Question

Basically, I have this function. After fgets I want the parent to make the child stop by changing its play variable to 0. How would I do that?

    void readQuestion(char * question) {
      int play = 1;
      char inputline[256];
      int s;
      char * holder;
      int p = fork();
      if (p == 0) {
        while(play) {
          holder = strsep(&question," ");
          if(holder) {
        printf("%s\n",holder);
        sleep(1);
          }
          else{
        play = 0;
          }
        }
      }
      else {
        fgets(inputline,256,stdin);
        printf("%s",inputline);
        kill();
      }
    }

Answer 1

To do that you want to take one of two approaches…

1. Send a message using a message API like signal(7) or socket(7)
2. If you really want to tweak the child’s memory you don’t want fork(2) but a thread library.