长度为0的数组

/*
 * size_0_test.c
 *
 *  Created on: 2012-2-23
 *      Author: root
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct line{
    int length;
    char contents[0];
};
int main(){
    struct line *l =(struct line *) malloc(sizeof(struct line)+8);
    char message[10]="hello";
    strcpy(l->contents,message);
    printf("size of line is :%s.\n",l->contents);
    return 0;
}

c语言中长度为0的字符数组不占用长度。用来支持变长数组。