如何包装的printf（）成一个函数或宏？ [英] How to wrap printf() into a function or macro?

问题描述

这听起来像一个面试问题了一点，但实际上是一个实际问题。

This sounds a little like an interview question,but is actually a practical problem.

我与嵌入式平台的工作，并具备只有这些功能的equivalets：

I am working with an embedded platform, and have available only the equivalets of those functions:

• 的printf（）


• 的snprintf（）

此外，printf（）的实现（和签名）很可能在不久的将来发生变化，所以将它的调用必须驻留在独立的模块中，为了易于以后迁移

Furthermore, the printf() implementation (and signature) is likely to change in the near future, so calls to it have to reside in a separate module, in order to be easy to migrate later.

鉴于这些，我可以换一些功能或宏记录通话。我们的目标是我的源$ C ​​$ C调用 THAT_MACRO（兔子数：％d，numBunnies）; 在千元地方，但调用上述功能只有在一个地方看到的。

Given those, can I wrap logging calls in some function or macro. The goal is that my source code calls THAT_MACRO("Number of bunnies: %d", numBunnies); in a thousand places, but calls to the above functions are seen only in one place.

编译器臂GCC -STC = C99

Compiler arm-gcc -stc=c99

推荐答案

由于可以使用C99，我将它包装在一个可变参数宏：

Since you can use C99, I'd wrap it in a variadic macro:

#define TM_PRINTF(f_, ...) printf((f_), __VA_ARGS__)
#define TM_SNPRINTF(s_, sz_, f_, ...) snprintf((s_), (sz_), (f_), __VA_ARGS__)

因为你没有说你有 vprintf 或类似的东西。如果你有类似的东西，你可以像谢尔盖L时他的回答已经提供了一个功能包裹。

since you didn't say that you have vprintf or something like it. If you do have something like it, you could wrap it in a function like Sergey L has provided in his answer.

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