我如何执行shell内置命令与C函数？ [英] How do I execute a Shell built-in command with a C function?

问题描述

我想通过像execv C语言函数来执行Linux命令PWD（）。

I would like to execute the Linux command "pwd" through a C language function like execv().

问题是，有没有所谓的PWD的可执行文件，我不能执行回声$ PWD，因为回声也是一个内置的命令，没有可执行程序被发现。

The issue is that there isn't an executable file called "pwd" and I'm unable to execute "echo $PWD", since echo is also a built-in command with no executable to be found.

推荐答案

您应该执行上海-c回声$ PWD ;一般 SH -c 将执行shell命令。

You should execute sh -c echo $PWD; generally sh -c will execute shell commands.

（事实上，系统（富）定义为 EXECL（嘘，嘘，-c，富， NULL），因而适用于shell内建的。）

(In fact, system(foo) is defined as execl("sh", "sh", "-c", foo, NULL) and thus works for shell built-ins.)

如果你只想值 PWD ，使用 GETENV ，虽然

If you just want the value of PWD, use getenv, though.

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