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':      break;
  62         case 'INT':      $value = (int)$value;
  63                          break;
  64         case 'SAFEDIR':  $value = preg_replace('/[^a-zA-Z0-9_-]/', '', $value);
  65                          break;
  66         case 'SAFEPATH': $value = preg_replace('/[^a-zA-Z0-9\/\._-]/', '', $value);
  67                          $value = preg_replace('/\.+/', '.', $value);
  68                          $value = preg_replace('#/+#', '/', $value);
  69                          break;
  70         default:         die("Coding error: incorrect parameter type specified ($type).");
  71     }
  72
  73     return $value;
  74 }
  75
  76 /**
  77  * This method tries to enable output compression if possible.
  78  * This function must be called before any output or headers.
  79  *
  80  * (IE6 is not supported at all.)
  81  *
  82  * @return boolean, true if compression enabled
  83  */
  84 function min_enable_zlib_compression() {
  85
  86     if (headers_sent()) {
  87         return false;
  88     }
  89
  90     // zlib.output_compression is preferred over ob_gzhandler()
  91     if (!empty($_SERVER['HTTP_USER_AGENT'])) {
  92         $agent = $_SERVER['HTTP_USER_AGENT'];
  93         // try to detect IE6 and prevent gzip because it is extremely buggy browser
  94         $parts = explode(';', $agent);
  95         if (isset($parts[1])) {
  96             $parts = explode(' ', trim($parts[1]));
  97             if (count($parts) > 1) {
  98                 if ($parts[0] === 'MSIE' and (float)$parts[1] < 7) {
  99                     @ini_set('zlib.output_compression', '0');
 100                     return false;
 101                 }
 102             }
 103         }
 104     }
 105
 106     @ini_set('output_handler', '');
 107
 108     /*
 109      * docs clearly say 'on' means enable and number means size of buffer,
 110      * but unfortunately some PHP version break when we set 'on' here.
 111      * 1 probably sets chunk size to 4096. our CSS and JS scripts are much bigger,
 112      * so let's try some bigger sizes.
 113      */
 114     @ini_set('zlib.output_compression', 65536);
 115
 116     return true;
 117 }