cppFileIOPlayersAdvanced

#include <iostream>
#include <fstream>

const int maxNameLen{ 50 };
struct Player
{
    int id;
    char* name {nullptr};
    int rank;

    void init(int idP, const char* nameP, int rankP)
    {
        id = idP;

        setName(nameP);

        rank = rankP;
    }

    void print()
    {
        std::cout << id << ' ' << name << ' ' << rank << '\n';
    }

    void clear()
    {
        delete[] name;
    }

    void setName(const char* nameP)
    {
        size_t len{ strlen(nameP) + 1 };
        if (!name)
        {
            name = new char[len];
        }
        else if (name and strlen(name)+1 < len)
        {
            delete[] name;
            name = new char[len];
        }

        strcpy_s(name, len, nameP);
    }

    void fileWrite(std::ostream& outf)
    {
        outf.write((char*)&id, sizeof(int));
        size_t nameLen = strlen(name) + 1;
        outf.write(name, nameLen);
        if (nameLen < maxNameLen) { outf.seekp(maxNameLen - nameLen, std::ios::cur); };
        outf.write((char*)&rank, sizeof(int));
    }

    void fileRead(std::istream& inf)
    {
        const int bufSize{ maxNameLen + 1 };
        char buf[bufSize];

        inf.read((char*)&id, sizeof(int));
        for (int i{ 0 }; inf.read(buf + i, 1), buf[i] and i < bufSize; ++i);
        int nameLen = strlen(buf) + 1;

        setName(buf);

        if (nameLen < maxNameLen) { inf.seekg(maxNameLen - nameLen, std::ios::cur); };
        inf.read((char*)&rank, sizeof(int));
    }

    void changeName(const char* name)
    {
        std::fstream file;
        file.open("file.dat", std::ios::in | std::ios::out | std::ios::binary);
        int searchId{ 0 };
        int nameLen{ 0 };
        while(!file.eof())
        {
            file.read((char*)&searchId, sizeof(int));

            if (file.fail()) { break; }

            if (searchId == id)
            {
                nameLen = strlen(name) + 1;
                file.seekp((int)file.tellg(), std::ios::beg);
                file.write(name, nameLen);
                file.close();

                setName(name);

                return;
            }
            file.seekg(maxNameLen + sizeof(int), std::ios::cur);
        }
        file.close();
    }
};

void writePlayers(Player* begin, Player* end)
{
    std::ofstream outf;
    outf.open("file.dat", std::ios::binary);
    for (auto player{ begin }; player != end; ++player)
    {
        player->fileWrite(outf);
    }
    outf.close();
}

void readPlayers(Player* begin, Player* end)
{
    std::ifstream inf;
    inf.open("file.dat", std::ios::binary);
    for (auto player{ begin }; player != end; ++player)
    {
        player->fileRead(inf);
    }
    inf.close();
}

void writePlayersFile(Player* playersArr, int playersSize, int append = 0)
{
    std::ofstream outf;
    outf.open("file.dat", std::ios::binary | (append ? std::ios::app : 0));
    for (int i{ 0 }; i < playersSize; ++i)
    {
        outf.write((char*)&playersArr[i].id, sizeof(int));
        size_t nameLen = strlen(playersArr[i].name) + 1;
        outf.write(playersArr[i].name, nameLen);
        if (nameLen < maxNameLen) { outf.seekp(maxNameLen - nameLen, std::ios::cur); };
        outf.write((char*)&playersArr[i].rank, sizeof(int));
    }
    outf.close();
}

void readPlayersFile(Player* playersArr, int playersSize)
{
    std::ifstream inf;
    inf.open("file.dat", std::ios::binary);
    const int bufSzie{ 100 };
    char buf[bufSzie];
    for (int i{ 0 }; i < playersSize; ++i)
    {
        inf.read((char*)&playersArr[i].id, sizeof(int));
        for (int i{ 0 }; inf.read(buf + i, 1), buf[i] and i < bufSzie; ++i);
        int nameLen = strlen(buf) + 1;
        playersArr[i].name = new char[nameLen];
        strcpy_s(playersArr[i].name, nameLen, buf);
        if (nameLen < maxNameLen) { inf.seekg(maxNameLen - nameLen, std::ios::cur); };
        inf.read((char*)&playersArr[i].rank, sizeof(int));
    }
    inf.close();
}

int changePlayersFileById(int searchId, const char* name)
{
    std::fstream file;
    file.open("file.dat", std::ios::in | std::ios::out | std::ios::binary);

    int id{ 0 };
    int nameLen{ 0 };
    for (int i{ 0 }; i < 3; ++i)
    {

        file.read((char*)&id, sizeof(id));
        if (id == searchId)
        {
            nameLen = strlen(name) + 1;
            file.seekp((int)file.tellg(), std::ios::beg);
            file.write(name, nameLen);
            file.close();
            return 0;
        }
        file.seekg(maxNameLen + sizeof(int), std::ios::cur);
    }
    file.close();
    return 1;
}
void printPlayers(Player* begin, Player* end)
{
    for (auto player{ begin }; player != end; ++player)
    {
        player->print();
    }
}

void clearPlayers(Player* begin, Player* end)
{
    for (auto player{ begin }; player != end; ++player)
    {
        player->clear();
    }
}

int main()
{
    const int playersCount{ 3 };
    Player players[playersCount];
    Player* const playersEnd{ players + playersCount };

    players[0].init(2607, "MadMax", 39);
    players[0].setName("MaddyMax");
    players[1].init(2802, "Batman", 25);
    players[2].init(2902, "Joker", 15);

    printPlayers(players, playersEnd);

    writePlayers(players, playersEnd);

    readPlayers(players, playersEnd);

    printPlayers(players, playersEnd);

    players[0].changeName("MAD_MAX");

    readPlayers(players, playersEnd);

    printPlayers(players, playersEnd);

    clearPlayers(players, playersEnd);

    //Player players[3]{ {2607, new char[sizeof("MadMax")]{"MadMax"}, 39},{2802, new char[sizeof("Batman")]{"Batman"}, 25},{2902, new char[sizeof("Joker")]{"Joker"}, 15} };
    //writePlayersFile(players, 3);
    //for (int i{ 0 }; i < 3; ++i) { delete[] players[i].name; };

    //Player readPlayers[3]{};
    //readPlayersFile(readPlayers, 3);
    //printPlayersArr(readPlayers, 3);
    //for (int i{ 0 }; i < 3; ++i) { delete[] readPlayers[i].name; };

    //changePlayersFileById(2802, "BATMAN FOREVER YOUNG!");
    //changePlayersFileById(2902, "Joker Rockker :]");
    //readPlayersFile(readPlayers, 3);
    //printPlayersArr(readPlayers, 3);
    //for (int i{ 0 }; i < 3; ++i) { delete[] readPlayers[i].name; };
}