c - 在 C 中扫描文本文件中的值时如何清除输入缓冲区？

Question

#include <stdio.h>
#define MAX_TITLE_SIZE 20
#define MAX_BOOKS 10

struct Book {
    int _isbn;
    float _price;
    int _year;
    char _title[MAX_TITLE_SIZE + 1];
    int _qty;
};

void clear(void);
int readRecord(FILE *fp, struct Book *b2read);
void displayInventory(const char filename[]);



int main(void) {

  struct Book myBook;
  char filename[21] = "144_w9_inventory.txt";

  displayInventory(filename);

    return 0;
}

void clear(void) {

    while (getchar() != '\n');

}

int readRecord(FILE *fp, struct Book *b2read){

    //Define a variable int rv = 0
    int rv = 0;


    rv = fscanf(fp, "%d;%f;%d;%d;%20[^\n]", &(b2read->_isbn), &(b2read->_price), &(b2read->_year), &(b2read->_qty), b2read->_title);
    //return rv;

    return rv;
}

void displayInventory(const char filename[]) {

    struct Book myBook;

    FILE *fp = NULL;
    int i;

    fp = fopen(filename, "r");  //open the file for reading

    if (fp != NULL) {

        printf("\n\nInventory\n");
        printf("===================================================\n");
        printf("ISBN      Title               Year Price  Quantity\n");
        printf("---------+-------------------+----+-------+--------\n");

        while(readRecord(fp, &myBook) == 5){
         printf("%-10.0d%-20s%-5d$%-8.2f%-8d\n", myBook._isbn, myBook._title, myBook._year, myBook._price, myBook._qty); 
        }
        printf("===================================================\n");
        printf("\n");

        fclose(fp);
    }
    else {
        printf("Failed to open file\n");
    }
}

文本文件中的内容是:

234562;23.99;2010;3;Harry Potter
567890;12.67;2015;4;The Hunger Games
109821;53.20;2017;2;Stranger Things

输出:

Inventory
===================================================
ISBN      Title               Year Price  Quantity
---------+-------------------+----+-------+--------
234562    Harry Potter
       2010 $23.99   3       
567890    The Hunger Games
   2015 $12.67   4       
109821    Stranger Things     2017 $53.20   2       
===================================================

当我输出程序时，我能够获取所有值，但由于某种原因，当我打印这些值时，整个字符串被减半并向下移动一行。

如果您想看一下，repl.it 就在这里:

https://repl.it/JbRy/69

如何获得以单行打印的输出；如果是这样的话，而不是读取\n“换行符”？

Answer 1

它与“清除输入缓冲区”无关。 fscanf() 根据您指定的内容使用它。它不需要“清除”，它需要正确扫描。不知何故，你在标题中得到了行终止符。更正您的 fscanf() 格式字符串。