function downloadToString()
{
$crlf = "\r\n";
// generate request
$req = 'GET ' . $this->_uri . ' HTTP/1.0' . $crlf . 'Host: ' . $this->_host . $crlf . $crlf;
// fetch
$this->_fp = fsockopen(($this->_protocol == 'https' ? 'ssl://' : '') . $this->_host, $this->_port);
fwrite($this->_fp, $req);
while (is_resource($this->_fp) && $this->_fp && !feof($this->_fp)) {
$response .= fread($this->_fp, 1024);
}
fclose($this->_fp);
// split header and body
$pos = strpos($response, $crlf . $crlf);
if ($pos === false) {
return $response;
}
$header = substr($response, 0, $pos);
$body = substr($response, $pos + 2 * strlen($crlf));
// parse headers
$headers = array();
$lines = explode($crlf, $header);
foreach ($lines as $line) {
if (($pos = strpos($line, ':')) !== false) {
$headers[strtolower(trim(substr($line, 0, $pos)))] = trim(substr($line, $pos + 1));
}
}
// redirection?
if (isset($headers['location'])) {
$http = new ilHttpRequest($headers['location']);
return $http->DownloadToString($http);
} else {
return $body;
}
}
/**
* Check latex cgi script
*
* @param string latex cgi url
* @return boolean true -> OK | false -> not OK
*/
function testLatex($a_latex_url)
{
// latex is optional, so empty path is ok
if (trim($a_latex_url) == "") {
return "";
}
// open the URL
include_once "./setup/classes/class.ilHttpRequest.php";
$http = new ilHttpRequest(ilUtil::stripSlashes($a_latex_url) . "?x_0");
$result = @$http->downloadToString();
if (strpos(substr($result, 0, 5), "PNG") !== FALSE || strpos(substr($result, 0, 5), "GIF") !== FALSE) {
return "";
} else {
return "check_failed_latex";
}
}
