通过php连接到ipp

Question

我怎样才能连接到 ipp 服务器并在没有任何库的情况下找到工作？我在 ubuntu 18 上安装了 cups 2.2。 我尝试过这段代码但不起作用。

$host = "server-ip";
$path = "/jobs";

$fp = fsockopen($host, 631, $errno, $errstr, 30);

if (!$fp) {
    echo "$errstr ($errno)<br />\n";
} else {

    $username = "user";
    $password = "secret";

    $pass = base64_encode($username . ":" . $password);

$dataString = "";

    $dataString .= chr(0x01) . chr(0x01) // 1.1  | version-number
        . chr(0x00) . chr(0x0A) // Get-Jobs | operation-id
        . 1 //           request-id
        . chr(0x01) // start operation-attributes | operation-attributes-tag
        . "utf-8" //charset
        . "en-US" //language
        . "https://server-ip/printers/Virtual_Printer" //printer_uri
        . $username
        . 0 //limit
        . "not-completed" //which_jobs
        . false; //my_jobs

$string = sprintf("POST %s HTTP/1.1\r\n", "/jobs");
    $string .= sprintf("%s: %s\r\n", "User-Agent", "PRINTIPP/0.81+CVS");
    $string .= sprintf("%s: %s\r\n", "Host", $host);
    $string .= sprintf("%s: %s\r\n", "Content-length", strlen($dataString));
    $string .= sprintf("%s: %s\r\n", "Content-type", "application/ipp");
    $string .= sprintf("%s: %s\r\n", "Authorization", "Basic ".$pass);
    $string .= sprintf("%s: %s\r\n", "Data", $dataString);
    $string .= "\r\n";



    fwrite($fp, $string);

    while (!feof($fp)) {
        echo fgets($fp, 1024);
    }

}
    fclose($fp);

我找到了这些库，但对我来说没有用

• https://github.com/nateobray/IPP
• https://github.com/smalot/cups-ipp
• http://www.nongnu.org/phpprintipp/

我想了解 ipp 协议的工作原理并进行连接它。