作者HollisterCo (HCO)
看板C_and_CPP
標題[問題] fscanf
時間Thu Feb 19 21:33:31 2009
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct data *ptr;
struct data
{
char name[5];
int birth_year;
int birth_month;
int birth_day;
char phone[10];
struct data *next;
};
typedef struct data node;
/*void print_data(ptr head)
{
while(head->next!=NULL)
{
printf("%-5s\t%-4d/%-2d/%-2d\t%-10s\n",
head->name,head->birth_year,head->birth_month,head->birth_day,
head->phone);
head=head->next;
}
}*/
ptr Build_data(ptr head,char Build_name[5],
int Build_birthyear,int Build_birthmonth,int Build_birthday,char Build_phone[10])
{
ptr tmp=(ptr)malloc(sizeof(struct data));
strcpy(tmp->name,Build_name);
tmp->birth_year=Build_birthyear;
tmp->birth_month=Build_birthmonth;
tmp->birth_day=Build_birthday;
strcpy(tmp->phone,Build_phone);
tmp->next=head;
head=tmp;
return head;
}
int main()
{
FILE *fp=fopen("input.txt","r+");
ptr start=NULL;
char data_name[5];
int data_birth_year;
int data_birth_month;
int data_birth_day;
char data_phone[10];
while(fscanf(fp,"%s\t%d\t%d\t%d\t%s",data_name,
&data_birth_year,&data_birth_month,&data_birth_day,data_phone)!=EOF)
{
start=Build_data(start,data_name,
data_birth_year,data_birth_month,data_birth_day,data_phone);
}
fprintf(fp,"\n%-5s\t%-10s\t%-10s\n","Name","Birthday","Phone");
while(start!=NULL)
{
fprintf(fp,"%-5s\t%-4d/%2d/%2d\t%-10s\n",start->name,
start->birth_year,start->birth_month,start->birth_day,start->phone);
start=start->next;
}
//print_data(fp);
fclose(fp);
system("pause");
return 0;
}
------------------------------------------------------------------------------
------------------------------------------------------------------------------
input.txt
Ken 1986 10 29 0928-123456
Mary 1988 1 30 04-25687755
Evan 1990 6 4 0937-845663
----------------------------------------------
我執行結果
Ken 1986 10 29 0928-123456
Mary 1988 1 30 04-25687755
Evan 1990 6 4 0937-845663
Name Birthday Phone
Evan 1990/ 6/ 4 0937-845663
Mary 1988/ 1/30 04-25687755
Ken 1986/10/29 0928-123456
---------------------------------------------
我想請問為什麼我fscanf資料出來了那最後fprintf還有原來資料??
謝謝大大~~!
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1F：推 leslieha:fscnaf完file offset停在file尾巴 你直接fprintf就append 02/19 21:55
2F：→ HollisterCo:謝謝樓上 原來加個rewind就好了耶... 02/19 22:10
3F：→ leslieha:若你寫入的資料量比原來的少 rewind後原本資料不會全覆蓋 02/19 22:32
4F：→ leslieha:保險就fclose();fopen(xxx,"w"); 02/19 22:33