C / C++ / MFC

multiple definition of.....

28-Jan-10 23:19

There is the COleDateTimeSpan class for that, see the MSDN example: "Elapsed Time: Automation Classes".
Smile | :)

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krish_kumar28-Jan-10 22:02

krish_kumar

28-Jan-10 22:02

hii
Here I give my header file and .c file

/* main.h*/

#include <stdio.h>
#include <stdlib.h>

struct linked_list{
int data;
struct linked_list *next;
};

typedef struct linked_list node_t;

void display (void);
node_t *root = 0;
----------------------------------------------------------------------
/* display.c */

#include "./../inc/main.h"

extern node_t *root;

void display ( )
{
node_t *temp = root;
while (temp -> next != root)
printf(" %d", temp->data);
}

----------------------------------------------------------------------------
while compiling it gives this error

qs2/src/display.c:8: multiple definition of `root'
obj/create.o:/qs2/src/create.c:6: first defined here
obj/display.o: In function `display':

I think this error reltes to node_t *root = 0; ,extern node_t *root;

but I dont know how to clear it ...???

seeking help ...!!

Thnaking you

CPallini28-Jan-10 22:10

28-Jan-10 22:10

krish_kumar wrote:
node_t *root = 0;

You must NOT initialize the global variable inside the header (.h) file, change it to:

node_t *root;

Then inside just one source (.c) file (e.g. create.c) initialize it this way:

node_t *root = 0;

KingsGambit28-Jan-10 22:48

28-Jan-10 22:48

If root is already declared inside the main.h file and that header is included in the display.c, then why the extern node_t *root; is declared in display.c? I think you can remove extern node_t *root; from display.c

CPallini28-Jan-10 23:05

28-Jan-10 23:05

That (probably) will not solve his problem, since (apparently) the header file is included both by display.c and create.c (incidentally this shows why you should never define a variable inside a header file).
Smile | :)

KingsGambit28-Jan-10 23:32

28-Jan-10 23:32

Yes, it is better not to declare variable inside the headers.

I was pointing out, when the header is included in the c file, it become a single translation unit. So, the unit already has the variable. Then there is no extern is required.

David Crow30-Jan-10 5:30

David Crow

30-Jan-10 5:30

Rejeesh.T.S wrote:
Yes, it is better not to declare variable inside the headers.

I think you are confusing declaring with defining.

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KingsGambit31-Jan-10 17:58

31-Jan-10 17:58

Thanks for correcting. I would have mentioned "defining". Smile | :)

member function confusion

Avi Berger29-Jan-10 8:07

Avi Berger

29-Jan-10 8:07

You have it backwards.

Your extern node_t *root; belongs in your .h file. It declares to anyone that includes it that there is such a variable that is created someplace and can be used.

Your node_t *root = 0; belongs in exactly one .c file and no .h file. It defines (creates) the variable. You only do this once. If you put this in a header file, than each .c file that uses that header would create a separate variable of that name. Those multiple variables of the same name which are globally visible and accessible would conflict with each other, hence the error multiple definition of `root'

tasumisra28-Jan-10 20:10

tasumisra

28-Jan-10 20:10

Hi Guys i have a member function and a variable .. while accessing member function can we have access the variable also....

vikas da

Cedric Moonen28-Jan-10 20:15

Cedric Moonen

28-Jan-10 20:15

Can you show with some sample code what you are trying to do. I really didn't get your question.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

CPallini28-Jan-10 21:05

28-Jan-10 21:05

tasumisra wrote:
Hi Guys i have a member function and a variable .. while accessing member function can we have access the variable also....

If you have also a C++ book, please read it. Roll eyes | :rolleyes:

On the serious side: read the f#*?in' book!
There are some rules about information hiding in C++, and what you said doesn't help us answering the question.
Smile | :)

Nelek28-Jan-10 21:59

Nelek

28-Jan-10 21:59

If you couldn't... you wouldn't be able to use Get/Set functions (a.k.a = accessing a function that access the variable)

If that is not the answer you expected, then ask something ~~a bit~~ quite more concrete

Regards.
--------
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If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
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CPallini28-Jan-10 22:05

28-Jan-10 22:05

Nelek wrote:
f that is not the answer you expected, then ask something a bit quite more concrete

May I have a Beer | [beer]

sir (plz plz urgenz)? Big Grin | :-D

Nelek28-Jan-10 22:22

Nelek

28-Jan-10 22:22

Yes of course you may have it, but not drink it Poke tongue | ;-P

drinking is not allowed at job Roll eyes | :rolleyes:

Regards.
--------
M.D.V. Wink | ;)

CPallini28-Jan-10 22:28

28-Jan-10 22:28

Nelek wrote:
drinking is not allowed at job

Nah, they allow me drinking here. They know, when drunk, I'm more productive... Big Grin | :-D

Microsoft Visual C++ Runtime Library! Stuck in the issue! What could b the way around?

Nelek28-Jan-10 23:02

Nelek

28-Jan-10 23:02

Regards.
--------
M.D.V. Wink | ;)

bilal haider28-Jan-10 20:02

bilal haider

28-Jan-10 20:02

I am stuck in the issue. When I run a multi threaded windows service during process I got following error message:

"Microsoft Visual C++ Runtime Library

Runtime Error

This application has requested the Runtime to terminate it in an unusual way. Please contact the applications support team for more information. "

The OS is Microsoft windows xp 2002 sp3. Plz tell me how can i troubleshoot the problem. D'Oh! | :doh:

What could be the cause. How can I find the problematic code? Confused | :confused:

Thanks for your time.

Re: Microsoft Visual C++ Runtime Library! Stuck in the issue! What could b the way around?

Cedric Moonen28-Jan-10 20:17

Cedric Moonen

28-Jan-10 20:17

bilal haider wrote:
Plz tell me how can i troubleshoot the problem.

Use your debugger to track down the problem.

Cédric Moonen
Software developer

Charting control [v3.0]
OpenGL game tutorial in C++

Re: Microsoft Visual C++ Runtime Library! Stuck in the issue! What could b the way around?

KarstenK28-Jan-10 23:34

KarstenK

28-Jan-10 23:34

ofetn a multi-thread versus single thread linking issue

Press F1 for help or google it.
Greetings from Germany

VS2008 EXE not working in another machine

Anu_Bala28-Jan-10 19:36

Anu_Bala

28-Jan-10 19:36

Hi,
I developed my application in VS2008,.Net framework version 3.5 SP1.

Its runs in my machine.But when i run it in another machine its not running.It shows the error

This application has failed to start because the application configuration is incorrect.Reinstalling the application may fix the problem

In that machine VC++6.0 is installed.

How can i avoid this error?
I have to send this applciation to client.I dont know whether they have VS2008

Anu

Re: VS2008 EXE not working in another machine

KingsGambit28-Jan-10 20:28