C / C++ / MFC

24-Mar-09 5:11

Hy folks,
I have a little question of reading out the amount of memory that one can use for a program.
I know there exists the method filling up the memory until you get an exception, but this isn't a nice way, right?

So my question: Is there a way to read out memory specs in windows and other platforms as well?
I was just wondering if one of you can thing of a nice platform independent function or approach to calculate the amount of memory available in the system.

Also I am interested to find out the amount of processors to calculate the amount of threads for that platform.

I am sorry for the leaking of knowledge. Sigh | :sigh:

Cheers

You have the thought that modern physics just relay on assumptions, that somehow depends on a smile of a cat, which isn’t there.( Albert Einstein)

modified on Tuesday, March 24, 2009 11:41 AM

Michael Schubert24-Mar-09 5:23

24-Mar-09 5:23

Check out GlobalMemoryStatusEx() and the structure MEMORYSTATUSEX on MSDN.

Fatbuddha 124-Mar-09 5:33

24-Mar-09 5:33

Thanks.
But this is just for windows, right? Or do you thing I have to check the op system before doing something. If that is possible.
I am also interested in reading out the sys specs in general. For example the amount of processors to calculate how many threads I could start..

But thanks for pointing me in a direction.

Cheers.

You have the thought that modern physics just relay on assumptions, that somehow depends on a smile of a cat, which isn’t there.( Albert Einstein)

Michael Schubert24-Mar-09 5:45

24-Mar-09 5:45

Yes, only for Windows (unless you use something like Wine on Linux).

There are articles about system info in this section: http://www.codeproject.com/KB/system/[^]

Fatbuddha 124-Mar-09 6:19

24-Mar-09 6:19

Thanks you very much.
But still either I am blind or just not seeing it, I can not find a nice function or a set of functions that return me system information.
Actually, if I am allow to keep you busy, I am lacking of knowledge to detecting on which op I am on.
I mean if I can detect what Os I am facing, it is straight forward to use your suggestion for windows and in Linux, I think, the specs are written in a file.
Macs fights for their owns. Smile | :)

But thanks for the great answers.
Cheers

You have the thought that modern physics just relay on assumptions, that somehow depends on a smile of a cat, which isn’t there.( Albert Einstein)

Michael Schubert24-Mar-09 6:28

24-Mar-09 6:28

Fatbuddha 1 wrote:
But still either I am blind or just not seeing it, I can not find a nice function or a set of functions that return me system information.

Well, you have to read the articles and look at the code.

Fatbuddha 1 wrote:
I am lacking of knowledge to detecting on which op I am on.

Do you mean which version of the OS? Like Win XP, 2000 etc.? Or Linux, MacOS, Windows?

David Crow24-Mar-09 6:39

David Crow

24-Mar-09 6:39

Fatbuddha 1 wrote:
I mean if I can detect what Os I am facing...

To my knowledge, there is not a platform-independent way of determining this. For Windows, check out GetVersionEx().

"Old age is like a bank account. You withdraw later in life what you have deposited along the way." - Unknown

"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer24-Mar-09 8:39

24-Mar-09 8:39

You can't compile a program and expect it to then be copied to any computer and run. So, it's not that bad to make a function in your own code that does different things depending on which operating system it is compiled for (you may be cross compiling for all I know)

Ie:

DWORD HowManyMegaBytesDoIHave ()
{
#ifdef _WINDOWS
  return ThatWindowsAPIFunction ();
#endif
#ifdef _MACOS9
etc

}

I hope that made sense. I'm pretty sure the windows one is real, no idea about the other, but they're just meant to illustrate. You'll have to the same #ifdef with the headers too.

If you want one codebase to work identically on all OS's, then you'll have to scale back your desires a long way.

Good luck,

Iain.

In the process of moving to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), give me a job!

Fatbuddha 126-Mar-09 22:52

segmentation fault en strcat()

26-Mar-09 22:52

Sorry for the late answer.
Of course you are right, what was I thinking??
Spend to much time on Java Smile | :)

.

So to conclude either your way, or I simply provide a version of my prog for win and unix. This might be even the cleaner style.

Thanks and have a nice weekend.
Cheers

You have the thought that modern physics just relay on assumptions, that somehow depends on a smile of a cat, which isn’t there.( Albert Einstein)

sankariyo24-Mar-09 4:58

24-Mar-09 4:58

Hello.

My program gets "segmentation fault" in "strcat(string,stringaux)" and it is strange because I am sure that string always has space for adding the new stringaux due to before call strcat I check if size of the destiny plus new stringaux is less than string capacity:

char string[100];
char stringaux[3];

void Function()
{
if ((strlen(string)+strlen(stringaux))<100)
{
strcat(string,stringaux)
}
}

In this way strcat() never can make string be longer than 100. But still I get SEGMENTATION DEFAULT.

I have been reading, and the explanation can be that the Stack gets full due to I have many local variables or ...

Is there anybody can tell me some ideas about why SEGMENTATION DEFAULT is produced in strcat() when I am sure that is not because there is not space in the destiny string?

Thanks in advance.

Code-o-mat24-Mar-09 5:17

Code-o-mat

24-Mar-09 5:17

Are you completely sure the segfault comes from strcat? How did you determine this (setting breakpoints, putting traces in the code...)?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

sankariyo24-Mar-09 22:26

24-Mar-09 22:26

Because If I add a comment in the strcat() the segmentation fault does not appear and if I take the comment away the segmentation fault appears.

Code-o-mat24-Mar-09 23:04

Code-o-mat

24-Mar-09 23:04

Hmm...what happens if you increate the string buffer to -let's say- 150 chars? Or increase your stringaux to -let's say- 10 chars? Does anything change? Also, before the strcat, try displaying the 2 strings to see what is in them, printf or puts should do it...

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <

Michael Schubert24-Mar-09 5:37

24-Mar-09 5:37

Remember that strlen returns the length without the terminating null character.

sankariyo24-Mar-09 22:39

24-Mar-09 22:39

That is not the point!
Even if I am taking care your comment and in the example I change <100 by <99 the problem is not there.

Because as I said before I am sure that the segmentation fault is not because there is not space in the destiny, even if I make bigger the destiny [1000] I still get the segmentation fault.

David Crow24-Mar-09 6:20

David Crow

24-Mar-09 6:20

strcat() appends source to destination, overwriting the null character. Does string have one?

CPallini24-Mar-09 7:09

CPallini

24-Mar-09 7:09

Probably yes, since strlen appears (or as someone already suspected, maybe that the segmention fault occur before the actual call to strcat) to succeed.
Smile | :)

David Crow24-Mar-09 7:14

David Crow

24-Mar-09 7:14

Yeah, I did not bother to fully scrutinize his code. It's possible that stringaux has a '\0' but not within the 3 bytes allocated to it.

CPallini24-Mar-09 7:25

CPallini

24-Mar-09 7:25

DavidCrow wrote:
It's possible that stringaux has a '\0' but not within the 3 bytes allocated to it.

But, I suppose, that doesn't harm (it is string the indictee...). Smile | :)

sankariyo24-Mar-09 22:42

24-Mar-09 22:42

I am sure that the problem is in strcat and not in strlen.

CPallini24-Mar-09 22:48

CPallini

24-Mar-09 22:48

Why?
Could you please post a test case (i.e. the input values for the two string) showing the failure?
Smile | :)