I was using this program for select a set of data from a txt file and create a histogram:

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

using namespace std;

int GetPowerOfTen(unsigned int i){
    if(i==0) return 0;
    else return (int)log10(i);
}

int main(int argc, char* argv[]){

    //Variables containing general information are declared here
    string inputFileName;
    string outputFileName = "output.txt";
    int rebinFactor = 1;

    if(argc < 2){
        cout << "Error: not enough parameters!" << endl;
        cout << "For help type " << endl;
        cout << "./RawToHisto -h " << endl;
        return -1;
    }

    //User interface
    for(int i=1; i<argc; i++){
        string option = string(argv[i]);

        if( option == "-h" || option == "--help" ){
            cout << "Usage:n";
            cout << "./RawToHisto [options, ...] n";
            cout << "t-intfilenametttSpecify input file namen";
            cout << "t-outtfilenametttSpecify output file name (default is output.txt)n";
            cout << "t-rebint[#]tttSpecify rebin factor (default is 1)n";
            cout << endl;
            return 0;
        }

        if ( option == "-in"){
            inputFileName = string(argv[++i]);
            continue;
        }

        if ( option == "-out"){
            outputFileName = string(argv[++i]);
            continue;
        }

        if ( option == "-rebin"){
            rebinFactor = stoi(argv[++i]);
            continue;
        }

        cout << "Option " << option << " not implemented" << endl;
        return -1;
    }

    cout << "Converting raw data to histogram format with the following parameters:n";
    cout << "Input file name: " << inputFileName << "n";
    cout << "Output file name: " << outputFileName << "n";
    cout << "Rebin factor: " << rebinFactor << "n";
    cout << endl;

    //Here we open the input file
    ifstream fin (inputFileName.c_str());
    if(!fin.is_open()){
        cout << "Error: cannot open input file " << inputFileName << endl;
        return -1;
    } else cout << "Input file opened" << endl;

    //Here we open the output file
    ofstream fout (outputFileName.c_str());
    if(!fout.is_open()){
        cout << "Error: cannot open output file " << inputFileName << endl;
        return -1;
    } else cout << "Output file created" << endl;

    //first we load all the input data in a vector
    string temp;
    vector<int>data;
    while(getline(fin,temp,',')){
        data.push_back(stoi(temp));
    }
    cout << "Data loaded in memory" << endl;
    cout << "Size of vector is " << data.size() << endl;

    int powerOfTen;

    int binAdded = 0;
    double binCenter = 0;
    double binContent = 0;

    for(unsigned int i=0; i<(data.size()-1); i++){

        powerOfTen = GetPowerOfTen(i);
        switch(powerOfTen){
            case 0: binCenter+=data.at(i) % 10 + 0.5; break;
            case 1: binCenter+=data.at(i) % 100 + 0.5; break;
            case 2: binCenter+=data.at(i) % 1000 + 0.5; break;
            case 3: binCenter+=data.at(i) % 10000 + 0.5; break;
            default: cout << "Error: powerOfTen is " << powerOfTen << endl; break;
        }
        
        powerOfTen = GetPowerOfTen(i+1);
        switch(powerOfTen){
            case 0: binContent+=data.at(i+1) / 10; break;
            case 1: binContent+=data.at(i+1) / 100; break;
            case 2: binContent+=data.at(i+1) / 1000; break;
            case 3: binContent+=data.at(i+1) / 10000; break;
            default: cout << "Error: powerOfTen is " << powerOfTen << endl; break;
        }
        binAdded++;

        if(binAdded == rebinFactor){
            //we calculate the average as the binCenter
            binCenter = binCenter / binAdded;

            fout << binCenter << "t" << binContent << "n";

            binAdded = 0;
            binCenter = 0;
            binContent = 0;
        }
    }

    //check if we wrote the last bin
    if(binAdded != 0){
        //we calculate the average as the binCenter
        binCenter = binCenter / binAdded;

        fout << binCenter << "t" << binContent << "n";
    }

    cout << "nRaw data successfully converted to histogram format" << endl;

    return 0;
}

but when I run it from the terminal the output file is totaly blank and I don’t know why, I’m sorry for this stupid question but I’m new to Mac OS and when I run this program for the first time I was using linux and there everything worked fine

Jack@airjack dati % g++ -Wall rawtohisto.cpp -o histo
Jack@airjack dati % ./histo -in dati1min.txt -out dati1.txt
Converting raw data to histogram format with the following parameters:
Input file name: dati1min.txt
Output file name: dati1.txt
Rebin factor: 1

Input file opened
Output file created
Data loaded in memory
Size of vector is 1

Raw data successfully converted to histogram format