c - 使用 fopen_s 打开文件流时出现未处理的异常访问冲突

Question

我很难弄清楚为什么我的代码无法工作。

该程序的目标是从给定的数组中生成一系列随机句子，然后将它们输出到屏幕或文本文件。

我不太确定问题是什么，但是当我输入文件标题时，我收到一个未处理的异常错误。

如果我将 FILE** 流参数更改为 NULL，而不是写入 fopen_s，则会出现调试断言错误。

我相信问题出在我声明指针的方式上。

#include <.stdio.h>
#include <.conio.h>

int main()
{
    char * article[5] = { "the", "one","some","any","a" };
    char * noun[5] = { "boy","girl","dog","town","car" };
    char * verb[5] = { "drove","jumped","ran","walked","skipped" };
    char * preposition[5] = { "to","from","over","under","on" };
    int x = 0;
    char * output[100] = {0};

    //char output = { "" };

    FILE ** write = "C:\Users\dilli\Downloads\test.txt";

    while (5) {
        printf("Enter one(1) to output to screen, two(2) to output to file:\n");
        scanf_s("%d",&x);
        if(x==1)
            printf_s("%s %s %s %s %s %s.\n", article[rand() % 5], noun[rand() % 5], verb[rand() % 5],
                preposition[rand() % 5], article[rand() % 5], noun[rand() % 5]);
        else if (x == 2)
        {
            printf("Enter name of output file:\n");
            scanf_s("%s",&output,100);
            printf("output:\n%s",output);
            fopen_s(write,output, "w");//This is where we are getting an unhandled exception.
            fprintf("%s %s %s %s %s %s.\n", article[rand() % 5], noun[rand() % 5], verb[rand() % 5],
                preposition[rand() % 5], article[rand() % 5], noun[rand() % 5]);
            fclose(write);
        }
    }
}

Answer 1

首先，您不能将字符串文字分配给FILE**变量。那甚至不应该编译。无论如何，您甚至没有使用字符串文字，因为您正在提示用户输入输出文件名。所以只需去掉字符串文字即可。

其次，您滥用了 fopen_s() 和 scanf_s()，这就是您的代码崩溃的原因。

• 当提示用户输入文件名时，您要求 scanf_s() 读入指针数组而不是字符数组。仅此一点就可能会崩溃，或者至少在您稍后尝试访问数组的内容时导致未定义的行为。

• 之后，您将无效的 FILE** 指针和无效的 char[] 数组传递给 fopen_s().它希望您传递一个指向有效 FILE* 变量的指针和一个以 null 结尾的 char 字符串，而不是 char* 指针数组.

第三，您根本没有将打开的 FILE* 传递给 fprintf()。

话虽如此，试试这个:

#include <stdio.h>
#include <conio.h>

int main()
{
    const char* article[5] = { "the", "one","some","any","a" };
    const char* noun[5] = { "boy","girl","dog","town","car" };
    const char* verb[5] = { "drove","jumped","ran","walked","skipped" };
    const char* preposition[5] = { "to","from","over","under","on" };
    char fileName[260] = {0};
    FILE *write = NULL;
    int i, x;

    for (i = 0; i < 5; ++i) {
        printf("Enter one(1) to output to screen, two(2) to output to file:\n");
        x = 0;
        scanf_s("%d", &x);
        if (x == 1) {
            printf_s("%s %s %s %s %s %s.\n", article[rand() % 5], noun[rand() % 5], verb[rand() % 5], preposition[rand() % 5], article[rand() % 5], noun[rand() % 5]);
        }
        else if (x == 2) {
            printf("Enter name of output file:\n");
            scanf_s("%s", fileName, 260);
            printf("output:\n%s", fileName);
            if (fopen_s(&write, fileName, "w") == 0) {
                fprintf(write, "%s %s %s %s %s %s.\n", article[rand() % 5], noun[rand() % 5], verb[rand() % 5], preposition[rand() % 5], article[rand() % 5], noun[rand() % 5]);
                fclose(write);
            }
        }
    }

    return 0;
}