#include <iostream>
#include <unistd.h>
#include <stdio.h>
#include <sys/wait.h>
#include <string.h>

using namespace std;

int main() {

    int fd[2];
    int info;

    if (pipe(fd)) {
        perror("Pipe failed");
	    return 1;
    }

    // form the reader end of the pipe
    switch(fork()) {
       case 0:
          // close the write end of the pipe, we will not need it.
	      close(fd[1]);
	      // dup the read end of the pipe to stdin
	      if( -1 == dup2(fd[0],STDIN_FILENO)) {
             perror("\tError dup2 :");
          }
	      execl("talker","talker",nullptr);
	      perror("Exec failed");
	      return 3;
       case -1:
          perror("Fork failed");
	      return 2;
    }

    const char * a="A message from the parent\n";

    write(fd[1],a, strlen(a));

    // form the writer end of the pipe
    switch(fork()) {
       case 0:
          // close the read end of the pipe, we will not need it.
	      close(fd[0]);
	      // dup the write end of the pipe to stdin
	      if (-1 == dup2(fd[1],STDOUT_FILENO)) {
             perror("\tError dup2 :");
          }
	      execl("smallCounter","smallCounter",nullptr);
	      perror("Exec failed");
	      return 3;
       case -1:
          perror("Fork failed");
	  return 2;
    }

    
    // close the pipe ends, I don't need them.
    // this is important, if you don't do this, the reader will not get
    // and eof when the writer closes the pipe.
    close(fd[0]);
    close(fd[1]);

    int count = 0;
    while (count < 2) {
        pid_t pid =  wait(&info);
	    count ++;
	    cout << "A child has returned (" << pid << ") " << endl;
    }

    cout << endl;
    cout << "All children have exited " << endl;
    cout << endl;
    return 0;
}