trein-307.cpp

trein-307.cpp

#include <fstream>
#include <iostream>
#include <vector>

using namespace std;

int main()
{
  string line_passwd, line_group;

  struct
  {
    fstream readFile(string file)
    {
      fstream arq(file, ios::in);
      if (!arq.is_open()) {
        cout << "Não foi possível abrir o arquivo " << file;
        exit(0);
      }
      return arq;
    };

    vector<string> explode(string separador, string frase)
    {
      int prox = separador.size();
      vector<string> ret;
      string::size_type ini, fim;
      ini = fim = 0;
      while (true) {
        fim = frase.find(separador, ini);
        if (fim == string::npos) {
          ret.push_back(frase.substr(ini, frase.size() - ini));
          break;
        }
        ret.push_back(frase.substr(ini, fim - ini));
        ini = fim + prox;
      }
      return ret;
    }
  } wl;

  vector<pair<string, string>> users;

  fstream file_group = wl.readFile("/etc/group");
  fstream file_passwd = wl.readFile("/etc/passwd");
  fstream arq("teste.txt", ios::out);

  while (getline(file_passwd, line_passwd)) {
    vector<string> passwd_fields = wl.explode(":", line_passwd);
    users.push_back(make_pair(passwd_fields[0], passwd_fields[3]));
  }

  while (getline(file_group, line_group)) {
    vector<string> group_fields = wl.explode(":", line_group);
    for (pair<string, string> arr : users) {
      if (group_fields[2] == arr.second) {
        arq << arr.first << " -> " << arr.second << " -> " << group_fields[0]
            << endl;
      }
    }
  }

  file_passwd.close();
  file_group.close();
  arq.close();
  exit(0);
}