compares the latest tag name to the one provided to the function and returns either true/false if it matches

compare_online_tag_to_our_tag.cpp

#include <curl\curl.h>

#include <nlohmann/json.hpp>
using json = nlohmann::json;

size_t WriteCallback(char* contents, size_t size, size_t nmemb, void* userp)
{
    ((std::string*)userp)->append((char*)contents, size * nmemb);
    return size * nmemb;
}

bool compare_online_tag_to_our_tag(const char* szRepoAndOwner, const char* szCurrentTag)
{
	bool result = true;
	curl_global_init(CURL_GLOBAL_ALL);

	CURL* curl = curl_easy_init();
	if (curl) {
		struct curl_slist* headers = NULL;
		curl_slist_append(headers, "Content-Type: application/json");

		curl_easy_setopt(curl, CURLOPT_URL, std::string("https://api.github.com/repos/").append(szRepoAndOwner).append("/releases/latest").c_str());
#		ifdef _DEBUG
			curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
#		endif
		curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
		curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
		curl_easy_setopt(curl, CURLOPT_USERAGENT, "GitHub API/1.0");
		curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);

		std::string response;
		curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);

		CURLcode res = curl_easy_perform(curl);
		if (res != CURLE_OK) {
#			ifdef _DEBUG
				printf("curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
#			endif
		} else {
			json j = json::parse(response);
			
			if (j.contains("tag_name")) {
				auto tag_name = j["tag_name"].get<std::string>();
				if (!strstr(tag_name.c_str(), szCurrentTag))
					result = false;
			}
		}
		curl_easy_cleanup(curl);
	}
#ifdef _DEBUG
	else
		printf("curl_easy_init() failed\n");
#endif

	curl_global_cleanup();
	return result;
}

// ...

static void thread(void) {
    if(!compare_online_tag_to_our_tag("LemonHaze420/CoolRepo", "v1.0")) {
        // incorrect version!
    }

}