<?php
class Util
{
/**
* Displays an error message and stops script execution.
* If CONFIG_DEBUG is true, it will also dump a stack trace
* and all globally defined variables.
* (As this might reveal sensistive data you should never enable it in production)
*/
public static function traceError($message)
{
Header('Content-Type: text/plain; charset=utf-8');
echo "--------------------\nFlagrant system error:\n$message\n--------------------\n\n";
if (defined('CONFIG_DEBUG') && CONFIG_DEBUG) {
debug_print_backtrace();
echo "\n\n";
print_r($GLOBALS);
}
exit(0);
}
/**
* Redirects the user via a '302 Moved' header.
* An active session will be saved, any messages that haven't
* been displayed yet will be appended to the redirect.
*/
public static function redirect($location)
{
Session::save();
$messages = Message::toRequest();
if (!empty($messages)) {
if (strpos($location, '?') === false) {
$location .= '?' . $messages;
} else {
$location .= '&' . $messages;
}
}
Header('Location: ' . $location);
exit(0);
}
/**
* Verify the user's token that protects agains CSRF.
* If the user is logged in and there is no token variable set in
* the request, or the submitted token does not match the user's
* token, this function will return false and display an error.
* If the token matches, or the user is not logged in, it will return true.
*/
public static function verifyToken()
{
if (Session::get('token') === false) return true;
if (isset($_REQUEST['token']) && Session::get('token') === $_REQUEST['token']) return true;
Message::addError('token');
return false;
}
/**
* Simple markup "rendering":
* *word* is bold
* /word/ is italics
* _word_ is underlined
* \n is line break
*/
public static function markup($string)
{
$string = htmlspecialchars($string);
$string = preg_replace('#(^|[\n \-_/\.])\*(.+?)\*($|[ \-_/\.\!\?,:])#is', '$1<b>$2</b>$3', $string);
$string = preg_replace('#(^|[\n \-\*/\.])_(.+?)_($|[ \-\*/\.\!\?,:])#is', '$1<u>$2</u>$3', $string);
$string = preg_replace('#(^|[\n \-_\*\.])/(.+?)/($|[ \-_\*\.\!\?,:])#is', '$1<i>$2</i>$3', $string);
return nl2br($string);
}
/**
* Common initialization for download and downloadToFile
* Return file handle to header file
*/
private static function initCurl($url, $timeout, &$head)
{
$ch = curl_init();
if ($ch === false) Util::traceError('Could not initialize cURL');
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, ceil($timeout / 2));
curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_AUTOREFERER, true);
curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);
curl_setopt($ch, CURLOPT_MAXREDIRS, 6);
$tmpfile = '/tmp/' . mt_rand() . '-' . time();
$head = fopen($tmpfile, 'w+b');
if ($head === false) Util::traceError("Could not open temporary head file $tmpfile for writing.");
curl_setopt($ch, CURLOPT_WRITEHEADER, $head);
return $ch;
}
/**
* Read 10kb from the given file handle, seek to 0 first,
* close the file after reading. Returns data read
*/
private static function getContents($fh)
{
fseek($fh, 0, SEEK_SET);
$data = fread($fh, 10000);
fclose($fh);
return $data;
}
/**
* Download file, obey given timeout in seconds
* Return data on success, false on failure
*/
public static function download($url, $timeout, &$code)
{
$ch = self::initCurl($url, $timeout, $head);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$data = curl_exec($ch);
$head = self::getContents($head);
if (preg_match('#^HTTP/\d+\.\d+ (\d+) #', $head, $out)) {
$code = (int)$out[1];
} else {
$code = 999;
}
curl_close($ch);
return $data;
}
/**
* Download file, obey given timeout in seconds
* Return true on success, false on failure
*/
public static function downloadToFile($target, $url, $timeout, &$code)
{
$fh = fopen($target, 'wb');
if ($fh === false) Util::traceError("Could not open $target for writing.");
$ch = self::initCurl($url, $timeout, $head);
curl_setopt($ch, CURLOPT_FILE, $fh);
$res = curl_exec($ch);
$head = self::getContents($head);
curl_close($ch);
fclose($fh);
if ($res === false) {
@unlink($target);
return false;
}
if (preg_match('#^HTTP/\d+\.\d+ (\d+) #', $head, $out)) {
$code = (int)$out[1];
} else {
$code = '999 ' . curl_error($ch);
}
return true;
}
}
