#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<malloc.h>
#define LEN sizeof(struct student)

struct student
{
   char name[20];
   char phone[20];
   struct student *next;
};

void face(void)
{
  printf("1,addend\n2,dispaly\n3,delete\n4,save\n5,exit\n");
}

void print(struct student *head)
{
   struct student *p;
   p=head;
   printf("the list\n");
   if(head!=NULL)
       do
       {
      printf("name:%s\n",p->name);
      printf("phone:%s\n",p->phone);
      p=p->next;
    }
    while(p!=NULL);
    else
        {
         printf("NO ONE\n");
        }
}

struct student *append(struct student *head)
{
   
   struct student *p0=NULL;
   printf("input the address information:\n");
   p0=(struct student *)malloc(LEN);
   
   
   printf("input name:\n");
      scanf("%s",p0->name);
      
   printf("input phone:\n");
      scanf("%s",p0->phone);

      printf("%s\n",p0->name);
   printf("you addend is succs\n");

      return head;
   
}

struct student *del(struct student *head)
{
   struct student *p1,*p2;
   char name[12];
   printf("input del information:\n");
   scanf("%s\n",name);
   p1 = head;
   if(head == NULL)
       {
      printf("NO information.\n");
      return(head);  
    }
   while(p1!=NULL)
       {
          if(strcmp(p1->name,name)==0)
              {
                 if(p1==head)
               head=p1->next;
           else
               p2->next=p1->next;
           printf("del done\n");
           return(head);
              }
       p2=p1;
       p1=p1->next;
       }
   printf("no information\n");
   return head;
}

int save(struct student *head)//估计错在这里，addend的函数没有传进来，这么改都改不了。
{
   FILE *fp,*fp1;
   struct student *p;
   p=head;
   fp=fopen("address.txt","w+");
   fp1=fopen("address1.txt","w+");
   fprintf(fp1,"information list\n");
   //printf("%s,%s",p->name,p->phone);
   
   while(p!=NULL)
       {
       //fprintf(fp,"%s,%s",p->name,p->phone);
   
    printf("%s\n",p->name);
    printf("%s\n",p->phone);
   
    fprintf(fp1,"name:%s\n",p->name);
    fprintf(fp1,"phone:%s\n",p->phone);
    p=p->next;
       }
   if(p==NULL)
       {printf("this is NULL.\n");}
   

   fclose(fp1);
   fclose(fp);
   printf("save done\n");
   exit(1);
   //return 0;
       }

struct student *load(void)
{
   FILE *fp;
   struct student *head=NULL,*p1=NULL,*p2=NULL;
   char c;
   int i;
   fp=fopen("address.txt","r");
   for(i=1;(c=fgetc(fp))!=-1;i++)
       {
          p1=(struct student *)malloc(LEN);
       if(i==1)
              {
           head=p1;p2=p1;
                 }
       else
              {
           p2->next=p1;p2=p1;
              }
       }
       if(p1==NULL)
           {fclose(fp);return(head);}
       p2->next=NULL;
       fclose(fp);
       return(head);
        
}


int main()
       {
       FILE *fp1,*fp2;
    int c=0;
    struct student *head=NULL;
    if((fp1=fopen("address.txt","r"))==NULL);
        {
            fp2=fopen("address.txt","w");
               fclose(fp2);
        }
    head=load();
    while(1)
        {
        face();
        //int c=0;
        printf("choice\n");
        scanf("%d",&c);

        switch(c)
            {
            case 1:head=append(head);break;
                   //save(qhead);break;
            case 2:print(head);break;
            case 3:head=del(head);break;
            case 4:save(head);break;
            case 5:exit(0);break;
            default:printf("Enter error\n");break;
            }
        printf("Enter\n");
        //face();
        }
    return 0;
}

可以

具体的就是3L他指出的问题，我有的解决了，有的还没有，只要是3，4，5点。

append。从名字上看是想完成向电话薄中添加信息的功能，但实际你没有实现。新结点p0虽然被赋值，但并没有添加到链表当中，还造成了内存泄漏。

del。删除指定名字的电话薄记录对吧。P2在没有赋值前就参与了操作，这会引发异常导致程序中断退出。

save。准备将电话薄保存到文件当中。fp1应该是你调试中加入的临时元素吧。还用exit在这里退出？你的思维很混乱。

load。想载入文件中的电话薄？读数据的指令呢？你写数据用的是fprintf，其中还包含些画蛇添足的说明文字，怎么读数据用起了fgetc？动态申请了一个新结点，但没往结点里填数据，这个链表有什么意义？