lib/configonlylib.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * Minimalistic library, usable even when no other moodle libs are loaded.
  20  *
  21  * The only library that gets loaded if you define ABORT_AFTER_CONFIG
  22  * before including main config.php. You can resume normal script operation
  23  * if you define ABORT_AFTER_CONFIG_CANCEL and require the setup.php
  24  *
  25  * @package   core
  26  * @copyright 2009 Petr Skoda (skodak)
  27  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  28  */
  29
  30 /**
  31  * Minimalistic parameter validation function.
  32  * Can not use optional param because moodlelib.php is not loaded yet
  33  * @param string $name
  34  * @param mixed $default
  35  * @param string $type
  36  * @return mixed
  37  */
  38 function min_optional_param($name, $default, $type) {
  39     $value = $default;
  40     if (isset($_GET[$name])) {
  41         $value = $_GET[$name];
  42
  43     } else if (isset($_GET['amp;'.$name])) {
  44         // very, very, very ugly hack, unfortunately $OUTPUT->pix_url() is not used properly in javascript code :-(
  45         $value = $_GET['amp;'.$name];
  46     }
  47
  48     return min_clean_param($value, $type);
  49 }
  50
  51 /**
  52  * Minimalistic parameter cleaning function.
  53  * Can not use optional param because moodlelib.php is not loaded yet
  54  * @param string $name
  55  * @param mixed $default
  56  * @param string $type
  57  * @return mixed
  58  */
  59 function min_clean_param($value, $type) {
  60     switch($type) {
  61         case 'RAW':      $value = iconv('UTF-8', 'UTF-8//IGNORE', $value);
  62                          break;
  63         case 'INT':      $value = (int)$value;
  64                          break;
  65         case 'SAFEDIR':  $value = preg_replace('/[^a-zA-Z0-9_-]/', '', $value);
  66                          break;
  67         case 'SAFEPATH': $value = preg_replace('/[^a-zA-Z0-9\/\._-]/', '', $value);
  68                          $value = preg_replace('/\.+/', '.', $value);
  69                          $value = preg_replace('#/+#', '/', $value);
  70                          break;
  71         default:         die("Coding error: incorrect parameter type specified ($type).");
  72     }
  73
  74     return $value;
  75 }
  76
  77 /**
  78  * This method tries to enable output compression if possible.
  79  * This function must be called before any output or headers.
  80  *
  81  * (IE6 is not supported at all.)
  82  *
  83  * @return boolean, true if compression enabled
  84  */
  85 function min_enable_zlib_compression() {
  86
  87     if (headers_sent()) {
  88         return false;
  89     }
  90
  91     // zlib.output_compression is preferred over ob_gzhandler()
  92     if (!empty($_SERVER['HTTP_USER_AGENT'])) {
  93         $agent = $_SERVER['HTTP_USER_AGENT'];
  94         // try to detect IE6 and prevent gzip because it is extremely buggy browser
  95         $parts = explode(';', $agent);
  96         if (isset($parts[1])) {
  97             $parts = explode(' ', trim($parts[1]));
  98             if (count($parts) > 1) {
  99                 if ($parts[0] === 'MSIE' and (float)$parts[1] < 7) {
 100                     @ini_set('zlib.output_compression', '0');
 101                     return false;
 102                 }
 103             }
 104         }
 105     }
 106
 107     @ini_set('output_handler', '');
 108
 109     /*
 110      * docs clearly say 'on' means enable and number means size of buffer,
 111      * but unfortunately some PHP version break when we set 'on' here.
 112      * 1 probably sets chunk size to 4096. our CSS and JS scripts are much bigger,
 113      * so let's try some bigger sizes.
 114      */
 115     @ini_set('zlib.output_compression', 65536);
 116
 117     return true;
 118 }