在活着和跑步时读取和写入子进程

Question

我正在寻找管道父母和孩子之间的信息。目前，我通过读取文件描述符的另一端读取父节点的STDERR到孩子的STDIN并读取孩子的STDOUT。我已经完成了以下内容，但是在我能够阅读之前我正在努力与孩子需要退出。我怎样才能不断地读取一行一行孩子的输出子女之间

循环处理

for (int currentP = 0; currentP < inputs.playerCount; currentP++) { 
      char currentPlayerC[2]; 
      sprintf(currentPlayerC, "%d", currentP); 
      char* currentPlayerT = argv[3+currentP]; 

      int fds[2]; 
      int fds1[2]; 
      pipe(fds); 
      pipe(fds1); 
      char buff[10]; 
      memset(buff, 0, sizeof(buff)); 
      if ((pids[currentP] = fork()) < 0) { 
        perror("fork"); 
        abort(); 
      } else if (pids[currentP] == 0) { //Child 
        close(fds[PIPE_READ]); 
        close(fds1[PIPE_WRITE]); 
        dup2(fds[PIPE_WRITE], STDOUT_FILENO); 
        dup2(fds1[PIPE_READ], STDIN_FILENO); 
        close(fds1[PIPE_READ]); 
        close(fds[PIPE_WRITE]); 
        execlp(CHILD PROCESS THAT PRINTS TO STDOUT READS FROM STDIN)) 
        _exit(0); 
        return BADSTART; 
      } else { //parent 
        dup2(fds1[PIPE_WRITE], STDERR_FILENO); 
        close(fds[PIPE_WRITE]); 
        close(fds1[PIPE_READ]); 
        fprintf(stderr, "game_over\n"); //ENDS CHILD 
        read(fds[PIPE_READ], buff, sizeof(buff)); 
        //Will continue forever unless I put in game_over 
        close(fds1[PIPE_WRITE]); 
        close(fds[PIPE_READ]); 
      } 

}

Answer 1

这一行：

read(fds[PIPE_READ], buff, sizeof(buff)); 

将永远等待，如果孩子退出。

推荐：

if(wanting child to exit) 
{ 
    int status; 
    fprintf(stderr, "game_over\n"); //ENDS CHILD 
    wait(&status); 
    return 0; 
} 

fprintf(stderr, "next command to child\n"); 
read(fds[PIPE_READ], buff, sizeof(buff));