The following function will work only once when called multiple times.  My guess is that the file pointer have to be reset (feof($fp) shows true after the first time the function is called).

function get_data() {
        $fp = fsockopen("www.php.net", 80, &$errno, &$errstr);

        if (!$fp) {
                echo "$errstr ($errno)<br>\n";
                $err = 1;
        } else {
                fputs($fp,"GET /quote.asp?Symbol=$ticker HTTP/1.0\n\n");
                echo "$fp, ", feof($fp), "\n";
                while(!feof($fp)) {
                        $resp .= fgetss($fp,4096);
                }
                fclose($fp);
        }
        echo $resp;
}


Let's say I do the following:

for ($i=0;$i<10;$i++) {
        echo "start...\n";
        get_data();
}

It will return valid output for the first time, and the rest will just be blank.