ifstream problem

Im trying to do this in dev c++

Im basically open a large list which contains filenames to parse
and store the results.

Now what im trying to do here is to open an close a file in order to be able to "parse" a number of files (which are saved in a list)

Code:

 ifstream l_file("list.txt"); //text containing list of files.
  ifstream a_file; //the file to be parsed
  ofstream b_file("final.txt"); //file which will be filled with the result

  while (!l_file.eof()) //open the file list
  {
   l_file>>fname; //send the file to the filename
   a_file.open(fname); //open the text containing emails
   cout<<"filename:"<<fname<<":"<<a_file.is_open()<<endl;
   while (!a_file.eof())
   {
        a_file>>str;
        if (parseline(str)!='\0')
        {
            cout<<"linea:"<<str<<endl;
            cout<<"lineap :"<<parseline(str)<<endl;
            b_file<<parseline(str)<<endl;      //save the parsed data
        }
   }

   a_file.close();
   a_file.clear();
  }
  l_file.close ();
  b_file.close ();

getch();
return 0;
}

I know Is not an ellegant solution (Suggestions accepted ) but is the first one I thought of

It looks like it should work right? well when I try to open the a_file for a second time, the program crashes. thats why I added a_file.clear but it doesnt work. is there a way to use an ifstream with 2 diferent files without crashing? how do you actually close a filestream?

p.s.
oh yeah, the list contains the same file like this

example.txt
example.txt

so is not a file missing problem.

Try to use getline instead of >> when getting the filenames. Also, always check wether your File.open() succeeds or fails. I guess that this is why your program crashes (no need for clear, you can reopen a file assuming you close it first, which you did).
The code below works just fine.

Code:

#include <fstream.h>

int main()
{
   //Data
   char Buffer;
   char FileName[256];
   ifstream FileList;
   ifstream File;
   ofstream NewFile;

   //Attempt to open the list of filenames
   FileList.open("FileList.txt", ios::in);
   if(FileList.fail())
   {
      return 0;
   }

   //Attempt to open the output file
   NewFile.open("Result.txt", ios::out);
   if(NewFile.fail())
   {
      FileList.close();
      return 0;
   }

   //Loops though all filenames in the list
   while(!FileList.eof())
   {
      //Open the files in the list one by one
      FileList.getline(FileName, 255);
      File.open(FileName, ios::in);
      if(!File.fail())
      {
         while(!File.eof())
         {
            //Read one byte
            File.get(Buffer);

            //Filter out EOF character
            //(There must be a better way than this...)
            if(Buffer != 'ÿ')
            {
            	NewFile << Buffer;
            }
         }
         //Add a newline (formating purposes)
         NewFile << endl;
         File.close();
      }
   }

   //Exit
   FileList.close();
   NewFile.close();
   return 0;
}

If someone knows a better way to remove the EOF character at the end of the file, plz tell :).

Well that didnt solved the problem but you did gave me a head start on where to look, aparently the best way to do this is to use dynamic memory allocation to close and recreate this kind of streams in dev c++ it might not be entirely correct since I havent used it much, but it worked for me.


Thanks for the tips anyway.