如何通过用户输入连续写入文件?C 语言

Question

我正在使用一个必须读取用户输入（姓氏、名字和分数）并将此信息写入文本文件中的程序。我创建了一个循环，用于提示输入并为每个输入权限设置标志。当收集所有输入并且用户不想添加任何其他内容时，循环应结束。

问题是我设置了变量来保存名称，但我需要一种方法来重用这些变量进行循环的下一次迭代。因此，循环启动，收集用户输入，写入文件，然后它应该"清除"新迭代的变量。

用户应该能够在文件中插入尽可能多的数据。但是现在，我只能添加一组数据：（姓氏，名字和分数）。

void enter_data(void)
{
/* create file */
    FILE *fp;
    /*variables*/
    char answer;
    int flag1 = 0;
    int flag2 = 0;
    int flag3 = 0;
    int score = 0;  
    int test;
    char leave[SIZE] = "exit";
    char input_lname[SIZENAME];
    char input_fname[SIZENAME];
    char input_score[5];
    char input_answer[5];
    char lname[SIZENAME];
    char fname[SIZENAME];


    /*check if file was created */
    if((fp = fopen("students.dat", "ab+")) == 0){
        perror("fopen");
    }

    /* start of interaction */
    while(!(flag1 && flag2 && flag3))
    {
        flag1 = 0;
        flag2 = 0;
        flag3 = 0;
        /* ask for last name */
        while(flag1 != 1)
        {
            printf("Enter last name:n");
            if(!fgets(input_lname, SIZENAME, stdin))
            {
                clearerr(stdin);
                break;
            }   
            /* validate last name. if not digit... */
            if(!sscanf(input_lname, "%d", &test) == 1)
                /*put first word in lname */
                sscanf(input_lname, "%16s", lname);
            if(strcmp(input_lname, leave) != 0)
            {
                flag1 = 1;
                break;
            }
        }

        /* ask for first name */
        while(flag2 != 1)
        {
            printf("Enter first name:n");
            if(!fgets(input_fname, SIZENAME, stdin))
            {
                clearerr(stdin);
                break;
            }   
            /* validate first name. if not digit... * */
            if(!sscanf(input_fname, "%d", &test ) == 1)
            {
                /*put first word in fname */
                sscanf(input_fname, "%16s", fname);
                flag2 = 1;
                break;
            }
        }

        /* ask for score */
        while(flag3 != 1)
        {
            printf("Enter score:n");
            if(!fgets(input_score, SIZENAME, stdin))
            {
                clearerr(stdin);
                break;
            }
            /* validate last name */
            if(sscanf(input_score, "%3d", &score) == 1)
            {
                if((score >= 0) && (score <= 100))
                {
                    flag3 = 1;
                    break;
                } else if (score == -1)
                    break;
            }
        }
        /* store record in file */
        if((flag1 == 1) && (flag2 == 1) && (flag3 == 1))
        {
            printf("r %16s, %16s, %5d", lname, fname, score);
            fprintf(fp, "%16s %16s %5d", lname, fname, score);

        }
        /* ask for another student */
        printf("Would you like to enter data for another student?n");
        if(!fgets(input_answer, SIZE, stdin))
        {
            clearerr(stdin);
            break;
        }   
        if(sscanf(input_answer, "%s", &answer)  == 1)
        {
            if(answer == 'y') 
            {
                flag1 = 0;
                flag2 = 0;
                flag3 = 0;
                continue;
            } else
                break;
        }
        flag1 = 0;
        flag2 = 0;
        flag3 = 0;
        fclose(fp);
        /* finish asking */
    }

}

Answer 1

   struct Record {
    /*variables*/
    char answer;
    int flag1;
    int flag2;
    int flag3;
    int score;  
    int test;
    char leave[SIZE];
    char input_lname[SIZENAME];
    char input_fname[SIZENAME];
    char input_score[5];
    char input_answer[5];
    char lname[SIZENAME];
    char fname[SIZENAME];
   }
   while ( /* condition */ ) {
       // Create a record to keep the user inputs.
       Record oneRecord;
       oneRecord.flag1 = 1;
       oneRecord.flag2 = 2;
       ....
       // Write to file or other else.
   }

"结构"语法可能会对您有所帮助。