구조체 데이터 파일 저장 (소스)

#include <stdio.h>
#include <stdlib.h>
#define MAXTITL 40
#define MAXAUTL 40
#define MAXBKS 10
struct book{
   char title[MAXTITL];
   char author[MAXAUTL];
   float value;
};
int main(void)
{
   struct book libry[MAXBKS];
   int count = 0;
   int index, filecount;
   FILE * pbooks;
   int size = sizeof(struct book);

   if((pbooks = fopen("book.dat", "a+")) == NULL)
   {
      fputs("Can't open book.dat file\n", stderr);
      exit(1);
   }
   rewind(pbooks);
   while(count < MAXBKS && fread(&libry[count], size, 1, pbooks) == 1)
   {
      if(count == 0)
         puts("Current contents of book.dat:");
      printf("%s by %s: $%.2f\n", libry[count].title,libry[count].author, libry[count].value);
      count++;
   }
   filecount = count;
   if(count == MAXBKS)
   {
      fputs("The book.dat file is full.", stderr);
      exit(2);
   }
   puts("Please add new book titles.");
   puts("Press [enter] at the start of a line to stop.");
   while(count < MAXBKS && gets(libry[count].title) != NULL && libry[count].title[0] != '\0')
   {
      puts("Now enter the author.");
      gets(libry[count].author);
      puts("Now enter the value.");
      scanf("%f", &libry[count++].value);
      while(getchar() != '\n')
         continue;
      if(count < MAXBKS)
         puts("Enter the next title.");
   }
   puts("Here is the list of your books:");
   for(index = 0; index < count; index++)
      printf("%s by %s: $%.2f\n", libry[index].title, libry[index].author, libry[index].value);
   fwrite(&libry[filecount],size, count - filecount, pbooks);
   fclose(pbooks);
   return 0;
}