i can't understand why this result is showed~

[Jung Seng Won]

if i input three string, test1 test2 test3 and result is test1 test2 test3 test3 as you can see, test3 show two times. why that result come? void main() { char data[100]; int i; FILE *fp = fopen("D:\\Code\\test\\input.txt","rt"); int lens; int num; char ch; if(fp == NULL) { puts("Error"); exit(0); } while ( !feof(fp) ) { fgets(data, sizeof(data)-1, fp); fputs(data, stdout); } fclose(fp); }

firstly, i am sorry, i am from korea. and i am not good in wriitting english so please understand~ Thank you everyone~

[_AnsHUMAN_]

Your code appears to be correct. Did you cross check if that file contains three entries only?

Somethings seem HARD to do, until we know how to do them. ;-)_AnShUmAn_

[Cedric Moonen]

Check the documentation of fgets: If the End-of-File is encountered and no characters have been read, the contents of str remain unchanged and a null pointer is returned. The end of file is detected once you try to read after the last character of your file. So, in your case, you will still execute fputs even if the eof was detected. You should do something like this instead:

char* pTemp = fgets(data, sizeof(data)-1, fp);
while (pTemp)
{
fputs(data, stdout);
pTemp = fgets(data, sizeof(data)-1, fp);
}

EDIT: oh and BTW, this kind of problem can be tracked quite easily by using your debugger. It is much faster than asking a question on a forum ;) .

Cédric Moonen Software developer
Charting control [v1.4] OpenGL game tutorial in C++

[SandipG]

Jung Seng Won wrote:

while ( !feof(fp) ) { fgets(data, sizeof(data)-1, fp); fputs(data, stdout); }

Modify your while loop as below

while ( !feof(fp) )
{
if( fgets(data, sizeof(data)-1, fp) == NULL)
break;
else
fputs(data, stdout);
}

Regards, Sandip.

[CPallini]

Jung Seng Won wrote:

why that result come?

Because: Your file ends with an empty line and your program doesn't check fgets return value. Change

Jung Seng Won wrote:

fgets(data, sizeof(data)-1, fp); fputs(data, stdout);

with

if( fgets(data, sizeof(data)-1, fp) )
fputs(data, stdout);

:)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong. -- Iain Clarke
[My articles]

[Stephen Hewitt]

Assuming you're using C++ forget about all that C-style file manipulation bollocks and do something like the following:

// VanillaConsole.cpp : Defines the entry point for the console application.
//
 
#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
 
int main()
{
ifstream ifs("C:\\Data.txt");
if (!ifs)
{
cerr << "Failed to open file!" << endl;
return -1;
}
 
string line;
while (getline(ifs, line))
{
cout << line << endl;
}
 
return 0;
}

Easier to understand and no limit on the length of a line.

Steve