是一个main（）需要一个C程序？ [英] Is a main() required for a C program?

问题描述

嘛标题说明了一切。是一个的main（）函数的C程序绝对必要的？

Well the title says it all. Is a main() function absolutely essential for a C program?

我问这个，因为我一直在寻找在Linux内核code，我没有看到一个main（）函数。

I am asking this because I was looking at the Linux kernel code, and I didn't see a main() function.

推荐答案

没有，ISO C标准规定，一个主函数只需要一个托管环境（如为一个与底层OS）。

No, the ISO C standard states that a main function is only required for a hosted environment (such as one with an underlying OS).

对于像嵌入式系统独立环境（或操作系统本身），它的定义实现。从C99 5.1.2 ：

For a freestanding environment like an embedded system (or an operating system itself), it's implementation defined. From C99 5.1.2:

两个执行环境定义为：独立和主持。在这两种情况下，当一个指定的C函数是由执行环境调用程序启动时发生。

Two execution environments are defined: freestanding and hosted. In both cases, program startup occurs when a designated C function is called by the execution environment.

在独立环境中（其中C程序的执行可能发生没有操作系统的任何利益），名字叫在程序启动时的函数类型是实现定义的。

In a freestanding environment (in which C program execution may take place without any benefit of an operating system), the name and type of the function called at program startup are implementation-defined.

至于Linux本身是如何开始，Linux内核的起点的在start_kernel 不过，对于整个启动过程的一个更全面的了解，你应该开始的这里。

As to how Linux itself starts, the start point for the Linux kernel is start_kernel though, for a more complete picture of the entire boot process, you should start here.

这篇关于是一个main（）需要一个C程序？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！