How do I split a record of text into text file in C-CodePudding

So I'm working on a simple file manipulating project where I need to append a new text on a single line, so, to visualize that suppose I have a text file called main.txt and in that file it contains a row of text that looks like this:

[AB]
1
2

Now that lets say I want to add another text: [CB] & 4,5, then I want the updated file to looked like this:

[AB] [CB]

1     4

2     5

But turns out it looked like this instead:

[Ab]
1
2
    [CB]
    4
    5

Here's what I've tried so far

#include <iostream>
#include <stdio.h>
#include <fstream>
#include <string>

int main() {

    std::ofstream file("C:\users\USER\Documents\CPPPRoject\nice.txt",std::ios::out|std::ios::app);
    file << "\t" << "[CB]" << "\n";
    file << "\t" << 4 << "\n";
    file << "\t" << 5 << "\n";

    return 0;
}

CodePudding user response：

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    // we have only 1 column in this example and also we have only 2 rows of data
    int columnCount = 1, dataRows = 2;
    string newColumnName;
    int data1, data2;
    cout << "enter the column name: ";
    cin >> newColumnName;
    // getting the new datas based on the amount of the rows
    int *data = new int[dataRows];
    for (int i = 0; i < dataRows; i  )
        cin >> data[i];
    // opening the orginal.txt and pasting it into copy.txt with new data
    fstream original, copy;
    original.open("original.txt", ios::in);
    copy.open("copy.txt", ios::out);
    // copy & paste the columns
    string inStr;
    for (int i = 0; i < columnCount; i  )
    {
        original >> inStr;
        copy << inStr << " ";
    }
    copy << newColumnName << "\n";
    // copy past the columns
    int inData;
    for (int i = 0; i < dataRows; i  )
    {
        for (int j = 0; j < columnCount; j  )
        {
            original >> inData;
            copy << inData << "    ";
        }
        copy << data[i] << "\n";
    }
    original.close();
    copy.close();
    // deleting the original and renaming the copy.txt
    remove("original.txt");
    rename("copy.txt", "original.txt");
    return 0;
}

this is a simple code to add a column to the text file which only have 1 column of data , for doing it to larger file you can adjust columnCount and dataRows .

sample test of code :

original.txt before running the code

[AB]
5
6

program inputs ( column name and new data to insert)

enter the column name: [CD]
1 2

original.txt file after execution of the code

[AB] [CD]
5    1
6    2