includes/MimeMagic.php

   1 <?php
   2 /** Module defining helper functions for detecting and dealing with mime types.
   3  *
   4  */
   5
   6  /** Defines a set of well known mime types
   7  * This is used as a fallback to mime.types files.
   8  * An extensive list of well known mime types is provided by
   9  * the file mime.types in the includes directory.
  10  */
  11 define('MM_WELL_KNOWN_MIME_TYPES',<<<END_STRING
  12 application/ogg ogg ogm
  13 application/pdf pdf
  14 application/x-javascript js
  15 application/x-shockwave-flash swf
  16 audio/midi mid midi kar
  17 audio/mpeg mpga mpa mp2 mp3
  18 audio/x-aiff aif aiff aifc
  19 audio/x-wav wav
  20 audio/ogg ogg
  21 image/x-bmp bmp
  22 image/gif gif
  23 image/jpeg jpeg jpg jpe
  24 image/png png
  25 image/svg+xml image/svg svg
  26 image/tiff tiff tif
  27 image/vnd.djvu djvu
  28 image/x-portable-pixmap ppm
  29 text/plain txt
  30 text/html html htm
  31 video/ogg ogm ogg
  32 video/mpeg mpg mpeg
  33 END_STRING
  34 );
  35
  36  /** Defines a set of well known mime info entries
  37  * This is used as a fallback to mime.info files.
  38  * An extensive list of well known mime types is provided by
  39  * the file mime.info in the includes directory.
  40  */
  41 define('MM_WELL_KNOWN_MIME_INFO', <<<END_STRING
  42 application/pdf [OFFICE]
  43 text/javascript application/x-javascript [EXECUTABLE]
  44 application/x-shockwave-flash [MULTIMEDIA]
  45 audio/midi [AUDIO]
  46 audio/x-aiff [AUDIO]
  47 audio/x-wav [AUDIO]
  48 audio/mp3 audio/mpeg [AUDIO]
  49 application/ogg audio/ogg video/ogg [MULTIMEDIA]
  50 image/x-bmp image/bmp [BITMAP]
  51 image/gif [BITMAP]
  52 image/jpeg [BITMAP]
  53 image/png [BITMAP]
  54 image/svg+xml [DRAWING]
  55 image/tiff [BITMAP]
  56 image/vnd.djvu [BITMAP]
  57 image/x-portable-pixmap [BITMAP]
  58 text/plain [TEXT]
  59 text/html [TEXT]
  60 video/ogg [VIDEO]
  61 video/mpeg [VIDEO]
  62 unknown/unknown application/octet-stream application/x-empty [UNKNOWN]
  63 END_STRING
  64 );
  65
  66 #note: because this file is possibly included by a function,
  67 #we need to access the global scope explicitely!
  68 global $wgLoadFileinfoExtension;
  69
  70 if ($wgLoadFileinfoExtension) {
  71         if(!extension_loaded('fileinfo')) dl('fileinfo.' . PHP_SHLIB_SUFFIX);
  72 }
  73
  74 /**
  75  * Implements functions related to mime types such as detection and mapping to
  76  * file extension.
  77  *
  78  * Instances of this class are stateles, there only needs to be one global instance
  79  * of MimeMagic. Please use MimeMagic::singleton() to get that instance.
  80  */
  81 class MimeMagic {
  82
  83         /**
  84         * Mapping of media types to arrays of mime types.
  85         * This is used by findMediaType and getMediaType, respectively
  86         */
  87         var $mMediaTypes= NULL;
  88
  89         /** Map of mime type aliases
  90         */
  91         var $mMimeTypeAliases= NULL;
  92
  93         /** map of mime types to file extensions (as a space seprarated list)
  94         */
  95         var $mMimeToExt= NULL;
  96
  97         /** map of file extensions types to mime types (as a space seprarated list)
  98         */
  99         var $mExtToMime= NULL;
 100
 101         /** The singleton instance
 102          */
 103         private static $instance;
 104
 105         /** Initializes the MimeMagic object. This is called by MimeMagic::singleton().
 106         *
 107         * This constructor parses the mime.types and mime.info files and build internal mappings.
 108         */
 109         function __construct() {
 110                 /*
 111                 *   --- load mime.types ---
 112                 */
 113
 114                 global $wgMimeTypeFile;
 115
 116                 $types= MM_WELL_KNOWN_MIME_TYPES;
 117
 118                 if ($wgMimeTypeFile) {
 119                         if (is_file($wgMimeTypeFile) and is_readable($wgMimeTypeFile)) {
 120                                 wfDebug("MimeMagic::MimeMagic: loading mime types from $wgMimeTypeFile\n");
 121
 122                                 $types.= "\n";
 123                                 $types.= file_get_contents($wgMimeTypeFile);
 124                         }
 125                         else wfDebug("MimeMagic::MimeMagic: can't load mime types from $wgMimeTypeFile\n");
 126                 }
 127                 else wfDebug("MimeMagic::MimeMagic: no mime types file defined, using build-ins only.\n");
 128
 129                 $types= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$types);
 130                 $types= str_replace("\t"," ",$types);
 131
 132                 $this->mMimeToExt= array();
 133                 $this->mToMime= array();
 134
 135                 $lines= explode("\n",$types);
 136                 foreach ($lines as $s) {
 137                         $s= trim($s);
 138                         if (empty($s)) continue;
 139                         if (strpos($s,'#')===0) continue;
 140
 141                         $s= strtolower($s);
 142                         $i= strpos($s,' ');
 143
 144                         if ($i===false) continue;
 145
 146                         #print "processing MIME line $s<br>";
 147
 148                         $mime= substr($s,0,$i);
 149                         $ext= trim(substr($s,$i+1));
 150
 151                         if (empty($ext)) continue;
 152
 153                         if ( !empty($this->mMimeToExt[$mime])) $this->mMimeToExt[$mime] .= ' '.$ext;
 154                         else $this->mMimeToExt[$mime]= $ext;
 155
 156                         $extensions= explode(' ',$ext);
 157
 158                         foreach ($extensions as $e) {
 159                                 $e= trim($e);
 160                                 if (empty($e)) continue;
 161
 162                                 if ( !empty($this->mExtToMime[$e])) $this->mExtToMime[$e] .= ' '.$mime;
 163                                 else $this->mExtToMime[$e]= $mime;
 164                         }
 165                 }
 166
 167                 /*
 168                 *   --- load mime.info ---
 169                 */
 170
 171                 global $wgMimeInfoFile;
 172
 173                 $info= MM_WELL_KNOWN_MIME_INFO;
 174
 175                 if ($wgMimeInfoFile) {
 176                         if (is_file($wgMimeInfoFile) and is_readable($wgMimeInfoFile)) {
 177                                 wfDebug("MimeMagic::MimeMagic: loading mime info from $wgMimeInfoFile\n");
 178
 179                                 $info.= "\n";
 180                                 $info.= file_get_contents($wgMimeInfoFile);
 181                         }
 182                         else wfDebug("MimeMagic::MimeMagic: can't load mime info from $wgMimeInfoFile\n");
 183                 }
 184                 else wfDebug("MimeMagic::MimeMagic: no mime info file defined, using build-ins only.\n");
 185
 186                 $info= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$info);
 187                 $info= str_replace("\t"," ",$info);
 188
 189                 $this->mMimeTypeAliases= array();
 190                 $this->mMediaTypes= array();
 191
 192                 $lines= explode("\n",$info);
 193                 foreach ($lines as $s) {
 194                         $s= trim($s);
 195                         if (empty($s)) continue;
 196                         if (strpos($s,'#')===0) continue;
 197
 198                         $s= strtolower($s);
 199                         $i= strpos($s,' ');
 200
 201                         if ($i===false) continue;
 202
 203                         #print "processing MIME INFO line $s<br>";
 204
 205                         $match= array();
 206                         if (preg_match('!\[\s*(\w+)\s*\]!',$s,$match)) {
 207                                 $s= preg_replace('!\[\s*(\w+)\s*\]!','',$s);
 208                                 $mtype= trim(strtoupper($match[1]));
 209                         }
 210                         else $mtype= MEDIATYPE_UNKNOWN;
 211
 212                         $m= explode(' ',$s);
 213
 214                         if (!isset($this->mMediaTypes[$mtype])) $this->mMediaTypes[$mtype]= array();
 215
 216                         foreach ($m as $mime) {
 217                                 $mime= trim($mime);
 218                                 if (empty($mime)) continue;
 219
 220                                 $this->mMediaTypes[$mtype][]= $mime;
 221                         }
 222
 223                         if (sizeof($m)>1) {
 224                                 $main= $m[0];
 225                                 for ($i=1; $i<sizeof($m); $i+= 1) {
 226                                         $mime= $m[$i];
 227                                         $this->mMimeTypeAliases[$mime]= $main;
 228                                 }
 229                         }
 230                 }
 231
 232         }
 233
 234         /**
 235          * Get an instance of this class
 236          */
 237         static function &singleton() {
 238                 if ( !isset( self::$instance ) ) {
 239                         self::$instance = new MimeMagic;
 240                 }
 241                 return self::$instance;
 242         }
 243
 244         /** returns a list of file extensions for a given mime type
 245         * as a space separated string.
 246         */
 247         function getExtensionsForType($mime) {
 248                 $mime= strtolower($mime);
 249
 250                 $r= @$this->mMimeToExt[$mime];
 251
 252                 if (@!$r and isset($this->mMimeTypeAliases[$mime])) {
 253                         $mime= $this->mMimeTypeAliases[$mime];
 254                         $r= @$this->mMimeToExt[$mime];
 255                 }
 256
 257                 return $r;
 258         }
 259
 260         /** returns a list of mime types for a given file extension
 261         * as a space separated string.
 262         */
 263         function getTypesForExtension($ext) {
 264                 $ext= strtolower($ext);
 265
 266                 $r= isset( $this->mExtToMime[$ext] ) ? $this->mExtToMime[$ext] : null;
 267                 return $r;
 268         }
 269
 270         /** returns a single mime type for a given file extension.
 271         * This is always the first type from the list returned by getTypesForExtension($ext).
 272         */
 273         function guessTypesForExtension($ext) {
 274                 $m= $this->getTypesForExtension( $ext );
 275                 if( is_null($m) ) return NULL;
 276
 277                 $m= trim( $m );
 278                 $m= preg_replace('/\s.*$/','',$m);
 279
 280                 return $m;
 281         }
 282
 283
 284         /** tests if the extension matches the given mime type.
 285         * returns true if a match was found, NULL if the mime type is unknown,
 286         * and false if the mime type is known but no matches where found.
 287         */
 288         function isMatchingExtension($extension,$mime) {
 289                 $ext= $this->getExtensionsForType($mime);
 290
 291                 if (!$ext) {
 292                         return NULL;  //unknown
 293                 }
 294
 295                 $ext= explode(' ',$ext);
 296
 297                 $extension= strtolower($extension);
 298                 if (in_array($extension,$ext)) {
 299                         return true;
 300                 }
 301
 302                 return false;
 303         }
 304
 305         /** returns true if the mime type is known to represent
 306         * an image format supported by the PHP GD library.
 307         */
 308         function isPHPImageType( $mime ) {
 309                 #as defined by imagegetsize and image_type_to_mime
 310                 static $types = array(
 311                         'image/gif', 'image/jpeg', 'image/png',
 312                         'image/x-bmp', 'image/xbm', 'image/tiff',
 313                         'image/jp2', 'image/jpeg2000', 'image/iff',
 314                         'image/xbm', 'image/x-xbitmap',
 315                         'image/vnd.wap.wbmp', 'image/vnd.xiff',
 316                         'image/x-photoshop',
 317                         'application/x-shockwave-flash',
 318                 );
 319
 320                 return in_array( $mime, $types );
 321         }
 322
 323         /**
 324          * Returns true if the extension represents a type which can
 325          * be reliably detected from its content. Use this to determine
 326          * whether strict content checks should be applied to reject
 327          * invalid uploads; if we can't identify the type we won't
 328          * be able to say if it's invalid.
 329          *
 330          * @todo Be more accurate when using fancy mime detector plugins;
 331          *       right now this is the bare minimum getimagesize() list.
 332          * @return bool
 333          */
 334         function isRecognizableExtension( $extension ) {
 335                 static $types = array(
 336                         'gif', 'jpeg', 'jpg', 'png', 'swf', 'psd',
 337                         'bmp', 'tiff', 'tif', 'jpc', 'jp2',
 338                         'jpx', 'jb2', 'swc', 'iff', 'wbmp',
 339                         'xbm', 'djvu'
 340                 );
 341                 return in_array( strtolower( $extension ), $types );
 342         }
 343
 344
 345         /** mime type detection. This uses detectMimeType to detect the mime type of the file,
 346         * but applies additional checks to determine some well known file formats that may be missed
 347         * or misinterpreter by the default mime detection (namely xml based formats like XHTML or SVG).
 348         *
 349         * @param string $file The file to check
 350         * @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
 351         *
 352         * @return string the mime type of $file
 353         */
 354         function guessMimeType( $file, $useExt=true ) {
 355                 $fname = 'MimeMagic::guessMimeType';
 356                 $mime= $this->detectMimeType($file,$useExt);
 357
 358                 // Read a chunk of the file
 359                 $f = fopen( $file, "rt" );
 360                 if( !$f ) return "unknown/unknown";
 361                 $head = fread( $f, 1024 );
 362                 fclose( $f );
 363
 364                 $sub4 =  substr( $head, 0, 4 );
 365                 if ( $sub4 == "\x01\x00\x09\x00" || $sub4 == "\xd7\xcd\xc6\x9a" ) {
 366                         // WMF kill kill kill
 367                         // Note that WMF may have a bare header, no magic number.
 368                         // The former of the above two checks is theoretically prone to false positives
 369                         $mime = "application/x-msmetafile";
 370                 }
 371
 372                 if (strpos($mime,"text/")===0 || $mime==="application/xml") {
 373
 374                         $xml_type= NULL;
 375                         $script_type= NULL;
 376
 377                         /*
 378                         * look for XML formats (XHTML and SVG)
 379                         */
 380                         if ($mime==="text/sgml" ||
 381                             $mime==="text/plain" ||
 382                             $mime==="text/html" ||
 383                             $mime==="text/xml" ||
 384                             $mime==="application/xml") {
 385
 386                                 if (substr($head,0,5)=="<?xml") $xml_type= "ASCII";
 387                                 elseif (substr($head,0,8)=="\xef\xbb\xbf<?xml") $xml_type= "UTF-8";
 388                                 elseif (substr($head,0,10)=="\xfe\xff\x00<\x00?\x00x\x00m\x00l") $xml_type= "UTF-16BE";
 389                                 elseif (substr($head,0,10)=="\xff\xfe<\x00?\x00x\x00m\x00l\x00") $xml_type= "UTF-16LE";
 390
 391                                 if ($xml_type) {
 392                                         if ($xml_type!=="UTF-8" && $xml_type!=="ASCII") $head= iconv($xml_type,"ASCII//IGNORE",$head);
 393
 394                                         $match= array();
 395                                         $doctype= "";
 396                                         $tag= "";
 397
 398                                         if (preg_match('%<!DOCTYPE\s+[\w-]+\s+PUBLIC\s+["'."'".'"](.*?)["'."'".'"].*>%sim',$head,$match)) $doctype= $match[1];
 399                                         if (preg_match('%<(\w+).*>%sim',$head,$match)) $tag= $match[1];
 400
 401                                         #print "<br>ANALYSING $file ($mime): doctype= $doctype; tag= $tag<br>";
 402
 403                                         if (strpos($doctype,"-//W3C//DTD SVG")===0) $mime= "image/svg+xml";
 404                                         elseif ($tag==="svg") $mime= "image/svg+xml";
 405                                         elseif (strpos($doctype,"-//W3C//DTD XHTML")===0) $mime= "text/html";
 406                                         elseif ($tag==="html") $mime= "text/html";
 407                                 }
 408                         }
 409
 410                         /*
 411                         * look for shell scripts
 412                         */
 413                         if (!$xml_type) {
 414                                 $script_type= NULL;
 415
 416                                 #detect by shebang
 417                                 if (substr($head,0,2)=="#!") $script_type= "ASCII";
 418                                 elseif (substr($head,0,5)=="\xef\xbb\xbf#!") $script_type= "UTF-8";
 419                                 elseif (substr($head,0,7)=="\xfe\xff\x00#\x00!") $script_type= "UTF-16BE";
 420                                 elseif (substr($head,0,7)=="\xff\xfe#\x00!") $script_type= "UTF-16LE";
 421
 422                                 if ($script_type) {
 423                                         if ($script_type!=="UTF-8" && $script_type!=="ASCII") $head= iconv($script_type,"ASCII//IGNORE",$head);
 424
 425                                         $match= array();
 426                                         $prog= "";
 427
 428                                         if (preg_match('%/?([^\s]+/)(w+)%sim',$head,$match)) {
 429                                                 $script= $match[2]; // FIXME: $script variable not used; should this be "$prog = $match[2];" instead?
 430                                         }
 431
 432                                         $mime= "application/x-$prog";
 433                                 }
 434                         }
 435
 436                         /*
 437                         * look for PHP
 438                         */
 439                         if( !$xml_type && !$script_type ) {
 440
 441                                 if( ( strpos( $head, '<?php' ) !== false ) ||
 442                                     ( strpos( $head, '<? ' ) !== false ) ||
 443                                     ( strpos( $head, "<?\n" ) !== false ) ||
 444                                     ( strpos( $head, "<?\t" ) !== false ) ||
 445                                     ( strpos( $head, "<?=" ) !== false ) ||
 446
 447                                     ( strpos( $head, "<\x00?\x00p\x00h\x00p" ) !== false ) ||
 448                                     ( strpos( $head, "<\x00?\x00 " ) !== false ) ||
 449                                     ( strpos( $head, "<\x00?\x00\n" ) !== false ) ||
 450                                     ( strpos( $head, "<\x00?\x00\t" ) !== false ) ||
 451                                     ( strpos( $head, "<\x00?\x00=" ) !== false ) ) {
 452
 453                                         $mime= "application/x-php";
 454                                 }
 455                         }
 456
 457                 }
 458
 459                 if (isset($this->mMimeTypeAliases[$mime])) $mime= $this->mMimeTypeAliases[$mime];
 460
 461                 wfDebug("$fname: final mime type of $file: $mime\n");
 462                 return $mime;
 463         }
 464
 465         /** Internal mime type detection, please use guessMimeType() for application code instead.
 466         * Detection is done using an external program, if $wgMimeDetectorCommand is set.
 467         * Otherwise, the fileinfo extension and mime_content_type are tried (in this order), if they are available.
 468         * If the dections fails and $useExt is true, the mime type is guessed from the file extension, using guessTypesForExtension.
 469         * If the mime type is still unknown, getimagesize is used to detect the mime type if the file is an image.
 470         * If no mime type can be determined, this function returns "unknown/unknown".
 471         *
 472         * @param string $file The file to check
 473         * @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
 474         *
 475         * @return string the mime type of $file
 476         * @access private
 477         */
 478         function detectMimeType( $file, $useExt=true ) {
 479                 $fname = 'MimeMagic::detectMimeType';
 480
 481                 global $wgMimeDetectorCommand;
 482
 483                 $m= NULL;
 484                 if ($wgMimeDetectorCommand) {
 485                         $fn= wfEscapeShellArg($file);
 486                         $m= `$wgMimeDetectorCommand $fn`;
 487                 }
 488                 else if (function_exists("finfo_open") && function_exists("finfo_file")) {
 489
 490                         # This required the fileinfo extension by PECL,
 491                         # see http://pecl.php.net/package/fileinfo
 492                         # This must be compiled into PHP
 493                         #
 494                         # finfo is the official replacement for the deprecated
 495                         # mime_content_type function, see below.
 496                         #
 497                         # If you may need to load the fileinfo extension at runtime, set
 498                         # $wgLoadFileinfoExtension in LocalSettings.php
 499
 500                         $mime_magic_resource = finfo_open(FILEINFO_MIME); /* return mime type ala mimetype extension */
 501
 502                         if ($mime_magic_resource) {
 503                                 $m= finfo_file($mime_magic_resource, $file);
 504
 505                                 finfo_close($mime_magic_resource);
 506                         }
 507                         else wfDebug("$fname: finfo_open failed on ".FILEINFO_MIME."!\n");
 508                 }
 509                 else if (function_exists("mime_content_type")) {
 510
 511                         # NOTE: this function is available since PHP 4.3.0, but only if
 512                         # PHP was compiled with --with-mime-magic or, before 4.3.2, with --enable-mime-magic.
 513                         #
 514                         # On Windows, you must set mime_magic.magicfile in php.ini to point to the mime.magic file bundeled with PHP;
 515                         # sometimes, this may even be needed under linus/unix.
 516                         #
 517                         # Also note that this has been DEPRECATED in favor of the fileinfo extension by PECL, see above.
 518                         # see http://www.php.net/manual/en/ref.mime-magic.php for details.
 519
 520                         $m= mime_content_type($file);
 521
 522                         if ( $m == 'text/plain' ) {
 523                                 // mime_content_type sometimes considers DJVU files to be text/plain.
 524                                 $deja = new DjVuImage( $file );
 525                                 if( $deja->isValid() ) {
 526                                         wfDebug("$fname: (re)detected $file as image/vnd.djvu\n");
 527                                         $m = 'image/vnd.djvu';
 528                                 }
 529                         }
 530                 }
 531                 else wfDebug("$fname: no magic mime detector found!\n");
 532
 533                 if ($m) {
 534                         #normalize
 535                         $m= preg_replace('![;, ].*$!','',$m); #strip charset, etc
 536                         $m= trim($m);
 537                         $m= strtolower($m);
 538
 539                         if (strpos($m,'unknown')!==false) $m= NULL;
 540                         else {
 541                                 wfDebug("$fname: magic mime type of $file: $m\n");
 542                                 return $m;
 543                         }
 544                 }
 545
 546                 #if still not known, use getimagesize to find out the type of image
 547                 #TODO: skip things that do not have a well-known image extension? Would that be safe?
 548                 wfSuppressWarnings();
 549                 $gis = getimagesize( $file );
 550                 wfRestoreWarnings();
 551
 552                 $notAnImage= false;
 553
 554                 if ($gis && is_array($gis) && $gis[2]) {
 555                         switch ($gis[2]) {
 556                                 case IMAGETYPE_GIF: $m= "image/gif"; break;
 557                                 case IMAGETYPE_JPEG: $m= "image/jpeg"; break;
 558                                 case IMAGETYPE_PNG: $m= "image/png"; break;
 559                                 case IMAGETYPE_SWF: $m= "application/x-shockwave-flash"; break;
 560                                 case IMAGETYPE_PSD: $m= "application/photoshop"; break;
 561                                 case IMAGETYPE_BMP: $m= "image/bmp"; break;
 562                                 case IMAGETYPE_TIFF_II: $m= "image/tiff"; break;
 563                                 case IMAGETYPE_TIFF_MM: $m= "image/tiff"; break;
 564                                 case IMAGETYPE_JPC: $m= "image"; break;
 565                                 case IMAGETYPE_JP2: $m= "image/jpeg2000"; break;
 566                                 case IMAGETYPE_JPX: $m= "image/jpeg2000"; break;
 567                                 case IMAGETYPE_JB2: $m= "image"; break;
 568                                 case IMAGETYPE_SWC: $m= "application/x-shockwave-flash"; break;
 569                                 case IMAGETYPE_IFF: $m= "image/vnd.xiff"; break;
 570                                 case IMAGETYPE_WBMP: $m= "image/vnd.wap.wbmp"; break;
 571                                 case IMAGETYPE_XBM: $m= "image/x-xbitmap"; break;
 572                         }
 573
 574                         if ($m) {
 575                                 wfDebug("$fname: image mime type of $file: $m\n");
 576                                 return $m;
 577                         }
 578                         else $notAnImage= true;
 579                 } else {
 580                         // Also test DjVu
 581                         $deja = new DjVuImage( $file );
 582                         if( $deja->isValid() ) {
 583                                 wfDebug("$fname: detected $file as image/vnd.djvu\n");
 584                                 return 'image/vnd.djvu';
 585                         }
 586                 }
 587
 588                 #if desired, look at extension as a fallback.
 589                 if ($useExt) {
 590                         $i = strrpos( $file, '.' );
 591                         $e= strtolower( $i ? substr( $file, $i + 1 ) : '' );
 592
 593                         $m= $this->guessTypesForExtension($e);
 594
 595                         #TODO: if $notAnImage is set, do not trust the file extension if
 596                         # the results is one of the image types that should have been recognized
 597                         # by getimagesize
 598
 599                         if ($m) {
 600                                 wfDebug("$fname: extension mime type of $file: $m\n");
 601                                 return $m;
 602                         }
 603                 }
 604
 605                 #unknown type
 606                 wfDebug("$fname: failed to guess mime type for $file!\n");
 607                 return "unknown/unknown";
 608         }
 609
 610         /**
 611         * Determine the media type code for a file, using its mime type, name and possibly
 612         * its contents.
 613         *
 614         * This function relies on the findMediaType(), mapping extensions and mime
 615         * types to media types.
 616         *
 617         * @todo analyse file if need be
 618         * @todo look at multiple extension, separately and together.
 619         *
 620         * @param string $path full path to the image file, in case we have to look at the contents
 621         *        (if null, only the mime type is used to determine the media type code).
 622         * @param string $mime mime type. If null it will be guessed using guessMimeType.
 623         *
 624         * @return (int?string?) a value to be used with the MEDIATYPE_xxx constants.
 625         */
 626         function getMediaType($path=NULL,$mime=NULL) {
 627                 if( !$mime && !$path ) return MEDIATYPE_UNKNOWN;
 628
 629                 #if mime type is unknown, guess it
 630                 if( !$mime ) $mime= $this->guessMimeType($path,false);
 631
 632                 #special code for ogg - detect if it's video (theora),
 633                 #else label it as sound.
 634                 if( $mime=="application/ogg" && file_exists($path) ) {
 635
 636                         // Read a chunk of the file
 637                         $f = fopen( $path, "rt" );
 638                         if( !$f ) return MEDIATYPE_UNKNOWN;
 639                         $head = fread( $f, 256 );
 640                         fclose( $f );
 641
 642                         $head= strtolower( $head );
 643
 644                         #This is an UGLY HACK, file should be parsed correctly
 645                         if( strpos($head,'theora')!==false ) return MEDIATYPE_VIDEO;
 646                         elseif( strpos($head,'vorbis')!==false ) return MEDIATYPE_AUDIO;
 647                         elseif( strpos($head,'flac')!==false ) return MEDIATYPE_AUDIO;
 648                         elseif( strpos($head,'speex')!==false ) return MEDIATYPE_AUDIO;
 649                         else return MEDIATYPE_MULTIMEDIA;
 650                 }
 651
 652                 #check for entry for full mime type
 653                 if( $mime ) {
 654                         $type= $this->findMediaType($mime);
 655                         if( $type!==MEDIATYPE_UNKNOWN ) return $type;
 656                 }
 657
 658                 #check for entry for file extension
 659                 $e= NULL;
 660                 if( $path ) {
 661                         $i = strrpos( $path, '.' );
 662                         $e= strtolower( $i ? substr( $path, $i + 1 ) : '' );
 663
 664                         #TODO: look at multi-extension if this fails, parse from full path
 665
 666                         $type= $this->findMediaType('.'.$e);
 667                         if( $type!==MEDIATYPE_UNKNOWN ) return $type;
 668                 }
 669
 670                 #check major mime type
 671                 if( $mime ) {
 672                         $i= strpos($mime,'/');
 673                         if( $i !== false ) {
 674                                 $major= substr($mime,0,$i);
 675                                 $type= $this->findMediaType($major);
 676                                 if( $type!==MEDIATYPE_UNKNOWN ) return $type;
 677                         }
 678                 }
 679
 680                 if( !$type ) $type= MEDIATYPE_UNKNOWN;
 681
 682                 return $type;
 683         }
 684
 685         /** returns a media code matching the given mime type or file extension.
 686         * File extensions are represented by a string starting with a dot (.) to
 687         * distinguish them from mime types.
 688         *
 689         * This funktion relies on the mapping defined by $this->mMediaTypes
 690         * @access private
 691         */
 692         function findMediaType($extMime) {
 693
 694                 if (strpos($extMime,'.')===0) { #if it's an extension, look up the mime types
 695                         $m= $this->getTypesForExtension(substr($extMime,1));
 696                         if (!$m) return MEDIATYPE_UNKNOWN;
 697
 698                         $m= explode(' ',$m);
 699                 }
 700                 else { #normalize mime type
 701                         if (isset($this->mMimeTypeAliases[$extMime])) {
 702                                 $extMime= $this->mMimeTypeAliases[$extMime];
 703                         }
 704
 705                         $m= array($extMime);
 706                 }
 707
 708                 foreach ($m as $mime) {
 709                         foreach ($this->mMediaTypes as $type => $codes) {
 710                                 if (in_array($mime,$codes,true)) return $type;
 711                         }
 712                 }
 713
 714                 return MEDIATYPE_UNKNOWN;
 715         }
 716 }
 717
 718 ?>