1: <?php
  2: 
  3: /**
  4:  * functions/common.php
  5:  *
  6:  * Some common internet functions.
  7:  *
  8:  * PHP version 8
  9:  *
 10:  * LICENSE: This program is free software: you can redistribute it and/or modify
 11:  * it under the terms of the GNU Affero General Public License as
 12:  * published by the Free Software Foundation, either version 3 of the
 13:  * License, or (at your option) any later version.
 14:  * This program is distributed in the hope that it will be useful,
 15:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 16:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17:  * GNU Affero General Public License for more details.
 18:  * You should have received a copy of the GNU Affero General Public License
 19:  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 20:  *
 21:  * @category  Internet
 22:  * @package   Common
 23:  * @author    Henri Schumacher <henri.hulski@gazeta.pl>
 24:  * @copyright 2007-2014 Henri Schumacher
 25:  * @license   http://www.gnu.org/licenses/agpl.html GNU Affero General Public License v3
 26:  * @version   1.0
 27:  * @link      https://research.openhomeo.info/download/OpenHomeopath_1.0.2.tar.gz
 28:  */
 29: 
 30: function url_exists($url) {
 31:     $ch = curl_init($url);
 32:     curl_setopt($ch, CURLOPT_NOBODY, true); // set to HEAD request
 33:     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // don't output the response
 34:     curl_exec($ch);
 35:     $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
 36:     curl_close($ch);
 37:     return ($code >= 200 && $code < 400) ? true : false;
 38: }
 39: 
 40: function bot_detected() {
 41:     if (isset($_SERVER['HTTP_USER_AGENT']) && preg_match('/bot|crawl|slurp|spider/i', $_SERVER['HTTP_USER_AGENT'])) {
 42:         return true;
 43:     }
 44:     else {
 45:         return false;
 46:     }
 47: }
 48: 
 49: // retrieve the browser language
 50: function get_browser_language($allowed_languages, $default_language, $lang_variable = null, $strict_mode = true) {
 51:         // Use $_SERVER['HTTP_ACCEPT_LANGUAGE'] when no $lang_variable was parsed
 52:         if ($lang_variable === null) {
 53:                 $lang_variable = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
 54:         }
 55: 
 56:         // Some information send with $_SERVER['HTTP_ACCEPT_LANGUAGE']?
 57:         if (empty($lang_variable)) {
 58:                 // No? => use default language
 59:                 return $default_language;
 60:         }
 61: 
 62:         // split the header
 63:         $accepted_languages = preg_split('/,\s*/', $lang_variable);
 64: 
 65:         // set the default language
 66:         $current_lang = $default_language;
 67:         $current_q = 0;
 68: 
 69:         // parse all sent languages
 70:         foreach ($accepted_languages as $accepted_language) {
 71:                 // get all info about this language
 72:                 $res = preg_match ('/^([a-z]{1,8}(?:-[a-z]{1,8})*)'.
 73:                                    '(?:;\s*q=(0(?:\.[0-9]{1,3})?|1(?:\.0{1,3})?))?$/i', $accepted_language, $matches);
 74: 
 75:                 // is the syntax valid?
 76:                 if (!$res) {
 77:                         // No? 0 => ignore
 78:                         continue;
 79:                 }
 80: 
 81:                 // split the language code in parts
 82:                 $lang_code = explode ('-', $matches[1]);
 83: 
 84:                 // was a quality given?
 85:                 if (isset($matches[2])) {
 86:                         // use the quality
 87:                         $lang_quality = (float)$matches[2];
 88:                 } else {
 89:                         // compatibility mode: use quality 1
 90:                         $lang_quality = 1.0;
 91:                 }
 92: 
 93:                 // until the language code is empty...
 94:                 while (count ($lang_code)) {
 95:                         // check if the language is allowed
 96:                         if (in_array (strtolower (join ('-', $lang_code)), $allowed_languages)) {
 97:                                 // compare quality
 98:                                 if ($lang_quality > $current_q) {
 99:                                         // use this language
100:                                         $current_lang = strtolower (join ('-', $lang_code));
101:                                         $current_q = $lang_quality;
102:                                         break;
103:                                 }
104:                         }
105:                         // in strict mode we're not minimalizing the language code
106:                         if ($strict_mode) {
107:                                 break;
108:                         }
109:                         // delete the rightest part of the language code
110:                         array_pop ($lang_code);
111:                 }
112:         }
113: 
114:         // return the found language
115:         return $current_lang;
116: }
117: