c - 重复调用的函数中的静态变量 C

Question

我正在编写一个要被多次调用的函数，我想在其中有一个指向列表开头的静态指针。无论调用多少次，我都需要该函数来访问同一个列表，所以我有两个问题。

1. 我是否正确，如果我声明它 static t_line *begin = NULL; 其中 t_line 是我的结构，我相信它已经分配了正确的调用 main() 之前的空间，据我所知，static 变量所做的，然后这将给我一个具有正确分配大小的空指针。

2. 一旦我为该静态指针提供列表中第一个元素的地址，下次调用该函数并到达该声明行时，它不会只是将其重置为 NULL，我会丢失我的指针吗？

Answer 1

具有static 存储的变量仅初始化一次，您可以开始了。

引用 C11，第 6.2.4 章，强调我的

An object whose identifier is declared without the storage-class specifier _Thread_local, and either with external or internal linkage or with the storage-class specifier static, has static storage duration. Its lifetime is the entire execution of the program and its stored value is initialized only once, prior to program startup.

也就是说，关于保留最后存储的值，引用第 2 段，(再次强调)

The lifetime of an object is the portion of program execution during which storage is guaranteed to be reserved for it. An object exists, has a constant address,³³⁾ and retains its last-stored value throughout its lifetime.³⁴⁾ [....]

并且，对于 static 变量，如上所述

Its lifetime is the entire execution of the program