编辑“︁C 语言可变结构体”︁（章节）

== 代码示例 ==

=== 基础用法 ===
<syntaxhighlight lang="c">
#include <stdio.h>
#include <stdlib.h>

struct dynamic_string {
    size_t length;
    char str[]; // 可变字符数组
};

int main() {
    const char *hello = "Hello, FAM!";
    size_t needed_size = sizeof(struct dynamic_string) + strlen(hello) + 1;
    
    struct dynamic_string *dstr = malloc(needed_size);
    dstr->length = strlen(hello);
    strcpy(dstr->str, hello);
    
    printf("Length: %zu\nContent: %s\n", dstr->length, dstr->str);
    free(dstr);
    return 0;
}
</syntaxhighlight>

'''输出：'''
 Length: 11
 Content: Hello, FAM!

=== 实际应用：网络数据包 ===
网络编程中常用可变结构体表示不同长度的数据包：
<syntaxhighlight lang="c">
struct network_packet {
    uint32_t src_ip;
    uint16_t port;
    uint8_t protocol;
    uint8_t data[]; // 可变长度的载荷数据
};

void process_packet(const void *raw_data, size_t total_len) {
    size_t header_size = sizeof(struct network_packet);
    if (total_len < header_size) return;
    
    struct network_packet *packet = (struct network_packet *)raw_data;
    size_t data_len = total_len - header_size;
    
    printf("Packet from %X:%d, %zu bytes payload\n",
           packet->src_ip, packet->port, data_len);
}
</syntaxhighlight>