在PHP中获取没有文件扩展名的MIME类型

7
我有一个名为Prestashop的电商软件包。它允许你销售虚拟产品,可下载物品,如软件、电子书等。
他们的软件存在一个问题,即将可下载产品的物理文件名命名为40个字符的哈希值,没有扩展名。然后,当客户下载文件时,系统应该检查MIME类型,以便在将文件发送到客户浏览器之前设置文件头。
问题在于,他们使用了四种方法来确定MIME类型。
  1. finfo_open()函数,此扩展恰好未安装在我的主机上,因此失败。
  2. mime_content_type()函数,它采用没有扩展名的文件,并返回“text/plain”MIME类型,无论实际的MIME类型是什么。这个函数已经被弃用了,我认为他们根本不应该使用它。
  3. exec('file -bi '.escapeshellarg($file))。这也在我的主机上失败了。
  4. 一个扩展名数组,用于匹配MIME类型。
由于他们将文件添加到后台时没有扩展名,这使得我很难弄清楚这个问题是否起作用。我尝试了许多其他解决方案,包括从cURL调用中获取CURLINFO_CONTENT_TYPE来下载文件,顺便说一下,对于相同的文件,它返回“text/plain”。
你有什么解决这个问题的想法吗? 已使用的解决方案...
if (empty($mime_type))
{
    $bName = basename($filename);
    $bName = explode('.', $bName);
    $bName = strtolower($bName[count($bName) - 1]);

    $mimeTypes = array(
    'ez'        => 'application/andrew-inset',
    'atom'      => 'application/atom+xml',
    'jar'       => 'application/java-archive',
    'hqx'       => 'application/mac-binhex40',
    'cpt'       => 'application/mac-compactpro',
    'mathml'    => 'application/mathml+xml',
    'doc'       => 'application/msword',
    'dat'       => 'application/octet-stream',
    'oda'       => 'application/oda',
    'ogg'       => 'application/ogg',
    'pdf'       => 'application/pdf',
    'ai'        => 'application/postscript',
    'eps'       => 'application/postscript',
    'ps'        => 'application/postscript',
    'rdf'       => 'application/rdf+xml',
    'rss'       => 'application/rss+xml',
    'smi'       => 'application/smil',
    'smil'      => 'application/smil',
    'gram'      => 'application/srgs',
    'grxml'     => 'application/srgs+xml',
    'kml'       => 'application/vnd.google-earth.kml+xml',
    'kmz'       => 'application/vnd.google-earth.kmz',
    'mif'       => 'application/vnd.mif',
    'xul'       => 'application/vnd.mozilla.xul+xml',
    'xls'       => 'application/vnd.ms-excel',
    'xlb'       => 'application/vnd.ms-excel',
    'xlt'       => 'application/vnd.ms-excel',
    'xlam'      => 'application/vnd.ms-excel.addin.macroEnabled.12',
    'xlsb'      => 'application/vnd.ms-excel.sheet.binary.macroEnabled.12',
    'xlsm'      => 'application/vnd.ms-excel.sheet.macroEnabled.12',
    'xltm'      => 'application/vnd.ms-excel.template.macroEnabled.12',
    'docm'      => 'application/vnd.ms-word.document.macroEnabled.12',
    'dotm'      => 'application/vnd.ms-word.template.macroEnabled.12',
    'ppam'      => 'application/vnd.ms-powerpoint.addin.macroEnabled.12',
    'pptm'      => 'application/vnd.ms-powerpoint.presentation.macroEnabled.12',
    'ppsm'      => 'application/vnd.ms-powerpoint.slideshow.macroEnabled.12',
    'potm'      => 'application/vnd.ms-powerpoint.template.macroEnabled.12',
    'ppt'       => 'application/vnd.ms-powerpoint',
    'pps'       => 'application/vnd.ms-powerpoint',
    'odc'       => 'application/vnd.oasis.opendocument.chart',
    'odb'       => 'application/vnd.oasis.opendocument.database',
    'odf'       => 'application/vnd.oasis.opendocument.formula',
    'odg'       => 'application/vnd.oasis.opendocument.graphics',
    'otg'       => 'application/vnd.oasis.opendocument.graphics-template',
    'odi'       => 'application/vnd.oasis.opendocument.image',
    'odp'       => 'application/vnd.oasis.opendocument.presentation',
    'otp'       => 'application/vnd.oasis.opendocument.presentation-template',
    'ods'       => 'application/vnd.oasis.opendocument.spreadsheet',
    'ots'       => 'application/vnd.oasis.opendocument.spreadsheet-template',
    'odt'       => 'application/vnd.oasis.opendocument.text',
    'odm'       => 'application/vnd.oasis.opendocument.text-master',
    'ott'       => 'application/vnd.oasis.opendocument.text-template',
    'oth'       => 'application/vnd.oasis.opendocument.text-web',
    'potx'      => 'application/vnd.openxmlformats-officedocument.presentationml.template',
    'ppsx'      => 'application/vnd.openxmlformats-officedocument.presentationml.slideshow',
    'pptx'      => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
    'xlsx'      => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
    'xltx'      => 'application/vnd.openxmlformats-officedocument.spreadsheetml.template',
    'docx'      => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
    'dotx'      => 'application/vnd.openxmlformats-officedocument.wordprocessingml.template',
    'vsd'       => 'application/vnd.visio',
    'wbxml'     => 'application/vnd.wap.wbxml',
    'wmlc'      => 'application/vnd.wap.wmlc',
    'wmlsc'     => 'application/vnd.wap.wmlscriptc',
    'vxml'      => 'application/voicexml+xml',
    'bcpio'     => 'application/x-bcpio',
    'vcd'       => 'application/x-cdlink',
    'pgn'       => 'application/x-chess-pgn',
    'cpio'      => 'application/x-cpio',
    'csh'       => 'application/x-csh',
    'dcr'       => 'application/x-director',
    'dir'       => 'application/x-director',
    'dxr'       => 'application/x-director',
    'dvi'       => 'application/x-dvi',
    'spl'       => 'application/x-futuresplash',
    'tgz'       => 'application/x-gtar',
    'gtar'      => 'application/x-gtar',
    'hdf'       => 'application/x-hdf',
    'js'        => 'application/x-javascript',
    'skp'       => 'application/x-koan',
    'skd'       => 'application/x-koan',
    'skt'       => 'application/x-koan',
    'skm'       => 'application/x-koan',
    'latex'     => 'application/x-latex',
    'nc'        => 'application/x-netcdf',
    'cdf'       => 'application/x-netcdf',
    'sh'        => 'application/x-sh',
    'shar'      => 'application/x-shar',
    'swf'       => 'application/x-shockwave-flash',
    'sit'       => 'application/x-stuffit',
    'sv4cpio'   => 'application/x-sv4cpio',
    'sv4crc'    => 'application/x-sv4crc',
    'tar'       => 'application/x-tar',
    'tcl'       => 'application/x-tcl',
    'tex'       => 'application/x-tex',
    'texinfo'   => 'application/x-texinfo',
    'texi'      => 'application/x-texinfo',
    't'         => 'application/x-troff',
    'tr'        => 'application/x-troff',
    'roff'      => 'application/x-troff',
    'man'       => 'application/x-troff-man',
    'me'        => 'application/x-troff-me',
    'ms'        => 'application/x-troff-ms',
    'ustar'     => 'application/x-ustar',
    'src'       => 'application/x-wais-source',
    'xhtml'     => 'application/xhtml+xml',
    'xht'       => 'application/xhtml+xml',
    'xslt'      => 'application/xslt+xml',
    'xml'       => 'application/xml',
    'xsl'       => 'application/xml',
    'dtd'       => 'application/xml-dtd',
    'zip'       => 'application/zip',
    'au'        => 'audio/basic',
    'snd'       => 'audio/basic',
    'mid'       => 'audio/midi',
    'midi'      => 'audio/midi',
    'kar'       => 'audio/midi',
    'mpga'      => 'audio/mpeg',
    'mp2'       => 'audio/mpeg',
    'mp3'       => 'audio/mpeg',
    'aif'       => 'audio/x-aiff',
    'aiff'      => 'audio/x-aiff',
    'aifc'      => 'audio/x-aiff',
    'm3u'       => 'audio/x-mpegurl',
    'wma'       => 'audio/x-ms-wma',
    'wax'       => 'audio/x-ms-wax',
    'ram'       => 'audio/x-pn-realaudio',
    'ra'        => 'audio/x-pn-realaudio',
    'rm'        => 'application/vnd.rn-realmedia',
    'wav'       => 'audio/x-wav',
    'pdb'       => 'chemical/x-pdb',
    'xyz'       => 'chemical/x-xyz',
    'bmp'       => 'image/bmp',
    'cgm'       => 'image/cgm',
    'gif'       => 'image/gif',
    'ief'       => 'image/ief',
    'jpeg'      => 'image/jpeg',
    'jpg'       => 'image/jpeg',
    'jpe'       => 'image/jpeg',
    'png'       => 'image/png',
    'svg'       => 'image/svg+xml',
    'tiff'      => 'image/tiff',
    'tif'       => 'image/tiff',
    'djvu'      => 'image/vnd.djvu',
    'djv'       => 'image/vnd.djvu',
    'wbmp'      => 'image/vnd.wap.wbmp',
    'ras'       => 'image/x-cmu-raster',
    'ico'       => 'image/x-icon',
    'pnm'       => 'image/x-portable-anymap',
    'pbm'       => 'image/x-portable-bitmap',
    'pgm'       => 'image/x-portable-graymap',
    'ppm'       => 'image/x-portable-pixmap',
    'rgb'       => 'image/x-rgb',
    'xbm'       => 'image/x-xbitmap',
    'psd'       => 'image/x-photoshop',
    'xpm'       => 'image/x-xpixmap',
    'xwd'       => 'image/x-xwindowdump',
    'eml'       => 'message/rfc822',
    'igs'       => 'model/iges',
    'iges'      => 'model/iges',
    'msh'       => 'model/mesh',
    'mesh'      => 'model/mesh',
    'silo'      => 'model/mesh',
    'wrl'       => 'model/vrml',
    'vrml'      => 'model/vrml',
    'ics'       => 'text/calendar',
    'ifb'       => 'text/calendar',
    'css'       => 'text/css',
    'csv'       => 'text/csv',
    'html'      => 'text/html',
    'htm'       => 'text/html',
    'txt'       => 'text/plain',
    'asc'       => 'text/plain',
    'rtx'       => 'text/richtext',
    'rtf'       => 'text/rtf',
    'sgml'      => 'text/sgml',
    'sgm'       => 'text/sgml',
    'tsv'       => 'text/tab-separated-values',
    'wml'       => 'text/vnd.wap.wml',
    'wmls'      => 'text/vnd.wap.wmlscript',
    'etx'       => 'text/x-setext',
    'mpeg'      => 'video/mpeg',
    'mpg'       => 'video/mpeg',
    'mpe'       => 'video/mpeg',
    'qt'        => 'video/quicktime',
    'mov'       => 'video/quicktime',
    'mxu'       => 'video/vnd.mpegurl',
    'm4u'       => 'video/vnd.mpegurl',
    'flv'       => 'video/x-flv',
    'asf'       => 'video/x-ms-asf',
    'asx'       => 'video/x-ms-asf',
    'wmv'       => 'video/x-ms-wmv',
    'wm'        => 'video/x-ms-wm',
    'wmx'       => 'video/x-ms-wmx',
    'avi'       => 'video/x-msvideo',
    'ogv'       => 'video/ogg',
    'movie'     => 'video/x-sgi-movie',
    'ice'       => 'x-conference/x-cooltalk');  
    if (isset($mimeTypes[$bName]))
        $mime_type = $mimeTypes[$bName];
    else
        $mime_type = 'application/octet-stream';
}

顺便提一下,我所有可下载的文件都将是PDF格式。 - MB34
4
如果您可以访问代码,并且您知道所有文件将是PDF格式,那么您可以硬编码类型检测函数以返回“application/pdf”... - cHao
这是我们现在正在做的,但以防我们开始提供其他类型,我需要更加灵活。 - MB34
我很难弄清楚这个问题,因为当你在后台添加没有扩展名的文件时,它们会给文件命名。我很难想象这样做是否有效。 - chustar
1
如果mime_content_type()无法检测PDF文件,则您的服务器/usr/share/misc/magic可能存在问题。请检查它。 这是最平凡的测试。否则,请编写自己的函数,如果strpos(“%PDF-”,file_get_contents(...)) - mario
显示剩余3条评论
2个回答

2

0

由于你可以访问代码,你可以更改保存文件的方式,将其转换为哈希并添加一些代码块:
1) 在保存文件之前,自行保存扩展名。
2) 在生成哈希后,将扩展名追加到文件中并保存,或者将其记录在某个地方(数据文件、数据库等)。
3) 并且在生成哈希的任何地方更新,以考虑扩展名。

这可能不是解决软件实际问题的方法,但它应该允许你保留文件类型...


我成功地修改了代码,根据显示文件名的扩展名(即下载对话框中显示的文件名)来强制更改 MIME 类型。 - MB34

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