lib/filelib.php

   1 <?php //$Id$
   2
   3 define('BYTESERVING_BOUNDARY', 's1k2o3d4a5k6s7'); //unique string constant
   4
   5 function get_file_url($path, $options=null, $type='coursefile') {
   6     global $CFG, $HTTPSPAGEREQUIRED;
   7
   8     $path = str_replace('//', '/', $path);
   9     $path = trim($path, '/'); // no leading and trailing slashes
  10
  11     // type of file
  12     switch ($type) {
  13        case 'questionfile':
  14             $url = $CFG->wwwroot."/question/exportfile.php";
  15             break;
  16        case 'rssfile':
  17             $url = $CFG->wwwroot."/rss/file.php";
  18             break;
  19         case 'user':
  20             if (!empty($HTTPSPAGEREQUIRED)) {
  21                 $wwwroot = $CFG->httpswwwroot;
  22             }
  23             else {
  24                 $wwwroot = $CFG->wwwroot;
  25             }
  26             $url = $wwwroot."/user/pix.php";
  27             break;
  28         case 'usergroup':
  29             $url = $CFG->wwwroot."/user/pixgroup.php";
  30             break;
  31         case 'httpscoursefile':
  32             $url = $CFG->httpswwwroot."/file.php";
  33             break;
  34          case 'coursefile':
  35         default:
  36             $url = $CFG->wwwroot."/file.php";
  37     }
  38
  39     if ($CFG->slasharguments) {
  40         $parts = explode('/', $path);
  41         foreach ($parts as $key => $part) {
  42         /// anchor dash character should not be encoded
  43             $subparts = explode('#', $part);
  44             $subparts = array_map('rawurlencode', $subparts);
  45             $parts[$key] = implode('#', $subparts);
  46         }
  47         $path  = implode('/', $parts);
  48         $ffurl = $url.'/'.$path;
  49         $separator = '?';
  50     } else {
  51         $path = rawurlencode('/'.$path);
  52         $ffurl = $url.'?file='.$path;
  53         $separator = '&amp;';
  54     }
  55
  56     if ($options) {
  57         foreach ($options as $name=>$value) {
  58             $ffurl = $ffurl.$separator.$name.'='.$value;
  59             $separator = '&amp;';
  60         }
  61     }
  62
  63     return $ffurl;
  64 }
  65
  66 /**
  67  * Fetches content of file from Internet (using proxy if defined). Uses cURL extension if present.
  68  * Due to security concerns only downloads from http(s) sources are supported.
  69  *
  70  * @param string $url file url starting with http(s)://
  71  * @param array $headers http headers, null if none. If set, should be an
  72  *   associative array of header name => value pairs.
  73  * @param array $postdata array means use POST request with given parameters
  74  * @param bool $fullresponse return headers, responses, etc in a similar way snoopy does
  75  *   (if false, just returns content)
  76  * @param int $timeout timeout for complete download process including all file transfer
  77  *   (default 5 minutes)
  78  * @param int $connecttimeout timeout for connection to server; this is the timeout that
  79  *   usually happens if the remote server is completely down (default 20 seconds);
  80  *   may not work when using proxy
  81  * @param bool $skipcertverify If true, the peer's SSL certificate will not be checked. Only use this when already in a trusted location.
  82  * @return mixed false if request failed or content of the file as string if ok.
  83  */
  84 function download_file_content($url, $headers=null, $postdata=null, $fullresponse=false, $timeout=300, $connecttimeout=20, $skipcertverify=false) {
  85     global $CFG;
  86
  87     // some extra security
  88     $newlines = array("\r", "\n");
  89     if (is_array($headers) ) {
  90         foreach ($headers as $key => $value) {
  91             $headers[$key] = str_replace($newlines, '', $value);
  92         }
  93     }
  94     $url = str_replace($newlines, '', $url);
  95     if (!preg_match('|^https?://|i', $url)) {
  96         if ($fullresponse) {
  97             $response = new object();
  98             $response->status        = 0;
  99             $response->headers       = array();
 100             $response->response_code = 'Invalid protocol specified in url';
 101             $response->results       = '';
 102             $response->error         = 'Invalid protocol specified in url';
 103             return $response;
 104         } else {
 105             return false;
 106         }
 107     }
 108
 109
 110     if (!extension_loaded('curl') or ($ch = curl_init($url)) === false) {
 111         require_once($CFG->libdir.'/snoopy/Snoopy.class.inc');
 112         $snoopy = new Snoopy();
 113         $snoopy->read_timeout = $timeout;
 114         $snoopy->_fp_timeout  = $connecttimeout;
 115         $snoopy->proxy_host   = $CFG->proxyhost;
 116         $snoopy->proxy_port   = $CFG->proxyport;
 117         if (!empty($CFG->proxyuser) and !empty($CFG->proxypassword)) {
 118             // this will probably fail, but let's try it anyway
 119             $snoopy->proxy_user     = $CFG->proxyuser;
 120             $snoopy->proxy_password = $CFG->proxypassword;
 121         }
 122         if (is_array($headers) ) {
 123             $client->rawheaders = $headers;
 124         }
 125
 126         if (is_array($postdata)) {
 127             $fetch = @$snoopy->fetch($url, $postdata); // use more specific debug code bellow
 128         } else {
 129             $fetch = @$snoopy->fetch($url); // use more specific debug code bellow
 130         }
 131
 132         if ($fetch) {
 133             if ($fullresponse) {
 134                 //fix header line endings
 135                 foreach ($snoopy->headers as $key=>$unused) {
 136                     $snoopy->headers[$key] = trim($snoopy->headers[$key]);
 137                 }
 138                 $response = new object();
 139                 $response->status        = $snoopy->status;
 140                 $response->headers       = $snoopy->headers;
 141                 $response->response_code = trim($snoopy->response_code);
 142                 $response->results       = $snoopy->results;
 143                 $response->error         = $snoopy->error;
 144                 return $response;
 145
 146             } else if ($snoopy->status != 200) {
 147                 debugging("Snoopy request for \"$url\" failed, http response code: ".$snoopy->response_code, DEBUG_ALL);
 148                 return false;
 149
 150             } else {
 151                 return $snoopy->results;
 152             }
 153         } else {
 154             if ($fullresponse) {
 155                 $response = new object();
 156                 $response->status        = $snoopy->status;
 157                 $response->headers       = array();
 158                 $response->response_code = $snoopy->response_code;
 159                 $response->results       = '';
 160                 $response->error         = $snoopy->error;
 161                 return $response;
 162             } else {
 163                 debugging("Snoopy request for \"$url\" failed with: ".$snoopy->error, DEBUG_ALL);
 164                 return false;
 165             }
 166         }
 167     }
 168
 169     // set extra headers
 170     if (is_array($headers) ) {
 171         $headers2 = array();
 172         foreach ($headers as $key => $value) {
 173             $headers2[] = "$key: $value";
 174         }
 175         curl_setopt($ch, CURLOPT_HTTPHEADER, $headers2);
 176     }
 177
 178
 179     if ($skipcertverify) {
 180         curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
 181     }
 182
 183     // use POST if requested
 184     if (is_array($postdata)) {
 185         foreach ($postdata as $k=>$v) {
 186             $postdata[$k] = urlencode($k).'='.urlencode($v);
 187         }
 188         $postdata = implode('&', $postdata);
 189         curl_setopt($ch, CURLOPT_POST, true);
 190         curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata);
 191     }
 192
 193     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 194     curl_setopt($ch, CURLOPT_HEADER, true);
 195     curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $connecttimeout);
 196     curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);
 197     if (!ini_get('open_basedir') and !ini_get('safe_mode')) {
 198         // TODO: add version test for '7.10.5'
 199         curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
 200         curl_setopt($ch, CURLOPT_MAXREDIRS, 5);
 201     }
 202
 203     if (!empty($CFG->proxyhost)) {
 204         // SOCKS supported in PHP5 only
 205         if (!empty($CFG->proxytype) and ($CFG->proxytype == 'SOCKS5')) {
 206             if (defined('CURLPROXY_SOCKS5')) {
 207                 curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
 208             } else {
 209                 curl_close($ch);
 210                 if ($fullresponse) {
 211                     $response = new object();
 212                     $response->status        = '0';
 213                     $response->headers       = array();
 214                     $response->response_code = 'SOCKS5 proxy is not supported in PHP4';
 215                     $response->results       = '';
 216                     $response->error         = 'SOCKS5 proxy is not supported in PHP4';
 217                     return $response;
 218                 } else {
 219                     debugging("SOCKS5 proxy is not supported in PHP4.", DEBUG_ALL);
 220                     return false;
 221                 }
 222             }
 223         }
 224
 225         curl_setopt($ch, CURLOPT_HTTPPROXYTUNNEL, false);
 226
 227         if (empty($CFG->proxyport)) {
 228             curl_setopt($ch, CURLOPT_PROXY, $CFG->proxyhost);
 229         } else {
 230             curl_setopt($ch, CURLOPT_PROXY, $CFG->proxyhost.':'.$CFG->proxyport);
 231         }
 232
 233         if (!empty($CFG->proxyuser) and !empty($CFG->proxypassword)) {
 234             curl_setopt($ch, CURLOPT_PROXYUSERPWD, $CFG->proxyuser.':'.$CFG->proxypassword);
 235             if (defined('CURLOPT_PROXYAUTH')) {
 236                 // any proxy authentication if PHP 5.1
 237                 curl_setopt($ch, CURLOPT_PROXYAUTH, CURLAUTH_BASIC | CURLAUTH_NTLM);
 238             }
 239         }
 240     }
 241
 242     $data = curl_exec($ch);
 243
 244     // try to detect encoding problems
 245     if ((curl_errno($ch) == 23 or curl_errno($ch) == 61) and defined('CURLOPT_ENCODING')) {
 246         curl_setopt($ch, CURLOPT_ENCODING, 'none');
 247         $data = curl_exec($ch);
 248     }
 249
 250     if (curl_errno($ch)) {
 251         $error    = curl_error($ch);
 252         $error_no = curl_errno($ch);
 253         curl_close($ch);
 254
 255         if ($fullresponse) {
 256             $response = new object();
 257             if ($error_no == 28) {
 258                 $response->status    = '-100'; // mimic snoopy
 259             } else {
 260                 $response->status    = '0';
 261             }
 262             $response->headers       = array();
 263             $response->response_code = $error;
 264             $response->results       = '';
 265             $response->error         = $error;
 266             return $response;
 267         } else {
 268             debugging("cURL request for \"$url\" failed with: $error ($error_no)", DEBUG_ALL);
 269             return false;
 270         }
 271
 272     } else {
 273         $info = curl_getinfo($ch);
 274         curl_close($ch);
 275
 276         if (empty($info['http_code'])) {
 277             // for security reasons we support only true http connections (Location: file:// exploit prevention)
 278             $response = new object();
 279             $response->status        = '0';
 280             $response->headers       = array();
 281             $response->response_code = 'Unknown cURL error';
 282             $response->results       = ''; // do NOT change this!
 283             $response->error         = 'Unknown cURL error';
 284
 285         } else {
 286             // strip redirect headers and get headers array and content
 287             $data = explode("\r\n\r\n", $data, $info['redirect_count'] + 2);
 288             $results = array_pop($data);
 289             $headers = array_pop($data);
 290             $headers = explode("\r\n", trim($headers));
 291
 292             $response = new object();;
 293             $response->status        = (string)$info['http_code'];
 294             $response->headers       = $headers;
 295             $response->response_code = $headers[0];
 296             $response->results       = $results;
 297             $response->error         = '';
 298         }
 299
 300         if ($fullresponse) {
 301             return $response;
 302         } else if ($info['http_code'] != 200) {
 303             debugging("cURL request for \"$url\" failed, HTTP response code: ".$response->response_code, DEBUG_ALL);
 304             return false;
 305         } else {
 306             return $response->results;
 307         }
 308     }
 309 }
 310
 311 /**
 312  * @return List of information about file types based on extensions.
 313  *   Associative array of extension (lower-case) to associative array
 314  *   from 'element name' to data. Current element names are 'type' and 'icon'.
 315  *   Unknown types should use the 'xxx' entry which includes defaults.
 316  */
 317 function get_mimetypes_array() {
 318     return array (
 319         'xxx'  => array ('type'=>'document/unknown', 'icon'=>'unknown.gif'),
 320         '3gp'  => array ('type'=>'video/quicktime', 'icon'=>'video.gif'),
 321         'ai'   => array ('type'=>'application/postscript', 'icon'=>'image.gif'),
 322         'aif'  => array ('type'=>'audio/x-aiff', 'icon'=>'audio.gif'),
 323         'aiff' => array ('type'=>'audio/x-aiff', 'icon'=>'audio.gif'),
 324         'aifc' => array ('type'=>'audio/x-aiff', 'icon'=>'audio.gif'),
 325         'applescript'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 326         'asc'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 327         'asm'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 328         'au'   => array ('type'=>'audio/au', 'icon'=>'audio.gif'),
 329         'avi'  => array ('type'=>'video/x-ms-wm', 'icon'=>'avi.gif'),
 330         'bmp'  => array ('type'=>'image/bmp', 'icon'=>'image.gif'),
 331         'c'    => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 332         'cct'  => array ('type'=>'shockwave/director', 'icon'=>'flash.gif'),
 333         'cpp'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 334         'cs'   => array ('type'=>'application/x-csh', 'icon'=>'text.gif'),
 335         'css'  => array ('type'=>'text/css', 'icon'=>'text.gif'),
 336         'csv'  => array ('type'=>'text/csv', 'icon'=>'excel.gif'),
 337         'dv'   => array ('type'=>'video/x-dv', 'icon'=>'video.gif'),
 338         'dmg'  => array ('type'=>'application/octet-stream', 'icon'=>'dmg.gif'),
 339
 340         'doc'  => array ('type'=>'application/msword', 'icon'=>'word.gif'),
 341         'docx' => array ('type'=>'application/vnd.openxmlformats-officedocument.wordprocessingml.document', 'icon'=>'docx.gif'),
 342         'docm' => array ('type'=>'application/vnd.ms-word.document.macroEnabled.12', 'icon'=>'docm.gif'),
 343         'dotx' => array ('type'=>'application/vnd.openxmlformats-officedocument.wordprocessingml.template', 'icon'=>'dotx.gif'),
 344         'dotm' => array ('type'=>'application/vnd.ms-word.template.macroEnabled.12', 'icon'=>'dotm.gif'),
 345
 346         'dcr'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
 347         'dif'  => array ('type'=>'video/x-dv', 'icon'=>'video.gif'),
 348         'dir'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
 349         'dxr'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
 350         'eps'  => array ('type'=>'application/postscript', 'icon'=>'pdf.gif'),
 351         'fdf'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 352         'flv'  => array ('type'=>'video/x-flv', 'icon'=>'video.gif'),
 353         'gif'  => array ('type'=>'image/gif', 'icon'=>'image.gif'),
 354         'gtar' => array ('type'=>'application/x-gtar', 'icon'=>'zip.gif'),
 355         'tgz'  => array ('type'=>'application/g-zip', 'icon'=>'zip.gif'),
 356         'gz'   => array ('type'=>'application/g-zip', 'icon'=>'zip.gif'),
 357         'gzip' => array ('type'=>'application/g-zip', 'icon'=>'zip.gif'),
 358         'h'    => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 359         'hpp'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 360         'hqx'  => array ('type'=>'application/mac-binhex40', 'icon'=>'zip.gif'),
 361         'htc'  => array ('type'=>'text/x-component', 'icon'=>'text.gif'),
 362         'html' => array ('type'=>'text/html', 'icon'=>'html.gif'),
 363         'xhtml'=> array ('type'=>'application/xhtml+xml', 'icon'=>'html.gif'),
 364         'htm'  => array ('type'=>'text/html', 'icon'=>'html.gif'),
 365         'ico'  => array ('type'=>'image/vnd.microsoft.icon', 'icon'=>'image.gif'),
 366         'ics'  => array ('type'=>'text/calendar', 'icon'=>'text.gif'),
 367         'isf'  => array ('type'=>'application/inspiration', 'icon'=>'isf.gif'),
 368         'ist'  => array ('type'=>'application/inspiration.template', 'icon'=>'isf.gif'),
 369         'java' => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 370         'jcb'  => array ('type'=>'text/xml', 'icon'=>'jcb.gif'),
 371         'jcl'  => array ('type'=>'text/xml', 'icon'=>'jcl.gif'),
 372         'jcw'  => array ('type'=>'text/xml', 'icon'=>'jcw.gif'),
 373         'jmt'  => array ('type'=>'text/xml', 'icon'=>'jmt.gif'),
 374         'jmx'  => array ('type'=>'text/xml', 'icon'=>'jmx.gif'),
 375         'jpe'  => array ('type'=>'image/jpeg', 'icon'=>'image.gif'),
 376         'jpeg' => array ('type'=>'image/jpeg', 'icon'=>'image.gif'),
 377         'jpg'  => array ('type'=>'image/jpeg', 'icon'=>'image.gif'),
 378         'jqz'  => array ('type'=>'text/xml', 'icon'=>'jqz.gif'),
 379         'js'   => array ('type'=>'application/x-javascript', 'icon'=>'text.gif'),
 380         'latex'=> array ('type'=>'application/x-latex', 'icon'=>'text.gif'),
 381         'm'    => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 382         'mov'  => array ('type'=>'video/quicktime', 'icon'=>'video.gif'),
 383         'movie'=> array ('type'=>'video/x-sgi-movie', 'icon'=>'video.gif'),
 384         'm3u'  => array ('type'=>'audio/x-mpegurl', 'icon'=>'audio.gif'),
 385         'mp3'  => array ('type'=>'audio/mp3', 'icon'=>'audio.gif'),
 386         'mp4'  => array ('type'=>'video/mp4', 'icon'=>'video.gif'),
 387         'm4v'  => array ('type'=>'video/mp4', 'icon'=>'video.gif'),
 388         'm4a'  => array ('type'=>'audio/mp4', 'icon'=>'audio.gif'),
 389         'mpeg' => array ('type'=>'video/mpeg', 'icon'=>'video.gif'),
 390         'mpe'  => array ('type'=>'video/mpeg', 'icon'=>'video.gif'),
 391         'mpg'  => array ('type'=>'video/mpeg', 'icon'=>'video.gif'),
 392
 393         'odt'  => array ('type'=>'application/vnd.oasis.opendocument.text', 'icon'=>'odt.gif'),
 394         'ott'  => array ('type'=>'application/vnd.oasis.opendocument.text-template', 'icon'=>'odt.gif'),
 395         'oth'  => array ('type'=>'application/vnd.oasis.opendocument.text-web', 'icon'=>'odt.gif'),
 396         'odm'  => array ('type'=>'application/vnd.oasis.opendocument.text-master', 'icon'=>'odm.gif'),
 397         'odg'  => array ('type'=>'application/vnd.oasis.opendocument.graphics', 'icon'=>'odg.gif'),
 398         'otg'  => array ('type'=>'application/vnd.oasis.opendocument.graphics-template', 'icon'=>'odg.gif'),
 399         'odp'  => array ('type'=>'application/vnd.oasis.opendocument.presentation', 'icon'=>'odp.gif'),
 400         'otp'  => array ('type'=>'application/vnd.oasis.opendocument.presentation-template', 'icon'=>'odp.gif'),
 401         'ods'  => array ('type'=>'application/vnd.oasis.opendocument.spreadsheet', 'icon'=>'ods.gif'),
 402         'ots'  => array ('type'=>'application/vnd.oasis.opendocument.spreadsheet-template', 'icon'=>'ods.gif'),
 403         'odc'  => array ('type'=>'application/vnd.oasis.opendocument.chart', 'icon'=>'odc.gif'),
 404         'odf'  => array ('type'=>'application/vnd.oasis.opendocument.formula', 'icon'=>'odf.gif'),
 405         'odb'  => array ('type'=>'application/vnd.oasis.opendocument.database', 'icon'=>'odb.gif'),
 406         'odi'  => array ('type'=>'application/vnd.oasis.opendocument.image', 'icon'=>'odi.gif'),
 407
 408         'pct'  => array ('type'=>'image/pict', 'icon'=>'image.gif'),
 409         'pdf'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 410         'php'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 411         'pic'  => array ('type'=>'image/pict', 'icon'=>'image.gif'),
 412         'pict' => array ('type'=>'image/pict', 'icon'=>'image.gif'),
 413         'png'  => array ('type'=>'image/png', 'icon'=>'image.gif'),
 414
 415         'pps'  => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'powerpoint.gif'),
 416         'ppt'  => array ('type'=>'application/vnd.ms-powerpoint', 'icon'=>'powerpoint.gif'),
 417         'pptx' => array ('type'=>'application/vnd.openxmlformats-officedocument.presentationml.presentation', 'icon'=>'pptx.gif'),
 418         'pptm' => array ('type'=>'application/vnd.ms-powerpoint.presentation.macroEnabled.12', 'icon'=>'pptm.gif'),
 419         'potx' => array ('type'=>'application/vnd.openxmlformats-officedocument.presentationml.template', 'icon'=>'potx.gif'),
 420         'potm' => array ('type'=>'application/vnd.ms-powerpoint.template.macroEnabled.12', 'icon'=>'potm.gif'),
 421         'ppam' => array ('type'=>'application/vnd.ms-powerpoint.addin.macroEnabled.12', 'icon'=>'ppam.gif'),
 422         'ppsx' => array ('type'=>'application/vnd.openxmlformats-officedocument.presentationml.slideshow', 'icon'=>'ppsx.gif'),
 423         'ppsm' => array ('type'=>'application/vnd.ms-powerpoint.slideshow.macroEnabled.12', 'icon'=>'ppsm.gif'),
 424
 425         'ps'   => array ('type'=>'application/postscript', 'icon'=>'pdf.gif'),
 426         'qt'   => array ('type'=>'video/quicktime', 'icon'=>'video.gif'),
 427         'ra'   => array ('type'=>'audio/x-realaudio-plugin', 'icon'=>'audio.gif'),
 428         'ram'  => array ('type'=>'audio/x-pn-realaudio-plugin', 'icon'=>'audio.gif'),
 429         'rhb'  => array ('type'=>'text/xml', 'icon'=>'xml.gif'),
 430         'rm'   => array ('type'=>'audio/x-pn-realaudio-plugin', 'icon'=>'audio.gif'),
 431         'rtf'  => array ('type'=>'text/rtf', 'icon'=>'text.gif'),
 432         'rtx'  => array ('type'=>'text/richtext', 'icon'=>'text.gif'),
 433         'sh'   => array ('type'=>'application/x-sh', 'icon'=>'text.gif'),
 434         'sit'  => array ('type'=>'application/x-stuffit', 'icon'=>'zip.gif'),
 435         'smi'  => array ('type'=>'application/smil', 'icon'=>'text.gif'),
 436         'smil' => array ('type'=>'application/smil', 'icon'=>'text.gif'),
 437         'sqt'  => array ('type'=>'text/xml', 'icon'=>'xml.gif'),
 438         'svg'  => array ('type'=>'image/svg+xml', 'icon'=>'image.gif'),
 439         'svgz' => array ('type'=>'image/svg+xml', 'icon'=>'image.gif'),
 440         'swa'  => array ('type'=>'application/x-director', 'icon'=>'flash.gif'),
 441         'swf'  => array ('type'=>'application/x-shockwave-flash', 'icon'=>'flash.gif'),
 442         'swfl' => array ('type'=>'application/x-shockwave-flash', 'icon'=>'flash.gif'),
 443
 444         'sxw'  => array ('type'=>'application/vnd.sun.xml.writer', 'icon'=>'odt.gif'),
 445         'stw'  => array ('type'=>'application/vnd.sun.xml.writer.template', 'icon'=>'odt.gif'),
 446         'sxc'  => array ('type'=>'application/vnd.sun.xml.calc', 'icon'=>'odt.gif'),
 447         'stc'  => array ('type'=>'application/vnd.sun.xml.calc.template', 'icon'=>'odt.gif'),
 448         'sxd'  => array ('type'=>'application/vnd.sun.xml.draw', 'icon'=>'odt.gif'),
 449         'std'  => array ('type'=>'application/vnd.sun.xml.draw.template', 'icon'=>'odt.gif'),
 450         'sxi'  => array ('type'=>'application/vnd.sun.xml.impress', 'icon'=>'odt.gif'),
 451         'sti'  => array ('type'=>'application/vnd.sun.xml.impress.template', 'icon'=>'odt.gif'),
 452         'sxg'  => array ('type'=>'application/vnd.sun.xml.writer.global', 'icon'=>'odt.gif'),
 453         'sxm'  => array ('type'=>'application/vnd.sun.xml.math', 'icon'=>'odt.gif'),
 454
 455         'tar'  => array ('type'=>'application/x-tar', 'icon'=>'zip.gif'),
 456         'tif'  => array ('type'=>'image/tiff', 'icon'=>'image.gif'),
 457         'tiff' => array ('type'=>'image/tiff', 'icon'=>'image.gif'),
 458         'tex'  => array ('type'=>'application/x-tex', 'icon'=>'text.gif'),
 459         'texi' => array ('type'=>'application/x-texinfo', 'icon'=>'text.gif'),
 460         'texinfo'  => array ('type'=>'application/x-texinfo', 'icon'=>'text.gif'),
 461         'tsv'  => array ('type'=>'text/tab-separated-values', 'icon'=>'text.gif'),
 462         'txt'  => array ('type'=>'text/plain', 'icon'=>'text.gif'),
 463         'wav'  => array ('type'=>'audio/wav', 'icon'=>'audio.gif'),
 464         'wmv'  => array ('type'=>'video/x-ms-wmv', 'icon'=>'avi.gif'),
 465         'asf'  => array ('type'=>'video/x-ms-asf', 'icon'=>'avi.gif'),
 466         'xdp'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 467         'xfd'  => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 468         'xfdf' => array ('type'=>'application/pdf', 'icon'=>'pdf.gif'),
 469
 470         'xls'  => array ('type'=>'application/vnd.ms-excel', 'icon'=>'excel.gif'),
 471         'xlsx' => array ('type'=>'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet', 'icon'=>'xlsx.gif'),
 472         'xlsm' => array ('type'=>'application/vnd.ms-excel.sheet.macroEnabled.12', 'icon'=>'xlsm.gif'),
 473         'xltx' => array ('type'=>'application/vnd.openxmlformats-officedocument.spreadsheetml.template', 'icon'=>'xltx.gif'),
 474         'xltm' => array ('type'=>'application/vnd.ms-excel.template.macroEnabled.12', 'icon'=>'xltm.gif'),
 475         'xlsb' => array ('type'=>'application/vnd.ms-excel.sheet.binary.macroEnabled.12', 'icon'=>'xlsb.gif'),
 476         'xlam' => array ('type'=>'application/vnd.ms-excel.addin.macroEnabled.12', 'icon'=>'xlam.gif'),
 477
 478         'xml'  => array ('type'=>'application/xml', 'icon'=>'xml.gif'),
 479         'xsl'  => array ('type'=>'text/xml', 'icon'=>'xml.gif'),
 480         'zip'  => array ('type'=>'application/zip', 'icon'=>'zip.gif')
 481     );
 482 }
 483
 484 /**
 485  * Obtains information about a filetype based on its extension. Will
 486  * use a default if no information is present about that particular
 487  * extension.
 488  * @param string $element Desired information (usually 'icon'
 489  *   for icon filename or 'type' for MIME type)
 490  * @param string $filename Filename we're looking up
 491  * @return string Requested piece of information from array
 492  */
 493 function mimeinfo($element, $filename) {
 494     static $mimeinfo = null;
 495     if (is_null($mimeinfo)) {
 496         $mimeinfo = get_mimetypes_array();
 497     }
 498
 499     if (preg_match('/\.([a-zA-Z0-9]+)$/', $filename, $match)) {
 500         if (isset($mimeinfo[strtolower($match[1])][$element])) {
 501             return $mimeinfo[strtolower($match[1])][$element];
 502         } else {
 503             return $mimeinfo['xxx'][$element];   // By default
 504         }
 505     } else {
 506         return $mimeinfo['xxx'][$element];   // By default
 507     }
 508 }
 509
 510 /**
 511  * Obtains information about a filetype based on the MIME type rather than
 512  * the other way around.
 513  * @param string $element Desired information (usually 'icon')
 514  * @param string $mimetype MIME type we're looking up
 515  * @return string Requested piece of information from array
 516  */
 517 function mimeinfo_from_type($element, $mimetype) {
 518     static $mimeinfo;
 519     $mimeinfo=get_mimetypes_array();
 520
 521     foreach($mimeinfo as $values) {
 522         if($values['type']==$mimetype) {
 523             if(isset($values[$element])) {
 524                 return $values[$element];
 525             }
 526             break;
 527         }
 528     }
 529     return $mimeinfo['xxx'][$element]; // Default
 530 }
 531
 532 /**
 533  * Get information about a filetype based on the icon file.
 534  * @param string $element Desired information (usually 'icon')
 535  * @param string $icon Icon file path.
 536  * @return string Requested piece of information from array
 537  */
 538 function mimeinfo_from_icon($element, $icon) {
 539     static $mimeinfo;
 540     $mimeinfo=get_mimetypes_array();
 541
 542     if (preg_match("/\/(.*)/", $icon, $matches)) {
 543         $icon = $matches[1];
 544     }
 545     $info = $mimeinfo['xxx'][$element]; // Default
 546     foreach($mimeinfo as $values) {
 547         if($values['icon']==$icon) {
 548             if(isset($values[$element])) {
 549                 $info = $values[$element];
 550             }
 551             //No break, for example for 'excel.gif' we don't want 'csv'!
 552         }
 553     }
 554     return $info;
 555 }
 556
 557 /**
 558  * Obtains descriptions for file types (e.g. 'Microsoft Word document') from the
 559  * mimetypes.php language file.
 560  * @param string $mimetype MIME type (can be obtained using the mimeinfo function)
 561  * @param bool $capitalise If true, capitalises first character of result
 562  * @return string Text description
 563  */
 564 function get_mimetype_description($mimetype,$capitalise=false) {
 565     $result=get_string($mimetype,'mimetypes');
 566     // Surrounded by square brackets indicates that there isn't a string for that
 567     // (maybe there is a better way to find this out?)
 568     if(strpos($result,'[')===0) {
 569         $result=get_string('document/unknown','mimetypes');
 570     }
 571     if($capitalise) {
 572         $result=ucfirst($result);
 573     }
 574     return $result;
 575 }
 576
 577 /**
 578  * Handles the sending of temporary file to user, download is forced.
 579  * File is deleted after abort or succesful sending.
 580  * @param string $path path to file, preferably from moodledata/temp/something; or content of file itself
 581  * @param string $filename proposed file name when saving file
 582  * @param bool $path is content of file
 583  */
 584 function send_temp_file($path, $filename, $pathisstring=false) {
 585     global $CFG;
 586
 587     // close session - not needed anymore
 588     @session_write_close();
 589
 590     if (!$pathisstring) {
 591         if (!file_exists($path)) {
 592             header('HTTP/1.0 404 not found');
 593             error(get_string('filenotfound', 'error'), $CFG->wwwroot.'/');
 594         }
 595         // executed after normal finish or abort
 596         @register_shutdown_function('send_temp_file_finished', $path);
 597     }
 598
 599     //IE compatibiltiy HACK!
 600     if (ini_get('zlib.output_compression')) {
 601         ini_set('zlib.output_compression', 'Off');
 602     }
 603
 604     // if user is using IE, urlencode the filename so that multibyte file name will show up correctly on popup
 605     if (check_browser_version('MSIE')) {
 606         $filename = urlencode($filename);
 607     }
 608
 609     $filesize = $pathisstring ? strlen($path) : filesize($path);
 610
 611     @header('Content-Disposition: attachment; filename='.$filename);
 612     @header('Content-Length: '.$filesize);
 613     if (strpos($CFG->wwwroot, 'https://') === 0) { //https sites - watch out for IE! KB812935 and KB316431
 614         @header('Cache-Control: max-age=10');
 615         @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 616         @header('Pragma: ');
 617     } else { //normal http - prevent caching at all cost
 618         @header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
 619         @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 620         @header('Pragma: no-cache');
 621     }
 622     @header('Accept-Ranges: none'); // Do not allow byteserving
 623
 624     while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 625     if ($pathisstring) {
 626         echo $path;
 627     } else {
 628         readfile_chunked($path);
 629     }
 630
 631     die; //no more chars to output
 632 }
 633
 634 /**
 635  * Internal callnack function used by send_temp_file()
 636  */
 637 function send_temp_file_finished($path) {
 638     if (file_exists($path)) {
 639         @unlink($path);
 640     }
 641 }
 642
 643 /**
 644  * Handles the sending of file data to the user's browser, including support for
 645  * byteranges etc.
 646  * @param string $path Path of file on disk (including real filename), or actual content of file as string
 647  * @param string $filename Filename to send
 648  * @param int $lifetime Number of seconds before the file should expire from caches (default 24 hours)
 649  * @param int $filter 0 (default)=no filtering, 1=all files, 2=html files only
 650  * @param bool $pathisstring If true (default false), $path is the content to send and not the pathname
 651  * @param bool $forcedownload If true (default false), forces download of file rather than view in browser/plugin
 652  * @param string $mimetype Include to specify the MIME type; leave blank to have it guess the type from $filename
 653  */
 654 function send_file($path, $filename, $lifetime = 'default' , $filter=0, $pathisstring=false, $forcedownload=false, $mimetype='') {
 655     global $CFG, $COURSE, $SESSION;
 656
 657     // MDL-11789, apply $CFG->filelifetime here
 658     if ($lifetime === 'default') {
 659         if (!empty($CFG->filelifetime)) {
 660             $lifetime = $CFG->filelifetime;
 661         } else {
 662             $lifetime = 86400;
 663         }
 664     }
 665
 666     // Use given MIME type if specified, otherwise guess it using mimeinfo.
 667     // IE, Konqueror and Opera open html file directly in browser from web even when directed to save it to disk :-O
 668     // only Firefox saves all files locally before opening when content-disposition: attachment stated
 669     $isFF         = check_browser_version('Firefox', '1.5'); // only FF > 1.5 properly tested
 670     $mimetype     = ($forcedownload and !$isFF) ? 'application/x-forcedownload' :
 671                          ($mimetype ? $mimetype : mimeinfo('type', $filename));
 672
 673     // If the file is a Flash file and that the user flash player is outdated return a flash upgrader MDL-20841
 674     if (!empty($CFG->excludeoldflashclients) && $mimetype == 'application/x-shockwave-flash'&& !empty($SESSION->flashversion)) {
 675         $userplayerversion = explode('.', $SESSION->flashversion);
 676         $requiredplayerversion = explode('.', $CFG->excludeoldflashclients);
 677         if (($userplayerversion[0] <  $requiredplayerversion[0]) ||
 678             ($userplayerversion[0] == $requiredplayerversion[0] && $userplayerversion[1] < $requiredplayerversion[1]) ||
 679             ($userplayerversion[0] == $requiredplayerversion[0] && $userplayerversion[1] == $requiredplayerversion[1]
 680              && $userplayerversion[2] < $requiredplayerversion[2])) {
 681             $path = $CFG->dirroot."/lib/flashdetect/flashupgrade.swf";  // Alternate content asking user to upgrade Flash
 682             $filename = "flashupgrade.swf";
 683             $lifetime = 0;  // Do not cache
 684         }
 685     }
 686
 687     $lastmodified = $pathisstring ? time() : filemtime($path);
 688     $filesize     = $pathisstring ? strlen($path) : filesize($path);
 689
 690 /* - MDL-13949
 691     //Adobe Acrobat Reader XSS prevention
 692     if ($mimetype=='application/pdf' or mimeinfo('type', $filename)=='application/pdf') {
 693         //please note that it prevents opening of pdfs in browser when http referer disabled
 694         //or file linked from another site; browser caching of pdfs is now disabled too
 695         if (!empty($_SERVER['HTTP_RANGE'])) {
 696             //already byteserving
 697             $lifetime = 1; // >0 needed for byteserving
 698         } else if (empty($_SERVER['HTTP_REFERER']) or strpos($_SERVER['HTTP_REFERER'], $CFG->wwwroot)!==0) {
 699             $mimetype = 'application/x-forcedownload';
 700             $forcedownload = true;
 701             $lifetime = 0;
 702         } else {
 703             $lifetime = 1; // >0 needed for byteserving
 704         }
 705     }
 706 */
 707
 708     //IE compatibiltiy HACK!
 709     if (ini_get('zlib.output_compression')) {
 710         ini_set('zlib.output_compression', 'Off');
 711     }
 712
 713     //try to disable automatic sid rewrite in cookieless mode
 714     @ini_set("session.use_trans_sid", "false");
 715
 716     //do not put '@' before the next header to detect incorrect moodle configurations,
 717     //error should be better than "weird" empty lines for admins/users
 718     //TODO: should we remove all those @ before the header()? Are all of the values supported on all servers?
 719     header('Last-Modified: '. gmdate('D, d M Y H:i:s', $lastmodified) .' GMT');
 720
 721     // if user is using IE, urlencode the filename so that multibyte file name will show up correctly on popup
 722     if (check_browser_version('MSIE')) {
 723         $filename = rawurlencode($filename);
 724     }
 725
 726     if ($forcedownload) {
 727         @header('Content-Disposition: attachment; filename="'.$filename.'"');
 728     } else {
 729         @header('Content-Disposition: inline; filename="'.$filename.'"');
 730     }
 731
 732     if ($lifetime > 0) {
 733         @header('Cache-Control: max-age='.$lifetime);
 734         @header('Expires: '. gmdate('D, d M Y H:i:s', time() + $lifetime) .' GMT');
 735         @header('Pragma: ');
 736
 737         if (empty($CFG->disablebyteserving) && !$pathisstring && $mimetype != 'text/plain' && $mimetype != 'text/html') {
 738
 739             @header('Accept-Ranges: bytes');
 740
 741             if (!empty($_SERVER['HTTP_RANGE']) && strpos($_SERVER['HTTP_RANGE'],'bytes=') !== FALSE) {
 742                 // byteserving stuff - for acrobat reader and download accelerators
 743                 // see: http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35
 744                 // inspired by: http://www.coneural.org/florian/papers/04_byteserving.php
 745                 $ranges = false;
 746                 if (preg_match_all('/(\d*)-(\d*)/', $_SERVER['HTTP_RANGE'], $ranges, PREG_SET_ORDER)) {
 747                     foreach ($ranges as $key=>$value) {
 748                         if ($ranges[$key][1] == '') {
 749                             //suffix case
 750                             $ranges[$key][1] = $filesize - $ranges[$key][2];
 751                             $ranges[$key][2] = $filesize - 1;
 752                         } else if ($ranges[$key][2] == '' || $ranges[$key][2] > $filesize - 1) {
 753                             //fix range length
 754                             $ranges[$key][2] = $filesize - 1;
 755                         }
 756                         if ($ranges[$key][2] != '' && $ranges[$key][2] < $ranges[$key][1]) {
 757                             //invalid byte-range ==> ignore header
 758                             $ranges = false;
 759                             break;
 760                         }
 761                         //prepare multipart header
 762                         $ranges[$key][0] =  "\r\n--".BYTESERVING_BOUNDARY."\r\nContent-Type: $mimetype\r\n";
 763                         $ranges[$key][0] .= "Content-Range: bytes {$ranges[$key][1]}-{$ranges[$key][2]}/$filesize\r\n\r\n";
 764                     }
 765                 } else {
 766                     $ranges = false;
 767                 }
 768                 if ($ranges) {
 769                     byteserving_send_file($path, $mimetype, $ranges);
 770                 }
 771             }
 772         } else {
 773             /// Do not byteserve (disabled, strings, text and html files).
 774             @header('Accept-Ranges: none');
 775         }
 776     } else { // Do not cache files in proxies and browsers
 777         if (strpos($CFG->wwwroot, 'https://') === 0) { //https sites - watch out for IE! KB812935 and KB316431
 778             @header('Cache-Control: max-age=10');
 779             @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 780             @header('Pragma: ');
 781         } else { //normal http - prevent caching at all cost
 782             @header('Cache-Control: private, must-revalidate, pre-check=0, post-check=0, max-age=0');
 783             @header('Expires: '. gmdate('D, d M Y H:i:s', 0) .' GMT');
 784             @header('Pragma: no-cache');
 785         }
 786         @header('Accept-Ranges: none'); // Do not allow byteserving when caching disabled
 787     }
 788
 789     if (empty($filter)) {
 790         if ($mimetype == 'text/html' && !empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 791             //cookieless mode - rewrite links
 792             @header('Content-Type: text/html');
 793             $path = $pathisstring ? $path : implode('', file($path));
 794             $path = sid_ob_rewrite($path);
 795             $filesize = strlen($path);
 796             $pathisstring = true;
 797         } else if ($mimetype == 'text/plain') {
 798             @header('Content-Type: Text/plain; charset=utf-8'); //add encoding
 799         } else {
 800             @header('Content-Type: '.$mimetype);
 801         }
 802         @header('Content-Length: '.$filesize);
 803         while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 804         if ($pathisstring) {
 805             echo $path;
 806         } else {
 807             readfile_chunked($path);
 808         }
 809     } else {     // Try to put the file through filters
 810         if ($mimetype == 'text/html') {
 811             $options = new object();
 812             $options->noclean = true;
 813             $options->nocache = true; // temporary workaround for MDL-5136
 814             $text = $pathisstring ? $path : implode('', file($path));
 815
 816             $text = file_modify_html_header($text);
 817             $output = format_text($text, FORMAT_HTML, $options, $COURSE->id);
 818             if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 819                 //cookieless mode - rewrite links
 820                 $output = sid_ob_rewrite($output);
 821             }
 822
 823             @header('Content-Length: '.strlen($output));
 824             @header('Content-Type: text/html');
 825             while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 826             echo $output;
 827         // only filter text if filter all files is selected
 828         } else if (($mimetype == 'text/plain') and ($filter == 1)) {
 829             $options = new object();
 830             $options->newlines = false;
 831             $options->noclean = true;
 832             $text = htmlentities($pathisstring ? $path : implode('', file($path)));
 833             $output = '<pre>'. format_text($text, FORMAT_MOODLE, $options, $COURSE->id) .'</pre>';
 834             if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
 835                 //cookieless mode - rewrite links
 836                 $output = sid_ob_rewrite($output);
 837             }
 838
 839             @header('Content-Length: '.strlen($output));
 840             @header('Content-Type: text/html; charset=utf-8'); //add encoding
 841             while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 842             echo $output;
 843         } else {    // Just send it out raw
 844             @header('Content-Length: '.$filesize);
 845             @header('Content-Type: '.$mimetype);
 846             while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
 847             if ($pathisstring) {
 848                 echo $path;
 849             }else {
 850                 readfile_chunked($path);
 851             }
 852         }
 853     }
 854     die; //no more chars to output!!!
 855 }
 856
 857 function get_records_csv($file, $table) {
 858     global $CFG, $db;
 859
 860     if (!$metacolumns = $db->MetaColumns($CFG->prefix . $table)) {
 861         return false;
 862     }
 863
 864     if(!($handle = @fopen($file, 'r'))) {
 865         error('get_records_csv failed to open '.$file);
 866     }
 867
 868     $fieldnames = fgetcsv($handle, 4096);
 869     if(empty($fieldnames)) {
 870         fclose($handle);
 871         return false;
 872     }
 873
 874     $columns = array();
 875
 876     foreach($metacolumns as $metacolumn) {
 877         $ord = array_search($metacolumn->name, $fieldnames);
 878         if(is_int($ord)) {
 879             $columns[$metacolumn->name] = $ord;
 880         }
 881     }
 882
 883     $rows = array();
 884
 885     while (($data = fgetcsv($handle, 4096)) !== false) {
 886         $item = new stdClass;
 887         foreach($columns as $name => $ord) {
 888             $item->$name = $data[$ord];
 889         }
 890         $rows[] = $item;
 891     }
 892
 893     fclose($handle);
 894     return $rows;
 895 }
 896
 897 function put_records_csv($file, $records, $table = NULL) {
 898     global $CFG, $db;
 899
 900     if (empty($records)) {
 901         return true;
 902     }
 903
 904     $metacolumns = NULL;
 905     if ($table !== NULL && !$metacolumns = $db->MetaColumns($CFG->prefix . $table)) {
 906         return false;
 907     }
 908
 909     echo "x";
 910
 911     if(!($fp = @fopen($CFG->dataroot.'/temp/'.$file, 'w'))) {
 912         error('put_records_csv failed to open '.$file);
 913     }
 914
 915     $proto = reset($records);
 916     if(is_object($proto)) {
 917         $fields_records = array_keys(get_object_vars($proto));
 918     }
 919     else if(is_array($proto)) {
 920         $fields_records = array_keys($proto);
 921     }
 922     else {
 923         return false;
 924     }
 925     echo "x";
 926
 927     if(!empty($metacolumns)) {
 928         $fields_table = array_map(create_function('$a', 'return $a->name;'), $metacolumns);
 929         $fields = array_intersect($fields_records, $fields_table);
 930     }
 931     else {
 932         $fields = $fields_records;
 933     }
 934
 935     fwrite($fp, implode(',', $fields));
 936     fwrite($fp, "\r\n");
 937
 938     foreach($records as $record) {
 939         $array  = (array)$record;
 940         $values = array();
 941         foreach($fields as $field) {
 942             if(strpos($array[$field], ',')) {
 943                 $values[] = '"'.str_replace('"', '\"', $array[$field]).'"';
 944             }
 945             else {
 946                 $values[] = $array[$field];
 947             }
 948         }
 949         fwrite($fp, implode(',', $values)."\r\n");
 950     }
 951
 952     fclose($fp);
 953     return true;
 954 }
 955
 956
 957 /**
 958  * Recursively delete the file or folder with path $location. That is,
 959  * if it is a file delete it. If it is a folder, delete all its content
 960  * then delete it. If $location does not exist to start, that is not
 961  * considered an error.
 962  *
 963  * @param $location the path to remove.
 964  */
 965 function fulldelete($location) {
 966     if (is_dir($location) and !is_link($location)) {
 967         $currdir = opendir($location);
 968         while (false !== ($file = readdir($currdir))) {
 969             if ($file <> ".." && $file <> ".") {
 970                 $fullfile = $location."/".$file;
 971                 if (is_dir($fullfile)) {
 972                     if (!fulldelete($fullfile)) {
 973                         return false;
 974                     }
 975                 } else {
 976                     if (!unlink($fullfile)) {
 977                         return false;
 978                     }
 979                 }
 980             }
 981         }
 982         closedir($currdir);
 983         if (! rmdir($location)) {
 984             return false;
 985         }
 986
 987     } else if (file_exists($location)) {
 988         if (!unlink($location)) {
 989             return false;
 990         }
 991     }
 992     return true;
 993 }
 994
 995 /**
 996  * Improves memory consumptions and works around buggy readfile() in PHP 5.0.4 (2MB readfile limit).
 997  */
 998 function readfile_chunked($filename, $retbytes=true) {
 999     $chunksize = 1*(1024*1024); // 1MB chunks - must be less than 2MB!
1000     $buffer = '';
1001     $cnt =0;
1002     $handle = fopen($filename, 'rb');
1003     if ($handle === false) {
1004         return false;
1005     }
1006
1007     while (!feof($handle)) {
1008         @set_time_limit(60*60); //reset time limit to 60 min - should be enough for 1 MB chunk
1009         $buffer = fread($handle, $chunksize);
1010         echo $buffer;
1011         flush();
1012         if ($retbytes) {
1013             $cnt += strlen($buffer);
1014         }
1015     }
1016     $status = fclose($handle);
1017     if ($retbytes && $status) {
1018         return $cnt; // return num. bytes delivered like readfile() does.
1019     }
1020     return $status;
1021 }
1022
1023 /**
1024  * Send requested byterange of file.
1025  */
1026 function byteserving_send_file($filename, $mimetype, $ranges) {
1027     $chunksize = 1*(1024*1024); // 1MB chunks - must be less than 2MB!
1028     $handle = fopen($filename, 'rb');
1029     if ($handle === false) {
1030         die;
1031     }
1032     if (count($ranges) == 1) { //only one range requested
1033         $length = $ranges[0][2] - $ranges[0][1] + 1;
1034         @header('HTTP/1.1 206 Partial content');
1035         @header('Content-Length: '.$length);
1036         @header('Content-Range: bytes '.$ranges[0][1].'-'.$ranges[0][2].'/'.filesize($filename));
1037         @header('Content-Type: '.$mimetype);
1038         while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
1039         $buffer = '';
1040         fseek($handle, $ranges[0][1]);
1041         while (!feof($handle) && $length > 0) {
1042             @set_time_limit(60*60); //reset time limit to 60 min - should be enough for 1 MB chunk
1043             $buffer = fread($handle, ($chunksize < $length ? $chunksize : $length));
1044             echo $buffer;
1045             flush();
1046             $length -= strlen($buffer);
1047         }
1048         fclose($handle);
1049         die;
1050     } else { // multiple ranges requested - not tested much
1051         $totallength = 0;
1052         foreach($ranges as $range) {
1053             $totallength += strlen($range[0]) + $range[2] - $range[1] + 1;
1054         }
1055         $totallength += strlen("\r\n--".BYTESERVING_BOUNDARY."--\r\n");
1056         @header('HTTP/1.1 206 Partial content');
1057         @header('Content-Length: '.$totallength);
1058         @header('Content-Type: multipart/byteranges; boundary='.BYTESERVING_BOUNDARY);
1059         //TODO: check if "multipart/x-byteranges" is more compatible with current readers/browsers/servers
1060         while (@ob_end_flush()); //flush the buffers - save memory and disable sid rewrite
1061         foreach($ranges as $range) {
1062             $length = $range[2] - $range[1] + 1;
1063             echo $range[0];
1064             $buffer = '';
1065             fseek($handle, $range[1]);
1066             while (!feof($handle) && $length > 0) {
1067                 @set_time_limit(60*60); //reset time limit to 60 min - should be enough for 1 MB chunk
1068                 $buffer = fread($handle, ($chunksize < $length ? $chunksize : $length));
1069                 echo $buffer;
1070                 flush();
1071                 $length -= strlen($buffer);
1072             }
1073         }
1074         echo "\r\n--".BYTESERVING_BOUNDARY."--\r\n";
1075         fclose($handle);
1076         die;
1077     }
1078 }
1079
1080 /**
1081  * add includes (js and css) into uploaded files
1082  * before returning them, useful for themes and utf.js includes
1083  * @param string text - text to search and replace
1084  * @return string - text with added head includes
1085  */
1086 function file_modify_html_header($text) {
1087     // first look for <head> tag
1088     global $CFG;
1089
1090     $stylesheetshtml = '';
1091     foreach ($CFG->stylesheets as $stylesheet) {
1092         $stylesheetshtml .= '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'" />'."\n";
1093     }
1094
1095     $filters = explode(",", $CFG->textfilters);
1096     if (in_array('filter/mediaplugin', $filters)) {
1097         // this script is needed by most media filter plugins.
1098         $ufo = "\n".'<script type="text/javascript" src="'.$CFG->wwwroot.'/lib/ufo.js"></script>'."\n";
1099     } else {
1100         $ufo = '';
1101     }
1102
1103     preg_match('/\<head\>|\<HEAD\>/', $text, $matches);
1104     if ($matches) {
1105         $replacement = '<head>'.$ufo.$stylesheetshtml;
1106         $text = preg_replace('/\<head\>|\<HEAD\>/', $replacement, $text, 1);
1107         return $text;
1108     }
1109
1110     // if not, look for <html> tag, and stick <head> right after
1111     preg_match('/\<html\>|\<HTML\>/', $text, $matches);
1112     if ($matches) {
1113         // replace <html> tag with <html><head>includes</head>
1114         $replacement = '<html>'."\n".'<head>'.$ufo.$stylesheetshtml.'</head>';
1115         $text = preg_replace('/\<html\>|\<HTML\>/', $replacement, $text, 1);
1116         return $text;
1117     }
1118
1119     // if not, look for <body> tag, and stick <head> before body
1120     preg_match('/\<body\>|\<BODY\>/', $text, $matches);
1121     if ($matches) {
1122         $replacement = '<head>'.$ufo.$stylesheetshtml.'</head>'."\n".'<body>';
1123         $text = preg_replace('/\<body\>|\<BODY\>/', $replacement, $text, 1);
1124         return $text;
1125     }
1126
1127     // if not, just stick a <head> tag at the beginning
1128     $text = '<head>'.$ufo.$stylesheetshtml.'</head>'."\n".$text;
1129     return $text;
1130 }
1131
1132 ?>