Save a Struct Vector into a Tab delimited Text File

Question

I'm reading a 2 to 4 gb .txt file and then I manipulate some of the data and want to save my struct vector as a tab delimited .txt file. I read some of the other questions but still not clear to me how I'm going to do it in my program.

So my question is: How to save the Input vector results as a tab delimited .txt file?

Below is my code:

#include <iostream>
#include <sstream>
#include <string>
#include <fstream>
#include <vector>
#include <cstdio>

using namespace std;

struct Input_Spec {
    std::string Data;
    std::string Ativo;
    int Buy_Sell;
    double Sequencia;
    double Id;
    int Event;
    std::string Hr_Priority;
    double Priority;
    double Price;
    double Qtd_Total;
    double Qtd_Traded;
    std::string Data_Order;
    std::string Data_Time_Order;
    std::string State_Of_Order;
    std::string Condition_Of_Order;
    double Broker;
};

void split(const std::string &s, char delim, std::string elems[])
{
    std::stringstream ss(s);
    std::string item;

    long i = 0;

    while (std::getline(ss, item, delim))
    {
        elems[i++] = item;
    }
}

int main()
{    
    ifstream infile1("C:\\Teste\\Teste.txt");     
    ofstream output("output.txt");

    string word;
    string columns[16];

    string line;
    int row=0;
    long c=0;
    long filescol=0;

    for (int i = 0; std::getline(infile1, word); ++i)
    {
        row++;
    }

    //cout<<row;

    infile1.close();

    ifstream infile("C:\\Teste\\Teste.txt"); 

    vector<Input_Spec> Input(row);

    while( getline(infile, line))
    {
        split(line,';', columns);

        if (columns[0]!="")
        {
            Input[filescol].Data      =columns[0];
            Input[filescol].Ativo     =columns[1];
            Input[filescol].Buy_Sell   = stoi(columns[2]);
            Input[filescol].Sequencia = stod(columns[3]);
            Input[filescol].Id = stod(columns[4]);
            Input[filescol].Event = stoi(columns[5]);
            Input[filescol].Hr_Priority = columns[6];
            Input[filescol].Priority = stod(columns[7]);
            Input[filescol].Price = stod(columns[8]);
            Input[filescol].Qtd_Total = stod(columns[9]);
            Input[filescol].Qtd_Traded = stod(columns[10]);
            Input[filescol].Data_Order = columns[11];
            Input[filescol].Data_Time_Order = columns[12];
            Input[filescol].State_Of_Order = columns[13];
            Input[filescol].Condition_Of_Order = columns[14];
            Input[filescol].Broker = stod(columns[15]);

            filescol++;
            c++;
        }

        if (c>(999))
        {   
            break;
            infile.close();
            return 0;
        }
    }

    infile.close();
    return 0;
}

Answer 1

Here's a fragment:

ofstream output ("output.txt");
output << Input[filescol].Data << '\t';
output << Input[filescol].Ativo << '\t';
output << Input[filescol].Buy_Sell << '\t';
//...
output << Input[filescol].Broker << '\n';

Is this what you are talking about?

Answer 2

At first, please let me give you some hints on your code: You don't need to count all lines of the input file and you don't need to reserve memory for all items in your vector beforehand. You can use the push_back() function to add items to the vector . This saves you one iteration on the input file.

I put this improvement into the main() function below. I also expanded a little bit on the answer by @ThomasMatthews, so that you can see how to loop over the vector in order to save the data in it:

int main()
{
    ifstream infile("C:\\Teste\\Teste.txt"); 
    ofstream output("C:\\Teste\\output.txt");

    string line;
    string columns[16];

    vector<Input_Spec> Input;
    Input_Spec oneInput;

    while (getline(infile, line))
    {
        split(line, ';', columns);

        if (!columns[0].empty())
        {
            oneInput.Data               = columns[0];
            oneInput.Ativo              = columns[1];
            oneInput.Buy_Sell           = stoi(columns[2]);
            oneInput.Sequencia          = stod(columns[3]);
            oneInput.Id                 = stod(columns[4]);
            oneInput.Event              = stoi(columns[5]);
            oneInput.Hr_Priority        = columns[6];
            oneInput.Priority           = stod(columns[7]);
            oneInput.Price              = stod(columns[8]);
            oneInput.Qtd_Total          = stod(columns[9]);
            oneInput.Qtd_Traded         = stod(columns[10]);
            oneInput.Data_Order         = columns[11];
            oneInput.Data_Time_Order    = columns[12];
            oneInput.State_Of_Order     = columns[13];
            oneInput.Condition_Of_Order = columns[14];
            oneInput.Broker             = stod(columns[15]);

            Input.push_back(oneInput);
        }
    }

    // ----------------------
    // Modify your data here.
    // ----------------------

    for(vector<Input_Spec>::const_iterator it = Input.begin(); it != Input.end(); it++)
    {
        output << it->Data               << '\t';
        output << it->Ativo              << '\t';
        output << it->Buy_Sell           << '\t';
        output << it->Sequencia          << '\t'; 
        output << it->Id                 << '\t';
        output << it->Event              << '\t';
        output << it->Hr_Priority        << '\t';
        output << it->Priority           << '\t';
        output << it->Price              << '\t';
        output << it->Qtd_Total          << '\t';
        output << it->Qtd_Traded         << '\t';
        output << it->Data_Order         << '\t';
        output << it->Data_Time_Order    << '\t';
        output << it->State_Of_Order     << '\t';
        output << it->Condition_Of_Order << '\t';
        output << it->Broker             << '\n';
    }

    output.close();
    infile.close();
    return 0;
}

I guess that more improvements could be done to your code, but this should give you a good start.