#include <stdlib.h>
#include <stdio.h>
#include <curl/curl.h>

static size_t write_callback(char *ptr, size_t size, size_t nmemb, void *stream)
{
    size_t written = fwrite(ptr, size, nmemb, (FILE *)stream);
    return written;
}

int main(void)
{
    int ret = EXIT_FAILURE;
    if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
        fputs("error: curl_global_init failed.\n", stderr);
        return ret;
    }

    CURL *curl = curl_easy_init();
    if (!curl) {
        fputs("error: curl_easy_init failed.\n", stderr);
        goto GLOB_CLEAN;
    }

    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

    /* curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L); */

    char const* file_name = "example.html";
    FILE *stream = fopen(file_name, "w");
    if (!stream) {
        fprintf(stderr, "failed to open %s\n", file_name);
        goto EASY_CLEAN;
    }

    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void*)stream);

    CURLcode result = curl_easy_perform(curl);
    fclose(stream);

    if (result != CURLE_OK) {
        fprintf(stderr, "error: %s\n", curl_easy_strerror(result));
        goto EASY_CLEAN;
    }

    ret = EXIT_SUCCESS;

EASY_CLEAN:
    curl_easy_cleanup(curl);
GLOB_CLEAN:
    curl_global_cleanup();
    return ret;
}