在分叉的伪终端

Question

首先，我会向您展示一些小伪代码：

cpid = forkpty (&compipe, NULL, NULL, NULL);

//yes i have some error handling here, but its not important yet

if (cpid == 0) //child process
{
    //here are some pipes closed,
    //and the forked child will exec(ute) third party process
}

else //parent process
{
    //here are just closing some other pipe ends,
    //and settings up some fcntl flags like O_NONBLOCK

    if (string (execResult) == "fail")
    {
        //HERE ARE THE PROBLEM!!
        //This debug message will print to the pseudo-terminal (i think)
        //because it is not visible in "main"-terminal / console
        gui -> appendDbg (Output::EROR, "Could not execute FOO");
        printDbg (EROR, "Could not execute FOO");
    }

    else
    {
        //But I don't understand why this debug message prints to
        //the "main"-terminal where the application was started from
        printDbg (INFO, "Starting child process: 'FOO' with PID: " +to_string (cpid));
        printChildsOut();
    }
}

好的，我的问题在if-else部分中描述，其中将检查exec（ution）结果。

问题是我看不到我的调试消息'EROR ...''，但是我可以在我的“main”-terminal中看到名为'INFO ...'的信息调试消息，其中应用程序是从

顺便说一句，函数'printDbg'是我自己开发的，它只是通过'cout'来打印消息。