确定终止的进程的PID [英] Determine pid of terminated process

问题描述

我试图找出PID是发送SIGCHLD信号的过程是什么，我想这样做在我的SIGCHLD建立了一个信号处理程序。我会怎么做呢？我想：

I'm trying to figure out what the pid is of a process that sent the SIGCHLD signal, and I want to do this in a signal handler I created for SIGCHLD. How would I do this? I'm trying:

int pid = waitpid(-1, NULL, WNOHANG);

因为我想等待被产生的子进程。

because I want to wait for any child process that is spawned.

推荐答案

如果您使用 waitpid函数（）或多或少如图所示，你会被告知之一PID已经死去的子进程 - 通常是将是已死亡的唯一方法，但是如果你让他们乱舞，你可能会得到一个信号，许多尸体收集。因此，使用：

If you use waitpid() more or less as shown, you will be told the PID of one of the child processes that has died — usually that will be the only process that has died, but if you get a flurry of them, you might get one signal and many corpses to collect. So, use:

void sigchld_handler(int signum)
{
    pid_t pid;
    int   status;
    while ((pid = waitpid(-1, &status, WNOHANG)) != -1)
    {
        unregister_child(pid, status);   // Or whatever you need to do with the PID
    }
}

您可以替换＆放大器;状态与 NULL ，如果你不关心孩子的退出状态

You can replace &status with NULL if you don't care about the exit status of the child.

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