关于链表的读写,请高手指导
这是一段链表的c程序,想实现的的是通过读取文件建立链表(ReadData()),头插法加入新的链表(AddPassenger()),写入更改后的内容(WriteData())。编译通过后跑起来就崩,应该是内存上的问题,但不知道怎么改,请大神改下。
程序代码:#include <stdio.h>
#include <stdlib.h>
#define D:\\ FILENAME
//全局变量
typedef struct passenger{
struct passengerData{
char login_ID[200];
char password[99];
char name[20];
}*passengerDATA;
struct passenger *next;
}PASSENGER;
PASSENGER *head=NULL;
int ReadData();
PASSENGER* AddPassenger();
int WriteData();
int main()
{
ReadData();
AddPassenger();
WriteData();
}
int WriteData()
{
PASSENGER *p;
FILE *fp;
fp=fopen("FILENAME","wb");
if(fp==NULL)
{
printf("open error\n");
return 1;
}
p=head;
while(p!=NULL)
{
if(fwrite(p->passengerDATA,sizeof(struct passengerData),1,fp)!=1)
printf("Error");
else
p=p->next;
}
fclose(fp);
return 0;
}
PASSENGER* AddPassenger()
{
PASSENGER *newMem;
printf("to creat a new account\n");
newMem=(PASSENGER*)malloc(sizeof(PASSENGER));
printf("The ID\n");
scanf("%s",newMem->passengerDATA->login_ID);//->左边必须是指针类型,否则只能用.来寻址
printf("The pssword\n");
scanf("%s",newMem->passengerDATA->password);
printf("The name\n");
scanf("%s",newMem->passengerDATA->name);
newMem->next=head;
head=newMem;
return head;
}
int ReadData()//0正确,1错误
{
PASSENGER *newMem,*tail;
int i;
FILE *fp;
fp=fopen("FILENAME","rb");
if(fp==NULL)
{
printf("open Failed\n");
return 1;
}
newMem=(PASSENGER*)malloc(sizeof(PASSENGER));
while(feof(fp)!=0)
if(fread(head->passengerDATA,sizeof(struct passengerData),1,fp)==1){
head=newMem;
newMem->next=tail;
tail=head;
free(fp);
newMem=(PASSENGER*)malloc(sizeof(PASSENGER));
}
fclose(fp);
return 0;
}


