为什么带有 execlp 的 while 循环在一次迭代后退出循环？

Question

I am trying to run an execlp() command inside a while loop. The idea is it will take input from the user and depending on that it will execute the bash command (in this case, ls -la ).

In the while loop, if I get 'c', I will create a child and want this child to execute execlp and then exit the child process. The parent will wait until child exits then for safety I have used kill(PID, SIGKILL) to kill the child process. I thought it should go back to the loop as exec is executed by the child, not the parent. I need the parent to be alive. What is the mistake here and how can I achieve my goal. Below is the code:

pid_t child_pid;
int counter = 0;

int main()
{
   char c;

   while(1)
   {
      printf("enter choice: ");
      scanf(" %c", &c);
      // printf("\nyour choice was: %c\n", c);

      if (c == 'c')
      {
         int id = fork();
         if (id == 0){
            child_pid = getpid();
            printf("\ncreated child process at PID: %d\n", child_pid);
            execlp("ls", "ls",  "-la", (char *)0);
            // exit(0);
            }
         else{
            wait(NULL);
            kill(child_pid, SIGKILL);
            printf("\nkilled child\n");
            counter +=1;
         }
      }
      
      else if (c == 'e')
      {
         exit (0);
      }
    }

   return 0;
}

Answer 1

child_pid is assigned only in the child. In the parent process, it is 0 (an initialized global), and kill kills the entire process group, including the parent.