c - APPCRASH 内部开关语句 - C

Question

我正在尝试编写一个程序，该程序将根据用户的指定对“.au”文件执行线性淡入、线性淡出或线性交叉淡入淡出。

我根据用户输入的 int 创建了一个 switch 语句，根据输入的值，它将被定向到三种情况之一.

在每一种情况下，我都会提示用户填写他/她想要用于渐变的文件的完整路径，然后打开一个文件来写入渐变。

但是，似乎在文件打开后，我的程序崩溃了。我很确定我正确地使用了 switch，并且我确保在最后关闭每个文件，所以我不确定为什么程序总是崩溃。

int main()
{
    FILE *f1, *f2, *fout;
    int r1, choice;
    float dr;
    char yn = 'y', path1[100], path2[100];

    while(yn == 'y' || yn == 'Y')
    {
        printf("Fade Out(1) Fade In(2) Cross-fade(3): ");
        scanf("%i", &choice);

        printf("Specify duration of fade (in seconds): ");
        scanf("%d", &dr);
        switch(choice) 
        {
            case(1):
                printf("Please specify full path of file you want to fade out\n");
                scanf("%s", path1);
                f1 = fopen(path1, "r");
                if(f1 == NULL) 
                {
                    printf("Incorrect file path specifiation. Program terminating...\n");
                    break;
                }
                fout = fopen("out.au", "w");
                //r1 = read_header(f1, NULL, fout, choice, dr);
                printf("We've gotten this far!\n");
                break;
            case(2):
                printf("Please specify full path of file you want to fade in\n");
                scanf("%s", path1);
                f1 = fopen(path1, "r");
                if(f1 == NULL) 
                {
                    printf("Incorrect file path specifiation. Program terminating...\n");
                    break;
                }
                fout = fopen("out.au", "w");
                //r1 = read_header(f1, NULL, fout, choice, dr);
                break;
            case(3):
                printf("Specify first file used to cross-fade\n");
                scanf("%s", path1);
                printf("Specify second file used in cross-fade\n");
                scanf("%s", path2);
                f1 = fopen(path1, "r");
                f2 = fopen(path2, "r");
                if((f1 == NULL || f2 == NULL))
                {
                    if(f1 == NULL)
                        printf("Incorrect file path specification for first file. Program terminating...\n");
                    else
                        printf("Incorrect file path specification for second file. Program terminating...\n");
                    break;
                }
                fout = fopen("out.au", "w");
                //r1 = read_header(f1, f2, fout, choice, dr);
                break;
            default:
                printf("Not a valid option.\n");
                break;
        }
        fclose(f1);
        if(f2 != NULL)
            fclose(f2);
        fclose(fout);

        fflush(stdin);
        printf("Again (y/n)? ");
        scanf("%c", &yn);
    }

    return 0;
}

Answer 1

FILE *f1, *f2, *fout 行没有初始化变量。

然后，if(f2 != NULL) 访问一个未初始化的变量。

更糟糕的是，fclose(f2) 解引用了一个未初始化的指针。