C语言读取txt文件第一个数据读取异常

Question

C语言读取txt文件

使用vs2019时用fscanf_s读取txt文件内容，发现读取第一行第一个数据时出现读取不到的情况。下面是读取数据的函数。

stu* readdate(char* filename) {
    char s = 0;
    FILE* fp = fopen(filename, "rb");
    stu * p= NULL;
    stu * q = NULL;
    stu * head = NULL;
    if (fp != NULL) {
        for (;(s=getc(fp) )!=EOF; ) {
            q = (stu*)malloc(sizeof(stu));
            if (q != NULL) {
                fscanf_s(fp, "%d", &q->id);//这里
                fscanf_s(fp, "%s", q->name,20);
                fscanf_s(fp, "%d", &q->old);
                fscanf_s(fp, "%s", q->sex,5);
                fscanf_s(fp, "%f", &q->yu);
                fscanf_s(fp, "%f", &q->shu);
                fscanf_s(fp, "%f", &q->wai);
                fscanf_s(fp, "%f", &q->li);
                q->next = NULL;
                if (head == NULL) {
                    head = q;
                }
                else if (p != NULL) {
                    p->next = q;
                }
                p = q;
            }
            q = (stu*)malloc(sizeof(stu));
        }
    }
    return head;
}//信息读入

输入
id：1
读取
id：-842150451
输入
id：123456
读取
id：23456
只有第一组数据出现这种情况，后面输入的都没有这种情况

Answer 1

需要把循环条件换成读取id时候不为EOF，把q = (stu*)malloc(sizeof(stu));提到循环外

stu* readdate(char* filename) {
    char s = 0;
    FILE* fp = fopen(filename, "rb");
    stu* p = NULL;
    stu* q = NULL;
    stu* head = NULL;
    if (fp != NULL) {
        q = (stu*)malloc(sizeof(stu));
        for (; (fscanf_s(fp, "%d", &q->id)) != EOF; ) {
            //q = (stu*)malloc(sizeof(stu));
            if (q != NULL) {
                //fscanf_s(fp, "%d", &q->id);//这里
                fscanf_s(fp, "%s", q->name,20);
                fscanf_s(fp, "%d", &q->old);
                fscanf_s(fp, "%s", q->sex,5);
                fscanf_s(fp, "%f", &q->yu);
                fscanf_s(fp, "%f", &q->shu);
                fscanf_s(fp, "%f", &q->wai);
                fscanf_s(fp, "%f", &q->li);
                q->next = NULL;
                if (head == NULL) {
                    head = q;
                }
                else if (p != NULL) {
                    p->next = q;
                }
                p = q;
            }
            q = (stu*)malloc(sizeof(stu));
        }
    }
    return head;
}//信息读入