//  261.c
#include<stdio.h>
void main()
{
   FILE *fp,*fq;
   char a[100],name[20],x;
   gets(name);
   fp=fopen(name,"r");
   fgets(a,100,fp);
   printf("this file in's neirong is:");
   puts(a);
   gets(name);
   fq=fopen(name,"w");
   rewind(fp);
   while((x=fgetc(fp))!=EOF)
   {
      fputc(x,fq);
   }
   fclose(fp);
   fclose(fq);
   getch();
}

//  262.c
#include<stdio.h>
void main()
{
   FILE *fp;
   char a[200];
   fp=fopen("abc.txt","r");
   fseek(fp,4,0);
   fgets(a,15,fp);
   puts(a);
   getch();
}

//   263.c
#include<stdio.h>
void main()
{
   FILE *fp;
   char x;
   fp=fopen("abc.txt","r");
   do
   {

      while((x=fgetc(fp))!='\n'&&x!=EOF)
         putchar(x);
      printf("\n");
      while((x=fgetc(fp))!='\n'&&x!=EOF);
   }while(x!=EOF);
   getch();
}

//   264.c
#include<stdio.h>
void main()
{
   FILE *fp;
   char a[100];
   int n=0;
   fp=fopen("abc.txt","r");
   while(fgetc(fp)!='\n')n++;
   rewind(fp);
   while(1)
   {
      fgets(a,n+1,fp);
      puts(a);
      fseek(fp,n+3,SEEK_CUR);
      if(fgetc(fp)==EOF)break;
   }
   getch();
}

//   265.c
#include<stdio.h>
void main()
{
   FILE *fp;
   fp=fopen("abc.txt","r");
   fgetc(fp);
      fgetc(fp);
         fgetc(fp);
   printf("%d",ftell(fp));
   getch();
}

//   lianbiao.h
#include<malloc.h>
struct node
{
   int num;
   struct node *next;
};
void putfun(struct node *head)
{
   while(head!=NULL)
   {
      printf("%3d",head->num);
      head=head->next;
   }
}
struct node *fun(int n)
{
   struct node *head,*p1,*p2;
   int i=0;
   head=p1=p2=(struct node *)malloc(sizeof(struct node));
   scanf("%d",&head->num);
   i++;
   while(i<n)
   {
     p2=p1;
     p1=(struct node *)malloc(sizeof(struct node));
     scanf("%d",&p1->num);
     p2->next=p1;
     i++;
   }
   p1->next=NULL;
   return head;
}
struct node *fxfun(struct node *head)
{
    struct node *p1,*p2,*p3,*m;
    if(head->next==NULL)return head;
    m=NULL;
    p2=head;
    p1=p2->next;
    p3=p1->next;
    while(p3!=NULL)
    {
      p2->next=m;
      p1->next=p2;
      m=p2;
      p2=p1;
      p1=p3;
      p3=p3->next;
    }
    p2->next=m;
    p1->next=p2;
    return p1;
}
struct node *delfun(struct node *p,int n)
{
    struct node *head,*m;
    head=m=p;
    if(p->num==n){head=head->next;free(p);return head;}
    while(p!=NULL&&p->num!=n)
    {
       m=p;
       p=p->next;
    }
    if(p!=NULL)m->next=p->next;
    free(p);
    return head;
}
struct node *insfun(struct node *p,int n)
{
   struct node *head=p,*m,*q;
   q=(struct node *)malloc(sizeof(struct node));
   q->num=n;
   if(n<=head->num)
   {
      q->next=head;
      head=q;
      return head;
   }
   while(p->num<n&&p!=NULL)
   {
      m=p;
      p=p->next;
   }
   q->next=p;
   m->next=q;
   return head;
}