我似乎无法弄清楚为什么我在这个程序中遇到核心转储错误。包括初始化和读入动态结构数组的文件以及应将其读回的函数。
库.c 文件
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libraryStructures.h"
#include "library.h"
#include "user.h"
#include "librarian.h"
#include "utility.h"
void initLibrary(char *bookFile, Library *theLibrary)
{
theLibrary->maxBooks = 100;
theLibrary->maxBorrowed = 4;
// TO DO :
// dynamically allocate the bookList array for storing books
Book *bookList = malloc(100 * sizeof *bookList);
// check memory has been correctly allocated
if ( bookList == NULL )
{
printf("\nOut of memory!\n");
return;
}
// open the book file
FILE *books = fopen(bookFile, "r");
// use the readBooks function to read in the file and add the book records into the bookList array
readBooks(books, bookList);
// remember to close the file
fclose(books);
// Initialise the User data
return;
}
int readBooks(FILE *books, Book *bookList)
{
// TO DO:
/* read from the book file pointer
assign values to a Book structure in the bookList array for each complete record */
char buffer[50];
int end = 0;
int i = 0;
int numOfBooks = 0;
// while loop for reading book
while(end != 1)
{
while(fgets(buffer,50,books)!=NULL)
{
numOfBooks = numOfBooks + 1;
Book temp = bookList[numOfBooks];
i = 1;
for (int a = 0; a < 3; a++)
{
if (i == 1)
{
strcpy(temp.author, buffer);
fgets(buffer,50,books);
i = i + 1;
}
else if (i == 2)
{
strcpy(temp.title, buffer);
fgets(buffer,50,books);
i = i + 1;
}
else{
temp.available = 1;
bookList[numOfBooks] = temp;
}
}
}
end = 1;
}
// read data until the file ends
for (int i = 0; i <= numOfBooks; i++){printf("here %s", bookList[i].title);}
return numOfBooks;
}
void libraryCLI(char *bookFile)
{
int libraryOpen = 1;
int option;
// create the library structure
Library *theLibrary = (Library *)malloc(sizeof(Library));
initLibrary(bookFile, theLibrary);
while (libraryOpen)
{
printf("\n Main menu options\n 1 User login\n 2 Librarian login\n 3 Exit system\n Choice:");
option = optionChoice();
if (option == 1)
{
printf("\nUser login\n");
userCLI(theLibrary);
}
else if (option == 2)
{
printf("\nLibrarian login\n");
librarianCLI(theLibrary);
}
else if (option == 3)
{
libraryOpen = 0;
printf("\nClosing\n");
}
else
printf("\nUnknown option\n");
}
exitLibrary(theLibrary);
// free the library structure
free(theLibrary);
return;
}
这部分程序就是出现故障的地方
#include <stdio.h>
#include <stdlib.h>
#include "libraryStructures.h"
#include "librarian.h"
#include "utility.h"
void listBorrowedBooks(Book *bookList, int numBooks)
{
// TO DO :
// list the books in format "name - title"
printf("%s\n", bookList[1].author); //THIS CAUSES FAULT
return;
}
主要()
int main(int argc, char **argv)
{
FILE * file;
char *fileName = argv[1];
char bookFile[40];
// TO DO :
// assign command line value to filename string
if (argc <= 1)
{
fprintf(stderr, "Error: book file not chosen in command line. Please enter a book file.\n\n");
return 0;
}
else if(argc >= 3)
{
fprintf(stderr, "Error: too many arguments. Please enter one argument only.\n\n");
return 0;
}
//checking if file exists and can be opened
file = fopen(fileName, "r");
if (file)
{
//check size of file
fseek (file, 0, SEEK_END);
int size = ftell(file);
if (0 == size)
{
fprintf(stderr, "Error: file is empty. Please choose a file with content.\n\n");
fclose(file);
return 0;
}
else
{
// assign command line value to filename string
strcpy(bookFile, argv[1]);
fclose(file);
}
}
else
{
fprintf(stderr, "Error: file does note exist or you do not have permission to open it. Please check the file exists and you have the correct permissions.\n\n");
return 0;
}
结构
typedef struct _book {
char title[40];
char author[40];
int available;
} Book;
typedef struct _user {
Book *borrowed[4];
int numBorrowed;
} User;
typedef struct _library {
Book *bookList;
int numBooks;
int maxBooks;
User theUser;
int maxBorrowed;
} Library;
编辑
更改了 readBooks() 函数，使其在循环结束时而不是开始时递增，并且缓冲区长度更改为 40
当我尝试打印时，listBorrowedBooks 函数中仍然出现分段错误
int readBooks(FILE *books, Book *bookList)
{
// TO DO:
/* read from the book file pointer
assign values to a Book structure in the bookList array for each complete record */
char buffer[40];
int i = 0;
int numOfBooks = 0;
// while loop for reading book
while(fgets(buffer,50,books)!=NULL)
{
Book temp = bookList[numOfBooks];
i = 1;
for (int a = 0; a < 3; a++)
{
if (i == 1)
{
strcpy(temp.author, buffer);
fgets(buffer,50,books);
i = i + 1;
}
else if (i == 2)
{
strcpy(temp.title, buffer);
fgets(buffer,50,books);
i = i + 1;
}
else{
temp.available = 1;
bookList[numOfBooks] = temp;
numOfBooks++;
}
}
}
// read data until the file ends
return numOfBooks;
}
这就是调用 listBorrowedBooks 的地方
void librarianCLI(Library *theLibrary)
{
int librarianLoggedIn = 1;
int option;
while (librarianLoggedIn)
{
printf("\n Librarian options\n 1 List books\n 2 List borrowed books\n 3 Log out\n Choice:");
option = optionChoice();
if (option == 1)
{
printf("\nList of books:\n");
listBooks(theLibrary->bookList, theLibrary->numBooks);
}
else if (option == 2)
{
printf("\nList of borrowed books:\n");
listBorrowedBooks(theLibrary->bookList, theLibrary->numBooks);
}
else if (option == 3)
{
librarianLoggedIn = 0;
printf("\nLogging out\n");
}
else
printf("\nUnknown option\n");
}
return;
}
任何帮助表示赞赏！
问题（可能）是该语句的位置：
numOfBooks = numOfBooks + 1;代码永远不会填充
bookList[ 0 ]for (int i = 0; i <= numOfBooks; i++) {
printf("here %s", bookList[i].title);
}
将
<=<for()0n-1一旦加载完整记录，将增量从加载开始处移至后续：
else{
temp.available = 1;
bookList[numOfBooks] = temp;
numOfBooks++; // <-- increment count here
}
编辑
void initLibrary(char *bookFile, Library *theLibrary)
{
theLibrary->maxBooks = 100;
theLibrary->maxBorrowed = 4;
// TO DO :
// dynamically allocate the bookList array for storing books
Book *bookList = malloc(100 * sizeof *bookList); // LOCAL VARIABLE goes that out of scope.
bookListvoid