text: #include <stdio.h>
  #include <stdlib.h>
  #include <sys/types.h>
  #include <unistd.h>
  
  int main(void)
  {
      pid_t currentProcess = getpid();
      pid_t parentProcess = getppid();
  
      pid_t realOwner = getuid();
      pid_t realGroup = getgid();
  
      pid_t effectiveOwner = geteuid();
      pid_t effectiveGroup = getegid();
  
      printf("currentProcess : %d, parentProcess : %d\nrealOwner : %d, realGroup : %d\neffectiveOwner : %d, effectiveGroup : %d\n", 
              currentProcess, parentProcess,
              realOwner, realGroup,
              effectiveOwner, effectiveGroup);
  
      return EXIT_SUCCESS;
  }