Runtime C++ |verified| Download May 2026

// download_manager.h #pragma once #include <string> #include <functional> #include <thread> #include <atomic> #include <fstream> #include <memory> #include <curl/curl.h>

DownloadManager::~DownloadManager() cancel(); if (m_downloadThread.joinable()) m_downloadThread.join(); if (m_curl) curl_easy_cleanup(m_curl); curl_global_cleanup();

// Example usage #include <iostream> #include <chrono> runtime c++ download

# Install libcurl (Ubuntu/Debian) sudo apt-get install libcurl4-openssl-dev mkdir build && cd build cmake .. && make Run ./downloader

private: static size_t writeCallback(void* contents, size_t size, size_t nmemb, void* userp); static int progressCallback(void* userp, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow); struct DownloadContext std::ofstream file; size_t downloaded_bytes = 0; size_t total_bytes = 0; ProgressCallback progress_cb; std::string output_path; bool resume_mode = false; ; std::unique_ptr<DownloadContext> m_context; std::thread m_downloadThread; std::atomic<bool> m_activefalse; std::atomic<bool> m_cancelfalse; std::string m_lastError; CURL* m_curl; ; // download_manager

int DownloadManager::progressCallback(void* userp, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow) auto* ctx = static_cast<DownloadContext*>(userp); if (dltotal > 0) ctx->total_bytes = dltotal; if (ctx->progress_cb) float progress = (float)dlnow / dltotal; ctx->progress_cb(progress, dlnow, dltotal); return 0; // Return non-zero to cancel

// Helper: Get file size size_t getFileSize(const std::string& path) struct stat stat_buf; if (stat(path.c_str(), &stat_buf) == 0) return stat_buf.st_size; return 0; // download_manager.h #pragma once #include &lt

size_t DownloadManager::writeCallback(void* contents, size_t size, size_t nmemb, void* userp) size_t real_size = size * nmemb; auto* ctx = static_cast<DownloadContext*>(userp); if (ctx->file.is_open()) ctx->file.write(static_cast<char*>(contents), real_size); ctx->downloaded_bytes += real_size; // Trigger progress callback if (ctx->progress_cb && ctx->total_bytes > 0) float progress = (float)ctx->downloaded_bytes / ctx->total_bytes; ctx->progress_cb(progress, ctx->downloaded_bytes, ctx->total_bytes); return real_size; return 0;