在C中对结构元素进行排序

我有以下代码，在其中必须按字母顺序对书名进行排序。这是我的代码，不确定如何执行实际排序。由于会提示用户输入多达30本书，因此也将不胜感激有关如何对多于2本书进行分类的任何帮助。

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>

struct Books
{
    char title[256];
    char author[256];
    char genre[256];
    int qualityRATE;
    int pages;
};

int numberbook = 1;
int casee;
int booksnumber;
int i;

int main()
{
    char again;

    do
    {
        printf("how many books will you be entering today?");
        scanf("%i", &booksnumber);
        printf("Enter the information for your book.\n Name\n Author\n Genre\n quality rating\n\n");
        struct Books book1;
        struct Books book2;
        scanf("%s", book1.title);
        scanf("%s", book2.title);

        printf("The title of book %i is: %s\n", numberbook, book1.title);
        printf("The title of book %i is: %s\n", numberbook, book2.title);

        printf("how would you like to sort?\n 1: By title\n 2: by Author\n 3: by pages\n\n");
        scanf("%i", &casee);
        switch(casee) 
        {
            case 1:
                for(i = 1; i < booksnumber, i++;)
                {
                    if(strcmp(book[i].title, book[i+1].title) < 0)
                        strcpy(book[i+1].title, book[i].title);
                    else
                        if(strcmp(book[i+1].title, book[i].title) < 0)
                            strcpy(book[i].title, book[i+1].title);

                }
                printf("\n%s\n", book1.title);
                break;
            case 2:
                break;
        }

        printf("Another book?\n");
        numberbook++;
        scanf("%s", &again);
    }

    while(again == 'y');
    return 0;
}