C / C++ / MFC

vineeshV4-Jul-08 1:57

4-Jul-08 1:57

override the definition of FOPEN_MAX in your code not in stdio.h
as
#deinfe FOPEN_MAX <n> //n is the value you need to set .

vineesh

CPallini4-Jul-08 2:09

4-Jul-08 2:09

Do you really think such a #define will be of any help?
Smile | :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

vineeshV4-Jul-08 2:46

4-Jul-08 2:46

The actual definition of FOPEN_MAX in stdio.h
is

#define FOPEN_MAX 20

you can extend it to some limit (around 500)

The below code works fine

#include <stdio.h>
#include <windows.h>
#define FOPEN_MAX 500

FILE *stream, *stream2;

int main( void )
{
int numclosed;
int fd =3;

while (fd <= FOPEN_MAX)
{
if( (stream = fopen( "E:\\new.txt", "r" )) == NULL )
{

printf( "The file was not opened\n [%d] ",GetLastError());
getchar();
}
else
{
fd = fileno(stream);
printf( "The file was opened and fd is [%d] \n " ,fd);

}
}

numclosed = _fcloseall( );
printf( "Number of files closed by _fcloseall: %u\n", numclosed );

return 0;
}

============

vineesh

CPallini4-Jul-08 2:55

4-Jul-08 2:55

I don't get the point of doing that. Please see here [^] (as Iain explained very well the real purpose of FOPEN_MAX).
Smile | :)

vineeshV4-Jul-08 3:21

4-Jul-08 3:21

Yes Iain was correct ...

The actual libary code restrict the number of file open to 510 (i dont know the exact value ..).But normally the system will not allow you to open more than 20 files from a process .This is because of the FOPEN_MAX set to 20 in the header stdio.h .
#define FOPEN_MAX 20
We can only change the value below 510 .
#define FOPEN_MAX 510 //upto this will work
that means
#define FOPEN_MAX 511 may not work as it trying to override the max limit in the actual libray code

We cannot open infinite number of files using fopen ,but still we can extend the limit set in the stdio.h file as above .

The usage of CreateFile is an absolute replacement for fopen if you need to open file more than 500 times from a single process.

vineesh

CPallini4-Jul-08 2:07

4-Jul-08 2:07

Why do you think you can set it?

Iain Clarke, Warrior Programmer4-Jul-08 2:28

4-Jul-08 2:28

The limit will be in the actual library code - the constant in the header is just to let you know about the limit.

You may be able to recompile your own version of the libraries with a higher max value, but there may be other factors causing the limitation.

Or you could use API functions like CreateFile instead. The limit for that is "May as well be infinite. If you need to know the actual limit, you're in bigger trouble than you think".

Iain.

Plz sir... ^CPallini ^CPallini abuz drugz, plz plz help urgent.

C++ ATL DLL Addin for Windows Mail is blocked by Vista's DEP

Randor 4-Jul-08 5:54

Randor

4-Jul-08 5:54

http://msdn.microsoft.com/en-us/library/6e3b887c(VS.80).aspx[^]

http://msdn.microsoft.com/en-us/library/xt874334(VS.80).aspx[^]

http://www.codeproject.com/script/Forums/View.aspx?fid=1644&msg=2504818[^]

Best Wishes,
-David Delaune

dolly4-Jul-08 1:34

dolly

4-Jul-08 1:34

Hello Friends,

I am using Windows Vista and I am builing an c++ ATL DLL in Visual C++ 6.0, which is an addin DLL for Windows Mail. (Outlook Express)

When I run my Windows Mail, Vista's DEP (Data Execution Prevention) feature blocks it, and prompts that it blocked for security purpose as some other program tried to use windows mail data.

But I have to hook into Windows Mail as have to put an addin to customize its GUI.

I tried to turn DEP off for Windows Mail, but it didnt allow me (even in Full Admin Account).
Also I turned DEP off for my exe (which loads my addin DLL, which further hooks into Windows Mail), but despite that Windows Mail is blocked.

Also, when I build the project in Visual Studio 2005, it runs very well. (And I have not made any change in the project settings or code)

It seems, VC 6 uses older compilers and VS 2005 uses latest ones so are compatible with Vista!

But I have to use VC 6 only as it's my project's requirement!

Please Help!

Thanks a lot !!

dolly,
N,IN

Re: C++ ATL DLL Addin for Windows Mail is blocked by Vista's DEP

Iain Clarke, Warrior Programmer4-Jul-08 2:38

Re: C++ ATL DLL Addin for Windows Mail is blocked by Vista's DEP

4-Jul-08 2:38

Is it possible to use the ATL header files from 2005, but use the VC6 compiler?

Just a thought...

Iain.

Plz sir... ^CPallini ^CPallini abuz drugz, plz plz help urgent.

dolly7-Jul-08 18:45

dolly

7-Jul-08 18:45

Iain Clarke wrote:
Is it possible to use the ATL header files from 2005, but use the VC6 compiler?

Just a thought...

Iain.

As of now, no I am not able to do it.

dolly,
N,IN

Product ID and vendor ID of the devices

Y K Kishore Kumar4-Jul-08 1:30

Y K Kishore Kumar

4-Jul-08 1:30

Hi,

Can anybody help me in getting the VendorID and ProductID of a device separately. I need it for all classes of devices like Modems, Ports etc.

Thanks. Rose | [Rose]

Re: Product ID and vendor ID of the devices

_AnsHUMAN_ 4-Jul-08 1:59

_AnsHUMAN_

4-Jul-08 1:59

Does EnumDevices,EnumDisplayDevices... help

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

CreateProcessAsUser

vineeshV4-Jul-08 1:17

Create really long timers in MFC

4-Jul-08 1:17

In my code i am using CreateProcessAsUser to create new process.The purpopse of the code to execute any of the process (console applicaions and window applicaions ) .The code is build as a service and after the CreateProcessAsUser ,the process id of the newly created process will be returned .The functionality works fine for window based applications (notepad ,regedit ..etc..) but when console applications such as cmd are passed to the CreateProcessAsUser ,the function returns process id ,but no such process informations are found in the task manager .. I think the newly created processes getting exitied as soon as they are spawned ..
Can any body help me in this ...

vineesh

Re: CreateProcessAsUser

marcio k6-Jul-08 20:48

marcio k

6-Jul-08 20:48

can you show us the code?

cagespear4-Jul-08 0:49

cagespear

4-Jul-08 0:49

I have a requirement in my app where I need to take some action at lets say - 24 hours after the app has opened.

Clear case of using timers, but timers take input in "milisecs", is it a nice idea to give timers with very high interval like 24 hours which will come out to be -

24 * 3600 * 100 milisecs.

Regards
Amit

Iain Clarke, Warrior Programmer4-Jul-08 1:05

4-Jul-08 1:05

When you start calculating 24 hours in milliseconds (86400000) then you do get big numbers.

And 2^32 can only hold 49.7 days, so I think your reluctance is very wise.

There are alternative ways though - have a look at SetWaitableTimer. You can also set it to call a function at a certain time / date, so it may be more useful to you.

Good luck,

Iain.

Plz sir... ^CPallini ^CPallini abuz drugz, plz plz help urgent.

cagespear4-Jul-08 1:22

cagespear

4-Jul-08 1:22

well, actually your point is of great help to me. If it can store 49 days at max then I'll buy that as I only need it max for 24 hours which is considerably lesser.

Thanks a ton!
Cage

Iain Clarke, Warrior Programmer4-Jul-08 1:28

4-Jul-08 1:28

Just be very careful - you have a strong risk of wraparound.

Have a look at
http://blogs.msdn.com/oldnewthing/archive/2005/05/31/423407.aspx[^]
for a very useful explanation.

Iain.

Plz sir... ^CPallini ^CPallini abuz drugz, plz plz help urgent.

CPallini4-Jul-08 1:45

4-Jul-08 1:45

Iain Clarke wrote:
And 2^32 can only hold 49.7 days

Actually is the half Poke tongue | ;-P

, see [^].
Big Grin | :-D

cagespear4-Jul-08 1:52

cagespear

4-Jul-08 1:52

Still works for me Smile | :)

hope it doesn't shrink Big Grin | :-D

Iain Clarke, Warrior Programmer4-Jul-08 2:22