如何初始化一个指针在C结构？ [英] How to initialize a Pointer to a struct in C?

问题描述

鉴于这种结构：

struct PipeShm
{
    int init;
    int flag;
    sem_t *mutex;
    char * ptr1;
    char * ptr2;
    int status1;
    int status2;
    int semaphoreFlag;

};

这正常工作：

static struct PipeShm myPipe = { .init = 0 , .flag = FALSE , .mutex = NULL , .ptr1 = NULL , .ptr2 = NULL ,
        .status1 = -10 , .status2 = -10 , .semaphoreFlag = FALSE };

但是，当我宣布静态结构PipeShm * myPipe ，不工作，我假设我需要与运营商<$ C $初始化C> - ＆GT; ，但如何？

But when I declare static struct PipeShm * myPipe , that doesn't work , I'm assuming that I'd need to initialize with the operator -> , but how ? :

static struct PipeShm * myPipe = {.init = 0 , .flag = FALSE , .mutex = NULL , .ptr1 = NULL , .ptr2 = NULL ,
        .status1 = -10 , .status2 = -10 , .semaphoreFlag = FALSE };

是否有可能一个指针声明一个struct并使用初始化呢？

Is it possible to declare a pointer to a struct and use initialization with it ?

推荐答案

您可以像这样：

static struct PipeShm * myPipe = &(struct PipeShm) {
    .init = 0,
    /* ... */
};

此功能被称为复合文字，它应该，因为你已经在使用C99指定初始化为你工作。

This feature is called a "compound literal" and it should work for you since you're already using C99 designated initializers.

关于复合文字的存储：

6.5.2.5-5

6.5.2.5-5

如果复合文字发生功能的身体外，该
  对象具有静态存储时间;否则，它具有自动
  与封闭块相关的存储时间。

If the compound literal occurs outside the body of a function, the object has static storage duration; otherwise, it has automatic storage duration associated with the enclosing block.

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