Question

我正在编写一个文本游戏，其中将用户输入与我拥有的文本文件中可用的命令列表进行比较。

它工作正常，但我希望它循环播放，以便用户在输入打破循环并继续执行程序的命令之前可以执行多个操作。不幸的是，我的文件指针在循环的第二次迭代中变成NULL，因此完全脱离了程序。

缩进有点令人困惑，对此我深表歉意：

    int mansionOutside(void)
    {
        int stop = 1; //control variable for while, yeah I know its a shit method of doing it, sue me
        char choice[25]; //Variable to store user input
        char word_match[15] = "outside"; //counter and .txt will be strcat to it
        char text_line[73]; //size of line for txt files
        char line1[25]; //takes current line being read from file
        char temp[2]; //character and '\0' so counter can be made into a string and strcat into word_match
        int counter = 1; //counts number of lines
        int stop2 = 1;
        while (stop2 == 1)
        {
            FILE *fptr;
            fptr = fopen("mansion_commands.txt", "r"); //opens file
            int lookdoor_counter = 0;
            printf("%p\n", fptr);
            if (fptr == NULL)
            {
                perror("ERROR!"); //Error handling for not opening file
                exit(EXIT_FAILURE);
            }
            else
            {
                while (stop == 1)
                {   
                    puts(""); //newline, as the previous function ends in a text line
                    fgets(choice, sizeof choice, stdin); //store input in choice with buffer overflow protection

                    while (fgets(line1, 25, fptr) != NULL) //reads until newline
                    {
                        if (strcmp(line1, choice) == 0) //if choice is equal to the current line
                        {
                            //printf("%s\n", line1); //debugging print
                            if (strcmp(line1, "LOOK door") == 0)
                            {
                                lookdoor_counter++; //so that on entering LOOK door a second time, a different
                        //message will appear
                            }
                        stop = 0; // will exit from loop
                        break; //break ensures we can use the current counter value for later
                    }
                    else
                    {
                        counter++;
                        //printf("%s + %s\n", line1, choice); //debugging
                    }
                }

            if  (stop == 1)
            {
                printf("I dont understand\n"); 
                //printf("%d\n", counter);
                //printf("%s\n", line1);
                //printf("%s\n", choice);
                counter = 1; //counter is reset to be able to try again
                rewind(fptr);
            }
        }
        fclose(fptr);
        if (lookdoor_counter == 2)
        {
            counter += 1;
        }
        counter = counter + '0'; //convert counter digit to its equivalent ascii
        temp[0] = counter; 
        temp[1] = '\0'; //temp becomes a string with counter and EOF char
        //printf("%c\n", counter);

        strncat(word_match, temp , 1); //wordmatch gets counter strncat to it
        strcat(word_match, ".txt"); /*If the string is found on the second line
        word_match will be (outside2.txt), which contains the appropriate 
        message for that user command*/
        //printf("%s\n", word_match); //debugging
        if (strcmp(word_match, "outside4.txt") == 0)
        {
            stop2 = 0;
        }
        fptr = fopen(word_match, "r"); //we open word_match file
        if (fptr == NULL)
        {
            printf("ERROR!\n"); //error handling
            exit(EXIT_FAILURE);
        }
        else
        {
            //printf("Debugging : File opened Successfully\n");

            while (fgets (text_line, 72, fptr) != NULL)
            {
                printf("%s", text_line); // Prints every Line with a 2 sec delay
                //delay(2);
            }
        }
    }
    fclose(fptr);
}
return 1;

}

Answer 1

fptr = fopen("mansion_commands.txt", "r"); //opens file
if (!fptr)perror("fopen");

添加此if条件，然后查找实际错误是什么。也许您对fs没有权限，或者路径不正确，等等。

在while循环的第二次迭代中，文件指针变为NULL

1 个答案: