Ftp клиент

#include <iostream>
#include <istream>
#include <ostream>
#include <string>
#include <boost/asio.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/thread/thread.hpp>
 
using boost::asio::ip::tcp;
 
struct endPoint{
    std::string addr;
    int port;
};
 
std::string insertFrom(std::string input_str,int index,int count);
 
endPoint resultToendPoint(std::string result);
 
tcp::socket *socketPtr;
tcp::socket *socket_dataPtr;
 
void closeSocket();
 
int main(int argc, char* argv[]){
 
    endPoint endpoint;
    boost::asio::streambuf result;
    std::istream result_stream(&result);
    std::string resultstr;
    boost::asio::streambuf request;
    std::ostream request_stream(&request);
 
  try{
 
//connecting to command socket
    boost::asio::io_service io_service;
    tcp::resolver resolver(io_service);
    tcp::resolver::query query(argv[1], "ftp");
    tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);
    tcp::socket socket(io_service);
    boost::asio::connect(socket, endpoint_iterator);
 
//check
    if(socket.is_open()){
 
//send request
    request_stream << "USER "login""<<"\r\n";
    request_stream << "PASS "pass"\r\n"<<"\r\n";
    request_stream << "PASV"<<"\r\n";
    boost::asio::write(socket, request);
 
//wait one second
    boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
 
//get result and extract address and port for connecting to data socket
    boost::asio::read_until(socket, result, "\r\n");
    while(std::getline(result_stream,resultstr))
      if(insertFrom(resultstr,0,3)=="227")
            endpoint=resultToendPoint(resultstr);
    std::cout<<endpoint.addr<<std::endl;
    std::cout<<endpoint.port<<std::endl;
 
}else std::cout<<"connection to command socket is fail"<<std::endl;
 
//connecting to data socket
    tcp::endpoint ep(boost::asio::ip::address::from_string(endpoint.addr),endpoint.port);
    tcp::socket socket_data(io_service);
    socket_data.connect(ep);
 
//check
if(socket_data.is_open()){
 
//send request
    request_stream.flush();
    request_stream<<"LIST"<<"r\n";
    boost::asio::write(socket, request);
 
//wait one second
    boost::this_thread::sleep(boost::posix_time::milliseconds(1000));
 
//get result
     boost::asio::read(socket_data, result);
    while(std::getline(result_stream,resultstr))
    std::cout<<resultstr<<std::endl;
 
}else std::cout<<"connection to data socket is fail"<<std::endl;
 
    socketPtr=&socket;
    socket_dataPtr=&socket_data;
 
  }catch (std::exception& e){
        std::cout << "Exception: " << e.what() << "\n";
        closeSocket();
  }
 
//close sockets
    closeSocket();
 
    return 0;
}
 
 
// function extracting part of string from other string
std::string insertFrom(std::string input_str,int index,int count){
    std::string result;
    for(int i=index;i<index+count;i++)
        result.push_back(input_str[i]);
    return result;
}
 
 
// function geting endpoint from result string
endPoint resultToendPoint(std::string result){
 
    endPoint endpoint;
 
//geting base part as (xxx,xxx,xxx,xxx,xxx,xxx)
    for(int i=0;i<=result.size();i++)
        if(result[i]=="("[0])
            for(int u=i;u<result.size();u++)
                if(result[u]==")"[0])
                    for(int o=i+1;o<u;o++)
                        endpoint.addr.push_back(result[o]);
 
 
int s=0;
int p=0;
std::string port;
std::string addr=endpoint.addr;
 
 
//geting address from base string , replace ',' with '.' and geting base port as (xxx,xxx)
    for(int i=0;i<=endpoint.addr.size();i++)
        if(s<4){
if(addr[i]==","[0]){
    addr[i]="."[0];
    s++;
}
}else{
port.push_back(endpoint.addr[i]);
addr.erase(i-p,1);
p++;
    }
    addr.pop_back();
 
 
//spliting the port on two parts;
    bool flag=false;
    std::string a;
    std::string b;
    for(int i=0;i<=port.size()-1;i++){
        if(port[i]==","[0])
            flag=true;
        if(flag==false)
            a.push_back(port[i]);
        else
            b.push_back(port[i+1]);
    }
 
 
//calculating the port and writing the port and the address in the endpoint
    endpoint.port=atoi(a.c_str())*256+atoi(b.c_str());
    endpoint.addr=addr;
 
    return endpoint;
}
 
 
//function closing sockets
void closeSocket(){
    socketPtr->close();
    socket_dataPtr->close();
}