超市总营业额分析程序要求：使用文件，结构体输出每天的销售记录，包括（1）每笔销售记录存储3个数据，例如：得力固体胶22.5。它们代表品名，数量（个）单价（元）。（2）将每天的销售记录通过文件进行存储（3）每周末进行盘存，从文件读取数据，并汇总出周销售额。

好的，这个程序可以使用 C 语言编写。以下是一个简单的实现：

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

#define MAX_RECORDS 1000 // 最大销售记录数
#define MAX_NAME_LEN 20 // 品名的最大长度

// 销售记录结构体
typedef struct {
    char name[MAX_NAME_LEN];
    int quantity;
    float price;
} Record;

// 读取销售记录文件，返回记录数
int read_records(Record *records) {
    FILE *fp = fopen("sales.txt", "r");
    if (!fp) {
        printf("Failed to open file.\n");
        return 0;
    }

    int count = 0;
    while (fscanf(fp, "%s %d %f", records[count].name, &records[count].quantity, &records[count].price) == 3) {
        count++;
    }

    fclose(fp);
    return count;
}

// 写入销售记录文件
void write_records(Record *records, int count) {
    FILE *fp = fopen("sales.txt", "w");
    if (!fp) {
        printf("Failed to open file.\n");
        return;
    }

    for (int i = 0; i < count; i++) {
        fprintf(fp, "%s %d %.2f\n", records[i].name, records[i].quantity, records[i].price);
    }

    fclose(fp);
}

// 添加一条销售记录
void add_record(Record *records, int *count) {
    if (*count >= MAX_RECORDS) {
        printf("Failed to add record: maximum number of records reached.\n");
        return;
    }

    Record r;
    printf("Enter name, quantity and price (separated by spaces): ");
    scanf("%s %d %f", r.name, &r.quantity, &r.price);

    records[*count] = r;
    (*count)++;

    write_records(records, *count);
}

// 显示所有销售记录
void show_records(Record *records, int count) {
    printf("Name\tQuantity\tPrice\n");
    for (int i = 0; i < count; i++) {
        printf("%s\t%d\t%.2f\n", records[i].name, records[i].quantity, records[i].price);
    }
}

// 计算周销售额
float calculate_weekly_revenue(Record *records, int count) {
    float revenue = 0;
    for (int i = 0; i < count; i++) {
        revenue += records[i].quantity * records[i].price;
    }
    return revenue;
}

int main() {
    Record records[MAX_RECORDS];
    int count = read_records(records);

    while (1) {
        int choice;
        printf("\n1. Add record\n2. Show records\n3. Calculate weekly revenue\n4. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                add_record(records, &count);
                break;
            case 2:
                show_records(records, count);
                break;
            case 3:
                printf("Weekly revenue: %.2f\n", calculate_weekly_revenue(records, count));
                break;
            case 4:
                exit(0);
            default:
                printf("Invalid choice.\n");
        }
    }

    return 0;
}

这个程序使用一个 `Record` 结构体来存储每个销售记录，同时定义了一些函数来实现添加、显示、读取、写入销售记录文件以及计算周销售额等功能。在 `main` 函数中，使用一个无限循环来接受用户的输入，根据用户的选择进行相应的操作。