>
> int loadcnf(FILE *in)
> {
>       char indata[40];
>       int tmp;
>       /* Struct defed in menu.h... */
>       fscanf(in,"%s", &indata);
>       if (indata=="ON")
        ^-----------Here you are comparing the address of the
                first element of indata to the address
                of "O" in "ON". I don't think they will
                ever be equal

                You should use
                if (strcmp(indata,"ON")==0)
                instead of your if statement
>               {
>               tmp=1;
>               }
>               else
>               {
>               tmp=0;
>               }
>       /*Parms.Color = tmp;*/
>       /*indata="";*/
>       fscanf(in, "%s", &indata);
                         ^------Don't use the & here: indata as a
                parameter to fscanf is a pointer to its
                first  element (a char*, exactly what you need
                This applies to all your usages of fscanf
                           ^----Data is read in indata
>       Parms.EntryOne = indata; /* The beginnings of a long and
                     painful process...*/
                         ^-----EntryOne points to the first character of
                                        indata
>       /*indata="";*/
>       fscanf(in, "%s", &indata);
                         ^-----new data is read into indata
                               Now Params.EntryOne will point to the new
                value that is stored in indata
>       Parms.EntryOnePath = indata;
            ^------Params.EntryOnePath points to the same
                place, wherer Params.EntryOne Points
.
.
.


After your assignments, all the Params fields will point to the same place:
the last value read by fscanf in indata. I don't think this is what you
wanted.


In order to corrrect the problem, replace the assignmnents like this:

Instead of
Params.EntryOne=indata;

use:

if((Params.EntryOne=malloc(strlen(indata)+1))==NULL)
    {
        fprintf(stderr,"Not enough memory\n");
    exit(1);
    }
strcpy(Parrams.EntryOne,indata);



OR

redeclare  the fields in the Parms struct to be char[40] instead of
char*, and  instead of

Params.EntryOne=indata;

use

strcpy(Params.Entryone,indata);




>       /* YESSSSSSS!!!!!  I am *DONE* setting up the config
> reader!!!*/
>       return 0;
> }
> And the header file:
>
> /* Filling garbage...*/
> FILE *config;
> struct
> {
>       int *Color;
>       char *EntryOne;
>       char *EntryOnePath;
>       char *EntryTwo;
>       char *EntryTwoPath;
>       char *EntryThree;
>       char *EntryThreePath;
>       char *EntryFour;
>       char *EntryFourPath;
>       char *EntryFive;
>       char *EntryFivePath;
>       char *EntrySix;
>       char *EntrySixPath;
>       char *RegName;
> } Parms;
>
> int loadcnf(FILE *in);
>
> /*Parms data;*/
>
> Sorry for the mistake!!!  TTYL!
>
>

Hope that this helps.


                    Best regards,

                                    Emil