curl/libcurl获取打开网页平均网速

curl -o /dev/null -s -w %{http_code}:%{http_connect}:%{content_type}:%{time_namelookup}:%{time_redirect}:%{time_pretransfer}:%{time_connect}:%{time_starttransfer}:%{time_total}:%{speed_download} baidu.com

size_t WriteCallback(void *ptr, size_t size, size_t nmemb, void *data)

{

    /* we are not interested in the downloaded bytes itself,

    so we only return the size we would have saved ... */

    (void)ptr;  /* unused */

    (void)data; /* unused */

    return (size_t)(size * nmemb);

}

//获取下载网速

float GetDownloadSpeed(const string &strURL) {

#define CHKSPEED_VERSION "1.0"

    CURL *curl = curl_easy_init();

    float fNetSpeed = -;

    if (curl) {

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

        /* send all data to this function  */

        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);

        if (strURL.find("https:") != string::npos) {

           curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);

           curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);

        }

        /* some servers don't like requests that are made without a user-agent

        field, so we provide one */

        curl_easy_setopt(curl, CURLOPT_USERAGENT,

            "libcurl-speedchecker/" CHKSPEED_VERSION);

        /* Perform the request */

        CURLcode res = curl_easy_perform(curl);

        if (!res) {

            double speed;

            res = curl_easy_getinfo(curl, CURLINFO_SPEED_DOWNLOAD, &speed);

            if (!res) {

                fNetSpeed = speed / 1024.0;//kbyte/sec

            }

        }

    }

    /* cleanup curl stuff */

    curl_easy_cleanup(curl);

    return fNetSpeed;

}