通过C ++程序更改shell的目录 [英] Changing the directory of the shell through a C++ program

问题描述

我想写一个简单的C ++程序来执行Linux命令。我坚持改变目录（命令像 chdir 和 cd 不工作）。这是我到目前为止：

I'm trying to write a simple C++ program to execute Linux commands. I'm stuck at changing the directories (commands like chdir and cd don't work). This is what I have so far:

system("echo -n '1. Current Directory is '; pwd");
system("chdir Desktop");            

推荐答案

这是不可能的，如果你想改变目录（即 cd ，即 chdir（2） ...）的shell调用了你的程序。因此 cd 必须是 bash（1）内置。

This is not possible, if you want to change the directory (i.e. cd, that is chdir(2) ...) of the shell which has invoked your program. So cd has to be a bash(1) builtin.

原因是 chdir 仅影响调用进程（这将是你的C程序）而不是父进程。每个进程都有自己的当前目录。

The reason is that chdir affects only the calling process (which would be your C program) not the parent process. Each process has its own current directory.

如果调用 system（3）它会 fork（2）新的shell和 execve（2 ） / bin / sh -c ，因此只有分叉的shell可以更改其当前目录。

If you call system(3) it will fork(2) a new shell and execve(2) /bin/sh -c so only the forked shell can change its current directory.

您需要阅读高级Linux编程。

您可能想要直接在C程序中调用 chdir 。这将影响当前进程和所有未来的子进程（包括在C中的 system 或 popen 代码），直到它们终止或进一步调用 chdir 。但它不会影响你的终端（你开始你的C程序）的shell。

Perhaps you want to call chdir directly inside your C program. This will affect the current process and all future child processes (including those started with system or popen library functions inside your C code) till their termination or some further call to chdir. But it won't affect the shell in your terminal (where you started your C program).

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