xref: /dokuwiki/inc/pageutils.php (revision 6e0cc83a924bf9b5f90ae80f11ccdcf58ee415a7)
1b625487dSandi<?php
2b625487dSandi/**
3b625487dSandi * Utilities for handling pagenames
4b625487dSandi *
5b625487dSandi * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
6b625487dSandi * @author     Andreas Gohr <andi@splitbrain.org>
71380fc45SAndreas Gohr * @todo       Combine similar functions like {wiki,media,meta}FN()
8b625487dSandi */
9b625487dSandi
106c7843b5Sandi/**
116de3759aSAndreas Gohr * Fetch the an ID from request
126c7843b5Sandi *
136c7843b5Sandi * Uses either standard $_REQUEST variable or extracts it from
146c7843b5Sandi * the full request URI when userewrite is set to 2
156c7843b5Sandi *
1642905504SAndreas Gohr * For $param='id' $conf['start'] is returned if no id was found.
1742905504SAndreas Gohr * If the second parameter is true (default) the ID is cleaned.
186c7843b5Sandi *
196c7843b5Sandi * @author Andreas Gohr <andi@splitbrain.org>
206c7843b5Sandi */
2142905504SAndreas Gohrfunction getID($param='id',$clean=true){
226c7843b5Sandi  global $conf;
236c7843b5Sandi
2403c4aec3Schris  $id = isset($_REQUEST[$param]) ? $_REQUEST[$param] : null;
2548665d38SAndreas Gohr
266c7843b5Sandi  //construct page id from request URI
276c7843b5Sandi  if(empty($id) && $conf['userewrite'] == 2){
286c7843b5Sandi    //get the script URL
296c7843b5Sandi    if($conf['basedir']){
3081124000Sjan      $relpath = '';
3181124000Sjan      if($param != 'id') {
3281124000Sjan        $relpath = 'lib/exe/';
3381124000Sjan      }
3481124000Sjan      $script = $conf['basedir'].$relpath.basename($_SERVER['SCRIPT_FILENAME']);
356c7843b5Sandi    }elseif($_SERVER['DOCUMENT_ROOT'] && $_SERVER['SCRIPT_FILENAME']){
366c7843b5Sandi      $script = preg_replace ('/^'.preg_quote($_SERVER['DOCUMENT_ROOT'],'/').'/','',
376c7843b5Sandi                              $_SERVER['SCRIPT_FILENAME']);
386c7843b5Sandi      $script = '/'.$script;
396c7843b5Sandi    }else{
406c7843b5Sandi      $script = $_SERVER['SCRIPT_NAME'];
416c7843b5Sandi    }
426c7843b5Sandi
4352339126Sandi    //clean script and request (fixes a windows problem)
4452339126Sandi    $script  = preg_replace('/\/\/+/','/',$script);
4552339126Sandi    $request = preg_replace('/\/\/+/','/',$_SERVER['REQUEST_URI']);
4652339126Sandi
476c7843b5Sandi    //remove script URL and Querystring to gain the id
4852339126Sandi    if(preg_match('/^'.preg_quote($script,'/').'(.*)/',$request, $match)){
496c7843b5Sandi      $id = preg_replace ('/\?.*/','',$match[1]);
506c7843b5Sandi    }
516de3759aSAndreas Gohr    $id = urldecode($id);
5242905504SAndreas Gohr    //strip leading slashes
5342905504SAndreas Gohr    $id = preg_replace('!^/+!','',$id);
546c7843b5Sandi  }
5542905504SAndreas Gohr  if($clean) $id = cleanID($id);
560868021bSAndreas Gohr  if(empty($id) && $param=='id') $id = $conf['start'];
576c7843b5Sandi
586c7843b5Sandi  return $id;
596c7843b5Sandi}
60b625487dSandi
61b625487dSandi/**
62b625487dSandi * Remove unwanted chars from ID
63b625487dSandi *
64b625487dSandi * Cleans a given ID to only use allowed characters. Accented characters are
65b625487dSandi * converted to unaccented ones
66b625487dSandi *
67b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
68*6e0cc83aSchris * @param  string  $raw_id    The pageid to clean
698a831f2bSAndreas Gohr * @param  boolean $ascii     Force ASCII
70b625487dSandi */
71*6e0cc83aSchrisfunction cleanID($raw_id,$ascii=false){
72b625487dSandi  global $conf;
73b625487dSandi  global $lang;
744b5db43bSjoe.lapp  static $sepcharpat = null;
754b5db43bSjoe.lapp
76*6e0cc83aSchris  static $cache = array();
77*6e0cc83aSchris
78*6e0cc83aSchris  // check if it's already in the memory cache
79*6e0cc83aSchris  if (isset($cache[$raw_id])) {
80*6e0cc83aSchris    return $cache[$raw_id];
81*6e0cc83aSchris	}
82*6e0cc83aSchris
834b5db43bSjoe.lapp  $sepchar = $conf['sepchar'];
844b5db43bSjoe.lapp  if($sepcharpat == null) // build string only once to save clock cycles
854b5db43bSjoe.lapp    $sepcharpat = '#\\'.$sepchar.'+#';
864b5db43bSjoe.lapp
87*6e0cc83aSchris  $id = trim($raw_id);
88b625487dSandi  $id = utf8_strtolower($id);
89b625487dSandi
90b625487dSandi  //alternative namespace seperator
91b625487dSandi  $id = strtr($id,';',':');
92b625487dSandi  if($conf['useslash']){
93b625487dSandi    $id = strtr($id,'/',':');
94b625487dSandi  }else{
954eeffcd2SAndreas Gohr    $id = strtr($id,'/',$sepchar);
96b625487dSandi  }
97b625487dSandi
988a831f2bSAndreas Gohr  if($conf['deaccent'] == 2 || $ascii) $id = utf8_romanize($id);
998a831f2bSAndreas Gohr  if($conf['deaccent'] || $ascii) $id = utf8_deaccent($id,-1);
100b625487dSandi
101b625487dSandi  //remove specials
102ad81d431SAndreas Gohr  $id = utf8_stripspecials($id,$sepchar,'\*');
103b625487dSandi
1048a831f2bSAndreas Gohr  if($ascii) $id = utf8_strip($id);
1058a831f2bSAndreas Gohr
106b625487dSandi  //clean up
1074b5db43bSjoe.lapp  $id = preg_replace($sepcharpat,$sepchar,$id);
108b625487dSandi  $id = preg_replace('#:+#',':',$id);
109b625487dSandi  $id = trim($id,':._-');
110b625487dSandi  $id = preg_replace('#:[:\._\-]+#',':',$id);
111b625487dSandi
112*6e0cc83aSchris  $cache[$raw_id] = $id;
113b625487dSandi  return($id);
114b625487dSandi}
115b625487dSandi
116b625487dSandi/**
117b625487dSandi * Return namespacepart of a wiki ID
118b625487dSandi *
119b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
120b625487dSandi */
121b625487dSandifunction getNS($id){
122c4e0e4a1SAndreas Gohr  $pos = strrpos($id,':');
123c4e0e4a1SAndreas Gohr  if($pos!==false){
124c4e0e4a1SAndreas Gohr    return substr($id,0,$pos);
125b625487dSandi  }
126b625487dSandi  return false;
127b625487dSandi}
128b625487dSandi
129b625487dSandi/**
130b625487dSandi * Returns the ID without the namespace
131b625487dSandi *
132b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
133b625487dSandi */
134b625487dSandifunction noNS($id) {
1352844584fSBen Coburn  $pos = strrpos($id, ':');
1362844584fSBen Coburn  if ($pos!==false) {
1372844584fSBen Coburn    return substr($id, $pos+1);
1382844584fSBen Coburn  } else {
1392844584fSBen Coburn    return $id;
1402844584fSBen Coburn  }
141b625487dSandi}
142b625487dSandi
143b625487dSandi/**
144b625487dSandi * returns the full path to the datafile specified by ID and
145b625487dSandi * optional revision
146b625487dSandi *
147b625487dSandi * The filename is URL encoded to protect Unicode chars
148b625487dSandi *
149b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
150b625487dSandi */
151*6e0cc83aSchrisfunction wikiFN($raw_id,$rev='',$clean=true){
152b625487dSandi  global $conf;
153*6e0cc83aSchris
154*6e0cc83aSchris  static $cache = array();
155*6e0cc83aSchris  if (isset($cache[$raw_id]) && isset($cache[$raw_id][$rev])) {
156*6e0cc83aSchris    return $cache[$raw_id][$rev];
157*6e0cc83aSchris  }
158*6e0cc83aSchris
159*6e0cc83aSchris  $id = $raw_id;
160*6e0cc83aSchris
1610d8ea614Schris  if ($clean) $id = cleanID($id);
162b625487dSandi  $id = str_replace(':','/',$id);
163b625487dSandi  if(empty($rev)){
164b625487dSandi    $fn = $conf['datadir'].'/'.utf8_encodeFN($id).'.txt';
165b625487dSandi  }else{
166b625487dSandi    $fn = $conf['olddir'].'/'.utf8_encodeFN($id).'.'.$rev.'.txt';
167ff3ed99fSmarcel    if($conf['compression']){
168ff3ed99fSmarcel      //test for extensions here, we want to read both compressions
169ff3ed99fSmarcel       if (file_exists($fn . '.gz')){
170b625487dSandi          $fn .= '.gz';
171ff3ed99fSmarcel       }else if(file_exists($fn . '.bz2')){
172ff3ed99fSmarcel          $fn .= '.bz2';
173ff3ed99fSmarcel       }else{
174ff3ed99fSmarcel          //file doesnt exist yet, so we take the configured extension
175ff3ed99fSmarcel          $fn .= '.' . $conf['compression'];
176ff3ed99fSmarcel       }
177b625487dSandi    }
178b625487dSandi  }
179*6e0cc83aSchris
180*6e0cc83aSchris  $cache[$raw_id][$rev] = $fn;
181b625487dSandi  return $fn;
182b625487dSandi}
183b625487dSandi
184b625487dSandi/**
185c9b4bd1eSBen Coburn * Returns the full path to the file for locking the page while editing.
186c9b4bd1eSBen Coburn *
187c9b4bd1eSBen Coburn * @author Ben Coburn <btcoburn@silicodon.net>
188c9b4bd1eSBen Coburn */
189c9b4bd1eSBen Coburnfunction wikiLockFN($id) {
190c9b4bd1eSBen Coburn  global $conf;
191662ff478SAndreas Gohr  return $conf['lockdir'].'/'.md5(cleanID($id)).'.lock';
192c9b4bd1eSBen Coburn}
193c9b4bd1eSBen Coburn
194c9b4bd1eSBen Coburn
195c9b4bd1eSBen Coburn/**
1961380fc45SAndreas Gohr * returns the full path to the meta file specified by ID and extension
197b158d625SSteven Danz *
198b158d625SSteven Danz * The filename is URL encoded to protect Unicode chars
199b158d625SSteven Danz *
200b158d625SSteven Danz * @author Steven Danz <steven-danz@kc.rr.com>
201b158d625SSteven Danz */
2021380fc45SAndreas Gohrfunction metaFN($id,$ext){
203b158d625SSteven Danz  global $conf;
204b158d625SSteven Danz  $id = cleanID($id);
205b158d625SSteven Danz  $id = str_replace(':','/',$id);
2061380fc45SAndreas Gohr  $fn = $conf['metadir'].'/'.utf8_encodeFN($id).$ext;
207b158d625SSteven Danz  return $fn;
208b158d625SSteven Danz}
209b158d625SSteven Danz
210b158d625SSteven Danz/**
211e1f3d9e1SEsther Brunner * returns an array of full paths to all metafiles of a given ID
212e1f3d9e1SEsther Brunner *
213e1f3d9e1SEsther Brunner * @author Esther Brunner <esther@kaffeehaus.ch>
214e1f3d9e1SEsther Brunner */
215e1f3d9e1SEsther Brunnerfunction metaFiles($id){
216e1f3d9e1SEsther Brunner   $name   = noNS($id);
217e1f3d9e1SEsther Brunner   $dir    = metaFN(getNS($id),'');
218e1f3d9e1SEsther Brunner   $files  = array();
219e1f3d9e1SEsther Brunner
220e1f3d9e1SEsther Brunner   $dh = @opendir($dir);
2215011da9dSEsther Brunner   if(!$dh) return $files;
222e1f3d9e1SEsther Brunner   while(($file = readdir($dh)) !== false){
2231a54dfabSEsther Brunner     if(strpos($file,$name.'.') === 0 && !is_dir($dir.$file))
224e1f3d9e1SEsther Brunner       $files[] = $dir.$file;
225e1f3d9e1SEsther Brunner   }
226e1f3d9e1SEsther Brunner   closedir($dh);
227e1f3d9e1SEsther Brunner
228e1f3d9e1SEsther Brunner   return $files;
229e1f3d9e1SEsther Brunner}
230e1f3d9e1SEsther Brunner
231e1f3d9e1SEsther Brunner/**
232b625487dSandi * returns the full path to the mediafile specified by ID
233b625487dSandi *
234b625487dSandi * The filename is URL encoded to protect Unicode chars
235b625487dSandi *
236b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
237b625487dSandi */
238b625487dSandifunction mediaFN($id){
239b625487dSandi  global $conf;
240b625487dSandi  $id = cleanID($id);
241b625487dSandi  $id = str_replace(':','/',$id);
242b625487dSandi    $fn = $conf['mediadir'].'/'.utf8_encodeFN($id);
243b625487dSandi  return $fn;
244b625487dSandi}
245b625487dSandi
246b625487dSandi/**
247b625487dSandi * Returns the full filepath to a localized textfile if local
248b625487dSandi * version isn't found the english one is returned
249b625487dSandi *
250b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
251b625487dSandi */
252b625487dSandifunction localeFN($id){
253b625487dSandi  global $conf;
254bc3b6aecSandi  $file = DOKU_INC.'inc/lang/'.$conf['lang'].'/'.$id.'.txt';
255b625487dSandi  if(!@file_exists($file)){
256b625487dSandi    //fall back to english
257bc3b6aecSandi    $file = DOKU_INC.'inc/lang/en/'.$id.'.txt';
258b625487dSandi  }
259b625487dSandi  return $file;
260b625487dSandi}
261b625487dSandi
262b625487dSandi/**
263c4e0e4a1SAndreas Gohr * Resolve relative paths in IDs
264c4e0e4a1SAndreas Gohr *
265c4e0e4a1SAndreas Gohr * Do not call directly use resolve_mediaid or resolve_pageid
266c4e0e4a1SAndreas Gohr * instead
267c4e0e4a1SAndreas Gohr *
268c4e0e4a1SAndreas Gohr * Partyly based on a cleanPath function found at
269c4e0e4a1SAndreas Gohr * http://www.php.net/manual/en/function.realpath.php#57016
270c4e0e4a1SAndreas Gohr *
271c4e0e4a1SAndreas Gohr * @author <bart at mediawave dot nl>
272c4e0e4a1SAndreas Gohr */
273a6ef4796SAndreas Gohrfunction resolve_id($ns,$id,$clean=true){
274c4e0e4a1SAndreas Gohr  // if the id starts with a dot we need to handle the
275c4e0e4a1SAndreas Gohr  // relative stuff
276c4e0e4a1SAndreas Gohr  if($id{0} == '.'){
277c4e0e4a1SAndreas Gohr    // normalize initial dots without a colon
278c4e0e4a1SAndreas Gohr    $id = preg_replace('/^(\.+)(?=[^:\.])/','\1:',$id);
279c4e0e4a1SAndreas Gohr    // prepend the current namespace
280c4e0e4a1SAndreas Gohr    $id = $ns.':'.$id;
281c4e0e4a1SAndreas Gohr
282c4e0e4a1SAndreas Gohr    // cleanup relatives
283c4e0e4a1SAndreas Gohr    $result = array();
284c4e0e4a1SAndreas Gohr    $pathA  = explode(':', $id);
285c4e0e4a1SAndreas Gohr    if (!$pathA[0]) $result[] = '';
286c4e0e4a1SAndreas Gohr    foreach ($pathA AS $key => $dir) {
287c4e0e4a1SAndreas Gohr      if ($dir == '..') {
288c4e0e4a1SAndreas Gohr        if (end($result) == '..') {
289c4e0e4a1SAndreas Gohr          $result[] = '..';
290c4e0e4a1SAndreas Gohr        } elseif (!array_pop($result)) {
291c4e0e4a1SAndreas Gohr          $result[] = '..';
292c4e0e4a1SAndreas Gohr        }
293c4e0e4a1SAndreas Gohr      } elseif ($dir && $dir != '.') {
294c4e0e4a1SAndreas Gohr        $result[] = $dir;
295c4e0e4a1SAndreas Gohr      }
296c4e0e4a1SAndreas Gohr    }
297c4e0e4a1SAndreas Gohr    if (!end($pathA)) $result[] = '';
298c4e0e4a1SAndreas Gohr    $id = implode(':', $result);
299c4e0e4a1SAndreas Gohr  }elseif($ns !== false && strpos($id,':') === false){
300c4e0e4a1SAndreas Gohr    //if link contains no namespace. add current namespace (if any)
301c4e0e4a1SAndreas Gohr    $id = $ns.':'.$id;
302c4e0e4a1SAndreas Gohr  }
303c4e0e4a1SAndreas Gohr
304a6ef4796SAndreas Gohr  if($clean) $id = cleanID($id);
305a6ef4796SAndreas Gohr  return $id;
306c4e0e4a1SAndreas Gohr}
307c4e0e4a1SAndreas Gohr
308c4e0e4a1SAndreas Gohr/**
309b625487dSandi * Returns a full media id
310b625487dSandi *
311b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
312b625487dSandi */
31337e34a5eSandifunction resolve_mediaid($ns,&$page,&$exists){
314c4e0e4a1SAndreas Gohr  $page   = resolve_id($ns,$page);
315b625487dSandi  $file   = mediaFN($page);
316b625487dSandi  $exists = @file_exists($file);
317b625487dSandi}
318b625487dSandi
319b625487dSandi/**
320b625487dSandi * Returns a full page id
321b625487dSandi *
322b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
323b625487dSandi */
32437e34a5eSandifunction resolve_pageid($ns,&$page,&$exists){
325b625487dSandi  global $conf;
3260b7c14c2Sandi  $exists = false;
327b625487dSandi
328b625487dSandi  //keep hashlink if exists then clean both parts
32903c4aec3Schris  if (strpos($page,'#')) {
330b625487dSandi    list($page,$hash) = split('#',$page,2);
33103c4aec3Schris  } else {
33203c4aec3Schris    $hash = '';
33303c4aec3Schris  }
334b625487dSandi  $hash = cleanID($hash);
335a6ef4796SAndreas Gohr  $page = resolve_id($ns,$page,false); // resolve but don't clean, yet
336b625487dSandi
337a6ef4796SAndreas Gohr  // get filename (calls clean itself)
338b625487dSandi  $file = wikiFN($page);
339b625487dSandi
340a6ef4796SAndreas Gohr  // if ends with colon we have a namespace link
341a6ef4796SAndreas Gohr  if(substr($page,-1) == ':'){
342a6ef4796SAndreas Gohr    if(@file_exists(wikiFN($page.$conf['start']))){
343a6ef4796SAndreas Gohr      // start page inside namespace
344a6ef4796SAndreas Gohr      $page = $page.$conf['start'];
345a6ef4796SAndreas Gohr      $exists = true;
346a6ef4796SAndreas Gohr    }elseif(@file_exists(wikiFN($page.noNS(cleanID($page))))){
347a6ef4796SAndreas Gohr      // page named like the NS inside the NS
348a6ef4796SAndreas Gohr      $page = $page.noNS(cleanID($page));
349a6ef4796SAndreas Gohr      $exists = true;
350a6ef4796SAndreas Gohr    }elseif(@file_exists(wikiFN($page))){
351a6ef4796SAndreas Gohr      // page like namespace exists
352a6ef4796SAndreas Gohr      $page = $page;
353a6ef4796SAndreas Gohr      $exists = true;
354a6ef4796SAndreas Gohr    }else{
355a6ef4796SAndreas Gohr      // fall back to default
356a6ef4796SAndreas Gohr      $page = $page.$conf['start'];
357a6ef4796SAndreas Gohr    }
358a6ef4796SAndreas Gohr  }else{
359b625487dSandi    //check alternative plural/nonplural form
360b625487dSandi    if(!@file_exists($file)){
361b625487dSandi      if( $conf['autoplural'] ){
362b625487dSandi        if(substr($page,-1) == 's'){
363b625487dSandi          $try = substr($page,0,-1);
364b625487dSandi        }else{
365b625487dSandi          $try = $page.'s';
366b625487dSandi        }
367b625487dSandi        if(@file_exists(wikiFN($try))){
368b625487dSandi          $page   = $try;
369b625487dSandi          $exists = true;
370b625487dSandi        }
371b625487dSandi      }
372b625487dSandi    }else{
373b625487dSandi      $exists = true;
374b625487dSandi    }
375a6ef4796SAndreas Gohr  }
376a6ef4796SAndreas Gohr
377a6ef4796SAndreas Gohr  // now make sure we have a clean page
378a6ef4796SAndreas Gohr  $page = cleanID($page);
379b625487dSandi
380b625487dSandi  //add hash if any
381b2d7d3f2Sandi  if(!empty($hash)) $page .= '#'.$hash;
382b625487dSandi}
383b625487dSandi
38498407a7aSandi/**
38598407a7aSandi * Returns the name of a cachefile from given data
38698407a7aSandi *
38798407a7aSandi * The needed directory is created by this function!
38898407a7aSandi *
38998407a7aSandi * @author Andreas Gohr <andi@splitbrain.org>
39098407a7aSandi *
39198407a7aSandi * @param string $data  This data is used to create a unique md5 name
39298407a7aSandi * @param string $ext   This is appended to the filename if given
39398407a7aSandi * @return string       The filename of the cachefile
39498407a7aSandi */
39598407a7aSandifunction getCacheName($data,$ext=''){
39698407a7aSandi  global $conf;
39798407a7aSandi  $md5  = md5($data);
39898407a7aSandi  $file = $conf['cachedir'].'/'.$md5{0}.'/'.$md5.$ext;
39998407a7aSandi  io_makeFileDir($file);
40098407a7aSandi  return $file;
40198407a7aSandi}
40298407a7aSandi
4030dc92c6fSAndreas Gohr/**
4040dc92c6fSAndreas Gohr * Checks a pageid against $conf['hidepages']
4050dc92c6fSAndreas Gohr *
4060dc92c6fSAndreas Gohr * @author Andreas Gohr <gohr@cosmocode.de>
4070dc92c6fSAndreas Gohr */
4080dc92c6fSAndreas Gohrfunction isHiddenPage($id){
4090dc92c6fSAndreas Gohr  global $conf;
4100dc92c6fSAndreas Gohr  if(empty($conf['hidepages'])) return false;
4110dc92c6fSAndreas Gohr
4120dc92c6fSAndreas Gohr  if(preg_match('/'.$conf['hidepages'].'/ui',':'.$id)){
4130dc92c6fSAndreas Gohr    return true;
4140dc92c6fSAndreas Gohr  }
4150dc92c6fSAndreas Gohr  return false;
4160dc92c6fSAndreas Gohr}
4170dc92c6fSAndreas Gohr
4180dc92c6fSAndreas Gohr/**
4190dc92c6fSAndreas Gohr * Reverse of isHiddenPage
4200dc92c6fSAndreas Gohr *
4210dc92c6fSAndreas Gohr * @author Andreas Gohr <gohr@cosmocode.de>
4220dc92c6fSAndreas Gohr */
4230dc92c6fSAndreas Gohrfunction isVisiblePage($id){
4240dc92c6fSAndreas Gohr  return !isHiddenPage($id);
4250dc92c6fSAndreas Gohr}
4260dc92c6fSAndreas Gohr
427254e5c84SBen Coburn/**
428254e5c84SBen Coburn * Checks and sets HTTP headers for conditional HTTP requests
429254e5c84SBen Coburn *
430254e5c84SBen Coburn * @author   Simon Willison <swillison@gmail.com>
431254e5c84SBen Coburn * @link     http://simon.incutio.com/archive/2003/04/23/conditionalGet
4320ac9a84dSoliver * @param    timestamp $timestamp lastmodified time of the cache file
4330ac9a84dSoliver * @returns  void or void with previously header() commands executed
434254e5c84SBen Coburn */
435254e5c84SBen Coburnfunction http_conditionalRequest($timestamp){
436254e5c84SBen Coburn  // A PHP implementation of conditional get, see
437254e5c84SBen Coburn  //   http://fishbowl.pastiche.org/archives/001132.html
438254e5c84SBen Coburn  $last_modified = substr(date('r', $timestamp), 0, -5).'GMT';
439254e5c84SBen Coburn  $etag = '"'.md5($last_modified).'"';
440254e5c84SBen Coburn  // Send the headers
441254e5c84SBen Coburn  header("Last-Modified: $last_modified");
442254e5c84SBen Coburn  header("ETag: $etag");
443254e5c84SBen Coburn  // See if the client has provided the required headers
4440ac9a84dSoliver  if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])){
4450ac9a84dSoliver    $if_modified_since = stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']);
4460ac9a84dSoliver  }else{
4470ac9a84dSoliver    $if_modified_since = false;
4480ac9a84dSoliver  }
4490ac9a84dSoliver
4500ac9a84dSoliver  if (isset($_SERVER['HTTP_IF_NONE_MATCH'])){
4510ac9a84dSoliver    $if_none_match = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
4520ac9a84dSoliver  }else{
4530ac9a84dSoliver    $if_none_match = false;
4540ac9a84dSoliver  }
4550ac9a84dSoliver
456254e5c84SBen Coburn  if (!$if_modified_since && !$if_none_match){
457254e5c84SBen Coburn    return;
458254e5c84SBen Coburn  }
4590ac9a84dSoliver
460254e5c84SBen Coburn  // At least one of the headers is there - check them
461254e5c84SBen Coburn  if ($if_none_match && $if_none_match != $etag) {
462254e5c84SBen Coburn    return; // etag is there but doesn't match
463254e5c84SBen Coburn  }
4640ac9a84dSoliver
465254e5c84SBen Coburn  if ($if_modified_since && $if_modified_since != $last_modified) {
466254e5c84SBen Coburn    return; // if-modified-since is there but doesn't match
467254e5c84SBen Coburn  }
4680ac9a84dSoliver
469254e5c84SBen Coburn  // Nothing has changed since their last request - serve a 304 and exit
470254e5c84SBen Coburn  header('HTTP/1.0 304 Not Modified');
471254e5c84SBen Coburn  exit;
472254e5c84SBen Coburn}
473254e5c84SBen Coburn
474b625487dSandi//Setup VIM: ex: et ts=2 enc=utf-8 :
475