Download the latest version of Chromium for Windows using C++ and libCurl. Very similar to the C version.

main.cpp

/*
 * main.cpp

 * Copyright (c) 2013, Jeremiah LaRocco [email protected]

 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <iostream>
#include <algorithm>
#include <string>
#include <cstdio>

#include <curl/curl.h>

int progress_function(void *clientp, double dltotal, double dlnow, double ultotal, double ulnow) {
    int num = 50 * (dlnow/dltotal);
    std::string progBar;
    progBar.reserve(50);
    for (auto i=0; i < 50; ++i) {
        progBar += (i<num)?"#":" ";
    }
    std::cout << "|" << progBar << "| " << int(dlnow) << " of " << int(dltotal) << "\r";
    return 0;
}

const std::string download_to_memory(CURL *curl, std::string url, bool showProgress = false) {
    CURLcode res;

    if (curl == NULL) return false;

    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());

    if (showProgress) {
        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0);
        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progress_function);
    }
    std::string oStr;
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, 0);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,
                     [&oStr](void *buffer, size_t size, size_t nmemb, void *) {
                         size_t thisSize = size * nmemb;
                         oStr.reserve(oStr.size() + thisSize);
                         std::copy((uint8_t*)buffer, (uint8_t*)buffer + thisSize, std::back_inserter(oStr));
                         return thisSize;
                     });

    // Do the download
    res = curl_easy_perform(curl);
    if (res != 0) {
        std::cout << "An error occured while downloading \"" << url << "\"!\nres = " << res << "\n";
        oStr.clear();
        return "";
    }
    return oStr;
}

bool download_to_file(CURL *curl, const std::string &url, const std::string &fname, bool showProgress = true) {
    CURLcode res;

    if (curl == NULL) return false;

    curl_easy_setopt(curl, CURLOPT_URL, url.c_str());

    if (showProgress) {
        curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0);
        curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, progress_function);
    }

    FILE *outf = std::fopen(fname.c_str(), "wb");
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, outf);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite);

    res = curl_easy_perform(curl);
    if (res != 0) {
        std::cout << "An error occured while downloading \"" << url << "\"!\nres = " << res << "\n";
        return false;
    }
    std::fclose(outf);
    return true;
}

void initializeLibs(CURL **curl) {
    // Initialize cUrl
    curl_global_init(CURL_GLOBAL_DEFAULT);
    *curl = curl_easy_init();
}

void cleanupLibs(CURL *curl) {
    curl_easy_cleanup(curl);
    curl_global_cleanup();
}

int main(int argc, char *argv[]) {

    CURL *curl = NULL;
    initializeLibs(&curl);
    
    std::cout << "Fetching latest Chromium build ID.\n";
    const std::string version = download_to_memory(curl,
                                                   "http://commondatastorage.googleapis.com/chromium-browser-continuous/Win/LAST_CHANGE", version);
    if (version.size() == 0) {
        std::cout << "Could not fetch latest version number!\nAborting\n";
        cleanupLibs(curl);
        exit(1);
    }

    std::cout << "Downloading Chromium build: " << version << "\n";
    std::string installerFile = std::string(getenv("TEMP")) + "/mini_installer.exe";
    std::string url = "http://commondatastorage.googleapis.com/chromium-browser-continuous/Win/" + version + "/mini_installer.exe";

    if (!download_to_file(curl, url, installerFile)) {
        std::cout << "\nCould not download version " << version << " of Chromium.\n";
        cleanupLibs(curl);
        exit(1);
    }

    std::cout << "\nInstalling Chromium build " << version << "...\n";
    system(installerFile.c_str());

    std::cout << "Done.\n";

    cleanupLibs(curl);
    return 0;
}

Makefile

uchrome.exe: main.cpp Makefile
    g++ -Wall -O3 -m64 -std=c++11 -I d:\mingw\include -o uchrome.exe main.cpp -Ld:/mingw/bin -lcurl -lws2_32 -lwinmm -Ld:/mingw/lib64 -lssl