download stuff on windows

iedl.cpp

// This has more chance passing thorugh a (windows) firewall / proxy setup than anything else.
// Downloads files like IE would.

#include <stdio.h>
#include <iostream>
#include "windows.h"
#include "wininet.h"

int main(int argc, char* argv[])
{
  if (argc != 3) {
    std::cerr << "Usage; iedl URL OUTFILENAME" << std::endl;
    return -1;
  }

  char* url = argv[1];
  char *filename = argv[2];

  HINSTANCE h = LoadLibrary("wininet.dll");
  if (!h) {
    std::cerr << "Can't load wininet.dll" << std::endl;
    return -1;
  }

  InternetAttemptConnect(0);
  HINTERNET internet = InternetOpen("IEDL", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
  DWORD flags = INTERNET_FLAG_KEEP_CONNECTION | INTERNET_FLAG_EXISTING_CONNECT | INTERNET_FLAG_PASSIVE;

  HINTERNET connection = InternetOpenUrl(internet, url, NULL, 0, flags, 0);
  if (connection == NULL) {
    std::cerr << "Error making connection with: " << url << std::endl;
    return -1;
  }

  HttpSendRequest(connection, 0, 0, 0, 0);

  DWORD type, type_s;
  type_s = sizeof(type);
  InternetQueryOption (connection, INTERNET_OPTION_HANDLE_TYPE,
		       &type, &type_s);

  switch (type)
    {
    case INTERNET_HANDLE_TYPE_HTTP_REQUEST:
    case INTERNET_HANDLE_TYPE_CONNECT_HTTP:
      type_s = sizeof (DWORD);
      if (HttpQueryInfo (connection,
                         HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER,
                         &type, &type_s, NULL)) {
        if (type == 401) {
          std::cerr << type << " Authorization required" << std::endl;
          InternetCloseHandle(connection);
          return -1;
        }
        else if (type == 407) {
          std::cerr << type << " Proxy authorization required" << std::endl;
          InternetCloseHandle(connection);
          return -1;
        }
        else if (type >= 300) {
          std::cerr << type << " Error" << std::endl;
          InternetCloseHandle(connection);
          return -1;
        }
      }
    default:
      std::cout << type << " Conncetion OK" << std::endl;
    }

  FILE* fp = fopen(filename,"wb");
  if (fp == NULL) {
    std::cerr << "Error opening file" << filename << std::endl;
    InternetCloseHandle(connection);
    return -1;
  }

  DWORD actual = 0;
  char buf[1024];
  int ctr = 0;
  do {
    InternetReadFile(connection, buf, 1024, &actual);
    // std::cout << "Read " << actual << " byte(s)" << std::endl;
    ctr += actual;
    std::cout << "." ;;
    fwrite(buf, sizeof(char), actual, fp);
  } while (actual > 0);
  std::cout << "Read " << ctr << " bytes"<< std::endl;

  fclose(fp);
  InternetCloseHandle(connection);
}

Makefile

all: iedl.exe

iedl.exe: iedl.cpp
	g++ -g iedl.cpp -o iedl.exe -l wininet

clean:
	rm -rf iedl.exe