C语言文件写入问题

[qq_41320307]

如果文件不存在时就可以重复调用函数向文件写入数据，当文件存在时第二次运行程序就无法继续向里面写入数据，在fwrite后用fflush也没有解决问题，求指点

#include<stdio.h>
#include<stdlib.h>
#include<memory.h>
#include<string.h>
#define MAX 40
struct time
{
	int hour;
	int min;
};
struct order
{
	char name[30];
	int no;
	struct time ortime;
	int number;
};
struct order order1[MAX];
int input(void)
{
	FILE *or;
	int count = 0;
	int filecount, index, test, a, test1, test2;
	char judge;
	int size = sizeof(struct order);
	errno_t err;				
	system("cls");
	while ((err=fopen_s(&or,"order.dat", "a+b")) != 0)								
	{
		fputs("Can't creat the file\n", stderr);
		system("pause");
		exit(1);
	}
	rewind(or);
	while (fread(&order1[count], size, 1, or ) == 1 && order1[count].no != 0)
	{
		count++;
	}
	for (filecount = count; filecount < MAX; filecount++)
	{
		if (count == MAX)
		{
			printf("The order.dat file is full!\n");
			system("pause");
			break;
		}
		system("cls");
		do
		{
			printf("Please enter guest's No.:\n");
			a = scanf_s("%d", &order1[filecount].no);
			getchar();
			test = order1[filecount].no;
			if ((test < 1e-6 &&test>40)|| a == 0)
				printf("Unexpectable ,please enter a number in range 1-40\n");
		} while ((test < 1e-6 &&test>40) || a == 0);
		printf("Please enter guest's name:\n");
		gets(order1[filecount].name);
		do 
		{
			printf("Please enter the number of people:\n");
			a = scanf_s("%d", &order1[filecount].number);
			getchar();
			test = order1[filecount].number;
			if ((test < 1e-6 &&test>40) || a == 0)
				printf("Unexceptable ,please enter a number in range 1-40\n");
		} while ((test < 1e-6 &&test>40) || a == 0);

		do
		{
			printf("Please enter order time(XX,XX):\n");
			a=scanf_s("%d,%d", &order1[filecount].ortime.hour, &order1[filecount].ortime.min);
			getchar();
			test1 = order1[filecount].ortime.hour;
			test2 = order1[filecount].ortime.min;
			if ((test1 <= 0 || test1>24) || (test2 < 0 || test2>59) || a < 2)
			{
				printf("Unexceptable ,please enter right time\n");
			}
		} while ((test1 <= 0 || test1>24) || (test2 < 0 || test2>59) || a < 2);
		fwrite(&order1[filecount], size, 1, or );
		do
		{
			printf("Do you want continue?(y/n)\n");
			a = scanf_s("%c", &judge);
			while (getchar() != '\n')
				continue;
			if (judge != 'y' && judge != 'n' && judge != 'Y' && judge != 'N')
				printf("please try again!\n");
		} while (judge != 'y'&&judge != 'n' &&judge != 'Y'&& judge != 'N');
		if (judge == 'N' || judge == 'n')
			break;
	}
	fclose(or );
}
int main(void)
{
	int a, b, count;
	struct order guest[20];
	struct order *p;
	p = guest;
	for (count = 0; count < MAX; count++)
	{
		order1[count].no = 0;
		order1[count].name[40] = '\0';
		order1[count].number = 0;
		order1[count].ortime.hour = 0;
		order1[count].ortime.min = 0;
	}
	for (;;) 
	{
		system("cls");
		printf("----------Welcome To Guest Manager System----------\n");
		printf("                       MENU                        \n");
		printf("---------------------------------------------------\n");
		printf("|          1.Input guests information             |\n");
		printf("|          2.Sort guests information              |\n");
		printf("|          3.Read guests information              |\n");
		printf("|           4.Find guest information              |\n");
		printf("|           5.Edit guest information              |\n");
		printf("|          6.Delete guest information             |\n");
		printf("|                   7.Quit                        |\n");
		printf("---------------------------------------------------\n");
		for (;;)
		{
			printf("Please enter the function number: ");
			b = scanf_s("%d", &a);
			getchar();
			printf("\n");
			if (b == 0)
				printf("Wrong quest!Try again!\n");
			else break;
		}
		switch (a)
		{
		case 1:input(); break;
		case 2:sort(); break;
		case 3:read(); break;
		case 4:find(); break;
		case 5:edit(); break;
		case 6:del(); break;
		case 7:exit(1); break;
		}
	}
	return 0;
}

[自信男孩]

while ((err=fopen_s(&or,"order.dat", "a+b")) != 0)

打开文件的方式，有"a+b"，我记得有"ab+"，没见过"a+b"；

order1[count].name[40] = '\0';

这句是不是数组越界访问了，数组长度是30，下标应该从0~29；这儿用40，已经越界。

a = scanf_s("%c", &judge);

scanf_s缺少参数，是不是应该是这样：

a = scanf_s("%c", &judge， 1);

[qq_41320307]

引用 1 楼 自信男孩的回复:

while ((err=fopen_s(&or,"order.dat", "a+b")) != 0)

打开文件的方式，有"a+b"，我记得有"ab+"，没见过"a+b"；

order1[count].name[40] = '\0';

这句是不是数组越界访问了，数组长度是30，下标应该从0~29；这儿用40，已经越界。

a = scanf_s("%c", &judge);

scanf_s缺少参数，是不是应该是这样：

a = scanf_s("%c", &judge， 1);

多谢指点，但数据还是没有办法写入文件，a+b的写法是从C Primer plus上看来的，和ab+似乎是等价的，但似乎不是那个问题

[wodexiaojidan]

文件大小都被你搞死了，第一次就写满了40个单位大小，后面还怎么写

[qq_41320307]

引用 3 楼 wodexiaojidan的回复:

文件大小都被你搞死了，第一次就写满了40个单位大小，后面还怎么写

多谢指点，问题已解决，想再问一下如果想初始化结构体数组除了逐个赋值还有什么办法呢

[wodexiaojidan]

引用 4 楼 qq_41320307 的回复:

[quote=引用 3 楼 wodexiaojidan的回复:]文件大小都被你搞死了，第一次就写满了40个单位大小，后面还怎么写

多谢指点，问题已解决，想再问一下如果想初始化结构体数组除了逐个赋值还有什么办法呢[/quote]像普通数组一样

[wodexiaojidan]

引用 4 楼 qq_41320307 的回复:

[quote=引用 3 楼 wodexiaojidan的回复:]文件大小都被你搞死了，第一次就写满了40个单位大小，后面还怎么写

多谢指点，问题已解决，想再问一下如果想初始化结构体数组除了逐个赋值还有什么办法呢[/quote] 定义的时候就赋上初值