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;
}
										
					
	
											
	    
											