将多个文件连接为一个文件

Concatenating multiple files into one

本文关键字:文件 一个 连接      更新时间:2023-10-16

好的,所以我想将多个文件连接到一个文件中。问题是最终文件是空的。我想知道如何在不重写的情况下将内容写入文件。这是我的代码。提前感谢!

    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();
}

从循环外部删除result.open(),并尝试将代码更改为类似以下内容:

 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();
 }

如果fileToConcatenate在再次调用concatenate()之前已打开,则还应关闭它。