php各个版本curl上传文件的兼容实现

 // 以POST方式提交数据
    public function post_data($url, $param, $is_file = false, $return_array = true) {
       ........
        $ch = curl_init ();
        curl_setopt ( $ch, CURLOPT_URL, $url );
        curl_setopt ( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
        curl_setopt ( $ch, CURLOPT_SSL_VERIFYPEER, FALSE );
        curl_setopt ( $ch, CURLOPT_SSL_VERIFYHOST, FALSE );
        curl_setopt ( $ch, CURLOPT_HTTPHEADER, $header );
        curl_setopt ( $ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)' );
        curl_setopt ( $ch, CURLOPT_FOLLOWLOCATION, 1 );
        curl_setopt ( $ch, CURLOPT_AUTOREFERER, 1 );

        curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, true );
        if($is_file){
            if(version_compare(phpversion(),'5.6')>=0){
                if(version_compare(phpversion(),'7')>=0){
                    $param['media'] = new CURLFile(ltrim($param['media'], '@'));
                }else{
                    curl_setopt ( $ch, CURLOPT_SAFE_UPLOAD, false);
                }
            }
        }
        curl_setopt ( $ch, CURLOPT_POSTFIELDS, $param );

        $res = curl_exec ( $ch );

        curl_close ( $ch );

       .......

        return $res;
    }