PHP 模拟POST请求

 /**
     * 通过post方式提交表单到指定的url上
     * @param string host,array data
     * @return Object
     */
    function posttohost($url, $data) {
        $url = parse_url($url);
        if (!$url) return "couldn't parse url";
        if (!isset($url['port'])) { $url['port'] = ""; }
        if (!isset($url['query'])) { $url['query'] = ""; }
        $encoded = "";
        while (list($k,$v) = each($data)) {
            $encoded .= ($encoded ? "&" : "");
            $encoded .= rawurlencode($k)."=".rawurlencode($v);
        }
        $fp = fsockopen($url['host'], $url['port'] ? $url['port'] : 80);
        if (!$fp) return "Failed to open socket to $url[host]";
        fputs($fp, sprintf("POST %s%s%s HTTP/1.0
", $url['path'], $url['query'] ? "?" : "", $url['query']));
        fputs($fp, "Host: $url[host]
");
        fputs($fp, "Content-type: application/x-www-form-urlencoded
");
        fputs($fp, "Content-length: " . strlen($encoded) . "
");
        fputs($fp, "Connection: close

");
        fputs($fp, "$encoded
");
        $line = fgets($fp,1024);
        if (!preg_match("/^HTTP/1.. 200/i", $line)) return;
        $results = ""; $inheader = 1;
        while(!feof($fp)) {
            $line = fgets($fp,1024);
            if ($inheader && ($line == "
" || $line == "
")) {
                $inheader = 0;
            }
            elseif (!$inheader) {
                $results .= $line;
            }
        }
        fclose($fp);
        return $results;
    }

    function curlPost($url,$post_data){
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL,$url);
//        curl_setopt($ch, CURLOPT_HEADER, false);
//        curl_setopt($ch, CURLOPT_TIMEOUT, 5);
//        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);
        //启用时会发送一个常规的POST请求，类型为：application/x-www-form-urlencoded，就像表单提交的一样。
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch,CURLOPT_BINARYTRANSFER,true);
        curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS,$post_data);
        $info= curl_exec($ch);
        curl_close($ch);
        return $info;

    }

上面一个是使用 fsockopen 和curl进行post提交，我常用的是fsockopen方式。但是PHP的fsockopen、pfsockopen函数会被主机商禁用，只好使用curl模拟POST提交，上面两个都可以完成POST提交，只是为了防范万一某一个方法不行，另一个方法或许就是备用的。

附上生成随机数的方法:

 /**
     * 生成随机验证码
     * @param $length
     * @return null|string
     */
    function code($length){
        $str        = null;
        $strPol     = '1234567890ABCDEFGHIGKLMNOPQRSTUVWXYZabcdefghigklmnopqrstuvwxyz';
        $max        = strlen($strPol)-1;
        for($i=0;$i<$length;$i++){
            $str    .=  $strPol[rand(0,$max)];//rand($min,$max)生成介于min和max两个数之间的一个随机整数
        }
        return $str;
    }