#include <string.h> 
#include <stdio.h> 
#include <stdlib.h> 
struct info{ 
  int id; 
  char name[10]; 
  char sex[10]; 
  char col[10]; 
  char sub[15]; 
  char marks[20]; 
  struct info * prev; 
  struct info * next; 
}; 
typedef struct info *st; 
static st head = NULL;//链表头指针 
#define PRINT_ST(str) \ 
  "info:id=%d; name=%s; sex=%s;col=%s; sub=%s; marks=%s\n",\ 
  str->id,str->name, str->sex,str->col, str->sub, str->marks 
int temp = 1; 
int break_up(char *buffer);//分割字符串函数 
int put_in(char* str[]);//放入结构体 
int print_st(st str);//输出结构体，测试用 
char * char_filter( char *str);//去掉行末回车符 
int insert_list(st p);//插入链表 
int main(void) 
{ 
  FILE *stream; 
  char msg[100]; 
  char backup[100]; 
  st p1, p2; 
  /* open a file for update */ 
  stream = fopen("file.txt","r"); 
  /* seek to the start of the file */ 
  fseek(stream, 0, SEEK_SET);//指针指向文件头部 
  /*备份第一行内容*/ 
  fgets(msg, 100, stream) != NULL; 
  strcpy(backup, msg); 
  /* 从第二行开始去数据 */ 
  while( fgets(msg, 100, stream) != NULL) 
  { 
    printf("%s",msg); 
    break_up(msg); 
    memset(msg, 0, sizeof(msg)); 
  } 
  /*先读取一行内容，测试用 
     fgets(msg, 100, stream) != NULL; 
     printf("%s",msg); 
     break_up(msg); 
     */ 
  fclose(stream); 
   /*正序输出链表，测试用*/ 
  p1 = head; 
  puts("\n"); 
  while( p1 != NULL) 
  { 
    print_st(p1); 
    p1 = p1->next;   
  } 
  /*倒序输出链表，测试用*/ 
  p1 = head; 
  puts("\n"); 
  while(p1 != NULL) 
  { 
    p2 = p1; 
    p1 = p1->next; 
  } 
  while(p2 != NULL) 
  { 
    print_st(p2); 
    p2 = p2->prev; 
  } 
   
  /*下面新建文件，倒叙输出到一个新文件new.txt里面*/ 
  stream = fopen("new.txt","w+"); 
  if(fputs(backup, stream) < 0) 
    { 
      perror("fputs error:"); 
    } 
  p1 = head; 
  while(p1 != NULL) 
  { 
    p2 = p1; 
    p1 = p1->next; 
  } 
  while(p2 != NULL) 
  { 
    snprintf(msg, sizeof(msg), PRINT_ST(p2)); 
    printf("test_char:%s\n",msg); 
    fputs(msg, stream); 
    p2 = p2->prev; 
  } 
   
  fclose(stream);   
   
  /*释放链表*/ 
  p1 = head->next; 
  while (p1 != NULL) 
  {   
    p2 = p1; 
    p1 = p1->next; 
    free(p2); 
  } 
  free(head); 
  head = NULL; 
  return 0; 
} 
/*分割字符串*/ 
int break_up(char *buffer) 
{ 
  int i = 0, j = 0; 
  char *p[20]= {NULL}; 
  char *buf=buffer; 
  char *outer_ptr=NULL; 
  char *inner_ptr=NULL; 
  while((p[i]=strtok_r(buf,";",&outer_ptr))!=NULL)  
  { 
    i++; 
    buf=NULL;  
  } 
//  printf("Here we have %d strings\n",i);//测试用 
  for(j=0 ; j<i; j++) 
  { 
    printf("%s\n",p[j]);//输出分割字符串，测试用 
  } 
  put_in(p); 
  return 0; 
} 
/*放入结构体*/ 
int put_in(char* str[]) 
{ 
  st st1 = (st)malloc(sizeof(struct info)); 
  st1->id = atoi(str[0]); 
  strcpy(st1->name, str[1]); 
  strcpy(st1->sex, str[2]); 
  strcpy(st1->col, str[3]); 
  strcpy(st1->sub, str[4]); 
  str[5] = char_filter(str[5]); 
  strcpy(st1->marks, str[5] ); 
  st1->next = NULL; 
  st1->prev = NULL; 
  print_st(st1); 
  if(temp == 1) 
  { 
    head = st1; 
    temp++;   
    return 0; 
  } 
  insert_list(st1); 
  return 0; 
} 
int print_st(st str)// 
{ 
/*  printf("info:id=%d; name=%s; sex=%s; col=%s; sub=%s; marks=%s\n", 
      str->id,str->name, str->sex, str->col, str->sub, str->marks); 
      */ 
  printf(PRINT_ST(str)); 
}   
char *char_filter( char *str) 
{ 
  int i = strlen(str); 
  *(str + i - 1) = ‘\0‘; 
  return str; 
} 
int insert_list(st p) 
{ 
   
  st q = head; 
  while( q->next != NULL) 
  { 
    q = q->next; 
  } 
  q->next = p; 
  p->prev = q; 
  return 0; 
}