How to get a process's CPU usage in the program?

Question

I'm trying to get my program's CPU usage in my code. I used the code below but it returns total CPU usage. Is there a way to get only my program's usage?

int FileHandler;
char FileBuffer[1024];
float load;

FileHandler = open("/proc/loadavg", O_RDONLY);
if(FileHandler < 0) {
  return -1; }
read(FileHandler, FileBuffer, sizeof(FileBuffer) - 1);
sscanf(FileBuffer, "%f", &load);
close(FileHandler);
return (int)(load * 100);

Have you looked at:http://stackoverflow.com/questions/1420426/calculating-cpu-usage-of-a-process-in-linux ? — Jakub, Jul 17 '14 at 11:10

David Ranieri · Answer 1 · 2014-07-17T18:08:55.767

0

You can use popen() with ps as command:

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

FILE *popen(const char *command, const char *mode);
int pclose(FILE *stream);

int main(void)
{
    FILE *cmd;
    char s[64];
    double cpu;

    sprintf(s, "ps --no-headers -p %d -o %%cpu", (int)getpid());
    cmd = popen(s, "r");
    if (cmd == NULL) {
        perror("popen");
        exit(EXIT_FAILURE);
    }
    if (fgets(s, sizeof(s), cmd) != NULL) {
        cpu = strtod(s, NULL);
        printf("%f\n", cpu);
    }
    pclose(cmd);
    return 0;
}

edited Jul 17 '14 at 18:08

answered Jul 17 '14 at 11:51

David Ranieri

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Or check what that command actually does do that directly... – rubenvb Jul 17 '14 at 19:42
@rubenvb, sure, OP, you can check the source code of `ps` downloading the [procps](http://procps.sourceforge.net/) package – David Ranieri Jul 17 '14 at 20:06

How to get a process's CPU usage in the program?

1 Answers1