iPhone 上的 Fork()

发布于 2024-09-16 17:22:17 字数 782 浏览 6 评论 0原文

iPhone SDK 是否允许传统的 unix 函数 fork() 和 pipe() ？我似乎无法让他们工作。

编辑

问题已解决。在这里，我为遇到与我类似问题的任何人提供解决方案。我受到了这个帖子中的答案的启发。

在 iPhone 中，无法分叉进程。然而，实施管道并非不可能。在我的项目中，我创建了一个新的 POSIX 线程（请阅读 Apple 的文档以了解如何执行此操作）。子线程将与父线程共享由 pipeline() 创建的文件描述符。子线程和父线程可以通过管道进行通信。例如，我的子线程 dup2() fd[1] 到其标准输出。因此任何标准输出都可以在父线程中捕获。类似于fd[0]和标准输入。

伪代码（我没有可用的代码，但您明白了）：

int fd[2];
pipe(fd);
create_posix_thread(&myThread, fd);
char buffer[1024];
read(fd[0], buffer, 1024);
printf("%s", buffer); // == "Hello World"    

void myThread(int fd[])
{
  dup2(fd[1], STANDARD_OUTPUT);
  printf("Hello World");
}

如果您想在 iPhone 应用程序中使用第三方库，该策略非常方便。然而，问题是使用 printf() 的标准调试不再可用。在我的项目中，我只是将所有调试输出定向到标准错误，XCode 会将输出显示到其控制台。

原文

Does the the iPhone SDK allow fork() and pipe(), the traditional unix functions? I can't seem to make them work.

Edit

Problem solved. Here, I offer a solution to anybody who encounters problems similar to me. I was inspired by the answers in this thread.

In iPhone, there is no way to fork a process. However, it's not impossible to implement piping. In my project, I create a new POSIX thread (read Apple's documentation for how to do this). The child thread would share a file descriptor created by pipe() with the parent thread. Child and parent threads can communicate via pipes. For example, my child thread dup2() fd[1] to its standard output. So any standard output could be caught in the parent thread. Similar to fd[0] and standard input.

Pseudocode (I don't have the code available but you get the idea):

int fd[2];
pipe(fd);
create_posix_thread(&myThread, fd);
char buffer[1024];
read(fd[0], buffer, 1024);
printf("%s", buffer); // == "Hello World"    

void myThread(int fd[])
{
  dup2(fd[1], STANDARD_OUTPUT);
  printf("Hello World");
}

The strategy is very handy if you want to use a third-party library within your iPhone application. However, a problem is that standard debug using printf() is no longer available. In my project, I simply directed all debug outputs to standard error, XCode would display the outputs to its console.

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