Question

我正在尝试获取书籍信息的简单文本文件并将其存储到结构数组中。我只是在学习C而不是Java或C＃，我有点困惑。

我知道这与我编写代码的方式有关

我的文字文件是：

Magician:Apprentice
RaymondE.Feist 
Spectra(January1,1994) 
5.02 
0553564943 
512 
1 
Magician:Master 
RaymondE.Feist 
Spectra(January1,1994) 
7.99 
0553564935 
499 
1

然后我有我的代码，我不知道我做错了什么，我知道它与while有关（fgets（行......我知道如何显示所有文本，我只是遇到问题）正确地将文本存储到结构中。

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

typedef struct book{

char title[100];
char author[100];
char publisher[100];
float price;
char isbn[100];
int pages;
int copies;
} Book;

int main( void )
{

//addInventory( "Magician: Apprentice", "Raymond E. Feist",     5.02, "0553564943", 512, 1 );

//Book myBook = { "Magician: Apprentice", "Raymond E. Feist", "unknown", 5.02, "0553564943", 512, 1 };

//addInventory( myBook );

   char ch, file_name[25];
   FILE *fp;

  printf("Enter the name of file you wish to see\n");
  gets(file_name);

  fp = fopen(file_name,"r"); // read mode

  if( fp == NULL )
  {
  perror("Error while opening the file.\n");
  exit(EXIT_FAILURE);
  }

  //printf("The contents of %s file are :", file_name);

 /*while( ( ch = fgetc(fp) ) != EOF )
  printf("%c",ch);*/


    char line[9001];
    char *item;
    int reccount = 0;
    int k;
    int maxEntries = 100;



    while (fgets(line,9000,fp)) {
            printf("%s",line);


            item = strtok(line,"");
            strcpy(inventory[reccount].title,item);
            printf("1");

            item = strtok(line,"");
            strcpy(inventory[reccount].author,item);
            printf("2");

            item = strtok(line,"");
            strcpy(inventory[reccount].publisher,item);

            item = strtok(line,"");
            inventory[reccount].price = atof(item);

            item = strtok(line,"");
            strcpy(inventory[reccount].isbn,item);

            item = strtok(line,"");
            inventory[reccount].pages = atoi(item);

            item = strtok(line,"");
            inventory[reccount].copies = atoi(item);


            //printf("%s\n",inventory[reccount].publisher);
            reccount++;
            }



    fclose(fp);

printf("My Inventory:\n");  
int i;
for( i = 0; i < count; i++ )
{
    printf( "Title:\t\"%s\"\n", inventory[i].title );
    printf( "Author:\t%s\n", inventory[i].author );
    printf( "Publisher:\t%s\n", inventory[i].publisher );
    printf( "Price:\t$%.02f\n", inventory[i].price );
    printf( "ISBN:\t%s\n", inventory[i].isbn );
    printf( "Pages:\t%d\n", inventory[i].pages );
    printf( "Copies:\t%d\n", inventory[i].copies );
}

    return 0;

}

Answer 1

这不是fgets的问题首先，fgets从文件中读取一行文本，strtok使用分隔符拆分字符串。您可能希望像这样格式化文件：

Magician:Apprentice RaymondE.Feist Spectra(January1,1994) 5.02 0553564943 512 1 
Magician:Master RaymondE.Feist Spectra(January1,1994) 7.99 0553564935 499 1

然后使用" "作为分隔符。其次，在您第一次使用strtok后，请传递NULL而不是line。你可以这样做：

item = strtok(line," ");
strcpy(inventory[reccount].title,item);

item = strtok(NULL," ");
strcpy(inventory[reccount].author,item);

item = strtok(NULL," ");
strcpy(inventory[reccount].publisher,item);

item = strtok(NULL," ");
inventory[reccount].price = atof(item);

item = strtok(NULL," ");
strcpy(inventory[reccount].isbn,item);

item = strtok(NULL," ");
inventory[reccount].pages = atoi(item);

item = strtok(NULL," ");
inventory[reccount].copies = atoi(item);

您还可以使用其他分隔符（例如;，以便您可以在作者姓名中包含空格），然后您可以像这样格式化文件：

Magician:Apprentice;Raymond E. Feist;Spectra(January1,1994);5.02;0553564943;512;1 
Magician:Master;Raymond E. Feist;Spectra(January1,1994);7.99;0553564935;499;1

此外，count和inventory都未定义。你可以这样做（在while(fgets...)循环之前）：

int count = 2;
Book* inventory = malloc(count*sizeof(Book));

或者，如果您希望能够使用不同大小的文件，只需计算行数，然后关闭并重新打开该文件：

int count = 0;
while (fgets(line,9000,fp)) count++;
fclose(fp);
fp = fopen(file_name, "r");
Book* inventory = malloc(count*sizeof(Book));

修改：为了保持文件格式，您需要为每本书调用fgets 7次。不幸的是，fgets包含换行符，因此您需要使用strtok

删除换行符

int count = 0;
while (fgets(line,9000,fp)) count++;
count = count / 7;
fclose(fp);
fp = fopen(file_name, "r");
Book* inventory = malloc(count*sizeof(Book));
int i;

int reccount;
for (reccount = 0; reccount < count; reccount++){


    fgets(line,9000,fp);
    item = strtok(line, "\n");
    strcpy(inventory[reccount].title,item);

    fgets(line,9000,fp);
    item = strtok(line, "\n");
    strcpy(inventory[reccount].author,item);

    fgets(line,9000,fp);
    item = strtok(line, "\n");
    strcpy(inventory[reccount].publisher,item);

    fgets(line,9000,fp);
    inventory[reccount].price = atof(line);

    fgets(line,9000,fp);
    item = strtok(line, "\n");
    strcpy(inventory[reccount].isbn,item);

    fgets(line,9000,fp);
    inventory[reccount].pages = atoi(line);

    fgets(line,9000,fp);
    inventory[reccount].copies = atoi(line);


}

fclose(fp);

C文本文件到struct，array，然后out

1 个答案: