CODEWITHSUNDEEP
c++fileconcatenation
user3105558
user3105558

Reputation: 13

Concatenating multiple files into one

Okay, so I want to concatenate multiple files into one. The problem is that the final file is empty. I want to know how I can write stuff into a file without overwriting and so on. Here's my code. Thanks in advance!

    void concatenate()
{
    fstream fileToConcatenate, result;
    unsigned numberOfFiles = 0;
    char fileName[MAX], finalFileName[MAX];
    puts("Please tell me how many files you want to concatenate.");
    cin >> numberOfFiles;
    puts("Please tell me data for the resulted file.\n*Hint: full path followed by the file name.\n*E.g:C:\\Users\\IoanaAlexandra\\test.txt");
    cin >> finalFileName;
    result.open(finalFileName, ios::out|ios::ate);
    for (unsigned i = 0; i < numberOfFiles; i++)
        {
            switch (i)
            {
            case 0:puts("Please tell me the file data for the first file to be concatenated.\n*Hint: full path followed by the file name.\n*E.g:C:\\Users\\IoanaAlexandra\\test.txt"); break;
            case 1:puts("Please tell me the file data for the second file."); break;
            case 2:puts("Please tell me the file data for the third file."); break;
            default:cout << "Please tell me the file data for the " << i << "th file."; break;
            }
            cin >> fileName;
            fileToConcatenate.open(fileName, ios::in);
            if (result.is_open())
            {
                if (fileToConcatenate.is_open())
                {
                    result << fileToConcatenate.rdbuf();
                }
                else
                {
                    puts("The file you are trying to concatenate from doesn't exist!Try again!");
                    concatenate();
                }
            }
            else
            {
                puts("The result file could not be created! Try again!");
                concatenate();
            }
        }
    fileToConcatenate.close();
    result.close();
}

Upvotes: 1

Views: 4795

Answers (1)

Cyclonecode
Cyclonecode

Reputation: 30001

Remove the result.open() from the outside of the loop and try changing your code to something like:

 fileToConcatenate.open(fileName, ios::in);
 if (fileToConcatenate.is_open())
 {
      // open output file
      result.open(finalFileName, ios::out|ios::ate);
      // you should check so the output file really was opened correctly here
      result << fileToConcatenate.rdbuf();
      // close the input file
      fileToConcatenate.close();
      // close output file
      result.close();
 }
 else
 {
      puts("The file you are trying to concatenate from doesn't exist!Try again!");
      concatenate();
 }

You should also close the fileToConcatenate if it was opened before calling concatenate() again.

Upvotes: 3

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