C++ http download file

http_download.cpp

#include <iostream>
#include <stdio.h> 

#include <sys/socket.h> 
//#include <stdlib.h> 
#include <netinet/in.h> 
#include <string.h> 
#include <netdb.h>
#include <arpa/inet.h>
//#include <unistd.h>

#include <vector>
#include <fstream>

class HttpDownloader {
    
    
public:
    
    int download(const std::string& host, const std::string& path, const std::string& file){
        const std::string& remoteHostName = host;
        int port = 80;
        std::string remoteIP;
        std::string request;
        
        request.append("GET " + path + " HTTP/1.1\r\n");
        request.append("Host: " + remoteHostName + "\r\n");
        request.append("Connection: close\r\n\r\n");

        struct hostent* ghbn = gethostbyname(remoteHostName.c_str());
        if (!ghbn) {
            printf("Unable to resolve host: %s \n", ghbn->h_name);
            return -1;
        }
        
        remoteIP = inet_ntoa(*(struct in_addr *)ghbn->h_addr_list[0]);
        printf("Connecting to host: %s => %s\n", ghbn->h_name, remoteIP.c_str());
         
        struct sockaddr_in serv_addr; 
        int socket_;

        if ((socket_ = socket(AF_INET, SOCK_STREAM, 0)) < 0) { 
            printf("Socket creation error \n"); 
            return -2;
        } 
        
        memset(&serv_addr, '0', sizeof(serv_addr)); 
        serv_addr.sin_family = AF_INET; 
        serv_addr.sin_port = htons(port); 
           
        if(inet_pton(AF_INET, remoteIP.c_str(), &serv_addr.sin_addr)<=0) { 
            printf("Invalid address or address not supported \n"); 
            return -3;
        } 
       
        if (connect(socket_, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) { 
            printf("Connection failed \n"); 
            return -4;
        } 
        
        if(send(socket_, request.c_str(), strlen(request.c_str()), 0) == -1) {
            return -5;
        }

        std::string rcvStr;
        char buffer[1024] = {0}; 
        int valread = 0; 
        bool isHeader = true;
        std::vector<std::string> header;
        std::vector<char> data;
        std::ofstream fout(file, std::ios::out | std::ios::binary);
        int totalBytes = 0;
        int endOffset = 0;
        
        while ((valread = recv(socket_, buffer, 1024, 0)) > 0) {
            if(isHeader){
                for(int i = 0; i < valread; i++) {
                    if(buffer[i] == '\n') {
                        if(rcvStr.length() > 1){
                            //printf("TEST -> %d %s\n", rcvStr.length(), rcvStr.c_str());
                            header.push_back(rcvStr);
                            rcvStr.clear();
                        } else {
                            isHeader = false;
                            endOffset = i + 1;
                            break;
                        }
                    } else {
                        rcvStr += buffer[i];
                    }
                }
            }
            
            fout.write(&buffer[0] + endOffset, valread - endOffset);
            totalBytes += valread - endOffset;
            endOffset = 0;
        }
        
        fout.close();
        printf("total bytes %d \n", totalBytes);
        
        return 0;
    }
};



int main(int argc, char **argv) {
    
    HttpDownloader t;
    t.download("example.com", "/test", "test.tmp");
    
    return 0;
}