Чтение выхлопа процесса без ожидания его завершения

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <fcntl.h>

int main() {
  int filedes[2];
  if (pipe(filedes) == -1) {
    perror("pipe");
    exit(1);
  }

  pid_t pid = fork();
  if (pid == -1) {
    perror("fork");
    exit(1);
  } else if (pid == 0) {
    while ((dup2(filedes[1], STDOUT_FILENO) == -1) && (errno == EINTR)) {}
    close(filedes[1]);
    close(filedes[0]);
    execl("/tmp/sub.exe", "/tmp/sub.exe", (char * ) 0);
    perror("execl");
    _exit(1);
  }
  close(filedes[1]);

  int flags;
  flags = fcntl(filedes[0], F_GETFL, 0);
  flags |= O_NONBLOCK;
  fcntl(filedes[0], F_SETFL, flags);

  flags = fcntl(filedes[1], F_GETFL, 0);
  flags |= O_NONBLOCK;
  fcntl(filedes[1], F_SETFL, flags);

  printf("ready\n");

  char buffer[4096];
  while (1) {
    ssize_t count = read(filedes[0], buffer, sizeof(buffer));
    if (count == -1) {
      if (errno == EINTR || errno == EWOULDBLOCK) {
        continue;
      } else {
        perror("read");
        exit(1);
      }
    } else if (count == 0) {
      break;
    } else {
      printf("%u: %d/%s\n", time(NULL), (int) count, buffer);
    }
  }
  close(filedes[0]);
  wait(0);
}

#include <stdio.h>
#include <unistd.h>
# include <stdio.h>  
# include <string.h>  
# include <errno.h>  
#include <unistd.h>
#include <fcntl.h>

main() {
    printf("1111111111\n\n\n");
    sleep(1);
    printf("1111111111\n\n\n");
    sleep(1);
    printf("1111111111\n\n\n");
    sleep(1);
    printf("1111111111\n\n\n");
    sleep(1);
    printf("1111111111\n\n\n");
    sleep(1);
    printf("1111111111\n\n\n");
    sleep(1);
    printf("1111111111\n\n\n");
}