Question

我正在进行一项任务，这让我陷入困境数小时。有人可以帮我指出为什么这对我不起作用？


struct book
{
  char title[25];
  char author[50];
  char subject[20];
  int callNumber;
  char publisher[250];
  char publishDate[11];
  char location[20];
  char status[11];
  char type[12];
  int circulationPeriod;
  int costOfBook;
}; 

void PrintBookList(struct book **bookList)
{
  int i;
  for(i = 0; i < sizeof(bookList); i++)
  {
    struct book newBook = *bookList[i];
    printf("%s;%s;%s;%d;%s;%s;%s;%s;%s;%d;%d\n",newBook.title, newBook.author, newBook.subject, 
        newBook.callNumber,newBook.publisher, newBook.publishDate, newBook.location, newBook.status, 
        newBook.type,newBook.circulationPeriod, newBook.costOfBook);

  }
}

void GetBookList(struct book** bookList)
{
  FILE* file = fopen("book.txt", "r");
  struct book newBook[1024];
  int i = 0;

  while(fscanf(file, "%s;%s;%s;%d;%s;%s;%s;%s;%s;%d;%d",
        &newBook[i].title, &newBook[i].author, &newBook[i].subject, 
        &newBook[i].callNumber,&newBook[i].publisher, &newBook[i].publishDate, 
        &newBook[i].location, &newBook[i].status,
        &newBook[i].type,&newBook[i].circulationPeriod, &newBook[i].costOfBook) != EOF)
  {
    bookList[i] = &newBook[i];
    i++;
  }

  /*while(fscanf(file, "%s;%s;%s;%d;%s;%s;%s;%s;%s;%d;%d",
    &bookList[i].title, &bookList[i].author, &bookList[i].subject,
    &bookList[i].callNumber, &bookList[i].publisher, &bookList[i].publishDate,
    &bookList[i].location, &bookList[i].status, &bookList[i].type,
    &bookList[i].circulationPeriod, &bookList[i].costOfBook) != EOF)
  {
    i++;
  }*/

  PrintBookList(bookList);

  fclose(file);
}

int main()
{
  struct book *bookList[1024];
  GetBookList(bookList);
}

我在编译时没有错误或警告

它应该打印文件的内容，就像它在文件中一样。像这样：

OperatingSystems Internals and Design principles;William.S;IT;741012759;Upper Saddle River;2009;QA7676063;Available;circulation;3;11200
Communication skills handbook;Summers.J;Accounting;771239216;Milton;2010;BF637C451;Available;circulation;3;7900
Business marketing management:B2B;Hutt.D;Management;741912319;Mason;2010;HF5415131;Available;circulation;3;1053
Patient education rehabilitation;Dreeben.O;Education;745121511;Sudbury;2010;CF5671A98;Available;reference;0;6895  
Tomorrow's technology and you;Beekman.G;Science;764102174;Upper Saddle River;2009;QA76B41;Out;reserved;1;7825  
Property & security: selected essay;Cathy.S;Law;750131231;Rozelle;2010;D4A3C56;Available;reference;0;20075  
Introducing communication theory;Richard.W;IT;714789013;McGraw-Hill;2010;Q360W47;Available;circulation;3;12150  
Maths for computing and information technology;Giannasi.F;Mathematics;729890537;Longman;Scientific;1995;QA769M35G;Available;reference;0;13500  
Labor economics;George.J;Economics;715784761;McGraw-Hill;2010;HD4901B67;Available;circulation;3;7585  
Human physiology:from cells to systems;Sherwood.L;Physiology;707558936;Cengage Learning;2010;QP345S32;Out;circulation;3;11135  
bobs;thomas;IT;701000000;UC;1006;QA7548;Available;Circulation;7;5050

但是当我运行它时，它会输出：

OperatingSystems;;;0;;;;;;0;0  
Internals;;;0;;;;;;0;0  
and;;;0;;;;;;0;0  
Design;;;0;;;;;;0;0  
principles;William.S;IT;741012759;Upper;41012759;Upper;;0;;;;;;0;0  
Saddle;;;0;;;;;;0;0  
River;2009;QA7676063;Available;circulation;3;11200;lable;circulation;3;11200;;0;;;;;;0;0  
Communication;;;0;;;;;;0;0

提前致谢，你是一个救生员

Answer 1

我认为您的问题是您的字段包含空格。 fscanf会在看到空白字符时停止扫描字符串（%s）。您需要更改%s格式说明符以允许包含空格。您可以只排除分隔符，例如%[^;]或指定要包含的字符，例如%[ a-zA-Z0-9-]（我想我可能会选择第一个选项）。

% man fscanf

Answer 2

不是原因，但在您的PrintBookList方法中，您有

for(i = 0; i < sizeof(bookList); i++)

但你无法获得结构数组的大小（它返回4，指针的大小）。

标准做法是传递尺寸：

void PrintBookList(struct book **bookList, int numBooks)

Answer 3

不要忘记限制读取字符串的大小（不要忘记它们以'\ 0'符号结尾）（scanf不知道字段有多长）。

的scanf（“％24 [^]，...

你如何从一个文件读取到一个struct数组？

3 个答案: