C - 如何将值传递给结构变量，然后将结构写入文件

Question

如何将值传递给结构变量 我正在尝试从用户那里获取员工信息，然后将其写入文件，但在输入员工姓名后我得到了segmentation fault。这是我的代码。

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
struct record_em{
    int id;
    char name[20];
    int salary;
    int age;
};
int main( void )
{
    struct record_em employee;
    FILE *fp;
    int id, salary, age;
    char name[20];
    int n=1;
    fp = fopen("empRecord.dat","a");
    while(n==1){
        printf("nEnter Employee IDn");
        scanf("%d",&id);
        employee.id=id;
        printf("nEnter Employee Namen");
        scanf("%s",name);
        employee.name=name;
        printf("nEnter Employee Salaryn");
        scanf("%d",&salary);
        employee.salary=salary;
        printf("nEnter Employee Agen");
        scanf("%d",&age);
        employee.age=age;
        fwrite(&employee,sizeof(employee),1,fp);
        printf("Enter 1 to add new record n");
        scanf("%d",&n);
    }
    fclose(fp);
    return 0;
    }

输出（取自评论）：

Fatmahs-MacBook-Air：~ fatmah$ gcc -o em em.cFatmahs-MacBook-Air：~ fatmah$ ./em输入员工编号88输入员工姓名UU分段错误：11

Answer 1

更改

scanf("%s",name);
employee.name=name;

自

scanf("%s",name);
strcpy(employee.name, name);

的，更好的是，正如Dukeling和hmjd所建议的那样。

scanf("%19s", employee.name);

Answer 2

这是一个主要问题：

scanf("%s",name);
employee.name=name;

成员name是一个数组，您无法分配给它。而是使用strcpy复制到它。

Answer 3

1. 创建一个 typedef 结构record_t，使内容更短、更易于理解。

   typedef struct {
       int id;
       char name[20];
       int salary;
       int age;
   } record_t;
   

2. 首先创建文件并格式化。

   void file2Creator( FILE *fp )
   {
       int i; // Counter to create the file.
       record_t data = { 0, "", 0, 0 }; // A blank example to format the file.
       /* You will create 100 consecutive records*/
       for( i = 1; i <= 100; i++ ){
           fwrite( &data, sizeof( record_t ), 1, fp );
       }
       fclose( fp ); // You can close the file here or later however you need.  
   }
   

3. 编写函数以填充文件。

   void fillFile( FILE *fp )
   {
       int position;
       record_t data = { 0, "", 0, 0 };
   
       printf( "Enter the position to fill (1-100) 0 to finish:n?" );
       scanf( "%d", &position );
       while( position != 0 ){
           printf( "Enter the id, name, and the two other values (integers):n?" );
           fscanf( stdin, "%d%s%d%d", &data.id, data.name, data.salary, data.age );
           /* You have to seek the pointer. */
           fseek( fp, ( position - 1 ) * sizeof( record_t ), SEEK_SET );
           fwrite( &data, sizeof( record_t ), 1, fp );
           printf( "Enter a new position (1-100) 0 to finish:n?" );
           scanf( "%d", &position );
       }
       fclose( fPtr ); //You can close the file or not, depends in what you need.
   }
   

您可以将其用作参考 比较和检查两个文件中的列