Build number generator

main.cpp

/*
Simple program which generates a header file containing a build number.
If the header file is found to exist then the number is incremented and file updated.
If the file is unparsable in some way then it is discarded and a new file starting
with the build number 0 is written.

Include the generated binary as part of your build chain - ie execute it in the
pre-compile stage - and include the resulting output in your source code.
*/
#include <fstream>
#include <string>
#include <iostream>

const std::string LineMatch("BUILDNUMBER");

int main()
{
    std::ifstream file;
    file.open("buildnumber.hpp");

    int buildNumber = 0;

    if (file.good() && file.is_open())
    {
        std::string line;
        while (std::getline(file, line))
        {
            auto pos = line.find(LineMatch);
            if (pos != std::string::npos)
            {
                try
                {
                    buildNumber = std::stoi(line.substr(pos + LineMatch.size() + 1));
                    buildNumber++;
                    std::cout << "Build number set to: " << buildNumber << "\n";
                    break;
                }
                catch(...)
                {
                    //don't do anything we'll just overwrite the file starting at 0 again
                }
            }
        }
    }
    file.close();

    //just overwrite the old file
    std::ofstream oFile;
    oFile.open("buildnumber.hpp");
    if (oFile.good() && oFile.is_open())
    {
        oFile << "#pragma once\n";
        oFile << "#define BUILDNUMBER " << buildNumber << "\n";
        oFile << "#define BUILDNUMBER_STR \"" << buildNumber << "\"\n";
    }
    oFile.close();

    return 0;
}