xref: /dokuwiki/inc/pageutils.php (revision 6d88439ada7c841b10a8de3da846f7cc1cf5842a)
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>
686e0cc83aSchris * @param  string  $raw_id    The pageid to clean
698a831f2bSAndreas Gohr * @param  boolean $ascii     Force ASCII
70b625487dSandi */
716e0cc83aSchrisfunction cleanID($raw_id,$ascii=false){
72b625487dSandi  global $conf;
73b625487dSandi  global $lang;
744b5db43bSjoe.lapp  static $sepcharpat = null;
754b5db43bSjoe.lapp
76dc2c0e04Schris  global $cache_cleanid;
77dc2c0e04Schris  $cache = & $cache_cleanid;
786e0cc83aSchris
796e0cc83aSchris  // check if it's already in the memory cache
806e0cc83aSchris  if (isset($cache[$raw_id])) {
816e0cc83aSchris    return $cache[$raw_id];
826e0cc83aSchris	}
836e0cc83aSchris
844b5db43bSjoe.lapp  $sepchar = $conf['sepchar'];
854b5db43bSjoe.lapp  if($sepcharpat == null) // build string only once to save clock cycles
864b5db43bSjoe.lapp    $sepcharpat = '#\\'.$sepchar.'+#';
874b5db43bSjoe.lapp
886e0cc83aSchris  $id = trim($raw_id);
89b625487dSandi  $id = utf8_strtolower($id);
90b625487dSandi
91b625487dSandi  //alternative namespace seperator
92b625487dSandi  $id = strtr($id,';',':');
93b625487dSandi  if($conf['useslash']){
94b625487dSandi    $id = strtr($id,'/',':');
95b625487dSandi  }else{
964eeffcd2SAndreas Gohr    $id = strtr($id,'/',$sepchar);
97b625487dSandi  }
98b625487dSandi
998a831f2bSAndreas Gohr  if($conf['deaccent'] == 2 || $ascii) $id = utf8_romanize($id);
1008a831f2bSAndreas Gohr  if($conf['deaccent'] || $ascii) $id = utf8_deaccent($id,-1);
101b625487dSandi
102b625487dSandi  //remove specials
103ad81d431SAndreas Gohr  $id = utf8_stripspecials($id,$sepchar,'\*');
104b625487dSandi
1058a831f2bSAndreas Gohr  if($ascii) $id = utf8_strip($id);
1068a831f2bSAndreas Gohr
107b625487dSandi  //clean up
1084b5db43bSjoe.lapp  $id = preg_replace($sepcharpat,$sepchar,$id);
109b625487dSandi  $id = preg_replace('#:+#',':',$id);
110b625487dSandi  $id = trim($id,':._-');
111b625487dSandi  $id = preg_replace('#:[:\._\-]+#',':',$id);
112b625487dSandi
1136e0cc83aSchris  $cache[$raw_id] = $id;
114b625487dSandi  return($id);
115b625487dSandi}
116b625487dSandi
117b625487dSandi/**
118b625487dSandi * Return namespacepart of a wiki ID
119b625487dSandi *
120b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
121b625487dSandi */
122b625487dSandifunction getNS($id){
123c4e0e4a1SAndreas Gohr  $pos = strrpos($id,':');
124c4e0e4a1SAndreas Gohr  if($pos!==false){
125c4e0e4a1SAndreas Gohr    return substr($id,0,$pos);
126b625487dSandi  }
127b625487dSandi  return false;
128b625487dSandi}
129b625487dSandi
130b625487dSandi/**
131b625487dSandi * Returns the ID without the namespace
132b625487dSandi *
133b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
134b625487dSandi */
135b625487dSandifunction noNS($id) {
1362844584fSBen Coburn  $pos = strrpos($id, ':');
1372844584fSBen Coburn  if ($pos!==false) {
1382844584fSBen Coburn    return substr($id, $pos+1);
1392844584fSBen Coburn  } else {
1402844584fSBen Coburn    return $id;
1412844584fSBen Coburn  }
142b625487dSandi}
143b625487dSandi
144b625487dSandi/**
145b625487dSandi * returns the full path to the datafile specified by ID and
146b625487dSandi * optional revision
147b625487dSandi *
148b625487dSandi * The filename is URL encoded to protect Unicode chars
149b625487dSandi *
150b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
151b625487dSandi */
1526e0cc83aSchrisfunction wikiFN($raw_id,$rev='',$clean=true){
153b625487dSandi  global $conf;
1546e0cc83aSchris
155dc2c0e04Schris  global $cache_wikifn;
156dc2c0e04Schris  $cache = & $cache_wikifn;
157dc2c0e04Schris
1586e0cc83aSchris  if (isset($cache[$raw_id]) && isset($cache[$raw_id][$rev])) {
1596e0cc83aSchris    return $cache[$raw_id][$rev];
1606e0cc83aSchris  }
1616e0cc83aSchris
1626e0cc83aSchris  $id = $raw_id;
1636e0cc83aSchris
1640d8ea614Schris  if ($clean) $id = cleanID($id);
165b625487dSandi  $id = str_replace(':','/',$id);
166b625487dSandi  if(empty($rev)){
167b625487dSandi    $fn = $conf['datadir'].'/'.utf8_encodeFN($id).'.txt';
168b625487dSandi  }else{
169b625487dSandi    $fn = $conf['olddir'].'/'.utf8_encodeFN($id).'.'.$rev.'.txt';
170ff3ed99fSmarcel    if($conf['compression']){
171ff3ed99fSmarcel      //test for extensions here, we want to read both compressions
172d8186216SBen Coburn       if (@file_exists($fn . '.gz')){
173b625487dSandi          $fn .= '.gz';
174d8186216SBen Coburn       }else if(@file_exists($fn . '.bz2')){
175ff3ed99fSmarcel          $fn .= '.bz2';
176ff3ed99fSmarcel       }else{
177ff3ed99fSmarcel          //file doesnt exist yet, so we take the configured extension
178ff3ed99fSmarcel          $fn .= '.' . $conf['compression'];
179ff3ed99fSmarcel       }
180b625487dSandi    }
181b625487dSandi  }
1826e0cc83aSchris
18350602150SBen Coburn  if (!isset($cache[$raw_id])) { $cache[$raw_id] = array(); }
1846e0cc83aSchris  $cache[$raw_id][$rev] = $fn;
185b625487dSandi  return $fn;
186b625487dSandi}
187b625487dSandi
188b625487dSandi/**
189c9b4bd1eSBen Coburn * Returns the full path to the file for locking the page while editing.
190c9b4bd1eSBen Coburn *
191c9b4bd1eSBen Coburn * @author Ben Coburn <btcoburn@silicodon.net>
192c9b4bd1eSBen Coburn */
193c9b4bd1eSBen Coburnfunction wikiLockFN($id) {
194c9b4bd1eSBen Coburn  global $conf;
195662ff478SAndreas Gohr  return $conf['lockdir'].'/'.md5(cleanID($id)).'.lock';
196c9b4bd1eSBen Coburn}
197c9b4bd1eSBen Coburn
198c9b4bd1eSBen Coburn
199c9b4bd1eSBen Coburn/**
2001380fc45SAndreas Gohr * returns the full path to the meta file specified by ID and extension
201b158d625SSteven Danz *
202b158d625SSteven Danz * The filename is URL encoded to protect Unicode chars
203b158d625SSteven Danz *
204b158d625SSteven Danz * @author Steven Danz <steven-danz@kc.rr.com>
205b158d625SSteven Danz */
2061380fc45SAndreas Gohrfunction metaFN($id,$ext){
207b158d625SSteven Danz  global $conf;
208b158d625SSteven Danz  $id = cleanID($id);
209b158d625SSteven Danz  $id = str_replace(':','/',$id);
2101380fc45SAndreas Gohr  $fn = $conf['metadir'].'/'.utf8_encodeFN($id).$ext;
211b158d625SSteven Danz  return $fn;
212b158d625SSteven Danz}
213b158d625SSteven Danz
214b158d625SSteven Danz/**
215e1f3d9e1SEsther Brunner * returns an array of full paths to all metafiles of a given ID
216e1f3d9e1SEsther Brunner *
217e1f3d9e1SEsther Brunner * @author Esther Brunner <esther@kaffeehaus.ch>
218e1f3d9e1SEsther Brunner */
219e1f3d9e1SEsther Brunnerfunction metaFiles($id){
220e1f3d9e1SEsther Brunner   $name   = noNS($id);
221e1f3d9e1SEsther Brunner   $dir    = metaFN(getNS($id),'');
222e1f3d9e1SEsther Brunner   $files  = array();
223e1f3d9e1SEsther Brunner
224e1f3d9e1SEsther Brunner   $dh = @opendir($dir);
2255011da9dSEsther Brunner   if(!$dh) return $files;
226e1f3d9e1SEsther Brunner   while(($file = readdir($dh)) !== false){
2271a54dfabSEsther Brunner     if(strpos($file,$name.'.') === 0 && !is_dir($dir.$file))
228e1f3d9e1SEsther Brunner       $files[] = $dir.$file;
229e1f3d9e1SEsther Brunner   }
230e1f3d9e1SEsther Brunner   closedir($dh);
231e1f3d9e1SEsther Brunner
232e1f3d9e1SEsther Brunner   return $files;
233e1f3d9e1SEsther Brunner}
234e1f3d9e1SEsther Brunner
235e1f3d9e1SEsther Brunner/**
236b625487dSandi * returns the full path to the mediafile specified by ID
237b625487dSandi *
238b625487dSandi * The filename is URL encoded to protect Unicode chars
239b625487dSandi *
240b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
241b625487dSandi */
242b625487dSandifunction mediaFN($id){
243b625487dSandi  global $conf;
244b625487dSandi  $id = cleanID($id);
245b625487dSandi  $id = str_replace(':','/',$id);
246b625487dSandi    $fn = $conf['mediadir'].'/'.utf8_encodeFN($id);
247b625487dSandi  return $fn;
248b625487dSandi}
249b625487dSandi
250b625487dSandi/**
251b625487dSandi * Returns the full filepath to a localized textfile if local
252b625487dSandi * version isn't found the english one is returned
253b625487dSandi *
254b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
255b625487dSandi */
256b625487dSandifunction localeFN($id){
257b625487dSandi  global $conf;
258bc3b6aecSandi  $file = DOKU_INC.'inc/lang/'.$conf['lang'].'/'.$id.'.txt';
259b625487dSandi  if(!@file_exists($file)){
260b625487dSandi    //fall back to english
261bc3b6aecSandi    $file = DOKU_INC.'inc/lang/en/'.$id.'.txt';
262b625487dSandi  }
263b625487dSandi  return $file;
264b625487dSandi}
265b625487dSandi
266b625487dSandi/**
267c4e0e4a1SAndreas Gohr * Resolve relative paths in IDs
268c4e0e4a1SAndreas Gohr *
269c4e0e4a1SAndreas Gohr * Do not call directly use resolve_mediaid or resolve_pageid
270c4e0e4a1SAndreas Gohr * instead
271c4e0e4a1SAndreas Gohr *
272c4e0e4a1SAndreas Gohr * Partyly based on a cleanPath function found at
273c4e0e4a1SAndreas Gohr * http://www.php.net/manual/en/function.realpath.php#57016
274c4e0e4a1SAndreas Gohr *
275c4e0e4a1SAndreas Gohr * @author <bart at mediawave dot nl>
276c4e0e4a1SAndreas Gohr */
277a6ef4796SAndreas Gohrfunction resolve_id($ns,$id,$clean=true){
278c4e0e4a1SAndreas Gohr  // if the id starts with a dot we need to handle the
279c4e0e4a1SAndreas Gohr  // relative stuff
280c4e0e4a1SAndreas Gohr  if($id{0} == '.'){
281c4e0e4a1SAndreas Gohr    // normalize initial dots without a colon
282c4e0e4a1SAndreas Gohr    $id = preg_replace('/^(\.+)(?=[^:\.])/','\1:',$id);
283c4e0e4a1SAndreas Gohr    // prepend the current namespace
284c4e0e4a1SAndreas Gohr    $id = $ns.':'.$id;
285c4e0e4a1SAndreas Gohr
286c4e0e4a1SAndreas Gohr    // cleanup relatives
287c4e0e4a1SAndreas Gohr    $result = array();
288c4e0e4a1SAndreas Gohr    $pathA  = explode(':', $id);
289c4e0e4a1SAndreas Gohr    if (!$pathA[0]) $result[] = '';
290c4e0e4a1SAndreas Gohr    foreach ($pathA AS $key => $dir) {
291c4e0e4a1SAndreas Gohr      if ($dir == '..') {
292c4e0e4a1SAndreas Gohr        if (end($result) == '..') {
293c4e0e4a1SAndreas Gohr          $result[] = '..';
294c4e0e4a1SAndreas Gohr        } elseif (!array_pop($result)) {
295c4e0e4a1SAndreas Gohr          $result[] = '..';
296c4e0e4a1SAndreas Gohr        }
297c4e0e4a1SAndreas Gohr      } elseif ($dir && $dir != '.') {
298c4e0e4a1SAndreas Gohr        $result[] = $dir;
299c4e0e4a1SAndreas Gohr      }
300c4e0e4a1SAndreas Gohr    }
301c4e0e4a1SAndreas Gohr    if (!end($pathA)) $result[] = '';
302c4e0e4a1SAndreas Gohr    $id = implode(':', $result);
303c4e0e4a1SAndreas Gohr  }elseif($ns !== false && strpos($id,':') === false){
304c4e0e4a1SAndreas Gohr    //if link contains no namespace. add current namespace (if any)
305c4e0e4a1SAndreas Gohr    $id = $ns.':'.$id;
306c4e0e4a1SAndreas Gohr  }
307c4e0e4a1SAndreas Gohr
308a6ef4796SAndreas Gohr  if($clean) $id = cleanID($id);
309a6ef4796SAndreas Gohr  return $id;
310c4e0e4a1SAndreas Gohr}
311c4e0e4a1SAndreas Gohr
312c4e0e4a1SAndreas Gohr/**
313b625487dSandi * Returns a full media id
314b625487dSandi *
315b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
316b625487dSandi */
31737e34a5eSandifunction resolve_mediaid($ns,&$page,&$exists){
318c4e0e4a1SAndreas Gohr  $page   = resolve_id($ns,$page);
319b625487dSandi  $file   = mediaFN($page);
320b625487dSandi  $exists = @file_exists($file);
321b625487dSandi}
322b625487dSandi
323b625487dSandi/**
324b625487dSandi * Returns a full page id
325b625487dSandi *
326b625487dSandi * @author Andreas Gohr <andi@splitbrain.org>
327b625487dSandi */
32837e34a5eSandifunction resolve_pageid($ns,&$page,&$exists){
329b625487dSandi  global $conf;
3300b7c14c2Sandi  $exists = false;
331b625487dSandi
332b625487dSandi  //keep hashlink if exists then clean both parts
33303c4aec3Schris  if (strpos($page,'#')) {
334b625487dSandi    list($page,$hash) = split('#',$page,2);
33503c4aec3Schris  } else {
33603c4aec3Schris    $hash = '';
33703c4aec3Schris  }
338b625487dSandi  $hash = cleanID($hash);
339a6ef4796SAndreas Gohr  $page = resolve_id($ns,$page,false); // resolve but don't clean, yet
340b625487dSandi
341a6ef4796SAndreas Gohr  // get filename (calls clean itself)
342b625487dSandi  $file = wikiFN($page);
343b625487dSandi
3441179df0eSGuy Brand  // if ends with colon or slash we have a namespace link
3451179df0eSGuy Brand  if(substr($page,-1) == ':' || ($conf['useslash'] && substr($page,-1) == '/')){
346a6ef4796SAndreas Gohr    if(@file_exists(wikiFN($page.$conf['start']))){
347a6ef4796SAndreas Gohr      // start page inside namespace
348a6ef4796SAndreas Gohr      $page = $page.$conf['start'];
349a6ef4796SAndreas Gohr      $exists = true;
350a6ef4796SAndreas Gohr    }elseif(@file_exists(wikiFN($page.noNS(cleanID($page))))){
351a6ef4796SAndreas Gohr      // page named like the NS inside the NS
352a6ef4796SAndreas Gohr      $page = $page.noNS(cleanID($page));
353a6ef4796SAndreas Gohr      $exists = true;
354a6ef4796SAndreas Gohr    }elseif(@file_exists(wikiFN($page))){
355a6ef4796SAndreas Gohr      // page like namespace exists
356a6ef4796SAndreas Gohr      $page = $page;
357a6ef4796SAndreas Gohr      $exists = true;
358a6ef4796SAndreas Gohr    }else{
359a6ef4796SAndreas Gohr      // fall back to default
360a6ef4796SAndreas Gohr      $page = $page.$conf['start'];
361a6ef4796SAndreas Gohr    }
362a6ef4796SAndreas Gohr  }else{
363b625487dSandi    //check alternative plural/nonplural form
364b625487dSandi    if(!@file_exists($file)){
365b625487dSandi      if( $conf['autoplural'] ){
366b625487dSandi        if(substr($page,-1) == 's'){
367b625487dSandi          $try = substr($page,0,-1);
368b625487dSandi        }else{
369b625487dSandi          $try = $page.'s';
370b625487dSandi        }
371b625487dSandi        if(@file_exists(wikiFN($try))){
372b625487dSandi          $page   = $try;
373b625487dSandi          $exists = true;
374b625487dSandi        }
375b625487dSandi      }
376b625487dSandi    }else{
377b625487dSandi      $exists = true;
378b625487dSandi    }
379a6ef4796SAndreas Gohr  }
380a6ef4796SAndreas Gohr
381a6ef4796SAndreas Gohr  // now make sure we have a clean page
382a6ef4796SAndreas Gohr  $page = cleanID($page);
383b625487dSandi
384b625487dSandi  //add hash if any
385b2d7d3f2Sandi  if(!empty($hash)) $page .= '#'.$hash;
386b625487dSandi}
387b625487dSandi
38898407a7aSandi/**
38998407a7aSandi * Returns the name of a cachefile from given data
39098407a7aSandi *
39198407a7aSandi * The needed directory is created by this function!
39298407a7aSandi *
39398407a7aSandi * @author Andreas Gohr <andi@splitbrain.org>
39498407a7aSandi *
39598407a7aSandi * @param string $data  This data is used to create a unique md5 name
39698407a7aSandi * @param string $ext   This is appended to the filename if given
39798407a7aSandi * @return string       The filename of the cachefile
39898407a7aSandi */
39998407a7aSandifunction getCacheName($data,$ext=''){
40098407a7aSandi  global $conf;
40198407a7aSandi  $md5  = md5($data);
40298407a7aSandi  $file = $conf['cachedir'].'/'.$md5{0}.'/'.$md5.$ext;
40398407a7aSandi  io_makeFileDir($file);
40498407a7aSandi  return $file;
40598407a7aSandi}
40698407a7aSandi
4070dc92c6fSAndreas Gohr/**
4080dc92c6fSAndreas Gohr * Checks a pageid against $conf['hidepages']
4090dc92c6fSAndreas Gohr *
4100dc92c6fSAndreas Gohr * @author Andreas Gohr <gohr@cosmocode.de>
4110dc92c6fSAndreas Gohr */
4120dc92c6fSAndreas Gohrfunction isHiddenPage($id){
4130dc92c6fSAndreas Gohr  global $conf;
4140dc92c6fSAndreas Gohr  if(empty($conf['hidepages'])) return false;
4150dc92c6fSAndreas Gohr
4160dc92c6fSAndreas Gohr  if(preg_match('/'.$conf['hidepages'].'/ui',':'.$id)){
4170dc92c6fSAndreas Gohr    return true;
4180dc92c6fSAndreas Gohr  }
4190dc92c6fSAndreas Gohr  return false;
4200dc92c6fSAndreas Gohr}
4210dc92c6fSAndreas Gohr
4220dc92c6fSAndreas Gohr/**
4230dc92c6fSAndreas Gohr * Reverse of isHiddenPage
4240dc92c6fSAndreas Gohr *
4250dc92c6fSAndreas Gohr * @author Andreas Gohr <gohr@cosmocode.de>
4260dc92c6fSAndreas Gohr */
4270dc92c6fSAndreas Gohrfunction isVisiblePage($id){
4280dc92c6fSAndreas Gohr  return !isHiddenPage($id);
4290dc92c6fSAndreas Gohr}
4300dc92c6fSAndreas Gohr
431254e5c84SBen Coburn/**
432254e5c84SBen Coburn * Checks and sets HTTP headers for conditional HTTP requests
433254e5c84SBen Coburn *
434254e5c84SBen Coburn * @author   Simon Willison <swillison@gmail.com>
435254e5c84SBen Coburn * @link     http://simon.incutio.com/archive/2003/04/23/conditionalGet
4360ac9a84dSoliver * @param    timestamp $timestamp lastmodified time of the cache file
4370ac9a84dSoliver * @returns  void or void with previously header() commands executed
438254e5c84SBen Coburn */
439254e5c84SBen Coburnfunction http_conditionalRequest($timestamp){
440254e5c84SBen Coburn  // A PHP implementation of conditional get, see
441254e5c84SBen Coburn  //   http://fishbowl.pastiche.org/archives/001132.html
442*6d88439aSAndreas Gohr  $last_modified = substr(gmdate('r', $timestamp), 0, -5).'GMT';
443254e5c84SBen Coburn  $etag = '"'.md5($last_modified).'"';
444254e5c84SBen Coburn  // Send the headers
445254e5c84SBen Coburn  header("Last-Modified: $last_modified");
446254e5c84SBen Coburn  header("ETag: $etag");
447254e5c84SBen Coburn  // See if the client has provided the required headers
4480ac9a84dSoliver  if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])){
4490ac9a84dSoliver    $if_modified_since = stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']);
4500ac9a84dSoliver  }else{
4510ac9a84dSoliver    $if_modified_since = false;
4520ac9a84dSoliver  }
4530ac9a84dSoliver
4540ac9a84dSoliver  if (isset($_SERVER['HTTP_IF_NONE_MATCH'])){
4550ac9a84dSoliver    $if_none_match = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
4560ac9a84dSoliver  }else{
4570ac9a84dSoliver    $if_none_match = false;
4580ac9a84dSoliver  }
4590ac9a84dSoliver
460254e5c84SBen Coburn  if (!$if_modified_since && !$if_none_match){
461254e5c84SBen Coburn    return;
462254e5c84SBen Coburn  }
4630ac9a84dSoliver
464254e5c84SBen Coburn  // At least one of the headers is there - check them
465254e5c84SBen Coburn  if ($if_none_match && $if_none_match != $etag) {
466254e5c84SBen Coburn    return; // etag is there but doesn't match
467254e5c84SBen Coburn  }
4680ac9a84dSoliver
469254e5c84SBen Coburn  if ($if_modified_since && $if_modified_since != $last_modified) {
470254e5c84SBen Coburn    return; // if-modified-since is there but doesn't match
471254e5c84SBen Coburn  }
4720ac9a84dSoliver
473254e5c84SBen Coburn  // Nothing has changed since their last request - serve a 304 and exit
474254e5c84SBen Coburn  header('HTTP/1.0 304 Not Modified');
475254e5c84SBen Coburn  exit;
476254e5c84SBen Coburn}
477254e5c84SBen Coburn
478b625487dSandi//Setup VIM: ex: et ts=2 enc=utf-8 :
479