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I need to find the PID of a certain program on Mac OSX using C++ and save it as an variable. I have been looking for the answer for this question for a while, and I can't find a detailed one, or one that works. If anyone has an idea on how to do this, please reply. Thanks!

N T
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    Try `ps -aef` in the Terminal. Then chose one process and try finding that, e.g. `pgrep coreaudiod` or `pgrep USBAgent`. Then maybe think about using `popen()` to do the same from your program in C++. https://stackoverflow.com/q/44610978/2836621 – Mark Setchell Mar 27 '18 at 07:28
  • @MarkSetchell I don't think this applies. I am using this to modify, not output. Honestly, I just want to know how to find the PID using C++ before I get into anymore things. – N T Mar 27 '18 at 07:51
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    How can it not apply? If you want to find the `processid` of process `"fred"`, you run `pgrep fred` in the Terminal and it prints the `processid`, surely? In your C++ program, you do exactly the same, then read that number using `popen("/usr/bin/pgrep fred")`. – Mark Setchell Mar 27 '18 at 08:54
  • I am using popen to find the process ID and in some rare occasions on MacOS Big Sur and Catalina, I found that it's stuck for ~10 minutes on that. Why might that happen? Is there any way to avoid that or add some timeout value to that? – Masum Feb 17 '21 at 19:10

1 Answers1

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You can use proc_listpids in conjunction with proc_pidinfo:

#include <libproc.h>
#include <stdio.h>
#include <string.h>

void find_pids(const char *name)
{
    pid_t pids[2048];
    int bytes = proc_listpids(PROC_ALL_PIDS, 0, pids, sizeof(pids));
    int n_proc = bytes / sizeof(pids[0]);
    for (int i = 0; i < n_proc; i++) {
        struct proc_bsdinfo proc;
        int st = proc_pidinfo(pids[i], PROC_PIDTBSDINFO, 0,
                             &proc, PROC_PIDTBSDINFO_SIZE);
        if (st == PROC_PIDTBSDINFO_SIZE) {
            if (strcmp(name, proc.pbi_name) == 0) {
                /* Process PID */
                printf("%d [%s] [%s]\n", pids[i], proc.pbi_comm, proc.pbi_name);                
            }
        }       
    }
}


int main()
{
    find_pids("bash");
    return 0;
}
el.pescado - нет войне
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  • This code can also be easily modified to return a boolean if the program is running. I used this code to check whether a program was running or not. – Matthew Barclay Sep 02 '19 at 15:10