Task: Append a record to the end of a text file


C++: #include <iostream>
#include <fstream>
#include <string>
#include <vector>

std::ostream& operator<<(std::ostream& out, const std::string s) {
    return out << s.c_str();
}

struct gecos_t {
    std::string fullname, office, extension, homephone, email;

    friend std::ostream& operator<<(std::ostream&, const gecos_t&);
};

std::ostream& operator<<(std::ostream& out, const gecos_t& g) {
    return out << g.fullname << ',' << g.office << ',' << g.extension << ',' << g.homephone << ',' << g.email;
}

struct passwd_t {
    std::string account, password;
    int uid, gid;
    gecos_t gecos;
    std::string directory, shell;

    passwd_t(const std::string& a, const std::string& p, int u, int g, const gecos_t& ge, const std::string& d, const std::string& s)
        : account(a), password(p), uid(u), gid(g), gecos(ge), directory(d), shell(s)
    {
        
    }

    friend std::ostream& operator<<(std::ostream&, const passwd_t&);
};

std::ostream& operator<<(std::ostream& out, const passwd_t& p) {
    return out << p.account << ':' << p.password << ':' << p.uid << ':' << p.gid << ':' << p.gecos << ':' << p.directory << ':' << p.shell;
}

std::vector<passwd_t> passwd_list{
    {
        "jsmith", "x", 1001, 1000,
        {"Joe Smith", "Room 1007", "(234)555-8917", "(234)555-0077", "jsmith@rosettacode.org"},
        "/home/jsmith", "/bin/bash"
    },
    {
        "jdoe", "x", 1002, 1000,
        {"Jane Doe", "Room 1004", "(234)555-8914", "(234)555-0044", "jdoe@rosettacode.org"},
        "/home/jdoe", "/bin/bash"
    }
};

int main() {
    
    std::ofstream out_fd("passwd.txt");
    for (size_t i = 0; i < passwd_list.size(); ++i) {
        out_fd << passwd_list[i] << '\n';
    }
    out_fd.close();

    
    out_fd.open("passwd.txt", std::ios::app);
    out_fd << passwd_t("xyz", "x", 1003, 1000, { "X Yz", "Room 1003", "(234)555-8913", "(234)555-0033", "xyz@rosettacode.org" }, "/home/xyz", "/bin/bash") << '\n';
    out_fd.close();

    
    std::ifstream in_fd("passwd.txt");
    std::string line, temp;
    while (std::getline(in_fd, temp)) {
        
        if (!temp.empty()) {
            line = temp;
        }
    }
    if (line.substr(0, 4) == "xyz:") {
        std::cout << "Appended record: " << line << '\n';
    } else {
        std::cout << "Failed to find the expected record appended.\n";
    }

    return 0;
}


C#: using System;
using System.IO;

namespace AppendPwdRosetta
{
    class PasswordRecord
    {
        public string account, password, fullname, office, extension, homephone, email, directory, shell;
        public int UID, GID;
        public PasswordRecord(string account, string password, int UID, int GID, string fullname, string office, string extension, string homephone, 
            string email, string directory, string shell)
        {
            this.account = account; this.password = password; this.UID = UID; this.GID = GID; this.fullname = fullname; this.office = office;
            this.extension = extension; this.homephone = homephone; this.email = email; this.directory = directory; this.shell = shell;
        }
        public override string ToString()
        {
            var gecos = string.Join(",", new string[] { fullname, office, extension, homephone, email });
            return string.Join(":", new string[] { account, password, UID.ToString(), GID.ToString(), gecos, directory, shell });
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            var jsmith = new PasswordRecord("jsmith", "x", 1001, 1000, "Joe Smith", "Room 1007", "(234)555-8917", "(234)555-0077", "jsmith@rosettacode.org", 
                "/home/jsmith", "/bin/bash");
            var jdoe = new PasswordRecord("jdoe", "x", 1002, 1000, "Jane Doe", "Room 1004", "(234)555-8914", "(234)555-0044", "jdoe@rosettacode.org", "/home/jdoe", 
                "/bin/bash");
            var xyz = new PasswordRecord("xyz", "x", 1003, 1000, "X Yz", "Room 1003", "(234)555-8913", "(234)555-0033", "xyz@rosettacode.org", "/home/xyz", "/bin/bash");

            
            File.WriteAllLines("passwd.txt", new string[] { jsmith.ToString(), jdoe.ToString() });

            
            File.AppendAllText("passwd.txt", xyz.ToString());

            
            string[] lines = File.ReadAllLines("passwd.txt");
            Console.WriteLine("Appended record: " + lines[2]);
        }
    }
}