用 C 创建一个程序来保存和显示数据

Question

我是 C 语言的新手，在大学里他们让我们创建一个程序，可以保存用户引入的数据，读取数据并检查它是否引入良好。之后，它必须将数据保存在每个可用空间中，您有 10 个空白空间用于保存数据。保存所有数据后，它还必须显示数据并将其与引入的所有数据进行比较。我做了阅读介绍的数据并检查是否可以的部分。我遇到的问题是我不知道如何创建数据库并显示该数据。这是我到目前为止所拥有的代码。

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

    typedef struct {
       char name[30];
       int num_sample;
       char section;
       int cabin;
       int day;
       int month;
       int year;
    }Species;

    int menu() {

        int op = 0;

        printf ("\nPrototype Nature Reserve.\n");
        printf ("1. Insert a new species.\n");
        printf ("2. List the species housed.\n");
        printf ("3. Show stadistics.\n");
        printf ("4. Exit.\n");
        printf ("\nIntroduce an option: ");
        scanf ("%d", &op);

        return op;
    }

    void New_species() {

        Species e;
        int i, j;
        char species[100];
        char aux[10];
        printf("Enter data:\n");
        //A fflush is made to not have a problem with the number entered in the menu
        fflush(stdin);
        gets (species);
        //While it is different from - read the text
        for (i = 0; species[i] != '-'; i++) {
          e.name[i] = species[i];
        }
        e.name[i] = '\0';
        i++;
        //We add 1 to the position i because is ending in - and should start reading from the following
        for (j = 0; species[i] != '-'; i++,j++) {
            aux[j] = species[i];
        }
        aux[j] = '\0';
        e.num_sample = My_atoi(aux);
        // Check that the sample is a number and not a character
        if (e.num_sample <= 0 || e.num_sample >= 100) {
            printf ("--> Error in data format.\n");
        }
        i++;
        //Reads the day introduced
        for (j = 0; species[i] != '/'; i++, j++) {
             aux[j] = species[i];
        }
        aux[j] = '\0';
        e.day = My_atoi(aux);
        //Controls the format of the day
        if (e.day <= 0 || e.day > 31) {
            printf ("--> Error in data format.\n");
        }
        i++;
        //Reads the month introduced
        for (j = 0; species[i] != '/'; i++, j++) {
            aux[j] = species[i];
        }
        aux[j] = '\0';
        e.month = My_atoi(aux);
        //Controls the format of the month
        if (e.month <= 0 || e.month > 12) {
            printf ("--> Error in data format.\n");
        }
        i++;
        //Reads the year introduced
        for (j = 0; species[i] != '-'; i++, j++) {
            aux[j] = species[i];
        }
        aux[j] = '\0';
        e.year = My_atoi(aux);
        //Controls the format of the year
        if (e.year < 1970 || e.year > 2060) {
            printf ("--> Error in data format.\n");
        }
        i++;
        //Reads the section introduced
        e.section = species[i];
        //Controls that the section is in capital letters
        if (e.section < 'A' || e.section > 'Z') {
            printf ("--> Error in data format.\n");
        }
        i+= 2;
        //As the cabin is at the end it must reach the \0
        for (j = 0; species[i] != '\0'; i++, j++) {
            aux[j] = species[i];
        }
        aux[j] = '\0';
        e.cabin = My_atoi(aux);
        if (e.cabin < 0 || e.cabin > 20) {
            printf ("--> Error in data format.\n");
        }
        printf ("Species stored successfully (%d/10 free).");
        //This printf is just to ensure that the data entered was read correctly
        printf ("\n%s", species);
    }

    int My_atoi(char cad[10]) {
        int r = 0;
        int i;
        for (i = 0; cad[i] != '\0'; i++) {
           r = r * 10;
           r += cad[i] - '0';
        }
        return r;
    }

    void list_species() {

    }

    void stadistics() {

    }

    void executeOption(int op) {
       switch (op) {
            case 1:
                New_species();
                break;
            case 2:
                list_species();
                break;
            case 3:
                stadistics();
                break;
            default:
                break;
        }
    }

    int main() {
        int op = 0;
        do {
            op = menu();
            executeOption(op);
        } while (op != 4);
        return 0;
    }

我已经看到您可以使用文件*，以便它可以创建一个 .txt 文件进行存储，但我不知道如何使用它，并且我认为此程序中不允许这样做。

我会留下一张它应该如何的照片 work

谢谢。

Answer 1

好的，您需要将数据保存到文件并从文件加载。这是我的读取和写入的简短代码:

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


typedef struct worker
{
int sal;
char name[25];  
}W;


void main()
{

 FILE *f;
 int i,j=4;
 W a[3];

 while(j!=3)
 {
 printf("\nEnter\n[1]write\n[2]read\n[3]exit\n");
 scanf("%d",&j);    
if(j==1)
{
if (f==NULL)
 {
    printf("Error!!\n");
    exit(0);
}   
f=fopen("workers.txt","w");
for(i=0;i<3;i++)
 {
printf("\nEnter worker name:   ");
scanf("%s",&a[i].name); 
printf("\nEnter worker sal:    ");
scanf("%d",&a[i].sal);      
fprintf(f,"%s %d",a[i].name,a[i].sal);  
}       

if(j==2)
{
if (f==NULL)
{
    printf("Error!!\n");
    exit(0);
}   
f=fopen("workers.txt","r");
for(i=0;i<3;i++)
{
 fscanf(f,"%s %d",a[i].name,&a[i].sal);
printf("\n%s %d",a[i].name,a[i].sal);
}   
}   
}

fclose(f);}