LinuxQuestions.org - PID of a running process in C++

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PID of a running process in C++

I am writing a code and I want to set CPU affinity of a process for which I need its PID . How can I read the pid of running processes in C++ code.

Any help is appreciable.

There's a C-library getpid() function that returns the PID of the current process. You can use getppid() to get the PID of the parent.

Hi Hazel , thanks for your reply . Actually I am looking for another independent process's id whose I know only the name . Its neither the child or parent process of my program.

How about something like this?

Code:

#include <stdio.h>

#include <stdlib.h>

#define LEN 10



int main()

{

        char line[LEN];

        FILE *cmd = popen("pidof -s cbatticon", "r");

        long pid = 0;



        fgets(line, LEN, cmd);

        pid = strtoul(line, NULL, 10);

        

        printf("%ld\n", pid);

        

        pclose(cmd);

        

        return 0;

}

My output:

Code:

$ ./myPidof 

365

My output from terminal:

Code:

pidof -s cbatticon

365

ps aux | grep cbatti | grep -v grep

HMW    365  0.0  1.1  63368 24276 tty1    Sl  18:51  0:02 cbatticon

Probably bug prone as hell, no expert at C (read: amateur!), mostly stolen from here:
http://stackoverflow.com/questions/8...x-in-c#8166467

Best regards,
HMW

Bear in mind, also, that "CPU affinity" is customarily set by rules, or heuristics, which do not presume prior knowledge of a particular PID. The exceptions are low-level system calls which presume that the PID is already known, e.g. by its parent.