Increase number of files that can be opened - C / C++ / MFC Discussion Boards

Converting existing VC++ Applications to be Compatible with Vista

NiceNaidu4-Jul-08 3:30

4-Jul-08 3:30

Hi All,
We have a project of converting the VC++ application to be compatible with Vista(as Administrator as well as Standard User).
The application should run successfully as Standard User.
The application consists of around 100 EXEs(Few run as services) and 200 Dlls and Ocxs .
So,we started identifying the areas that need to taken care like Registry, Messaging(SendMessage(), PostMessage()),CreateProcess(),GlobalObjects,Impersonation).

I have gone through so many links related to Vista(Esp. UAC).
But i have not found any link that gives the information regarding the conversion of legacy applications to Vista compatible.

Please post me any such link,so that i am not going to miss anything.

Thanks in Advance.

Appu..
"Never explain yourself to anyone.
Because the person who likes you does n't need it.
And the person who dislikes you won't believe it."

Re: Converting existing VC++ Applications to be Compatible with Vista

Mark Salsbery4-Jul-08 11:39

Mark Salsbery

4-Jul-08 11:39

The development guidelines you should have been following have been around since Windows 2000.
Only in Vista are they finally enforced.

Developer Best Practices and Guidelines for Applications in a Least Privileged Environment[^]

Also, search for the XP logo requirements document. There's a bunch of specific
stuff in section 3 (if I remember right) pertaining to proper registry and folder use.

Mark

Re: Converting existing VC++ Applications to be Compatible with Vista

NiceNaidu6-Jul-08 4:43

NiceNaidu

6-Jul-08 4:43

Thanks Mark.

Appu..
"Never explain yourself to anyone.
Because the person who likes you does n't need it.
And the person who dislikes you won't believe it."

Dialogbar shown as modal dialog

ilgale4-Jul-08 3:19

ilgale

4-Jul-08 3:19

Is it possible to show a CDialogBar as a modal dialog (I mean to be blocking) ?

If it is not possible... can I let the CDialogBar to be "a part"
of a CDialog ?

Thanks a lot!

How can I handle right-click of my application itself ?

SherTeks4-Jul-08 2:10

SherTeks

4-Jul-08 2:10

I have an end application (say Click.exe) which is placed on my desktop.

Now, I want to handle the Right click event of this exe itself ie.

if I right-click on the exe, I must be able to see a customized menu.

I know I don't have any control over the application Click.exe as such
because it is not yet started (ie. double-clicked).

Is this possible preferably by any VC++ way of handling events.

Any other solution like shell scripting ideas are also welcome.

Thanks in advance.

Re: How can I handle right-click of my application itself ?

Iain Clarke, Warrior Programmer4-Jul-08 2:25

Iain Clarke, Warrior Programmer

4-Jul-08 2:25

It's a rather brute force approach, but you could set a context menu handler (See Michael Dunn's superb shell series) for all exe, but only bother putting up for option if the file being right clicked on is called click.exe.

There are weak points to the idea - renaming, must be at least a partial admin to install shell extensions, what if the user makes a shortcut for the exe [*]?

Iain.

[*] I have a suspicion that the system resolves shortcuts for extensions for this very reason, but you'd have to check.

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

Re: How can I handle right-click of my application itself ?

Nibu babu thomas4-Jul-08 2:37

Nibu babu thomas

4-Jul-08 2:37

SherTeks wrote:
Now, I want to handle the Right click event of this exe itself ie.

if I right-click on the exe, I must be able to see a customized menu.

Is this what you are look for...

http://www.codeproject.com/KB/shell/shellextguide1.aspx[^]

Nibu babu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http://nibuthomas.wordpress.com

Increase number of files that can be opened

Amit4u4-Jul-08 1:41

Amit4u

4-Jul-08 1:41

in windows,
how do i set maximum open number of files ?
i tried to set FOPEN_MAX in stdio.h file, but it's not working....
need help....
thanks in advance...

xyz

Re: Increase number of files that can be opened

vineeshV4-Jul-08 1:57

vineeshV

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

Re: Increase number of files that can be opened

CPallini4-Jul-08 2:09

CPallini

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]

Re: Increase number of files that can be opened

vineeshV4-Jul-08 2:46

vineeshV

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

Re: Increase number of files that can be opened

CPallini4-Jul-08 2:55

CPallini

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 | :)

Re: Increase number of files that can be opened

vineeshV4-Jul-08 3:21

vineeshV

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

Re: Increase number of files that can be opened

CPallini4-Jul-08 2:07

CPallini

4-Jul-08 2:07

Why do you think you can set it?

Re: Increase number of files that can be opened

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

Iain Clarke, Warrior Programmer

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.

Re: Increase number of files that can be opened

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

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

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

Iain Clarke, Warrior Programmer

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.

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

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

vineeshV

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?

Create really long timers in MFC

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

Re: Create really long timers in MFC

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

Iain Clarke, Warrior Programmer

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.

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