lib/filelib.php

   1 <?php //$Id$
   2
   3 require_once($CFG->libdir.'/libcurlemu/libcurlemu.inc.php'); // might be moved to setup.php later
   4
   5 define('BYTESERVING_BOUNDARY', 's1k2o3d4a5k6s7'); //unique string constant
   6
   7 /**
   8  * Fetches content of file from Internet (using proxy if defined).
   9  *
  10  * @return mixed false if request failed or content of the file as string if ok.
  11  */
  12 function download_file_content($url) {
  13     global $CFG;
  14
  15     $ch = curl_init($url);
  16     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
  17     curl_setopt($ch, CURLOPT_HEADER, false);
  18     if (!empty($CFG->proxyhost)) {
  19         // don't CONNECT for non-https connections
  20         curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, false);
  21
  22         if (empty($CFG->proxyport)) {
  23             curl_setopt($ch, CURLOPT_PROXY, $CFG->proxyhost);
  24         } else {
  25             curl_setopt($ch, CURLOPT_PROXY, $CFG->proxyhost.':'.$CFG->proxyport);
  26         }
  27         if(!empty($CFG->proxyuser) and !empty($CFG->proxypassword)) {
  28             curl_setopt($ch, CURLOPT_PROXYUSERPWD, $CFG->proxyuser.':'.$CFG->proxypassword);
  29         }
  30     }
  31     $result = curl_exec($ch);
  32
  33     if (curl_errno($ch)) {
  34         $curlerror = "CURL request for \"$url\" failed with: ". curl_error($ch);
  35         debugging($curlerror, DEBUG_DEVELOPER);
  36     }
  37
  38     curl_close($ch);
  39     return $result;
  40 }
  41
  42 /**
  43  * @return List of information about file types based on extensions.
  44  *   Associative array of extension (lower-case) to associative array
  45  *   from 'element name' to data. Current element names are 'type' and 'icon'.
  46  *   Unknown types should use the 'xxx' entry which includes defaults.
  47  */
  48 function get_mimetypes_array() {
  49     return array (
  50         'xxx'  => array ('type'=>'document/unknown', 'icon'=>'unknown.gif'),
  51         '3gp'  => array ('type'=>'video/quicktime', 'icon'=>'video.gif'),
  52         'ai'   => array ('type'=>'application/postscript', 'icon'=>'image.gif'),
  53         'aif'  => array ('type'=>'audio/x-aiff', 'icon'=>'audio.gif'),
  54         'aiff' => array ('type'=>'audio/x-aiff', 'icon'=>'audio.gif'),
  55         'aifc' => array ('type'=>'audio/x-aiff', 'icon'=>'audio.gif'),
  56         'applescript'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  57         'asc'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  58         'asm'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  59         'au'   => array ('type'=>'audio/au', 'icon'=>'audio.gif'),
  60         'avi'  => array ('type'=>'video/x-ms-wm', 'icon'=>'avi.gif'),
  61         'bmp'  => array ('type'=>'image/bmp', 'icon'=>'image.gif'),
  62         'c'    => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  63         'cct'  => array ('type'=>'shockwave/director', 'icon'=>'flash.gif'),
  64         'cpp'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  65         'cs'   => array ('type'=>'application/x-csh', 'icon'=>'text.gif'),
  66         'css'  => array ('type'=>'text/css', 'icon'=>'text.gif'),
  67         'csv'  => array ('type'=>'text/csv', 'icon'=>'excel.gif'),
  68         'dv'   => array ('type'=>'video/x-dv', 'icon'=>'video.gif'),
  69         'dmg'  => array ('type'=>'application/octet-stream', 'icon'=>'dmg.gif'),
  70         'doc'  => array ('type'=>'application/msword', 'icon'=>'word.gif'),
  71         'docx' => array ('type'=>'application/msword', 'icon'=>'docx.gif'),
  72         'docm' => array ('type'=>'application/msword', 'icon'=>'docm.gif'),
  73         'dotx' => array ('type'=>'application/msword', 'icon'=>'dotx.gif'),
  74         'dcr'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
  75         'dif'  => array ('type'=>'video/x-dv', 'icon'=>'video.gif'),
  76         'dir'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
  77         'dxr'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
  78         'eps'  => array ('type'=>'application/postscript', 'icon'=>'pdf.gif'),
  79         'fdf'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
  80         'flv'  => array ('type'=>'video/x-flv', 'icon'=>'video.gif'),
  81         'gif'  => array ('type'=>'image/gif', 'icon'=>'image.gif'),
  82         'gtar' => array ('type'=>'application/x-gtar', 'icon'=>'zip.gif'),
  83         'tgz'  => array ('type'=>'application/g-zip', 'icon'=>'zip.gif'),
  84         'gz'   => array ('type'=>'application/g-zip', 'icon'=>'zip.gif'),
  85         'gzip' => array ('type'=>'application/g-zip', 'icon'=>'zip.gif'),
  86         'h'    => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  87         'hpp'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  88         'hqx'  => array ('type'=>'application/mac-binhex40', 'icon'=>'zip.gif'),
  89         'htc'  => array ('type'=>'text/x-component', 'icon'=>'text.gif'),
  90         'html' => array ('type'=>'text/html', 'icon'=>'html.gif'),
  91         'xhtml'=> array ('type'=>'application/xhtml+xml', 'icon'=>'html.gif'),
  92         'htm'  => array ('type'=>'text/html', 'icon'=>'html.gif'),
  93         'ico'  => array ('type'=>'image/vnd.microsoft.icon', 'icon'=>'image.gif'),
  94         'isf'  => array ('type'=>'application/inspiration', 'icon'=>'isf.gif'),
  95         'ist'  => array ('type'=>'application/inspiration.template', 'icon'=>'isf.gif'),
  96         'java' => array ('type'=>'text/plain', 'icon'=>'text.gif'),
  97         'jcb'  => array ('type'=>'text/xml', 'icon'=>'jcb.gif'),
  98         'jcl'  => array ('type'=>'text/xml', 'icon'=>'jcl.gif'),
  99         'jcw'  => array ('type'=>'text/xml', 'icon'=>'jcw.gif'),
 100         'jmt'  => array ('type'=>'text/xml', 'icon'=>'jmt.gif'),
 101         'jmx'  => array ('type'=>'text/xml', 'icon'=>'jmx.gif'),
 102         'jpe'  => array ('type'=>'image/jpeg', 'icon'=>'image.gif'),
 103         'jpeg' => array ('type'=>'image/jpeg', 'icon'=>'image.gif'),
 104         'jpg'  => array ('type'=>'image/jpeg', 'icon'=>'image.gif'),
 105         'jqz'  => array ('type'=>'text/xml', 'icon'=>'jqz.gif'),
 106         'js'   => array ('type'=>'application/x-javascript', 'icon'=>'text.gif'),
 107         'latex'=> array ('type'=>'application/x-latex', 'icon'=>'text.gif'),
 108         'm'    => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 109         'mov'  => array ('type'=>'video/quicktime', 'icon'=>'video.gif'),
 110         'movie'=> array ('type'=>'video/x-sgi-movie', 'icon'=>'video.gif'),
 111         'm3u'  => array ('type'=>'audio/x-mpegurl', 'icon'=>'audio.gif'),
 112         'mp3'  => array ('type'=>'audio/mp3', 'icon'=>'audio.gif'),
 113         'mp4'  => array ('type'=>'video/mp4', 'icon'=>'video.gif'),
 114         'mpeg' => array ('type'=>'video/mpeg', 'icon'=>'video.gif'),
 115         'mpe'  => array ('type'=>'video/mpeg', 'icon'=>'video.gif'),
 116         'mpg'  => array ('type'=>'video/mpeg', 'icon'=>'video.gif'),
 117
 118         'odt'  => array ('type'=>'application/vnd.oasis.opendocument.text', 'icon'=>'odt.gif'),
 119         'ott'  => array ('type'=>'application/vnd.oasis.opendocument.text-template', 'icon'=>'odt.gif'),
 120         'oth'  => array ('type'=>'application/vnd.oasis.opendocument.text-web', 'icon'=>'odt.gif'),
 121         'odm'  => array ('type'=>'application/vnd.oasis.opendocument.text-master', 'icon'=>'odm.gif'),
 122         'odg'  => array ('type'=>'application/vnd.oasis.opendocument.graphics', 'icon'=>'odg.gif'),
 123         'otg'  => array ('type'=>'application/vnd.oasis.opendocument.graphics-template', 'icon'=>'odg.gif'),
 124         'odp'  => array ('type'=>'application/vnd.oasis.opendocument.presentation', 'icon'=>'odp.gif'),
 125         'otp'  => array ('type'=>'application/vnd.oasis.opendocument.presentation-template', 'icon'=>'odp.gif'),
 126         'ods'  => array ('type'=>'application/vnd.oasis.opendocument.spreadsheet', 'icon'=>'ods.gif'),
 127         'ots'  => array ('type'=>'application/vnd.oasis.opendocument.spreadsheet-template', 'icon'=>'ods.gif'),
 128         'odc'  => array ('type'=>'application/vnd.oasis.opendocument.chart', 'icon'=>'odc.gif'),
 129         'odf'  => array ('type'=>'application/vnd.oasis.opendocument.formula', 'icon'=>'odf.gif'),
 130         'odb'  => array ('type'=>'application/vnd.oasis.opendocument.database', 'icon'=>'odb.gif'),
 131         'odi'  => array ('type'=>'application/vnd.oasis.opendocument.image', 'icon'=>'odi.gif'),
 132
 133         'pct'  => array ('type'=>'image/pict', 'icon'=>'image.gif'),
 134         'pdf'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 135         'php'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 136         'pic'  => array ('type'=>'image/pict', 'icon'=>'image.gif'),
 137         'pict' => array ('type'=>'image/pict', 'icon'=>'image.gif'),
 138         'png'  => array ('type'=>'image/png', 'icon'=>'image.gif'),
 139         'pps'  => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'powerpoint.gif'),
 140         'ppt'  => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'powerpoint.gif'),
 141         'pptx' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'pptx.gif'),
 142         'pptm' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'pptm.gif'),
 143         'potx' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'potx.gif'),
 144         'potm' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'potm.gif'),
 145         'ppam' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'ppam.gif'),
 146         'ppsx' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'ppsx.gif'),
 147         'ppsm' => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'ppsm.gif'),
 148         'ps'   => array ('type'=>'application/postscript', 'icon'=>'pdf.gif'),
 149         'qt'   => array ('type'=>'video/quicktime', 'icon'=>'video.gif'),
 150         'ra'   => array ('type'=>'audio/x-realaudio', 'icon'=>'audio.gif'),
 151         'ram'  => array ('type'=>'audio/x-pn-realaudio', 'icon'=>'audio.gif'),
 152         'rhb'  => array ('type'=>'text/xml', 'icon'=>'xml.gif'),
 153         'rm'   => array ('type'=>'audio/x-pn-realaudio', 'icon'=>'audio.gif'),
 154         'rtf'  => array ('type'=>'text/rtf', 'icon'=>'text.gif'),
 155         'rtx'  => array ('type'=>'text/richtext', 'icon'=>'text.gif'),
 156         'sh'   => array ('type'=>'application/x-sh', 'icon'=>'text.gif'),
 157         'sit'  => array ('type'=>'application/x-stuffit', 'icon'=>'zip.gif'),
 158         'smi'  => array ('type'=>'application/smil', 'icon'=>'text.gif'),
 159         'smil' => array ('type'=>'application/smil', 'icon'=>'text.gif'),
 160         'sqt'  => array ('type'=>'text/xml', 'icon'=>'xml.gif'),
 161         'svg'  => array ('type'=>'image/svg+xml', 'icon'=>'image.gif'),
 162         'svgz' => array ('type'=>'image/svg+xml', 'icon'=>'image.gif'),
 163         'swa'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
 164         'swf'  => array ('type'=>'application/x-shockwave-flash', 'icon'=>'flash.gif'),
 165         'swfl' => array ('type'=>'application/x-shockwave-flash', 'icon'=>'flash.gif'),
 166
 167         'sxw'  => array ('type'=>'application/vnd.sun.xml.writer', 'icon'=>'odt.gif'),
 168         'stw'  => array ('type'=>'application/vnd.sun.xml.writer.template', 'icon'=>'odt.gif'),
 169         'sxc'  => array ('type'=>'application/vnd.sun.xml.calc', 'icon'=>'odt.gif'),
 170         'stc'  => array ('type'=>'application/vnd.sun.xml.calc.template', 'icon'=>'odt.gif'),
 171         'sxd'  => array ('type'=>'application/vnd.sun.xml.draw', 'icon'=>'odt.gif'),
 172         'std'  => array ('type'=>'application/vnd.sun.xml.draw.template', 'icon'=>'odt.gif'),
 173         'sxi'  => array ('type'=>'application/vnd.sun.xml.impress', 'icon'=>'odt.gif'),
 174         'sti'  => array ('type'=>'application/vnd.sun.xml.impress.template', 'icon'=>'odt.gif'),
 175         'sxg'  => array ('type'=>'application/vnd.sun.xml.writer.global', 'icon'=>'odt.gif'),
 176         'sxm'  => array ('type'=>'application/vnd.sun.xml.math', 'icon'=>'odt.gif'),
 177
 178         'tar'  => array ('type'=>'application/x-tar', 'icon'=>'zip.gif'),
 179         'tif'  => array ('type'=>'image/tiff', 'icon'=>'image.gif'),
 180         'tiff' => array ('type'=>'image/tiff', 'icon'=>'image.gif'),
 181         'tex'  => array ('type'=>'application/x-tex', 'icon'=>'text.gif'),
 182         'texi' => array ('type'=>'application/x-texinfo', 'icon'=>'text.gif'),
 183         'texinfo'  => array ('type'=>'application/x-texinfo', 'icon'=>'text.gif'),
 184         'tsv'  => array ('type'=>'text/tab-separated-values', 'icon'=>'text.gif'),
 185         'txt'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 186         'wav'  => array ('type'=>'audio/wav', 'icon'=>'audio.gif'),
 187         'wmv'  => array ('type'=>'video/x-ms-wmv', 'icon'=>'avi.gif'),
 188         'asf'  => array ('type'=>'video/x-ms-asf', 'icon'=>'avi.gif'),
 189         'xdp'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 190         'xfd'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 191         'xfdf' => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 192         'xls'  => array ('type'=>'application/vnd.ms-excel', 'icon'=>'excel.gif'),
 193         'xlsx' => array ('type'=>'application/vnd.ms-excel', 'icon'=>'xlsx.gif'),
 194         'xlsm' => array ('type'=>'application/vnd.ms-excel', 'icon'=>'xlsm.gif'),
 195         'xltx' => array ('type'=>'application/vnd.ms-excel', 'icon'=>'xltx.gif'),
 196         'xltm' => array ('type'=>'application/vnd.ms-excel', 'icon'=>'xltm.gif'),
 197         'xlsb' => array ('type'=>'application/vnd.ms-excel', 'icon'=>'xlsb.gif'),
 198         'xlam' => array ('type'=>'application/vnd.ms-excel', 'icon'=>'xlam.gif'),
 199         'xml'  => array ('type'=>'application/xml', 'icon'=>'xml.gif'),
 200         'xsl'  => array ('type'=>'text/xml', 'icon'=>'xml.gif'),
 201         'zip'  => array ('type'=>'application/zip', 'icon'=>'zip.gif')
 202     );
 203 }
 204
 205 /**
 206  * Obtains information about a filetype based on its extension. Will
 207  * use a default if no information is present about that particular
 208  * extension.
 209  * @param string $element Desired information (usually 'icon'
 210  *   for icon filename or 'type' for MIME type)
 211  * @param string $filename Filename we're looking up
 212  * @return string Requested piece of information from array
 213  */
 214 function mimeinfo($element, $filename) {
 215     static $mimeinfo;
 216     $mimeinfo=get_mimetypes_array();
 217
 218     if (eregi('\.([a-z0-9]+)$', $filename, $match)) {
 219         if (isset($mimeinfo[strtolower($match[1])][$element])) {
 220             return $mimeinfo[strtolower($match[1])][$element];
 221         } else {
 222             return $mimeinfo['xxx'][$element];   // By default
 223         }
 224     } else {
 225         return $mimeinfo['xxx'][$element];   // By default
 226     }
 227 }
 228
 229 /**
 230  * Obtains information about a filetype based on the MIME type rather than
 231  * the other way around.
 232  * @param string $element Desired information (usually 'icon')
 233  * @param string $mimetype MIME type we're looking up
 234  * @return string Requested piece of information from array
 235  */
 236 function mimeinfo_from_type($element, $mimetype) {
 237     static $mimeinfo;
 238     $mimeinfo=get_mimetypes_array();
 239
 240     foreach($mimeinfo as $values) {
 241         if($values['type']==$mimetype) {
 242             if(isset($values[$element])) {
 243                 return $values[$element];
 244             }
 245             break;
 246         }
 247     }
 248     return $mimeinfo['xxx'][$element]; // Default
 249 }
 250
 251 /**
 252  * Get information about a filetype based on the icon file.
 253  * @param string $element Desired information (usually 'icon')
 254  * @param string $icon Icon file path.
 255  * @return string Requested piece of information from array
 256  */
 257 function mimeinfo_from_icon($element, $icon) {
 258     static $mimeinfo;
 259     $mimeinfo=get_mimetypes_array();
 260
 261     if (preg_match("/\/(.*)/", $icon, $matches)) {
 262         $icon = $matches[1];
 263     }
 264     $info = $mimeinfo['xxx'][$element]; // Default
 265     foreach($mimeinfo as $values) {
 266         if($values['icon']==$icon) {
 267             if(isset($values[$element])) {
 268                 $info = $values[$element];
 269             }
 270             //No break, for example for 'excel.gif' we don't want 'csv'!
 271         }
 272     }
 273     return $info;
 274 }
 275
 276 /**
 277  * Obtains descriptions for file types (e.g. 'Microsoft Word document') from the
 278  * mimetypes.php language file.
 279  * @param string $mimetype MIME type (can be obtained using the mimeinfo function)
 280  * @param bool $capitalise If true, capitalises first character of result
 281  * @return string Text description
 282  */
 283 function get_mimetype_description($mimetype,$capitalise=false) {
 284     $result=get_string($mimetype,'mimetypes');
 285     // Surrounded by square brackets indicates that there isn't a string for that
 286     // (maybe there is a better way to find this out?)
 287     if(strpos($result,'[')===0) {
 288         $result=get_string('document/unknown','mimetypes');
 289     }
 290     if($capitalise) {
 291         $result=ucfirst($result);
 292     }
 293     return $result;
 294 }
 295
 296 /**
 297  * Handles the sending of file data to the user's browser, including support for
 298  * byteranges etc.
 299  * @param string $path Path of file on disk (including real filename), or actual content of file as string
 300  * @param string $filename Filename to send
 301  * @param int $lifetime Number of seconds before the file should expire from caches (default 24 hours)
 302  * @param int $filter 0 (default)=no filtering, 1=all files, 2=html files only
 303  * @param bool $pathisstring If true (default false), $path is the content to send and not the pathname
 304  * @param bool $forcedownload If true (default false), forces download of file rather than view in browser/plugin
 305  * @param string $mimetype Include to specify the MIME type; leave blank to have it guess the type from $filename
 306  */
 307 function send_file($path, $filename, $lifetime=86400 , $filter=0, $pathisstring=false, $forcedownload=false, $mimetype='') {
 308     global $CFG, $COURSE;
 309
 310     // Use given MIME type if specified, otherwise guess it using mimeinfo.
 311     // IE, Konqueror and Opera open html file directly in browser from web even when directed to save it to disk :-O
 312     // only Firefox saves all files locally before opening when content-disposition: attachment stated
 313     $isFF         = check_browser_version('Firefox', '1.5'); // only FF > 1.5 properly tested
 314     $mimetype     = ($forcedownload and !$isFF) ? 'application/x-forcedownload' :
 315                          ($mimetype ? $mimetype : mimeinfo('type', $filename));
 316     $lastmodified = $pathisstring ? time() : filemtime($path);
 317     $filesize     = $pathisstring ? strlen($path) : filesize($path);
 318
 319     //Adobe Acrobat Reader XSS prevention
 320     if ($mimetype=='application/pdf' or mimeinfo('type', $filename)=='application/pdf') {
 321         //please note that it prevents opening of pdfs in browser when http referer disabled
 322         //or file linked from another site; browser caching of pdfs is now disabled too
 323         if (!empty($_SERVER['HTTP_RANGE'])) {
 324             //already byteserving
 325             $lifetime = 1; // >0 needed for byteserving
 326         } else if (empty($_SERVER['HTTP_REFERER']) or strpos($_SERVER['HTTP_REFERER'], $CFG->wwwroot)!==0) {
 327             $mimetype = 'application/x-forcedownload';
 328             $forcedownload = true;
 329             $lifetime = 0;
 330         } else {
 331             $lifetime = 1; // >0 needed for byteserving
 332         }
 333     }
 334
 335     //IE compatibiltiy HACK!
 336     if (ini_get('zlib.output_compression')) {
 337         ini_set('zlib.output_compression', 'Off');
 338     }
 339
 340     //try to disable automatic sid rewrite in cookieless mode
 341     @ini_set("session.use_trans_sid", "false");
 342
 343     //do not put '@' before the next header to detect incorrect moodle configurations,
 344     //error should be better than "weird" empty lines for admins/users
 345     //TODO: should we remove all those @ before the header()? Are all of the values supported on all servers?
 346     header('Last-Modified: '. gmdate('D, d M Y H:i:s', $lastmodified) .' GMT');
 347
 348     // if user is using IE, urlencode the filename so that multibyte file name will show up correctly on popup
 349     if (check_browser_version('MSIE')) {
 350         $filename = urlencode($filename);
 351     }
 352
 353     if ($forcedownload) {
 354         @header('Content-Disposition: attachment; filename='.$filename);
 355     } else {
 356         @header('Content-Disposition: inline; filename='.$filename);
 357     }
 358
 359     if ($lifetime > 0) {
 360         @header('Cache-Control: max-age='.$lifetime);
 361         @header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 362         @header('Pragma: ');
 363
 364         if (empty($CFG->disablebyteserving) && !$pathisstring && $mimetype != 'text/plain' && $mimetype != 'text/html') {
 365
 366             @header('Accept-Ranges: bytes');
 367
 368             if (!empty($_SERVER['HTTP_RANGE']) && strpos($_SERVER['HTTP_RANGE'],'bytes=') !== FALSE) {
 369                 // byteserving stuff - for acrobat reader and download accelerators
 370                 // see: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35
 371                 // inspired by: http://www.coneural.org/florian/papers/04_byteserving.php
 372                 $ranges = false;
 373                 if (preg_match_all('/(\d*)-(\d*)/', $_SERVER['HTTP_RANGE'], $ranges, PREG_SET_ORDER)) {
 374                     foreach ($ranges as $key=>$value) {
 375                         if ($ranges[$key][1] == '') {
 376                             //suffix case
 377                             $ranges[$key][1] = $filesize - $ranges[$key][2];
 378                             $ranges[$key][2] = $filesize - 1;
 379                         } else if ($ranges[$key][2] == '' || $ranges[$key][2] > $filesize - 1) {
 380                             //fix range length
 381                             $ranges[$key][2] = $filesize - 1;
 382                         }
 383                         if ($ranges[$key][2] != '' && $ranges[$key][2] < $ranges[$key][1]) {
 384                             //invalid byte-range ==> ignore header
 385                             $ranges = false;
 386                             break;
 387                         }
 388                         //prepare multipart header
 389                         $ranges[$key][0] =  "\r\n--".BYTESERVING_BOUNDARY."\r\nContent-Type: $mimetype\r\n";
 390                         $ranges[$key][0] .= "Content-Range: bytes {$ranges[$key][1]}-{$ranges[$key][2]}/$filesize\r\n\r\n";
 391                     }
 392                 } else {
 393                     $ranges = false;
 394                 }
 395                 if ($ranges) {
 396                     byteserving_send_file($path, $mimetype, $ranges);
 397                 }
 398             }
 399         } else {
 400             /// Do not byteserve (disabled, strings, text and html files).
 401             @header('Accept-Ranges: none');
 402         }
 403     } else { // Do not cache files in proxies and browsers
 404         if (strpos($CFG->wwwroot, 'https://') === 0) { //https sites - watch out for IE! KB812935 and KB316431
 405             @header('Cache-Control: max-age=10');
 406             @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 407             @header('Pragma: ');
 408         } else { //normal http - prevent caching at all cost
 409             @header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
 410             @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 411             @header('Pragma: no-cache');
 412         }
 413         @header('Accept-Ranges: none'); // Do not allow byteserving when caching disabled
 414     }
 415
 416     if (empty($filter)) {
 417         if ($mimetype == 'text/html' && !empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 418             //cookieless mode - rewrite links
 419             @header('Content-Type: text/html');
 420             $path = $pathisstring ? $path : implode('', file($path));
 421             $path = sid_ob_rewrite($path);
 422             $filesize = strlen($path);
 423             $pathisstring = true;
 424         } else if ($mimetype == 'text/plain') {
 425             @header('Content-Type: Text/plain; charset=utf-8'); //add encoding
 426         } else {
 427             @header('Content-Type: '.$mimetype);
 428         }
 429         @header('Content-Length: '.$filesize);
 430         while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 431         if ($pathisstring) {
 432             echo $path;
 433         } else {
 434             readfile_chunked($path);
 435         }
 436     } else {     // Try to put the file through filters
 437         if ($mimetype == 'text/html') {
 438             $options = new object();
 439             $options->noclean = true;
 440             $options->nocache = true; // temporary workaround for MDL-5136
 441             $text = $pathisstring ? $path : implode('', file($path));
 442
 443             $text = file_modify_html_header($text);
 444             $output = format_text($text, FORMAT_HTML, $options, $COURSE->id);
 445             if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 446                 //cookieless mode - rewrite links
 447                 $output = sid_ob_rewrite($output);
 448             }
 449
 450             @header('Content-Length: '.strlen($output));
 451             @header('Content-Type: text/html');
 452             while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 453             echo $output;
 454         // only filter text if filter all files is selected
 455         } else if (($mimetype == 'text/plain') and ($filter == 1)) {
 456             $options = new object();
 457             $options->newlines = false;
 458             $options->noclean = true;
 459             $text = htmlentities($pathisstring ? $path : implode('', file($path)));
 460             $output = '<pre>'. format_text($text, FORMAT_MOODLE, $options, $COURSE->id) .'</pre>';
 461             if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 462                 //cookieless mode - rewrite links
 463                 $output = sid_ob_rewrite($output);
 464             }
 465
 466             @header('Content-Length: '.strlen($output));
 467             @header('Content-Type: text/html; charset=utf-8'); //add encoding
 468             while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 469             echo $output;
 470         } else {    // Just send it out raw
 471             @header('Content-Length: '.$filesize);
 472             @header('Content-Type: '.$mimetype);
 473             while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 474             if ($pathisstring) {
 475                 echo $path;
 476             }else {
 477                 readfile_chunked($path);
 478             }
 479         }
 480     }
 481     die; //no more chars to output!!!
 482 }
 483
 484 function get_records_csv($file, $table) {
 485     global $CFG, $db;
 486
 487     if (!$metacolumns = $db->MetaColumns($CFG->prefix . $table)) {
 488         return false;
 489     }
 490
 491     if(!($handle = @fopen($file, 'r'))) {
 492         error('get_records_csv failed to open '.$file);
 493     }
 494
 495     $fieldnames = fgetcsv($handle, 4096);
 496     if(empty($fieldnames)) {
 497         fclose($handle);
 498         return false;
 499     }
 500
 501     $columns = array();
 502
 503     foreach($metacolumns as $metacolumn) {
 504         $ord = array_search($metacolumn->name, $fieldnames);
 505         if(is_int($ord)) {
 506             $columns[$metacolumn->name] = $ord;
 507         }
 508     }
 509
 510     $rows = array();
 511
 512     while (($data = fgetcsv($handle, 4096)) !== false) {
 513         $item = new stdClass;
 514         foreach($columns as $name => $ord) {
 515             $item->$name = $data[$ord];
 516         }
 517         $rows[] = $item;
 518     }
 519
 520     fclose($handle);
 521     return $rows;
 522 }
 523
 524 function put_records_csv($file, $records, $table = NULL) {
 525     global $CFG, $db;
 526
 527     if (empty($records)) {
 528         return true;
 529     }
 530
 531     $metacolumns = NULL;
 532     if ($table !== NULL && !$metacolumns = $db->MetaColumns($CFG->prefix . $table)) {
 533         return false;
 534     }
 535
 536     echo "x";
 537
 538     if(!($fp = @fopen($CFG->dataroot.'/temp/'.$file, 'w'))) {
 539         error('put_records_csv failed to open '.$file);
 540     }
 541
 542     $proto = reset($records);
 543     if(is_object($proto)) {
 544         $fields_records = array_keys(get_object_vars($proto));
 545     }
 546     else if(is_array($proto)) {
 547         $fields_records = array_keys($proto);
 548     }
 549     else {
 550         return false;
 551     }
 552     echo "x";
 553
 554     if(!empty($metacolumns)) {
 555         $fields_table = array_map(create_function('$a', 'return $a->name;'), $metacolumns);
 556         $fields = array_intersect($fields_records, $fields_table);
 557     }
 558     else {
 559         $fields = $fields_records;
 560     }
 561
 562     fwrite($fp, implode(',', $fields));
 563     fwrite($fp, "\r\n");
 564
 565     foreach($records as $record) {
 566         $array  = (array)$record;
 567         $values = array();
 568         foreach($fields as $field) {
 569             if(strpos($array[$field], ',')) {
 570                 $values[] = '"'.str_replace('"', '\"', $array[$field]).'"';
 571             }
 572             else {
 573                 $values[] = $array[$field];
 574             }
 575         }
 576         fwrite($fp, implode(',', $values)."\r\n");
 577     }
 578
 579     fclose($fp);
 580     return true;
 581 }
 582
 583
 584 /**
 585  * Recursively delete the file or folder with path $location. That is,
 586  * if it is a file delete it. If it is a folder, delete all its content
 587  * then delete it. If $location does not exist to start, that is not
 588  * considered an error.
 589  *
 590  * @param $location the path to remove.
 591  */
 592 function fulldelete($location) {
 593     if (is_dir($location)) {
 594         $currdir = opendir($location);
 595         while (false !== ($file = readdir($currdir))) {
 596             if ($file <> ".." && $file <> ".") {
 597                 $fullfile = $location."/".$file;
 598                 if (is_dir($fullfile)) {
 599                     if (!fulldelete($fullfile)) {
 600                         return false;
 601                     }
 602                 } else {
 603                     if (!unlink($fullfile)) {
 604                         return false;
 605                     }
 606                 }
 607             }
 608         }
 609         closedir($currdir);
 610         if (! rmdir($location)) {
 611             return false;
 612         }
 613
 614     } else if (file_exists($location)) {
 615         if (!unlink($location)) {
 616             return false;
 617         }
 618     }
 619     return true;
 620 }
 621
 622 /**
 623  * Improves memory consumptions and works around buggy readfile() in PHP 5.0.4 (2MB readfile limit).
 624  */
 625 function readfile_chunked($filename, $retbytes=true) {
 626     $chunksize = 1*(1024*1024); // 1MB chunks - must be less than 2MB!
 627     $buffer = '';
 628     $cnt =0;
 629     $handle = fopen($filename, 'rb');
 630     if ($handle === false) {
 631         return false;
 632     }
 633
 634     while (!feof($handle)) {
 635         @set_time_limit(60*60); //reset time limit to 60 min - should be enough for 1 MB chunk
 636         $buffer = fread($handle, $chunksize);
 637         echo $buffer;
 638         flush();
 639         if ($retbytes) {
 640             $cnt += strlen($buffer);
 641         }
 642     }
 643     $status = fclose($handle);
 644     if ($retbytes && $status) {
 645         return $cnt; // return num. bytes delivered like readfile() does.
 646     }
 647     return $status;
 648 }
 649
 650 /**
 651  * Send requested byterange of file.
 652  */
 653 function byteserving_send_file($filename, $mimetype, $ranges) {
 654     $chunksize = 1*(1024*1024); // 1MB chunks - must be less than 2MB!
 655     $handle = fopen($filename, 'rb');
 656     if ($handle === false) {
 657         die;
 658     }
 659     if (count($ranges) == 1) { //only one range requested
 660         $length = $ranges[0][2] - $ranges[0][1] + 1;
 661         @header('HTTP/1.1 206 Partial content');
 662         @header('Content-Length: '.$length);
 663         @header('Content-Range: bytes '.$ranges[0][1].'-'.$ranges[0][2].'/'.filesize($filename));
 664         @header('Content-Type: '.$mimetype);
 665         while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 666         $buffer = '';
 667         fseek($handle, $ranges[0][1]);
 668         while (!feof($handle) && $length > 0) {
 669             @set_time_limit(60*60); //reset time limit to 60 min - should be enough for 1 MB chunk
 670             $buffer = fread($handle, ($chunksize < $length ? $chunksize : $length));
 671             echo $buffer;
 672             flush();
 673             $length -= strlen($buffer);
 674         }
 675         fclose($handle);
 676         die;
 677     } else { // multiple ranges requested - not tested much
 678         $totallength = 0;
 679         foreach($ranges as $range) {
 680             $totallength += strlen($range[0]) + $range[2] - $range[1] + 1;
 681         }
 682         $totallength += strlen("\r\n--".BYTESERVING_BOUNDARY."--\r\n");
 683         @header('HTTP/1.1 206 Partial content');
 684         @header('Content-Length: '.$totallength);
 685         @header('Content-Type: multipart/byteranges; boundary='.BYTESERVING_BOUNDARY);
 686         //TODO: check if "multipart/x-byteranges" is more compatible with current readers/browsers/servers
 687         while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 688         foreach($ranges as $range) {
 689             $length = $range[2] - $range[1] + 1;
 690             echo $range[0];
 691             $buffer = '';
 692             fseek($handle, $range[1]);
 693             while (!feof($handle) && $length > 0) {
 694                 @set_time_limit(60*60); //reset time limit to 60 min - should be enough for 1 MB chunk
 695                 $buffer = fread($handle, ($chunksize < $length ? $chunksize : $length));
 696                 echo $buffer;
 697                 flush();
 698                 $length -= strlen($buffer);
 699             }
 700         }
 701         echo "\r\n--".BYTESERVING_BOUNDARY."--\r\n";
 702         fclose($handle);
 703         die;
 704     }
 705 }
 706
 707 /**
 708  * add includes (js and css) into uploaded files
 709  * before returning them, useful for themes and utf.js includes
 710  * @param string text - text to search and replace
 711  * @return string - text with added head includes
 712  */
 713 function file_modify_html_header($text) {
 714     // first look for <head> tag
 715     global $CFG;
 716
 717     $stylesheetshtml = '';
 718     foreach ($CFG->stylesheets as $stylesheet) {
 719         $stylesheetshtml .= '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'" />'."\n";
 720     }
 721
 722     $filters = explode(",", $CFG->textfilters);
 723     if (in_array('filter/mediaplugin', $filters)) {
 724         // this script is needed by most media filter plugins.
 725         $ufo = "\n".'<script type="text/javascript" src="'.$CFG->wwwroot.'/lib/ufo.js"></script>'."\n";
 726     } else {
 727         $ufo = '';
 728     }
 729
 730     preg_match('/\<head\>|\<HEAD\>/', $text, $matches);
 731     if ($matches) {
 732         $replacement = '<head>'.$ufo.$stylesheetshtml;
 733         $text = preg_replace('/\<head\>|\<HEAD\>/', $replacement, $text, 1);
 734         return $text;
 735     }
 736
 737     // if not, look for <html> tag, and stick <head> right after
 738     preg_match('/\<html\>|\<HTML\>/', $text, $matches);
 739     if ($matches) {
 740         // replace <html> tag with <html><head>includes</head>
 741         $replacement = '<html>'."\n".'<head>'.$ufo.$stylesheetshtml.'</head>';
 742         $text = preg_replace('/\<html\>|\<HTML\>/', $replacement, $text, 1);
 743         return $text;
 744     }
 745
 746     // if not, look for <body> tag, and stick <head> before body
 747     preg_match('/\<body\>|\<BODY\>/', $text, $matches);
 748     if ($matches) {
 749         $replacement = '<head>'.$ufo.$stylesheetshtml.'</head>'."\n".'<body>';
 750         $text = preg_replace('/\<body\>|\<BODY\>/', $replacement, $text, 1);
 751         return $text;
 752     }
 753
 754     // if not, just stick a <head> tag at the beginning
 755     $text = '<head>'.$ufo.$stylesheetshtml.'</head>'."\n".$text;
 756     return $text;
 757 }
 758
 759 ?>