c - fputs 或 fprintf 不写入字符串文件

Question

为什么 fputs() 或 fprintf() 没有写入 %s 的 file.txt ？我尝试了这两个函数，但它们似乎没有写入文件。但是，当对 %d 使用相同的函数时，它目前确实有效。至于预期输出与当前发生的情况，请在程序中选择选项 1 并输入 2 的正方形时查看以下示例。

当前发生的事情:

1
2
4
8

预期输出:

You have chosen option: 1
The side of the square is: 2
The square area is: 4
The square perimeter is: 8

关于可能导致此问题的任何想法？谢谢!

N.b. 此代码用于学习目的，因此您可能会发现我处理变量的方式不一致(即通过引用或值传递)。请无视这一点。

#include <stdio.h> 
#include <locale.h>
#include <string.h>
#define PI 3.14

void square_functions (int side, int *square_perimeter, int *square_area);
float circle_functions (float radius, float * area_circle, float * circumference, FILE *fich);

int main() 
{ 

    float radius, area_circle, circumference;
    int side, square_area, square_perimeter, choice;
    FILE *fich; /* esto como variable global penaliza! */
    fich=fopen("file.txt","w");

    while (1) 
    {
    printf("Enter 1 to calculate the square\n"); 
    printf("Enter 2 to calculate the circumference\n");
    printf("Enter your option:\n"); 
    scanf("%d",&choice);
    fprintf(fich,"%s\n", "You have chosen option:");
    fprintf(fich,"%d\n",choice);

    switch (choice) 
        { 
        case 1: 
            printf("Please enter the side of the square: ");
            scanf("%d", &side);
            fprintf(fich,"%s\n", "The side of the square is:");
            fprintf(fich,"%d\n",side);
            if(side > 0)
            {
                square_functions (side, &square_perimeter, &square_area);
                printf("\nSquare area: %d", square_area);
                printf("\nSquare perimeter: %d\n", square_perimeter);
                fprintf(fich,"%s\n", "The square area is:");
                fprintf(fich,"%d\n", square_area);
                fputs("The square perimeter is",fich);
                fprintf(fich,"%d\n", square_perimeter);
            }
            else
            {
                printf("The value is invalid, the operation has been cancelled");
            } 
        break;

        case 2: 
            printf("\n\nPlease enter the radius fo the circle: ");
            scanf("%f", &radius);

            if(radius > 0)
            {
                circle_functions (radius, &area_circle, &circumference, fich);  
                printf("Circle area: %f", area_circle);
                printf("circumference: %f", circumference);
            }
            else
            {
                printf("The value is invalid, the operation has been cancelled");
            }
        break;
        }
    }
fclose(fich);
return 0;
}

void square_functions (int side, int *square_perimeter, int *square_area)
{       
        *square_perimeter = side * 4;
        *square_area = side * side;
}

float circle_functions (float radius, float * area_circle, float * circumference, FILE *fich) 
{
        *area_circle = PI * radius * radius;
        *circumference = 2 * PI * radius;
        fputs("The area of the circle is",fich); 
        fprintf(fich,"%f\n",*area_circle);
        fputs("The circumference is",fich);
        fprintf(fich,"%f\n",*circumference);
        return 0;       
}

Answer 1

问题是您没有关闭文件。注意:您有 fclose(fich);，但无法访问。添加第三个条件，如下所示，它应该有效:

case 3:
    fclose(fich);
    return 0;

另一种方法是不使用无限循环 (while(1))，而是使用条件。例如:

bool run = true;
while(run)
{
    ...
    case 3:
        run = false;
        break;
    ...
}