超市库存管理系统，c语言，文件存储代码实现

以下是一个简单的超市库存管理系统的C语言代码实现，使用了文件存储来保存数据。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_PRODUCTS 100 // 最大商品数量
#define MAX_NAME_LEN 50 // 商品名称最大长度

// 商品结构体
typedef struct {
    char name[MAX_NAME_LEN];
    float price;
    int quantity;
} Product;

// 从文件中读取商品数据
int read_products(Product *products, int *num_products) {
    FILE *file = fopen("products.dat", "rb");
    if (file == NULL) {
        return 0;
    }

    fread(num_products, sizeof(int), 1, file);
    fread(products, sizeof(Product), *num_products, file);

    fclose(file);
    return 1;
}

// 将商品数据写入文件
int write_products(Product *products, int num_products) {
    FILE *file = fopen("products.dat", "wb");
    if (file == NULL) {
        return 0;
    }

    fwrite(&num_products, sizeof(int), 1, file);
    fwrite(products, sizeof(Product), num_products, file);

    fclose(file);
    return 1;
}

// 显示商品列表
void show_products(Product *products, int num_products) {
    printf("商品列表:\n");
    printf("名称\t\t价格\t数量\n");

    for (int i = 0; i < num_products; i++) {
        printf("%-15s\t%.2f\t%d\n", products[i].name, products[i].price, products[i].quantity);
    }
}

// 添加商品
void add_product(Product *products, int *num_products) {
    if (*num_products == MAX_PRODUCTS) {
        printf("商品数量已达到上限\n");
        return;
    }

    char name[MAX_NAME_LEN];
    float price;
    int quantity;

    printf("请输入商品名称: ");
    scanf("%s", name);

    printf("请输入商品价格: ");
    scanf("%f", &price);

    printf("请输入商品数量: ");
    scanf("%d", &quantity);

    strcpy(products[*num_products].name, name);
    products[*num_products].price = price;
    products[*num_products].quantity = quantity;

    (*num_products)++;
    printf("商品添加成功\n");
}

// 删除商品
void delete_product(Product *products, int *num_products) {
    if (*num_products == 0) {
        printf("没有商品可供删除\n");
        return;
    }

    char name[MAX_NAME_LEN];
    printf("请输入要删除的商品名称: ");
    scanf("%s", name);

    // 遍历商品列表，查找要删除的商品
    int found = 0;
    for (int i = 0; i < *num_products; i++) {
        if (strcmp(products[i].name, name) == 0) {
            found = 1;

            // 将该商品后面的所有商品向前移动一个位置
            for (int j = i; j < (*num_products - 1); j++) {
                products[j] = products[j + 1];
            }

            (*num_products)--;
            printf("商品删除成功\n");
            break;
        }
    }

    if (!found) {
        printf("未找到要删除的商品\n");
    }
}

// 修改商品
void modify_product(Product *products, int num_products) {
    if (num_products == 0) {
        printf("没有商品可供修改\n");
        return;
    }

    char name[MAX_NAME_LEN];
    printf("请输入要修改的商品名称: ");
    scanf("%s", name);

    // 遍历商品列表，查找要修改的商品
    int found = 0;
    for (int i = 0; i < num_products; i++) {
        if (strcmp(products[i].name, name) == 0) {
            found = 1;

            float price;
            int quantity;

            printf("请输入新的价格: ");
            scanf("%f", &price);

            printf("请输入新的数量: ");
            scanf("%d", &quantity);

            products[i].price = price;
            products[i].quantity = quantity;

            printf("商品修改成功\n");
            break;
        }
    }

    if (!found) {
        printf("未找到要修改的商品\n");
    }
}

// 按名称查找商品
void search_product(Product *products, int num_products) {
    if (num_products == 0) {
        printf("没有商品可供查找\n");
        return;
    }

    char name[MAX_NAME_LEN];
    printf("请输入要查找的商品名称: ");
    scanf("%s", name);

    // 遍历商品列表，查找要查找的商品
    int found = 0;
    for (int i = 0; i < num_products; i++) {
        if (strcmp(products[i].name, name) == 0) {
            found = 1;

            printf("名称\t\t价格\t数量\n");
            printf("%-15s\t%.2f\t%d\n", products[i].name, products[i].price, products[i].quantity);
            break;
        }
    }

    if (!found) {
        printf("未找到要查找的商品\n");
    }
}

int main() {
    Product products[MAX_PRODUCTS];
    int num_products = 0;

    if (!read_products(products, &num_products)) {
        printf("无法读取商品数据\n");
        return 1;
    }

    while (1) {
        printf("\n请选择操作:\n");
        printf("1. 显示商品列表\n");
        printf("2. 添加商品\n");
        printf("3. 删除商品\n");
        printf("4. 修改商品\n");
        printf("5. 按名称查找商品\n");
        printf("6. 退出\n");
        printf("请选择: ");

        int choice;
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                show_products(products, num_products);
                break;
            case 2:
                add_product(products, &num_products);
                write_products(products, num_products);
                break;
            case 3:
                delete_product(products, &num_products);
                write_products(products, num_products);
                break;
            case 4:
                modify_product(products, num_products);
                write_products(products, num_products);
                break;
            case 5:
                search_product(products, num_products);
                break;
            case 6:
                write_products(products, num_products);
                return 0;
            default:
                printf("无效的选择\n");
                break;
        }
    }
}