How to get the CPU utilzation in Linux through c code?

[sumin]

i want to get the CPU and Memory utilizatoin in Linux through C.

will be thank ful for any help.

[arne]

i want to get the CPU and Memory utilizatoin in Linux through C.

will be thank ful for any help.

Have a look at /proc/stat and /proc/meminfo. These contain the info you need (and they're used by most monitoring programs).

HTH,
arne

[sumin]

Thanx arne ..

But can i get some c function which calculates the like the following which calculates the memory used in solaris.

#include <stdio.h>
#include <unistd.h>

int main()
{

long numPages, pageSize, freePages, totalSize, totalUsed, totalFree;

numPages = sysconf(_SC_PHYS_PAGES)/1024;
pageSize = sysconf(_SC_PAGESIZE)/1024;
freePages = sysconf( _SC_AVPHYS_PAGES)/1024;
totalSize = numPages * pageSize;
totalFree = pageSize * freePages;
totalUsed = totalSize - totalFree;

printf("total memory == %u MB\n",totalSize);
printf("total free memory == %u MB\n",totalFree);
printf("total used memory == %u MB\n",totalUsed);

return(0);

}

[arne]

Thanx arne ..

But can i get some c function which calculates the like the following which calculates the memory used in solaris.

#include <stdio.h>
#include <unistd.h>

int main()
{

long numPages, pageSize, freePages, totalSize, totalUsed, totalFree;

numPages = sysconf(_SC_PHYS_PAGES)/1024;
pageSize = sysconf(_SC_PAGESIZE)/1024;
freePages = sysconf( _SC_AVPHYS_PAGES)/1024;
totalSize = numPages * pageSize;
totalFree = pageSize * freePages;
totalUsed = totalSize - totalFree;

printf("total memory == %u MB\n",totalSize);
printf("total free memory == %u MB\n",totalFree);
printf("total used memory == %u MB\n",totalUsed);

return(0);

}

Yes, try 'man sysconf'.

I ran your code on my Linux box and the values returned seem reasonable.

[sumin]

hi arne..
I searched in man.. but i am not able to find anythig related to CPU utlization

[arne]

hi arne..
I searched in man.. but i am not able to find anythig related to CPU utlization

No, me neither. Sorry, if i was not clear on that: the options you used I saw in the manpages, too. And the code you posted runs fine. I don't know if there is something similar for CPU utilisation.

[prn]

I don't recall just what the functions are, but I can give you a hint. Look for the source code for top. I know it's available because I recall needing to modify it when Solaris 2.6 first came out and we only had top code for Solaris 2.5. :)

Seriously, though, I'm sure a more current version is also available. There's going to be a lot more than you need just to get CPU and memory utilization, but it is in there.

Best Regards,
Paul