If it's using the same as your Windows configuration, you should be able to find it like this (untested, as I don't have a Windows server):
<?php
$proxyServerString = shell_exec('reg query "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings" | find /i "proxyserver"');
$proxyServerString = trim($proxyServerString);
/*
$proxyServerString should be 'ProxyServer REG_SZ http=127.0.0.1:8888;https=127.0.0.1:8888'
*/
preg_match("/ProxyServer *REG_SZ *(.*)/i", $proxyServerString, $match);
/*
$match[1] will be something like 'http=127.0.0.1:8888;https=127.0.0.1:8888'
*/
$proxyServersTemp = explode(";", $match[1]);
$proxyServers = array();
foreach ($proxyServersTemp as $proxyServerTemp) {
preg_match("/^(.*?)=(.*?):(.*?)$/", $proxyServerTemp, $proxyMatch);
$proxyServers[] = array(
"protocol" => $proxyMatch[1],
"address" => $proxyMatch[2],
"port" => $proxyMatch[3]
);
}
print_r($proxyServers);
?>
$proxyServers
should now contain something like the following:
Array
(
[0] => Array
(
[protocol] => http
[address] => 127.0.0.1
[port] => 8888
)
[1] => Array
(
[protocol] => https
[address] => 127.0.0.1
[port] => 8888
)
)