为什么我的脚本花这么长时间才能检索标头？

Question

<?php
set_time_limit(0);

$errorArr = array();
if (!isset($argv[1]))
{
    array_push($errorArr, "You forgot to enter a host.");
}
if ((isset($argv[1])) AND (!filter_var($argv[1], FILTER_VALIDATE_IP)))
{
    array_push($errorArr, "The host you entered is not a valid IP address.");
}
if (!isset($argv[2]))
{
    array_push($errorArr, "You forgot to select a port.");
}
if (!empty($errorArr))
{
    echo "You have the following errors:\n";
    print_r($errorArr);
    die("Syntax is as follows: php {$argv[0]} host port\n");
}

$host = $argv[1];
$port = $argv[2];

echo ":::Connecting...\n";
$fh = fsockopen($host, $port);
if (!$fh)
{
    die(":::Connection failed.\n:::Aborting.\n");
}
echo ":::Connected!\n:::Sending headers.\n";

$header = "PROPFIND /webdav/ HTTP/1.1\r\n";
$header .= "Host: {$host}\r\n";
$header .= "User-Agent: BitKinex/3.2.3\r\n";
$header .= "Accept: */*\r\n";
$header .= "Pragma: no-cache\r\n";
$header .= "Cache-Control: no-cache\r\n";
$header .= "Depth: 1\r\n";
$header .= "Content-Length: 220\r\n";
$header .= "Content-Type: text/xml\r\n\r\n\r\n";
if (!fwrite($fh, $header))
{
    die(":::Couldn't send headers. Aborting.\n");
}
$exHeader = explode("\r\n", $header);
foreach ($exHeader as $ecHeader)
{
    echo "<<<{$ecHeader}\n";
}
echo "\n:::Retrieving syntax...\n";
while(1)
{
    while ($data = fgets($fh, 512))
    {
        echo ">>>{$data}";
        flush();
    }
}
?>

I'm working on a script to connect to WebDAV, upload a file, and disconnect. It connects and sends headers fine, but then it takes forever to retrieve syntax. At times, it takes several minutes, and I can't understand why. Is it a problem in my code?

And yes, I realize there's an infinite while loop there. That's done on purpose, because I haven't figured out how to know when the server is done sending information to me. So I guess that's another question, if anyone could provide insight to that.

Thanks

Answer 1

Your problem is because you are sending the Content-Length header with a value of 220 , while not sending any content at all. The server hangs in there expecting content, but it never arrives...

And for your infinite loop thing, you don't need it at all. fgets will return false if the connection has closed. Send the Connection: close header to tell Apache to end the connection after the data has been sent. Your while loop will evaluate to false when the data has been read entirely and the connection has closed, and your loop will exit.

Answer 2

You might want to test it using cURL then. Try this one out: http://curl.haxx.se/mail/archive-2006-02/0000.html

That way you can see if it's server side or code side.

Answer 3

WebDAV can CHUG if the machine you are connecting to handles lots of traffic in general. And especially lots of web traffic. The reasons are complex, but solutions I have used in the past have primarily involved coding around the delay. Either by dumping things in a line to wait, or by pushing things to a box that isn't under heavy load but is more directly connected to the server in question and can push the files to it via different means.

This all requires access, however, and if you have control over the machines you are connecting to, you should be able to reconfigure them to give yourself priority. (which may not be an option if you are connecting to a production web server) However, I've never had to deal with this in PHP. So the problem certainly could be caused by other reasons.