xref: /dokuwiki/inc/common.php (revision b75887c89490a61d87189eaa4aba3a714a207a78) 
1<?php
2/**
3 * Common DokuWiki functions
4 *
5 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
6 * @author     Andreas Gohr <andi@splitbrain.org>
7 */
8
9use dokuwiki\Cache\CacheInstructions;
10use dokuwiki\Cache\CacheRenderer;
11use dokuwiki\ChangeLog\PageChangeLog;
12use dokuwiki\Subscriptions\PageSubscriptionSender;
13use dokuwiki\Subscriptions\SubscriberManager;
14use dokuwiki\Extension\AuthPlugin;
15use dokuwiki\Extension\Event;
16
17/**
18 * Wrapper around htmlspecialchars()
19 *
20 * @author Andreas Gohr <andi@splitbrain.org>
21 * @see    htmlspecialchars()
22 *
23 * @param string $string the string being converted
24 * @return string converted string
25 */
26function hsc($string) {
27    return htmlspecialchars($string, ENT_QUOTES, 'UTF-8');
28}
29
30/**
31 * Checks if the given input is blank
32 *
33 * This is similar to empty() but will return false for "0".
34 *
35 * Please note: when you pass uninitialized variables, they will implicitly be created
36 * with a NULL value without warning.
37 *
38 * To avoid this it's recommended to guard the call with isset like this:
39 *
40 * (isset($foo) && !blank($foo))
41 * (!isset($foo) || blank($foo))
42 *
43 * @param $in
44 * @param bool $trim Consider a string of whitespace to be blank
45 * @return bool
46 */
47function blank(&$in, $trim = false) {
48    if(is_null($in)) return true;
49    if(is_array($in)) return empty($in);
50    if($in === "\0") return true;
51    if($trim && trim($in) === '') return true;
52    if(strlen($in) > 0) return false;
53    return empty($in);
54}
55
56/**
57 * print a newline terminated string
58 *
59 * You can give an indention as optional parameter
60 *
61 * @author Andreas Gohr <andi@splitbrain.org>
62 *
63 * @param string $string  line of text
64 * @param int    $indent  number of spaces indention
65 */
66function ptln($string, $indent = 0) {
67    echo str_repeat(' ', $indent)."$string\n";
68}
69
70/**
71 * strips control characters (<32) from the given string
72 *
73 * @author Andreas Gohr <andi@splitbrain.org>
74 *
75 * @param string $string being stripped
76 * @return string
77 */
78function stripctl($string) {
79    return preg_replace('/[\x00-\x1F]+/s', '', $string);
80}
81
82/**
83 * Return a secret token to be used for CSRF attack prevention
84 *
85 * @author  Andreas Gohr <andi@splitbrain.org>
86 * @link    http://en.wikipedia.org/wiki/Cross-site_request_forgery
87 * @link    http://christ1an.blogspot.com/2007/04/preventing-csrf-efficiently.html
88 *
89 * @return  string
90 */
91function getSecurityToken() {
92    /** @var Input $INPUT */
93    global $INPUT;
94
95    $user = $INPUT->server->str('REMOTE_USER');
96    $session = session_id();
97
98    // CSRF checks are only for logged in users - do not generate for anonymous
99    if(trim($user) == '' || trim($session) == '') return '';
100    return \dokuwiki\PassHash::hmac('md5', $session.$user, auth_cookiesalt());
101}
102
103/**
104 * Check the secret CSRF token
105 *
106 * @param null|string $token security token or null to read it from request variable
107 * @return bool success if the token matched
108 */
109function checkSecurityToken($token = null) {
110    /** @var Input $INPUT */
111    global $INPUT;
112    if(!$INPUT->server->str('REMOTE_USER')) return true; // no logged in user, no need for a check
113
114    if(is_null($token)) $token = $INPUT->str('sectok');
115    if(getSecurityToken() != $token) {
116        msg('Security Token did not match. Possible CSRF attack.', -1);
117        return false;
118    }
119    return true;
120}
121
122/**
123 * Print a hidden form field with a secret CSRF token
124 *
125 * @author  Andreas Gohr <andi@splitbrain.org>
126 *
127 * @param bool $print  if true print the field, otherwise html of the field is returned
128 * @return string html of hidden form field
129 */
130function formSecurityToken($print = true) {
131    $ret = '<div class="no"><input type="hidden" name="sectok" value="'.getSecurityToken().'" /></div>'."\n";
132    if($print) echo $ret;
133    return $ret;
134}
135
136/**
137 * Determine basic information for a request of $id
138 *
139 * @author Andreas Gohr <andi@splitbrain.org>
140 * @author Chris Smith <chris@jalakai.co.uk>
141 *
142 * @param string $id         pageid
143 * @param bool   $htmlClient add info about whether is mobile browser
144 * @return array with info for a request of $id
145 *
146 */
147function basicinfo($id, $htmlClient=true){
148    global $USERINFO;
149    /* @var Input $INPUT */
150    global $INPUT;
151
152    // set info about manager/admin status.
153    $info = array();
154    $info['isadmin']   = false;
155    $info['ismanager'] = false;
156    if($INPUT->server->has('REMOTE_USER')) {
157        $info['userinfo']   = $USERINFO;
158        $info['perm']       = auth_quickaclcheck($id);
159        $info['client']     = $INPUT->server->str('REMOTE_USER');
160
161        if($info['perm'] == AUTH_ADMIN) {
162            $info['isadmin']   = true;
163            $info['ismanager'] = true;
164        } elseif(auth_ismanager()) {
165            $info['ismanager'] = true;
166        }
167
168        // if some outside auth were used only REMOTE_USER is set
169        if(!$info['userinfo']['name']) {
170            $info['userinfo']['name'] = $INPUT->server->str('REMOTE_USER');
171        }
172
173    } else {
174        $info['perm']       = auth_aclcheck($id, '', null);
175        $info['client']     = clientIP(true);
176    }
177
178    $info['namespace'] = getNS($id);
179
180    // mobile detection
181    if ($htmlClient) {
182        $info['ismobile'] = clientismobile();
183    }
184
185    return $info;
186 }
187
188/**
189 * Return info about the current document as associative
190 * array.
191 *
192 * @author Andreas Gohr <andi@splitbrain.org>
193 *
194 * @return array with info about current document
195 */
196function pageinfo() {
197    global $ID;
198    global $REV;
199    global $RANGE;
200    global $lang;
201    /* @var Input $INPUT */
202    global $INPUT;
203
204    $info = basicinfo($ID);
205
206    // include ID & REV not redundant, as some parts of DokuWiki may temporarily change $ID, e.g. p_wiki_xhtml
207    // FIXME ... perhaps it would be better to ensure the temporary changes weren't necessary
208    $info['id']  = $ID;
209    $info['rev'] = $REV;
210
211    $subManager = new SubscriberManager();
212    $info['subscribed'] = $subManager->userSubscription();
213
214    $info['locked']     = checklock($ID);
215    $info['filepath']   = wikiFN($ID);
216    $info['exists']     = file_exists($info['filepath']);
217    $info['currentrev'] = @filemtime($info['filepath']);
218    if($REV) {
219        //check if current revision was meant
220        if($info['exists'] && ($info['currentrev'] == $REV)) {
221            $REV = '';
222        } elseif($RANGE) {
223            //section editing does not work with old revisions!
224            $REV   = '';
225            $RANGE = '';
226            msg($lang['nosecedit'], 0);
227        } else {
228            //really use old revision
229            $info['filepath'] = wikiFN($ID, $REV);
230            $info['exists']   = file_exists($info['filepath']);
231        }
232    }
233    $info['rev'] = $REV;
234    if($info['exists']) {
235        $info['writable'] = (is_writable($info['filepath']) &&
236            ($info['perm'] >= AUTH_EDIT));
237    } else {
238        $info['writable'] = ($info['perm'] >= AUTH_CREATE);
239    }
240    $info['editable'] = ($info['writable'] && empty($info['locked']));
241    $info['lastmod']  = @filemtime($info['filepath']);
242
243    //load page meta data
244    $info['meta'] = p_get_metadata($ID);
245
246    //who's the editor
247    $pagelog = new PageChangeLog($ID, 1024);
248    if($REV) {
249        $revinfo = $pagelog->getRevisionInfo($REV);
250    } else {
251        if(!empty($info['meta']['last_change']) && is_array($info['meta']['last_change'])) {
252            $revinfo = $info['meta']['last_change'];
253        } else {
254            $revinfo = $pagelog->getRevisionInfo($info['lastmod']);
255            // cache most recent changelog line in metadata if missing and still valid
256            if($revinfo !== false) {
257                $info['meta']['last_change'] = $revinfo;
258                p_set_metadata($ID, array('last_change' => $revinfo));
259            }
260        }
261    }
262    //and check for an external edit
263    if($revinfo !== false && $revinfo['date'] != $info['lastmod']) {
264        // cached changelog line no longer valid
265        $revinfo                     = false;
266        $info['meta']['last_change'] = $revinfo;
267        p_set_metadata($ID, array('last_change' => $revinfo));
268    }
269
270    if($revinfo !== false){
271        $info['ip']   = $revinfo['ip'];
272        $info['user'] = $revinfo['user'];
273        $info['sum']  = $revinfo['sum'];
274        // See also $INFO['meta']['last_change'] which is the most recent log line for page $ID.
275        // Use $INFO['meta']['last_change']['type']===DOKU_CHANGE_TYPE_MINOR_EDIT in place of $info['minor'].
276
277        if($revinfo['user']) {
278            $info['editor'] = $revinfo['user'];
279        } else {
280            $info['editor'] = $revinfo['ip'];
281        }
282    }else{
283        $info['ip']     = null;
284        $info['user']   = null;
285        $info['sum']    = null;
286        $info['editor'] = null;
287    }
288
289    // draft
290    $draft = new \dokuwiki\Draft($ID, $info['client']);
291    if ($draft->isDraftAvailable()) {
292        $info['draft'] = $draft->getDraftFilename();
293    }
294
295    return $info;
296}
297
298/**
299 * Initialize and/or fill global $JSINFO with some basic info to be given to javascript
300 */
301function jsinfo() {
302    global $JSINFO, $ID, $INFO, $ACT;
303
304    if (!is_array($JSINFO)) {
305        $JSINFO = [];
306    }
307    //export minimal info to JS, plugins can add more
308    $JSINFO['id']                    = $ID;
309    $JSINFO['namespace']             = isset($INFO) ? (string) $INFO['namespace'] : '';
310    $JSINFO['ACT']                   = act_clean($ACT);
311    $JSINFO['useHeadingNavigation']  = (int) useHeading('navigation');
312    $JSINFO['useHeadingContent']     = (int) useHeading('content');
313}
314
315/**
316 * Return information about the current media item as an associative array.
317 *
318 * @return array with info about current media item
319 */
320function mediainfo(){
321    global $NS;
322    global $IMG;
323
324    $info = basicinfo("$NS:*");
325    $info['image'] = $IMG;
326
327    return $info;
328}
329
330/**
331 * Build an string of URL parameters
332 *
333 * @author Andreas Gohr
334 *
335 * @param array  $params    array with key-value pairs
336 * @param string $sep       series of pairs are separated by this character
337 * @return string query string
338 */
339function buildURLparams($params, $sep = '&amp;') {
340    $url = '';
341    $amp = false;
342    foreach($params as $key => $val) {
343        if($amp) $url .= $sep;
344
345        $url .= rawurlencode($key).'=';
346        $url .= rawurlencode((string) $val);
347        $amp = true;
348    }
349    return $url;
350}
351
352/**
353 * Build an string of html tag attributes
354 *
355 * Skips keys starting with '_', values get HTML encoded
356 *
357 * @author Andreas Gohr
358 *
359 * @param array $params           array with (attribute name-attribute value) pairs
360 * @param bool  $skipEmptyStrings skip empty string values?
361 * @return string
362 */
363function buildAttributes($params, $skipEmptyStrings = false) {
364    $url   = '';
365    $white = false;
366    foreach($params as $key => $val) {
367        if($key[0] == '_') continue;
368        if($val === '' && $skipEmptyStrings) continue;
369        if($white) $url .= ' ';
370
371        $url .= $key.'="';
372        $url .= htmlspecialchars($val);
373        $url .= '"';
374        $white = true;
375    }
376    return $url;
377}
378
379/**
380 * This builds the breadcrumb trail and returns it as array
381 *
382 * @author Andreas Gohr <andi@splitbrain.org>
383 *
384 * @return string[] with the data: array(pageid=>name, ... )
385 */
386function breadcrumbs() {
387    // we prepare the breadcrumbs early for quick session closing
388    static $crumbs = null;
389    if($crumbs != null) return $crumbs;
390
391    global $ID;
392    global $ACT;
393    global $conf;
394    global $INFO;
395
396    //first visit?
397    $crumbs = isset($_SESSION[DOKU_COOKIE]['bc']) ? $_SESSION[DOKU_COOKIE]['bc'] : array();
398    //we only save on show and existing visible readable wiki documents
399    $file = wikiFN($ID);
400    if($ACT != 'show' || $INFO['perm'] < AUTH_READ || isHiddenPage($ID) || !file_exists($file)) {
401        $_SESSION[DOKU_COOKIE]['bc'] = $crumbs;
402        return $crumbs;
403    }
404
405    // page names
406    $name = noNSorNS($ID);
407    if(useHeading('navigation')) {
408        // get page title
409        $title = p_get_first_heading($ID, METADATA_RENDER_USING_SIMPLE_CACHE);
410        if($title) {
411            $name = $title;
412        }
413    }
414
415    //remove ID from array
416    if(isset($crumbs[$ID])) {
417        unset($crumbs[$ID]);
418    }
419
420    //add to array
421    $crumbs[$ID] = $name;
422    //reduce size
423    while(count($crumbs) > $conf['breadcrumbs']) {
424        array_shift($crumbs);
425    }
426    //save to session
427    $_SESSION[DOKU_COOKIE]['bc'] = $crumbs;
428    return $crumbs;
429}
430
431/**
432 * Filter for page IDs
433 *
434 * This is run on a ID before it is outputted somewhere
435 * currently used to replace the colon with something else
436 * on Windows (non-IIS) systems and to have proper URL encoding
437 *
438 * See discussions at https://github.com/splitbrain/dokuwiki/pull/84 and
439 * https://github.com/splitbrain/dokuwiki/pull/173 why we use a whitelist of
440 * unaffected servers instead of blacklisting affected servers here.
441 *
442 * Urlencoding is ommitted when the second parameter is false
443 *
444 * @author Andreas Gohr <andi@splitbrain.org>
445 *
446 * @param string $id pageid being filtered
447 * @param bool   $ue apply urlencoding?
448 * @return string
449 */
450function idfilter($id, $ue = true) {
451    global $conf;
452    /* @var Input $INPUT */
453    global $INPUT;
454
455    if($conf['useslash'] && $conf['userewrite']) {
456        $id = strtr($id, ':', '/');
457    } elseif(strtoupper(substr(PHP_OS, 0, 3)) === 'WIN' &&
458        $conf['userewrite'] &&
459        strpos($INPUT->server->str('SERVER_SOFTWARE'), 'Microsoft-IIS') === false
460    ) {
461        $id = strtr($id, ':', ';');
462    }
463    if($ue) {
464        $id = rawurlencode($id);
465        $id = str_replace('%3A', ':', $id); //keep as colon
466        $id = str_replace('%3B', ';', $id); //keep as semicolon
467        $id = str_replace('%2F', '/', $id); //keep as slash
468    }
469    return $id;
470}
471
472/**
473 * This builds a link to a wikipage
474 *
475 * It handles URL rewriting and adds additional parameters
476 *
477 * @author Andreas Gohr <andi@splitbrain.org>
478 *
479 * @param string       $id             page id, defaults to start page
480 * @param string|array $urlParameters  URL parameters, associative array recommended
481 * @param bool         $absolute       request an absolute URL instead of relative
482 * @param string       $separator      parameter separator
483 * @return string
484 */
485function wl($id = '', $urlParameters = '', $absolute = false, $separator = '&amp;') {
486    global $conf;
487    if(is_array($urlParameters)) {
488        if(isset($urlParameters['rev']) && !$urlParameters['rev']) unset($urlParameters['rev']);
489        if(isset($urlParameters['at']) && $conf['date_at_format']) {
490            $urlParameters['at'] = date($conf['date_at_format'], $urlParameters['at']);
491        }
492        $urlParameters = buildURLparams($urlParameters, $separator);
493    } else {
494        $urlParameters = str_replace(',', $separator, $urlParameters);
495    }
496    if($id === '') {
497        $id = $conf['start'];
498    }
499    $id = idfilter($id);
500    if($absolute) {
501        $xlink = DOKU_URL;
502    } else {
503        $xlink = DOKU_BASE;
504    }
505
506    if($conf['userewrite'] == 2) {
507        $xlink .= DOKU_SCRIPT.'/'.$id;
508        if($urlParameters) $xlink .= '?'.$urlParameters;
509    } elseif($conf['userewrite']) {
510        $xlink .= $id;
511        if($urlParameters) $xlink .= '?'.$urlParameters;
512    } elseif($id !== '') {
513        $xlink .= DOKU_SCRIPT.'?id='.$id;
514        if($urlParameters) $xlink .= $separator.$urlParameters;
515    } else {
516        $xlink .= DOKU_SCRIPT;
517        if($urlParameters) $xlink .= '?'.$urlParameters;
518    }
519
520    return $xlink;
521}
522
523/**
524 * This builds a link to an alternate page format
525 *
526 * Handles URL rewriting if enabled. Follows the style of wl().
527 *
528 * @author Ben Coburn <btcoburn@silicodon.net>
529 * @param string       $id             page id, defaults to start page
530 * @param string       $format         the export renderer to use
531 * @param string|array $urlParameters  URL parameters, associative array recommended
532 * @param bool         $abs            request an absolute URL instead of relative
533 * @param string       $sep            parameter separator
534 * @return string
535 */
536function exportlink($id = '', $format = 'raw', $urlParameters = '', $abs = false, $sep = '&amp;') {
537    global $conf;
538    if(is_array($urlParameters)) {
539        $urlParameters = buildURLparams($urlParameters, $sep);
540    } else {
541        $urlParameters = str_replace(',', $sep, $urlParameters);
542    }
543
544    $format = rawurlencode($format);
545    $id     = idfilter($id);
546    if($abs) {
547        $xlink = DOKU_URL;
548    } else {
549        $xlink = DOKU_BASE;
550    }
551
552    if($conf['userewrite'] == 2) {
553        $xlink .= DOKU_SCRIPT.'/'.$id.'?do=export_'.$format;
554        if($urlParameters) $xlink .= $sep.$urlParameters;
555    } elseif($conf['userewrite'] == 1) {
556        $xlink .= '_export/'.$format.'/'.$id;
557        if($urlParameters) $xlink .= '?'.$urlParameters;
558    } else {
559        $xlink .= DOKU_SCRIPT.'?do=export_'.$format.$sep.'id='.$id;
560        if($urlParameters) $xlink .= $sep.$urlParameters;
561    }
562
563    return $xlink;
564}
565
566/**
567 * Build a link to a media file
568 *
569 * Will return a link to the detail page if $direct is false
570 *
571 * The $more parameter should always be given as array, the function then
572 * will strip default parameters to produce even cleaner URLs
573 *
574 * @param string  $id     the media file id or URL
575 * @param mixed   $more   string or array with additional parameters
576 * @param bool    $direct link to detail page if false
577 * @param string  $sep    URL parameter separator
578 * @param bool    $abs    Create an absolute URL
579 * @return string
580 */
581function ml($id = '', $more = '', $direct = true, $sep = '&amp;', $abs = false) {
582    global $conf;
583    $isexternalimage = media_isexternal($id);
584    if(!$isexternalimage) {
585        $id = cleanID($id);
586    }
587
588    if(is_array($more)) {
589        // add token for resized images
590        if(!empty($more['w']) || !empty($more['h']) || $isexternalimage){
591            $more['tok'] = media_get_token($id,$more['w'],$more['h']);
592        }
593        // strip defaults for shorter URLs
594        if(isset($more['cache']) && $more['cache'] == 'cache') unset($more['cache']);
595        if(empty($more['w'])) unset($more['w']);
596        if(empty($more['h'])) unset($more['h']);
597        if(isset($more['id']) && $direct) unset($more['id']);
598        if(isset($more['rev']) && !$more['rev']) unset($more['rev']);
599        $more = buildURLparams($more, $sep);
600    } else {
601        $matches = array();
602        if (preg_match_all('/\b(w|h)=(\d*)\b/',$more,$matches,PREG_SET_ORDER) || $isexternalimage){
603            $resize = array('w'=>0, 'h'=>0);
604            foreach ($matches as $match){
605                $resize[$match[1]] = $match[2];
606            }
607            $more .= $more === '' ? '' : $sep;
608            $more .= 'tok='.media_get_token($id,$resize['w'],$resize['h']);
609        }
610        $more = str_replace('cache=cache', '', $more); //skip default
611        $more = str_replace(',,', ',', $more);
612        $more = str_replace(',', $sep, $more);
613    }
614
615    if($abs) {
616        $xlink = DOKU_URL;
617    } else {
618        $xlink = DOKU_BASE;
619    }
620
621    // external URLs are always direct without rewriting
622    if($isexternalimage) {
623        $xlink .= 'lib/exe/fetch.php';
624        $xlink .= '?'.$more;
625        $xlink .= $sep.'media='.rawurlencode($id);
626        return $xlink;
627    }
628
629    $id = idfilter($id);
630
631    // decide on scriptname
632    if($direct) {
633        if($conf['userewrite'] == 1) {
634            $script = '_media';
635        } else {
636            $script = 'lib/exe/fetch.php';
637        }
638    } else {
639        if($conf['userewrite'] == 1) {
640            $script = '_detail';
641        } else {
642            $script = 'lib/exe/detail.php';
643        }
644    }
645
646    // build URL based on rewrite mode
647    if($conf['userewrite']) {
648        $xlink .= $script.'/'.$id;
649        if($more) $xlink .= '?'.$more;
650    } else {
651        if($more) {
652            $xlink .= $script.'?'.$more;
653            $xlink .= $sep.'media='.$id;
654        } else {
655            $xlink .= $script.'?media='.$id;
656        }
657    }
658
659    return $xlink;
660}
661
662/**
663 * Returns the URL to the DokuWiki base script
664 *
665 * Consider using wl() instead, unless you absoutely need the doku.php endpoint
666 *
667 * @author Andreas Gohr <andi@splitbrain.org>
668 *
669 * @return string
670 */
671function script() {
672    return DOKU_BASE.DOKU_SCRIPT;
673}
674
675/**
676 * Spamcheck against wordlist
677 *
678 * Checks the wikitext against a list of blocked expressions
679 * returns true if the text contains any bad words
680 *
681 * Triggers COMMON_WORDBLOCK_BLOCKED
682 *
683 *  Action Plugins can use this event to inspect the blocked data
684 *  and gain information about the user who was blocked.
685 *
686 *  Event data:
687 *    data['matches']  - array of matches
688 *    data['userinfo'] - information about the blocked user
689 *      [ip]           - ip address
690 *      [user]         - username (if logged in)
691 *      [mail]         - mail address (if logged in)
692 *      [name]         - real name (if logged in)
693 *
694 * @author Andreas Gohr <andi@splitbrain.org>
695 * @author Michael Klier <chi@chimeric.de>
696 *
697 * @param  string $text - optional text to check, if not given the globals are used
698 * @return bool         - true if a spam word was found
699 */
700function checkwordblock($text = '') {
701    global $TEXT;
702    global $PRE;
703    global $SUF;
704    global $SUM;
705    global $conf;
706    global $INFO;
707    /* @var Input $INPUT */
708    global $INPUT;
709
710    if(!$conf['usewordblock']) return false;
711
712    if(!$text) $text = "$PRE $TEXT $SUF $SUM";
713
714    // we prepare the text a tiny bit to prevent spammers circumventing URL checks
715    // phpcs:disable Generic.Files.LineLength.TooLong
716    $text = preg_replace(
717        '!(\b)(www\.[\w.:?\-;,]+?\.[\w.:?\-;,]+?[\w/\#~:.?+=&%@\!\-.:?\-;,]+?)([.:?\-;,]*[^\w/\#~:.?+=&%@\!\-.:?\-;,])!i',
718        '\1http://\2 \2\3',
719        $text
720    );
721    // phpcs:enable
722
723    $wordblocks = getWordblocks();
724    // how many lines to read at once (to work around some PCRE limits)
725    if(version_compare(phpversion(), '4.3.0', '<')) {
726        // old versions of PCRE define a maximum of parenthesises even if no
727        // backreferences are used - the maximum is 99
728        // this is very bad performancewise and may even be too high still
729        $chunksize = 40;
730    } else {
731        // read file in chunks of 200 - this should work around the
732        // MAX_PATTERN_SIZE in modern PCRE
733        $chunksize = 200;
734    }
735    while($blocks = array_splice($wordblocks, 0, $chunksize)) {
736        $re = array();
737        // build regexp from blocks
738        foreach($blocks as $block) {
739            $block = preg_replace('/#.*$/', '', $block);
740            $block = trim($block);
741            if(empty($block)) continue;
742            $re[] = $block;
743        }
744        if(count($re) && preg_match('#('.join('|', $re).')#si', $text, $matches)) {
745            // prepare event data
746            $data = array();
747            $data['matches']        = $matches;
748            $data['userinfo']['ip'] = $INPUT->server->str('REMOTE_ADDR');
749            if($INPUT->server->str('REMOTE_USER')) {
750                $data['userinfo']['user'] = $INPUT->server->str('REMOTE_USER');
751                $data['userinfo']['name'] = $INFO['userinfo']['name'];
752                $data['userinfo']['mail'] = $INFO['userinfo']['mail'];
753            }
754            $callback = function () {
755                return true;
756            };
757            return Event::createAndTrigger('COMMON_WORDBLOCK_BLOCKED', $data, $callback, true);
758        }
759    }
760    return false;
761}
762
763/**
764 * Return the IP of the client
765 *
766 * Honours X-Forwarded-For and X-Real-IP Proxy Headers
767 *
768 * It returns a comma separated list of IPs if the above mentioned
769 * headers are set. If the single parameter is set, it tries to return
770 * a routable public address, prefering the ones suplied in the X
771 * headers
772 *
773 * @author Andreas Gohr <andi@splitbrain.org>
774 *
775 * @param  boolean $single If set only a single IP is returned
776 * @return string
777 */
778function clientIP($single = false) {
779    /* @var Input $INPUT */
780    global $INPUT, $conf;
781
782    $ip   = array();
783    $ip[] = $INPUT->server->str('REMOTE_ADDR');
784    if($INPUT->server->str('HTTP_X_FORWARDED_FOR')) {
785        $ip = array_merge($ip, explode(',', str_replace(' ', '', $INPUT->server->str('HTTP_X_FORWARDED_FOR'))));
786    }
787    if($INPUT->server->str('HTTP_X_REAL_IP')) {
788        $ip = array_merge($ip, explode(',', str_replace(' ', '', $INPUT->server->str('HTTP_X_REAL_IP'))));
789    }
790
791    // remove any non-IP stuff
792    $cnt   = count($ip);
793    for($i = 0; $i < $cnt; $i++) {
794        $ip[$i] = filter_var($ip[$i], FILTER_VALIDATE_IP);
795        if(empty($ip[$i])) unset($ip[$i]);
796    }
797    $ip = array_values(array_unique($ip));
798    if(!$ip[0]) $ip[0] = '0.0.0.0'; // for some strange reason we don't have a IP
799
800    if(!$single) return join(',', $ip);
801
802    // skip trusted local addresses
803    foreach($ip as $i) {
804        if(!empty($conf['trustedproxy']) && preg_match('/'.$conf['trustedproxy'].'/', $i)) {
805            continue;
806        } else {
807            return $i;
808        }
809    }
810
811    // still here? just use the last address
812    // this case all ips in the list are trusted
813    return $ip[count($ip)-1];
814}
815
816/**
817 * Check if the browser is on a mobile device
818 *
819 * Adapted from the example code at url below
820 *
821 * @link http://www.brainhandles.com/2007/10/15/detecting-mobile-browsers/#code
822 *
823 * @deprecated 2018-04-27 you probably want media queries instead anyway
824 * @return bool if true, client is mobile browser; otherwise false
825 */
826function clientismobile() {
827    /* @var Input $INPUT */
828    global $INPUT;
829
830    if($INPUT->server->has('HTTP_X_WAP_PROFILE')) return true;
831
832    if(preg_match('/wap\.|\.wap/i', $INPUT->server->str('HTTP_ACCEPT'))) return true;
833
834    if(!$INPUT->server->has('HTTP_USER_AGENT')) return false;
835
836    $uamatches = join(
837        '|',
838        [
839            'midp', 'j2me', 'avantg', 'docomo', 'novarra', 'palmos', 'palmsource', '240x320', 'opwv',
840            'chtml', 'pda', 'windows ce', 'mmp\/', 'blackberry', 'mib\/', 'symbian', 'wireless', 'nokia',
841            'hand', 'mobi', 'phone', 'cdm', 'up\.b', 'audio', 'SIE\-', 'SEC\-', 'samsung', 'HTC', 'mot\-',
842            'mitsu', 'sagem', 'sony', 'alcatel', 'lg', 'erics', 'vx', 'NEC', 'philips', 'mmm', 'xx',
843            'panasonic', 'sharp', 'wap', 'sch', 'rover', 'pocket', 'benq', 'java', 'pt', 'pg', 'vox',
844            'amoi', 'bird', 'compal', 'kg', 'voda', 'sany', 'kdd', 'dbt', 'sendo', 'sgh', 'gradi', 'jb',
845            '\d\d\di', 'moto'
846        ]
847    );
848
849    if(preg_match("/$uamatches/i", $INPUT->server->str('HTTP_USER_AGENT'))) return true;
850
851    return false;
852}
853
854/**
855 * check if a given link is interwiki link
856 *
857 * @param string $link the link, e.g. "wiki>page"
858 * @return bool
859 */
860function link_isinterwiki($link){
861    if (preg_match('/^[a-zA-Z0-9\.]+>/u',$link)) return true;
862    return false;
863}
864
865/**
866 * Convert one or more comma separated IPs to hostnames
867 *
868 * If $conf['dnslookups'] is disabled it simply returns the input string
869 *
870 * @author Glen Harris <astfgl@iamnota.org>
871 *
872 * @param  string $ips comma separated list of IP addresses
873 * @return string a comma separated list of hostnames
874 */
875function gethostsbyaddrs($ips) {
876    global $conf;
877    if(!$conf['dnslookups']) return $ips;
878
879    $hosts = array();
880    $ips   = explode(',', $ips);
881
882    if(is_array($ips)) {
883        foreach($ips as $ip) {
884            $hosts[] = gethostbyaddr(trim($ip));
885        }
886        return join(',', $hosts);
887    } else {
888        return gethostbyaddr(trim($ips));
889    }
890}
891
892/**
893 * Checks if a given page is currently locked.
894 *
895 * removes stale lockfiles
896 *
897 * @author Andreas Gohr <andi@splitbrain.org>
898 *
899 * @param string $id page id
900 * @return bool page is locked?
901 */
902function checklock($id) {
903    global $conf;
904    /* @var Input $INPUT */
905    global $INPUT;
906
907    $lock = wikiLockFN($id);
908
909    //no lockfile
910    if(!file_exists($lock)) return false;
911
912    //lockfile expired
913    if((time() - filemtime($lock)) > $conf['locktime']) {
914        @unlink($lock);
915        return false;
916    }
917
918    //my own lock
919    @list($ip, $session) = explode("\n", io_readFile($lock));
920    if($ip == $INPUT->server->str('REMOTE_USER') || $ip == clientIP() || (session_id() && $session == session_id())) {
921        return false;
922    }
923
924    return $ip;
925}
926
927/**
928 * Lock a page for editing
929 *
930 * @author Andreas Gohr <andi@splitbrain.org>
931 *
932 * @param string $id page id to lock
933 */
934function lock($id) {
935    global $conf;
936    /* @var Input $INPUT */
937    global $INPUT;
938
939    if($conf['locktime'] == 0) {
940        return;
941    }
942
943    $lock = wikiLockFN($id);
944    if($INPUT->server->str('REMOTE_USER')) {
945        io_saveFile($lock, $INPUT->server->str('REMOTE_USER'));
946    } else {
947        io_saveFile($lock, clientIP()."\n".session_id());
948    }
949}
950
951/**
952 * Unlock a page if it was locked by the user
953 *
954 * @author Andreas Gohr <andi@splitbrain.org>
955 *
956 * @param string $id page id to unlock
957 * @return bool true if a lock was removed
958 */
959function unlock($id) {
960    /* @var Input $INPUT */
961    global $INPUT;
962
963    $lock = wikiLockFN($id);
964    if(file_exists($lock)) {
965        @list($ip, $session) = explode("\n", io_readFile($lock));
966        if($ip == $INPUT->server->str('REMOTE_USER') || $ip == clientIP() || $session == session_id()) {
967            @unlink($lock);
968            return true;
969        }
970    }
971    return false;
972}
973
974/**
975 * convert line ending to unix format
976 *
977 * also makes sure the given text is valid UTF-8
978 *
979 * @see    formText() for 2crlf conversion
980 * @author Andreas Gohr <andi@splitbrain.org>
981 *
982 * @param string $text
983 * @return string
984 */
985function cleanText($text) {
986    $text = preg_replace("/(\015\012)|(\015)/", "\012", $text);
987
988    // if the text is not valid UTF-8 we simply assume latin1
989    // this won't break any worse than it breaks with the wrong encoding
990    // but might actually fix the problem in many cases
991    if(!\dokuwiki\Utf8\Clean::isUtf8($text)) $text = utf8_encode($text);
992
993    return $text;
994}
995
996/**
997 * Prepares text for print in Webforms by encoding special chars.
998 * It also converts line endings to Windows format which is
999 * pseudo standard for webforms.
1000 *
1001 * @see    cleanText() for 2unix conversion
1002 * @author Andreas Gohr <andi@splitbrain.org>
1003 *
1004 * @param string $text
1005 * @return string
1006 */
1007function formText($text) {
1008    $text = str_replace("\012", "\015\012", $text);
1009    return htmlspecialchars($text);
1010}
1011
1012/**
1013 * Returns the specified local text in raw format
1014 *
1015 * @author Andreas Gohr <andi@splitbrain.org>
1016 *
1017 * @param string $id   page id
1018 * @param string $ext  extension of file being read, default 'txt'
1019 * @return string
1020 */
1021function rawLocale($id, $ext = 'txt') {
1022    return io_readFile(localeFN($id, $ext));
1023}
1024
1025/**
1026 * Returns the raw WikiText
1027 *
1028 * @author Andreas Gohr <andi@splitbrain.org>
1029 *
1030 * @param string $id   page id
1031 * @param string|int $rev  timestamp when a revision of wikitext is desired
1032 * @return string
1033 */
1034function rawWiki($id, $rev = '') {
1035    return io_readWikiPage(wikiFN($id, $rev), $id, $rev);
1036}
1037
1038/**
1039 * Returns the pagetemplate contents for the ID's namespace
1040 *
1041 * @triggers COMMON_PAGETPL_LOAD
1042 * @author Andreas Gohr <andi@splitbrain.org>
1043 *
1044 * @param string $id the id of the page to be created
1045 * @return string parsed pagetemplate content
1046 */
1047function pageTemplate($id) {
1048    global $conf;
1049
1050    if(is_array($id)) $id = $id[0];
1051
1052    // prepare initial event data
1053    $data = array(
1054        'id'        => $id, // the id of the page to be created
1055        'tpl'       => '', // the text used as template
1056        'tplfile'   => '', // the file above text was/should be loaded from
1057        'doreplace' => true // should wildcard replacements be done on the text?
1058    );
1059
1060    $evt = new Event('COMMON_PAGETPL_LOAD', $data);
1061    if($evt->advise_before(true)) {
1062        // the before event might have loaded the content already
1063        if(empty($data['tpl'])) {
1064            // if the before event did not set a template file, try to find one
1065            if(empty($data['tplfile'])) {
1066                $path = dirname(wikiFN($id));
1067                if(file_exists($path.'/_template.txt')) {
1068                    $data['tplfile'] = $path.'/_template.txt';
1069                } else {
1070                    // search upper namespaces for templates
1071                    $len = strlen(rtrim($conf['datadir'], '/'));
1072                    while(strlen($path) >= $len) {
1073                        if(file_exists($path.'/__template.txt')) {
1074                            $data['tplfile'] = $path.'/__template.txt';
1075                            break;
1076                        }
1077                        $path = substr($path, 0, strrpos($path, '/'));
1078                    }
1079                }
1080            }
1081            // load the content
1082            $data['tpl'] = io_readFile($data['tplfile']);
1083        }
1084        if($data['doreplace']) parsePageTemplate($data);
1085    }
1086    $evt->advise_after();
1087    unset($evt);
1088
1089    return $data['tpl'];
1090}
1091
1092/**
1093 * Performs common page template replacements
1094 * This works on data from COMMON_PAGETPL_LOAD
1095 *
1096 * @author Andreas Gohr <andi@splitbrain.org>
1097 *
1098 * @param array $data array with event data
1099 * @return string
1100 */
1101function parsePageTemplate(&$data) {
1102    /**
1103     * @var string $id        the id of the page to be created
1104     * @var string $tpl       the text used as template
1105     * @var string $tplfile   the file above text was/should be loaded from
1106     * @var bool   $doreplace should wildcard replacements be done on the text?
1107     */
1108    extract($data);
1109
1110    global $USERINFO;
1111    global $conf;
1112    /* @var Input $INPUT */
1113    global $INPUT;
1114
1115    // replace placeholders
1116    $file = noNS($id);
1117    $page = strtr($file, $conf['sepchar'], ' ');
1118
1119    $tpl = str_replace(
1120        array(
1121             '@ID@',
1122             '@NS@',
1123             '@CURNS@',
1124             '@!CURNS@',
1125             '@!!CURNS@',
1126             '@!CURNS!@',
1127             '@FILE@',
1128             '@!FILE@',
1129             '@!FILE!@',
1130             '@PAGE@',
1131             '@!PAGE@',
1132             '@!!PAGE@',
1133             '@!PAGE!@',
1134             '@USER@',
1135             '@NAME@',
1136             '@MAIL@',
1137             '@DATE@',
1138        ),
1139        array(
1140             $id,
1141             getNS($id),
1142             curNS($id),
1143             \dokuwiki\Utf8\PhpString::ucfirst(curNS($id)),
1144             \dokuwiki\Utf8\PhpString::ucwords(curNS($id)),
1145             \dokuwiki\Utf8\PhpString::strtoupper(curNS($id)),
1146             $file,
1147             \dokuwiki\Utf8\PhpString::ucfirst($file),
1148             \dokuwiki\Utf8\PhpString::strtoupper($file),
1149             $page,
1150             \dokuwiki\Utf8\PhpString::ucfirst($page),
1151             \dokuwiki\Utf8\PhpString::ucwords($page),
1152             \dokuwiki\Utf8\PhpString::strtoupper($page),
1153             $INPUT->server->str('REMOTE_USER'),
1154             $USERINFO ? $USERINFO['name'] : '',
1155             $USERINFO ? $USERINFO['mail'] : '',
1156             $conf['dformat'],
1157        ), $tpl
1158    );
1159
1160    // we need the callback to work around strftime's char limit
1161    $tpl = preg_replace_callback(
1162        '/%./',
1163        function ($m) {
1164            return strftime($m[0]);
1165        },
1166        $tpl
1167    );
1168    $data['tpl'] = $tpl;
1169    return $tpl;
1170}
1171
1172/**
1173 * Returns the raw Wiki Text in three slices.
1174 *
1175 * The range parameter needs to have the form "from-to"
1176 * and gives the range of the section in bytes - no
1177 * UTF-8 awareness is needed.
1178 * The returned order is prefix, section and suffix.
1179 *
1180 * @author Andreas Gohr <andi@splitbrain.org>
1181 *
1182 * @param string $range in form "from-to"
1183 * @param string $id    page id
1184 * @param string $rev   optional, the revision timestamp
1185 * @return string[] with three slices
1186 */
1187function rawWikiSlices($range, $id, $rev = '') {
1188    $text = io_readWikiPage(wikiFN($id, $rev), $id, $rev);
1189
1190    // Parse range
1191    list($from, $to) = explode('-', $range, 2);
1192    // Make range zero-based, use defaults if marker is missing
1193    $from = !$from ? 0 : ($from - 1);
1194    $to   = !$to ? strlen($text) : ($to - 1);
1195
1196    $slices = array();
1197    $slices[0] = substr($text, 0, $from);
1198    $slices[1] = substr($text, $from, $to - $from);
1199    $slices[2] = substr($text, $to);
1200    return $slices;
1201}
1202
1203/**
1204 * Joins wiki text slices
1205 *
1206 * function to join the text slices.
1207 * When the pretty parameter is set to true it adds additional empty
1208 * lines between sections if needed (used on saving).
1209 *
1210 * @author Andreas Gohr <andi@splitbrain.org>
1211 *
1212 * @param string $pre   prefix
1213 * @param string $text  text in the middle
1214 * @param string $suf   suffix
1215 * @param bool $pretty add additional empty lines between sections
1216 * @return string
1217 */
1218function con($pre, $text, $suf, $pretty = false) {
1219    if($pretty) {
1220        if($pre !== '' && substr($pre, -1) !== "\n" &&
1221            substr($text, 0, 1) !== "\n"
1222        ) {
1223            $pre .= "\n";
1224        }
1225        if($suf !== '' && substr($text, -1) !== "\n" &&
1226            substr($suf, 0, 1) !== "\n"
1227        ) {
1228            $text .= "\n";
1229        }
1230    }
1231
1232    return $pre.$text.$suf;
1233}
1234
1235/**
1236 * Checks if the current page version is newer than the last entry in the page's
1237 * changelog. If so, we assume it has been an external edit and we create an
1238 * attic copy and add a proper changelog line.
1239 *
1240 * This check is only executed when the page is about to be saved again from the
1241 * wiki, triggered in @see saveWikiText()
1242 *
1243 * @param string $id the page ID
1244 */
1245function detectExternalEdit($id) {
1246    global $lang;
1247
1248    $fileLastMod = wikiFN($id);
1249    $lastMod     = @filemtime($fileLastMod); // from page
1250    $pagelog     = new PageChangeLog($id, 1024);
1251    $lastRev     = $pagelog->getRevisions(-1, 1); // from changelog
1252    $lastRev     = (int) (empty($lastRev) ? 0 : $lastRev[0]);
1253
1254    if(!file_exists(wikiFN($id, $lastMod)) && file_exists($fileLastMod) && $lastMod >= $lastRev) {
1255        // add old revision to the attic if missing
1256        saveOldRevision($id);
1257        // add a changelog entry if this edit came from outside dokuwiki
1258        if($lastMod > $lastRev) {
1259            $fileLastRev = wikiFN($id, $lastRev);
1260            $revinfo = $pagelog->getRevisionInfo($lastRev);
1261            if(empty($lastRev) || !file_exists($fileLastRev) || $revinfo['type'] == DOKU_CHANGE_TYPE_DELETE) {
1262                $filesize_old = 0;
1263            } else {
1264                $filesize_old = io_getSizeFile($fileLastRev);
1265            }
1266            $filesize_new = filesize($fileLastMod);
1267            $sizechange = $filesize_new - $filesize_old;
1268
1269            addLogEntry(
1270                $lastMod,
1271                $id,
1272                DOKU_CHANGE_TYPE_EDIT,
1273                $lang['external_edit'],
1274                '',
1275                array('ExternalEdit' => true),
1276                $sizechange
1277            );
1278            // remove soon to be stale instructions
1279            $cache = new CacheInstructions($id, $fileLastMod);
1280            $cache->removeCache();
1281        }
1282    }
1283}
1284
1285/**
1286 * Saves a wikitext by calling io_writeWikiPage.
1287 * Also directs changelog and attic updates.
1288 *
1289 * @author Andreas Gohr <andi@splitbrain.org>
1290 * @author Ben Coburn <btcoburn@silicodon.net>
1291 *
1292 * @param string $id       page id
1293 * @param string $text     wikitext being saved
1294 * @param string $summary  summary of text update
1295 * @param bool   $minor    mark this saved version as minor update
1296 */
1297function saveWikiText($id, $text, $summary, $minor = false) {
1298    /* Note to developers:
1299       This code is subtle and delicate. Test the behavior of
1300       the attic and changelog with dokuwiki and external edits
1301       after any changes. External edits change the wiki page
1302       directly without using php or dokuwiki.
1303     */
1304    global $conf;
1305    global $lang;
1306    global $REV;
1307    /* @var Input $INPUT */
1308    global $INPUT;
1309
1310    // prepare data for event
1311    $svdta = array();
1312    $svdta['id']             = $id;
1313    $svdta['file']           = wikiFN($id);
1314    $svdta['revertFrom']     = $REV;
1315    $svdta['oldRevision']    = @filemtime($svdta['file']);
1316    $svdta['newRevision']    = 0;
1317    $svdta['newContent']     = $text;
1318    $svdta['oldContent']     = rawWiki($id);
1319    $svdta['summary']        = $summary;
1320    $svdta['contentChanged'] = ($svdta['newContent'] != $svdta['oldContent']);
1321    $svdta['changeInfo']     = '';
1322    $svdta['changeType']     = DOKU_CHANGE_TYPE_EDIT;
1323    $svdta['sizechange']     = null;
1324
1325    // select changelog line type
1326    if($REV) {
1327        $svdta['changeType']  = DOKU_CHANGE_TYPE_REVERT;
1328        $svdta['changeInfo'] = $REV;
1329    } else if(!file_exists($svdta['file'])) {
1330        $svdta['changeType'] = DOKU_CHANGE_TYPE_CREATE;
1331    } else if(trim($text) == '') {
1332        // empty or whitespace only content deletes
1333        $svdta['changeType'] = DOKU_CHANGE_TYPE_DELETE;
1334        // autoset summary on deletion
1335        if(blank($svdta['summary'])) {
1336            $svdta['summary'] = $lang['deleted'];
1337        }
1338    } else if($minor && $conf['useacl'] && $INPUT->server->str('REMOTE_USER')) {
1339        //minor edits only for logged in users
1340        $svdta['changeType'] = DOKU_CHANGE_TYPE_MINOR_EDIT;
1341    }
1342
1343    $event = new Event('COMMON_WIKIPAGE_SAVE', $svdta);
1344    if(!$event->advise_before()) return;
1345
1346    // if the content has not been changed, no save happens (plugins may override this)
1347    if(!$svdta['contentChanged']) return;
1348
1349    detectExternalEdit($id);
1350
1351    if(
1352        $svdta['changeType'] == DOKU_CHANGE_TYPE_CREATE ||
1353        ($svdta['changeType'] == DOKU_CHANGE_TYPE_REVERT && !file_exists($svdta['file']))
1354    ) {
1355        $filesize_old = 0;
1356    } else {
1357        $filesize_old = filesize($svdta['file']);
1358    }
1359    if($svdta['changeType'] == DOKU_CHANGE_TYPE_DELETE) {
1360        // Send "update" event with empty data, so plugins can react to page deletion
1361        $data = array(array($svdta['file'], '', false), getNS($id), noNS($id), false);
1362        Event::createAndTrigger('IO_WIKIPAGE_WRITE', $data);
1363        // pre-save deleted revision
1364        @touch($svdta['file']);
1365        clearstatcache();
1366        $svdta['newRevision'] = saveOldRevision($id);
1367        // remove empty file
1368        @unlink($svdta['file']);
1369        $filesize_new = 0;
1370        // don't remove old meta info as it should be saved, plugins can use
1371        // IO_WIKIPAGE_WRITE for removing their metadata...
1372        // purge non-persistant meta data
1373        p_purge_metadata($id);
1374        // remove empty namespaces
1375        io_sweepNS($id, 'datadir');
1376        io_sweepNS($id, 'mediadir');
1377    } else {
1378        // save file (namespace dir is created in io_writeWikiPage)
1379        io_writeWikiPage($svdta['file'], $svdta['newContent'], $id);
1380        // pre-save the revision, to keep the attic in sync
1381        $svdta['newRevision'] = saveOldRevision($id);
1382        $filesize_new = filesize($svdta['file']);
1383    }
1384    $svdta['sizechange'] = $filesize_new - $filesize_old;
1385
1386    $event->advise_after();
1387
1388    addLogEntry(
1389        $svdta['newRevision'],
1390        $svdta['id'],
1391        $svdta['changeType'],
1392        $svdta['summary'],
1393        $svdta['changeInfo'],
1394        null,
1395        $svdta['sizechange']
1396    );
1397
1398    // send notify mails
1399    notify($svdta['id'], 'admin', $svdta['oldRevision'], $svdta['summary'], $minor, $svdta['newRevision']);
1400    notify($svdta['id'], 'subscribers', $svdta['oldRevision'], $svdta['summary'], $minor, $svdta['newRevision']);
1401
1402    // update the purgefile (timestamp of the last time anything within the wiki was changed)
1403    io_saveFile($conf['cachedir'].'/purgefile', time());
1404
1405    // if useheading is enabled, purge the cache of all linking pages
1406    if(useHeading('content')) {
1407        $pages = ft_backlinks($id, true);
1408        foreach($pages as $page) {
1409            $cache = new CacheRenderer($page, wikiFN($page), 'xhtml');
1410            $cache->removeCache();
1411        }
1412    }
1413}
1414
1415/**
1416 * moves the current version to the attic and returns its
1417 * revision date
1418 *
1419 * @author Andreas Gohr <andi@splitbrain.org>
1420 *
1421 * @param string $id page id
1422 * @return int|string revision timestamp
1423 */
1424function saveOldRevision($id) {
1425    $oldf = wikiFN($id);
1426    if(!file_exists($oldf)) return '';
1427    $date = filemtime($oldf);
1428    $newf = wikiFN($id, $date);
1429    io_writeWikiPage($newf, rawWiki($id), $id, $date);
1430    return $date;
1431}
1432
1433/**
1434 * Sends a notify mail on page change or registration
1435 *
1436 * @param string     $id       The changed page
1437 * @param string     $who      Who to notify (admin|subscribers|register)
1438 * @param int|string $rev Old page revision
1439 * @param string     $summary  What changed
1440 * @param boolean    $minor    Is this a minor edit?
1441 * @param string[]   $replace  Additional string substitutions, @KEY@ to be replaced by value
1442 * @param int|string $current_rev  New page revision
1443 * @return bool
1444 *
1445 * @author Andreas Gohr <andi@splitbrain.org>
1446 */
1447function notify($id, $who, $rev = '', $summary = '', $minor = false, $replace = array(), $current_rev = false) {
1448    global $conf;
1449    /* @var Input $INPUT */
1450    global $INPUT;
1451
1452    // decide if there is something to do, eg. whom to mail
1453    if($who == 'admin') {
1454        if(empty($conf['notify'])) return false; //notify enabled?
1455        $tpl = 'mailtext';
1456        $to  = $conf['notify'];
1457    } elseif($who == 'subscribers') {
1458        if(!actionOK('subscribe')) return false; //subscribers enabled?
1459        if($conf['useacl'] && $INPUT->server->str('REMOTE_USER') && $minor) return false; //skip minors
1460        $data = array('id' => $id, 'addresslist' => '', 'self' => false, 'replacements' => $replace);
1461        Event::createAndTrigger(
1462            'COMMON_NOTIFY_ADDRESSLIST', $data,
1463            array(new SubscriberManager(), 'notifyAddresses')
1464        );
1465        $to = $data['addresslist'];
1466        if(empty($to)) return false;
1467        $tpl = 'subscr_single';
1468    } else {
1469        return false; //just to be safe
1470    }
1471
1472    // prepare content
1473    $subscription = new PageSubscriptionSender();
1474    return $subscription->sendPageDiff($to, $tpl, $id, $rev, $summary, $current_rev);
1475}
1476
1477/**
1478 * extracts the query from a search engine referrer
1479 *
1480 * @author Andreas Gohr <andi@splitbrain.org>
1481 * @author Todd Augsburger <todd@rollerorgans.com>
1482 *
1483 * @return array|string
1484 */
1485function getGoogleQuery() {
1486    /* @var Input $INPUT */
1487    global $INPUT;
1488
1489    if(!$INPUT->server->has('HTTP_REFERER')) {
1490        return '';
1491    }
1492    $url = parse_url($INPUT->server->str('HTTP_REFERER'));
1493
1494    // only handle common SEs
1495    if(!preg_match('/(google|bing|yahoo|ask|duckduckgo|babylon|aol|yandex)/',$url['host'])) return '';
1496
1497    $query = array();
1498    parse_str($url['query'], $query);
1499
1500    $q = '';
1501    if(isset($query['q'])){
1502        $q = $query['q'];
1503    }elseif(isset($query['p'])){
1504        $q = $query['p'];
1505    }elseif(isset($query['query'])){
1506        $q = $query['query'];
1507    }
1508    $q = trim($q);
1509
1510    if(!$q) return '';
1511    // ignore if query includes a full URL
1512    if(strpos($q, '//') !== false) return '';
1513    $q = preg_split('/[\s\'"\\\\`()\]\[?:!\.{};,#+*<>\\/]+/', $q, -1, PREG_SPLIT_NO_EMPTY);
1514    return $q;
1515}
1516
1517/**
1518 * Return the human readable size of a file
1519 *
1520 * @param int $size A file size
1521 * @param int $dec A number of decimal places
1522 * @return string human readable size
1523 *
1524 * @author      Martin Benjamin <b.martin@cybernet.ch>
1525 * @author      Aidan Lister <aidan@php.net>
1526 * @version     1.0.0
1527 */
1528function filesize_h($size, $dec = 1) {
1529    $sizes = array('B', 'KB', 'MB', 'GB');
1530    $count = count($sizes);
1531    $i     = 0;
1532
1533    while($size >= 1024 && ($i < $count - 1)) {
1534        $size /= 1024;
1535        $i++;
1536    }
1537
1538    return round($size, $dec)."\xC2\xA0".$sizes[$i]; //non-breaking space
1539}
1540
1541/**
1542 * Return the given timestamp as human readable, fuzzy age
1543 *
1544 * @author Andreas Gohr <gohr@cosmocode.de>
1545 *
1546 * @param int $dt timestamp
1547 * @return string
1548 */
1549function datetime_h($dt) {
1550    global $lang;
1551
1552    $ago = time() - $dt;
1553    if($ago > 24 * 60 * 60 * 30 * 12 * 2) {
1554        return sprintf($lang['years'], round($ago / (24 * 60 * 60 * 30 * 12)));
1555    }
1556    if($ago > 24 * 60 * 60 * 30 * 2) {
1557        return sprintf($lang['months'], round($ago / (24 * 60 * 60 * 30)));
1558    }
1559    if($ago > 24 * 60 * 60 * 7 * 2) {
1560        return sprintf($lang['weeks'], round($ago / (24 * 60 * 60 * 7)));
1561    }
1562    if($ago > 24 * 60 * 60 * 2) {
1563        return sprintf($lang['days'], round($ago / (24 * 60 * 60)));
1564    }
1565    if($ago > 60 * 60 * 2) {
1566        return sprintf($lang['hours'], round($ago / (60 * 60)));
1567    }
1568    if($ago > 60 * 2) {
1569        return sprintf($lang['minutes'], round($ago / (60)));
1570    }
1571    return sprintf($lang['seconds'], $ago);
1572}
1573
1574/**
1575 * Wraps around strftime but provides support for fuzzy dates
1576 *
1577 * The format default to $conf['dformat']. It is passed to
1578 * strftime - %f can be used to get the value from datetime_h()
1579 *
1580 * @see datetime_h
1581 * @author Andreas Gohr <gohr@cosmocode.de>
1582 *
1583 * @param int|null $dt      timestamp when given, null will take current timestamp
1584 * @param string   $format  empty default to $conf['dformat'], or provide format as recognized by strftime()
1585 * @return string
1586 */
1587function dformat($dt = null, $format = '') {
1588    global $conf;
1589
1590    if(is_null($dt)) $dt = time();
1591    $dt = (int) $dt;
1592    if(!$format) $format = $conf['dformat'];
1593
1594    $format = str_replace('%f', datetime_h($dt), $format);
1595    return strftime($format, $dt);
1596}
1597
1598/**
1599 * Formats a timestamp as ISO 8601 date
1600 *
1601 * @author <ungu at terong dot com>
1602 * @link http://php.net/manual/en/function.date.php#54072
1603 *
1604 * @param int $int_date current date in UNIX timestamp
1605 * @return string
1606 */
1607function date_iso8601($int_date) {
1608    $date_mod     = date('Y-m-d\TH:i:s', $int_date);
1609    $pre_timezone = date('O', $int_date);
1610    $time_zone    = substr($pre_timezone, 0, 3).":".substr($pre_timezone, 3, 2);
1611    $date_mod .= $time_zone;
1612    return $date_mod;
1613}
1614
1615/**
1616 * return an obfuscated email address in line with $conf['mailguard'] setting
1617 *
1618 * @author Harry Fuecks <hfuecks@gmail.com>
1619 * @author Christopher Smith <chris@jalakai.co.uk>
1620 *
1621 * @param string $email email address
1622 * @return string
1623 */
1624function obfuscate($email) {
1625    global $conf;
1626
1627    switch($conf['mailguard']) {
1628        case 'visible' :
1629            $obfuscate = array('@' => ' [at] ', '.' => ' [dot] ', '-' => ' [dash] ');
1630            return strtr($email, $obfuscate);
1631
1632        case 'hex' :
1633            return \dokuwiki\Utf8\Conversion::toHtml($email, true);
1634
1635        case 'none' :
1636        default :
1637            return $email;
1638    }
1639}
1640
1641/**
1642 * Removes quoting backslashes
1643 *
1644 * @author Andreas Gohr <andi@splitbrain.org>
1645 *
1646 * @param string $string
1647 * @param string $char backslashed character
1648 * @return string
1649 */
1650function unslash($string, $char = "'") {
1651    return str_replace('\\'.$char, $char, $string);
1652}
1653
1654/**
1655 * Convert php.ini shorthands to byte
1656 *
1657 * On 32 bit systems values >= 2GB will fail!
1658 *
1659 * -1 (infinite size) will be reported as -1
1660 *
1661 * @link   https://www.php.net/manual/en/faq.using.php#faq.using.shorthandbytes
1662 * @param string $value PHP size shorthand
1663 * @return int
1664 */
1665function php_to_byte($value) {
1666    switch (strtoupper(substr($value,-1))) {
1667        case 'G':
1668            $ret = intval(substr($value, 0, -1)) * 1024 * 1024 * 1024;
1669            break;
1670        case 'M':
1671            $ret = intval(substr($value, 0, -1)) * 1024 * 1024;
1672            break;
1673        case 'K':
1674            $ret = intval(substr($value, 0, -1)) * 1024;
1675            break;
1676        default:
1677            $ret = intval($value);
1678            break;
1679    }
1680    return $ret;
1681}
1682
1683/**
1684 * Wrapper around preg_quote adding the default delimiter
1685 *
1686 * @param string $string
1687 * @return string
1688 */
1689function preg_quote_cb($string) {
1690    return preg_quote($string, '/');
1691}
1692
1693/**
1694 * Shorten a given string by removing data from the middle
1695 *
1696 * You can give the string in two parts, the first part $keep
1697 * will never be shortened. The second part $short will be cut
1698 * in the middle to shorten but only if at least $min chars are
1699 * left to display it. Otherwise it will be left off.
1700 *
1701 * @param string $keep   the part to keep
1702 * @param string $short  the part to shorten
1703 * @param int    $max    maximum chars you want for the whole string
1704 * @param int    $min    minimum number of chars to have left for middle shortening
1705 * @param string $char   the shortening character to use
1706 * @return string
1707 */
1708function shorten($keep, $short, $max, $min = 9, $char = '…') {
1709    $max = $max - \dokuwiki\Utf8\PhpString::strlen($keep);
1710    if($max < $min) return $keep;
1711    $len = \dokuwiki\Utf8\PhpString::strlen($short);
1712    if($len <= $max) return $keep.$short;
1713    $half = floor($max / 2);
1714    return $keep .
1715        \dokuwiki\Utf8\PhpString::substr($short, 0, $half - 1) .
1716        $char .
1717        \dokuwiki\Utf8\PhpString::substr($short, $len - $half);
1718}
1719
1720/**
1721 * Return the users real name or e-mail address for use
1722 * in page footer and recent changes pages
1723 *
1724 * @param string|null $username or null when currently logged-in user should be used
1725 * @param bool $textonly true returns only plain text, true allows returning html
1726 * @return string html or plain text(not escaped) of formatted user name
1727 *
1728 * @author Andy Webber <dokuwiki AT andywebber DOT com>
1729 */
1730function editorinfo($username, $textonly = false) {
1731    return userlink($username, $textonly);
1732}
1733
1734/**
1735 * Returns users realname w/o link
1736 *
1737 * @param string|null $username or null when currently logged-in user should be used
1738 * @param bool $textonly true returns only plain text, true allows returning html
1739 * @return string html or plain text(not escaped) of formatted user name
1740 *
1741 * @triggers COMMON_USER_LINK
1742 */
1743function userlink($username = null, $textonly = false) {
1744    global $conf, $INFO;
1745    /** @var AuthPlugin $auth */
1746    global $auth;
1747    /** @var Input $INPUT */
1748    global $INPUT;
1749
1750    // prepare initial event data
1751    $data = array(
1752        'username' => $username, // the unique user name
1753        'name' => '',
1754        'link' => array( //setting 'link' to false disables linking
1755                         'target' => '',
1756                         'pre' => '',
1757                         'suf' => '',
1758                         'style' => '',
1759                         'more' => '',
1760                         'url' => '',
1761                         'title' => '',
1762                         'class' => ''
1763        ),
1764        'userlink' => '', // formatted user name as will be returned
1765        'textonly' => $textonly
1766    );
1767    if($username === null) {
1768        $data['username'] = $username = $INPUT->server->str('REMOTE_USER');
1769        if($textonly){
1770            $data['name'] = $INFO['userinfo']['name']. ' (' . $INPUT->server->str('REMOTE_USER') . ')';
1771        }else {
1772            $data['name'] = '<bdi>' . hsc($INFO['userinfo']['name']) . '</bdi> '.
1773                '(<bdi>' . hsc($INPUT->server->str('REMOTE_USER')) . '</bdi>)';
1774        }
1775    }
1776
1777    $evt = new Event('COMMON_USER_LINK', $data);
1778    if($evt->advise_before(true)) {
1779        if(empty($data['name'])) {
1780            if($auth) $info = $auth->getUserData($username);
1781            if($conf['showuseras'] != 'loginname' && isset($info) && $info) {
1782                switch($conf['showuseras']) {
1783                    case 'username':
1784                    case 'username_link':
1785                        $data['name'] = $textonly ? $info['name'] : hsc($info['name']);
1786                        break;
1787                    case 'email':
1788                    case 'email_link':
1789                        $data['name'] = obfuscate($info['mail']);
1790                        break;
1791                }
1792            } else {
1793                $data['name'] = $textonly ? $data['username'] : hsc($data['username']);
1794            }
1795        }
1796
1797        /** @var Doku_Renderer_xhtml $xhtml_renderer */
1798        static $xhtml_renderer = null;
1799
1800        if(!$data['textonly'] && empty($data['link']['url'])) {
1801
1802            if(in_array($conf['showuseras'], array('email_link', 'username_link'))) {
1803                if(!isset($info)) {
1804                    if($auth) $info = $auth->getUserData($username);
1805                }
1806                if(isset($info) && $info) {
1807                    if($conf['showuseras'] == 'email_link') {
1808                        $data['link']['url'] = 'mailto:' . obfuscate($info['mail']);
1809                    } else {
1810                        if(is_null($xhtml_renderer)) {
1811                            $xhtml_renderer = p_get_renderer('xhtml');
1812                        }
1813                        if(empty($xhtml_renderer->interwiki)) {
1814                            $xhtml_renderer->interwiki = getInterwiki();
1815                        }
1816                        $shortcut = 'user';
1817                        $exists = null;
1818                        $data['link']['url'] = $xhtml_renderer->_resolveInterWiki($shortcut, $username, $exists);
1819                        $data['link']['class'] .= ' interwiki iw_user';
1820                        if($exists !== null) {
1821                            if($exists) {
1822                                $data['link']['class'] .= ' wikilink1';
1823                            } else {
1824                                $data['link']['class'] .= ' wikilink2';
1825                                $data['link']['rel'] = 'nofollow';
1826                            }
1827                        }
1828                    }
1829                } else {
1830                    $data['textonly'] = true;
1831                }
1832
1833            } else {
1834                $data['textonly'] = true;
1835            }
1836        }
1837
1838        if($data['textonly']) {
1839            $data['userlink'] = $data['name'];
1840        } else {
1841            $data['link']['name'] = $data['name'];
1842            if(is_null($xhtml_renderer)) {
1843                $xhtml_renderer = p_get_renderer('xhtml');
1844            }
1845            $data['userlink'] = $xhtml_renderer->_formatLink($data['link']);
1846        }
1847    }
1848    $evt->advise_after();
1849    unset($evt);
1850
1851    return $data['userlink'];
1852}
1853
1854/**
1855 * Returns the path to a image file for the currently chosen license.
1856 * When no image exists, returns an empty string
1857 *
1858 * @author Andreas Gohr <andi@splitbrain.org>
1859 *
1860 * @param  string $type - type of image 'badge' or 'button'
1861 * @return string
1862 */
1863function license_img($type) {
1864    global $license;
1865    global $conf;
1866    if(!$conf['license']) return '';
1867    if(!is_array($license[$conf['license']])) return '';
1868    $try   = array();
1869    $try[] = 'lib/images/license/'.$type.'/'.$conf['license'].'.png';
1870    $try[] = 'lib/images/license/'.$type.'/'.$conf['license'].'.gif';
1871    if(substr($conf['license'], 0, 3) == 'cc-') {
1872        $try[] = 'lib/images/license/'.$type.'/cc.png';
1873    }
1874    foreach($try as $src) {
1875        if(file_exists(DOKU_INC.$src)) return $src;
1876    }
1877    return '';
1878}
1879
1880/**
1881 * Checks if the given amount of memory is available
1882 *
1883 * If the memory_get_usage() function is not available the
1884 * function just assumes $bytes of already allocated memory
1885 *
1886 * @author Filip Oscadal <webmaster@illusionsoftworks.cz>
1887 * @author Andreas Gohr <andi@splitbrain.org>
1888 *
1889 * @param int  $mem    Size of memory you want to allocate in bytes
1890 * @param int  $bytes  already allocated memory (see above)
1891 * @return bool
1892 */
1893function is_mem_available($mem, $bytes = 1048576) {
1894    $limit = trim(ini_get('memory_limit'));
1895    if(empty($limit)) return true; // no limit set!
1896    if($limit == -1) return true; // unlimited
1897
1898    // parse limit to bytes
1899    $limit = php_to_byte($limit);
1900
1901    // get used memory if possible
1902    if(function_exists('memory_get_usage')) {
1903        $used = memory_get_usage();
1904    } else {
1905        $used = $bytes;
1906    }
1907
1908    if($used + $mem > $limit) {
1909        return false;
1910    }
1911
1912    return true;
1913}
1914
1915/**
1916 * Send a HTTP redirect to the browser
1917 *
1918 * Works arround Microsoft IIS cookie sending bug. Exits the script.
1919 *
1920 * @link   http://support.microsoft.com/kb/q176113/
1921 * @author Andreas Gohr <andi@splitbrain.org>
1922 *
1923 * @param string $url url being directed to
1924 */
1925function send_redirect($url) {
1926    $url = stripctl($url); // defend against HTTP Response Splitting
1927
1928    /* @var Input $INPUT */
1929    global $INPUT;
1930
1931    //are there any undisplayed messages? keep them in session for display
1932    global $MSG;
1933    if(isset($MSG) && count($MSG) && !defined('NOSESSION')) {
1934        //reopen session, store data and close session again
1935        @session_start();
1936        $_SESSION[DOKU_COOKIE]['msg'] = $MSG;
1937    }
1938
1939    // always close the session
1940    session_write_close();
1941
1942    // check if running on IIS < 6 with CGI-PHP
1943    if($INPUT->server->has('SERVER_SOFTWARE') && $INPUT->server->has('GATEWAY_INTERFACE') &&
1944        (strpos($INPUT->server->str('GATEWAY_INTERFACE'), 'CGI') !== false) &&
1945        (preg_match('|^Microsoft-IIS/(\d)\.\d$|', trim($INPUT->server->str('SERVER_SOFTWARE')), $matches)) &&
1946        $matches[1] < 6
1947    ) {
1948        header('Refresh: 0;url='.$url);
1949    } else {
1950        header('Location: '.$url);
1951    }
1952
1953    // no exits during unit tests
1954    if(defined('DOKU_UNITTEST')) {
1955        // pass info about the redirect back to the test suite
1956        $testRequest = TestRequest::getRunning();
1957        if($testRequest !== null) {
1958            $testRequest->addData('send_redirect', $url);
1959        }
1960        return;
1961    }
1962
1963    exit;
1964}
1965
1966/**
1967 * Validate a value using a set of valid values
1968 *
1969 * This function checks whether a specified value is set and in the array
1970 * $valid_values. If not, the function returns a default value or, if no
1971 * default is specified, throws an exception.
1972 *
1973 * @param string $param        The name of the parameter
1974 * @param array  $valid_values A set of valid values; Optionally a default may
1975 *                             be marked by the key “default”.
1976 * @param array  $array        The array containing the value (typically $_POST
1977 *                             or $_GET)
1978 * @param string $exc          The text of the raised exception
1979 *
1980 * @throws Exception
1981 * @return mixed
1982 * @author Adrian Lang <lang@cosmocode.de>
1983 */
1984function valid_input_set($param, $valid_values, $array, $exc = '') {
1985    if(isset($array[$param]) && in_array($array[$param], $valid_values)) {
1986        return $array[$param];
1987    } elseif(isset($valid_values['default'])) {
1988        return $valid_values['default'];
1989    } else {
1990        throw new Exception($exc);
1991    }
1992}
1993
1994/**
1995 * Read a preference from the DokuWiki cookie
1996 * (remembering both keys & values are urlencoded)
1997 *
1998 * @param string $pref     preference key
1999 * @param mixed  $default  value returned when preference not found
2000 * @return string preference value
2001 */
2002function get_doku_pref($pref, $default) {
2003    $enc_pref = urlencode($pref);
2004    if(isset($_COOKIE['DOKU_PREFS']) && strpos($_COOKIE['DOKU_PREFS'], $enc_pref) !== false) {
2005        $parts = explode('#', $_COOKIE['DOKU_PREFS']);
2006        $cnt   = count($parts);
2007
2008        // due to #2721 there might be duplicate entries,
2009        // so we read from the end
2010        for($i = $cnt-2; $i >= 0; $i -= 2) {
2011            if($parts[$i] == $enc_pref) {
2012                return urldecode($parts[$i + 1]);
2013            }
2014        }
2015    }
2016    return $default;
2017}
2018
2019/**
2020 * Add a preference to the DokuWiki cookie
2021 * (remembering $_COOKIE['DOKU_PREFS'] is urlencoded)
2022 * Remove it by setting $val to false
2023 *
2024 * @param string $pref  preference key
2025 * @param string $val   preference value
2026 */
2027function set_doku_pref($pref, $val) {
2028    global $conf;
2029    $orig = get_doku_pref($pref, false);
2030    $cookieVal = '';
2031
2032    if($orig !== false && ($orig !== $val)) {
2033        $parts = explode('#', $_COOKIE['DOKU_PREFS']);
2034        $cnt   = count($parts);
2035        // urlencode $pref for the comparison
2036        $enc_pref = rawurlencode($pref);
2037        $seen = false;
2038        for ($i = 0; $i < $cnt; $i += 2) {
2039            if ($parts[$i] == $enc_pref) {
2040                if (!$seen){
2041                    if ($val !== false) {
2042                        $parts[$i + 1] = rawurlencode($val);
2043                    } else {
2044                        unset($parts[$i]);
2045                        unset($parts[$i + 1]);
2046                    }
2047                    $seen = true;
2048                } else {
2049                    // no break because we want to remove duplicate entries
2050                    unset($parts[$i]);
2051                    unset($parts[$i + 1]);
2052                }
2053            }
2054        }
2055        $cookieVal = implode('#', $parts);
2056    } else if ($orig === false && $val !== false) {
2057        $cookieVal = ($_COOKIE['DOKU_PREFS'] ? $_COOKIE['DOKU_PREFS'] . '#' : '') .
2058            rawurlencode($pref) . '#' . rawurlencode($val);
2059    }
2060
2061    $cookieDir = empty($conf['cookiedir']) ? DOKU_REL : $conf['cookiedir'];
2062    if(defined('DOKU_UNITTEST')) {
2063        $_COOKIE['DOKU_PREFS'] = $cookieVal;
2064    }else{
2065        setcookie('DOKU_PREFS', $cookieVal, time()+365*24*3600, $cookieDir, '', ($conf['securecookie'] && is_ssl()));
2066    }
2067}
2068
2069/**
2070 * Strips source mapping declarations from given text #601
2071 *
2072 * @param string &$text reference to the CSS or JavaScript code to clean
2073 */
2074function stripsourcemaps(&$text){
2075    $text = preg_replace('/^(\/\/|\/\*)[@#]\s+sourceMappingURL=.*?(\*\/)?$/im', '\\1\\2', $text);
2076}
2077
2078/**
2079 * Returns the contents of a given SVG file for embedding
2080 *
2081 * Inlining SVGs saves on HTTP requests and more importantly allows for styling them through
2082 * CSS. However it should used with small SVGs only. The $maxsize setting ensures only small
2083 * files are embedded.
2084 *
2085 * This strips unneeded headers, comments and newline. The result is not a vaild standalone SVG!
2086 *
2087 * @param string $file full path to the SVG file
2088 * @param int $maxsize maximum allowed size for the SVG to be embedded
2089 * @return string|false the SVG content, false if the file couldn't be loaded
2090 */
2091function inlineSVG($file, $maxsize = 2048) {
2092    $file = trim($file);
2093    if($file === '') return false;
2094    if(!file_exists($file)) return false;
2095    if(filesize($file) > $maxsize) return false;
2096    if(!is_readable($file)) return false;
2097    $content = file_get_contents($file);
2098    $content = preg_replace('/<!--.*?(-->)/s','', $content); // comments
2099    $content = preg_replace('/<\?xml .*?\?>/i', '', $content); // xml header
2100    $content = preg_replace('/<!DOCTYPE .*?>/i', '', $content); // doc type
2101    $content = preg_replace('/>\s+</s', '><', $content); // newlines between tags
2102    $content = trim($content);
2103    if(substr($content, 0, 5) !== '<svg ') return false;
2104    return $content;
2105}
2106
2107//Setup VIM: ex: et ts=2 :
2108