Programmatically check if a process is running on Mac

Question

Is there any Carbon/Cocoa/C API available on Macs that I can use to enumerate processes? I\'m looking for something like EnumProcesses on Windows.

My go

Answer 1

Late to the party, but if you really need a robust solution that can check whether any process is running (including BSD processes), you can do the following:

#include 
#include 
#include 

#include 
#include 

int main(int argc, const char* argv[]) {

  pid_t pid = atoi(argv[2]);  

  // This MIB array will get passed to sysctl()
  // See man 3 sysctl for details
  int name[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, pid };

  struct kinfo_proc result;
  size_t oldp_len = sizeof(result);

  // sysctl() refuses to fill the buffer if the PID does not exist,
  // so the only way to detect failure is to set all fields to 0 upfront
  memset(&result, 0, sizeof(struct kinfo_proc));

  if (sysctl(name, 4, &result, &oldp_len, NULL, 0) < 0) { 
    perror("sysctl");
    return 1;
  }

  // SZOMB means a zombie process, one that is still visible but is not running anymore
  if (result.kp_proc.p_pid > 0 && result.kp_proc.p_stat != SZOMB) {
    printf("Process is running.\n");
  } else {
    printf("Process is NOT running.\n");
  }

  return 0;

}

Note that the above code is a modified version of one of my private libraries and is untested. However, it should make clear how the API is used, and works successfully on macOS 10.14.5.