将内存分配给结构内的指针结构答案

【问题标题】：Allocating memory to pointer structures inside structures将内存分配给结构内的指针结构
【发布时间】：2010-10-26 11:47:48
【问题描述】：

如果我有这样的结构

typedef struct _people {
 char *name;

 bool *exists;

 struct _people **citizens;
} PEOPLE;

如何分配内存以便 people->citizens[0]->name 可访问？我试过了

info->citizens = malloc(sizeof(PEOPLE *)*numbPeople);

但是，当我尝试访问 info->citizens->name 时，我在 GDB 中收到错误消息：

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000008

【问题讨论】：

标签： c memory gcc gdb allocation

【解决方案1】：

（我无缘无故不喜欢 C 中的类型定义结构）

让 sizeof 为您完成这项工作。

info->citizens = malloc(numbPeople * sizeof *info->citizens)
if (!info->citizens) { /* could not malloc - do something */ }

int i;
for (i = 0; i < numbPeople; ++i) {
    info->citizens[i] = malloc(sizeof *info->citizens[i]);
    if (!info->citizens[i]) { /* could not malloc - do something */ }
}

【讨论】：