problem with fstream

ivotron

Hi,

I have very strange problem with std::fstream. I want to read a simple two-column space-separated file with the following code:

#include <iostream>
#include <fstream>

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 int main()

{

   std::ifstream file("file.txt");

   unsigned long oldval;

   unsigned long newval;
 
   while(!file.eof()) {

      file >> oldval;

      file >> newval;

      std::cout << oldval << " " << newval << std::endl;

   }

}

The file.txt contains ten lines only:

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 3036679276 4677957

3233819949 6457113

3602920021 7347886

6236944672 16846074

2487223488 3069408

2818574689 4363018

5419052468 13941073

9172944933 31529903

2818574690 4363020

9172944938 31529909

As output, I get an endless printing of the 3rd line. I have tried a lot of variants, like:

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 while(file>>oldval>>newval)

while(file.good())

and I always get the same behavior. It looks like the seek internal pointer of fstream is not moving. Any clues about this? I'm in RH with GCC3.4. Thanks for your time.

ivotron

Hi,

Still trying to solve this. I'm trying reading each line and then, with std::stringstream, pass

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 int main()

{

   std::ifstream file("file.txt");

   unsigned long oldval;

   unsigned long newval;

   std::string line;
 
   while(!file.eof()) {

      std::getline(file, line);

      std::stringstream linestream(line);

      linestream >> oldval;

      linestream >> newval;

      std::cout << oldval << " " << newval << std::endl;

   }

}

I get the following:

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 3036679276 4677957

3233819949 6457113

3602920021 7347886

3602920021 7347886

2487223488 3069408

2818574689 4363018

2818574689 4363018

2818574689 4363018

2818574690 4363020

2818574690 4363020

2818574690 4363020

????? I don't get it :S Any ideas??? I'm starting to believe that my computer is possessed

ivotron

Hi,

Still trying to solve this... I've printed the put pointer, to know if its moving:

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int main()

{

   std::ifstream file("file.txt");

   unsigned long oldval;

   unsigned long newval;
 
   while(!file.eof()) {

      file >> oldval;

      file >> newval;

      std::cout << oldval << " " << newval << std::endl << file.tellg() << std::endl;

   }

}

I get always -1. I also reinstalled gcc.

problem with fstream

re: problem with fstream

re: problem with fstream

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