curl and ping - how to check whether a website is either up or down?

something like this should work

    $url = 'yoururl';    $ch = curl_init($url);    curl_setopt($ch, CURLOPT_NOBODY, true);    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);    curl_exec($ch);    $retcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);    curl_close($ch);    if (200==$retcode) {        // All's well    } else {        // not so much    }

curl -Is $url | grep HTTP | cut -d ' ' -f2

function checkStatus($url) {    $agent = "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; pt-pt) AppleWebKit/533.20.25 (KHTML, like Gecko) Version/5.0.4 Safari/533.20.27";    // initializes curl session    $ch = curl_init();    // sets the URL to fetch    curl_setopt($ch, CURLOPT_URL, $url);    // sets the content of the User-Agent header    curl_setopt($ch, CURLOPT_USERAGENT, $agent);    // make sure you only check the header - taken from the answer above    curl_setopt($ch, CURLOPT_NOBODY, true);    // follow "Location: " redirects    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);    // return the transfer as a string    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);    // disable output verbose information    curl_setopt($ch, CURLOPT_VERBOSE, false);    // max number of seconds to allow cURL function to execute    curl_setopt($ch, CURLOPT_TIMEOUT, 5);    // execute    curl_exec($ch);    // get HTTP response code    $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);    curl_close($ch);    if ($httpcode >= 200 && $httpcode < 300)        return true;    else        return false;}// how to use//===================if ($this->checkStatus("http://www.dineshrabara.in"))    echo "Website is up";else    echo "Website is down";exit;