execlp() 系统调用错误输出 [英] execlp() system call error in output

问题描述

exec() 系统调用的这个非常简单的例子.在这里，我试图调用 execlp() 两次.但是，我没有得到例外输出.它仅显示当前目录下第一次调用的输出.

This very simple example of exec() system call. Here, I am trying to call execlp() twice. But, I am not getting excepted output. It shows output only for first call with current directory.

#include <stdio.h>
#include <unistd.h>

int main() { 

        int ret1,ret2;
        ret1 = execlp( "pwd", "pwd", (char *) 0);
        ret2 = execlp( "date", "date", (char *) 0);
        return 0;
}

输出:

/home/aniket

在这里，我看不到日期的输出.谁能解释一下为什么会这样?

Here, I can't see output for date. Can anyone please explain why is this happening?

推荐答案

execlp() 用新的过程映像替换当前的过程映像.它不返回(除非启动新进程时出错).

execlp() replaces the current process image with a new process image. It does not return (unless there was an error starting the new process).

因此永远不会到达第二个 execlp() 调用.

Therefore the second execlp() call is never reached.

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