Php определить mime тип файла

How to get the mime type of a file after using file_get_contents from a remote server

I’m reading a file in PHP from Alfresco and then outputting it to the browser. The only problem is the mime type or the extension of the file. This is the code I’m using:

I receive the name of the file from the get because, I don’t know how to get the name from alfresco. But I have to guess the mimetype somehow. If I echo $cnt in the first characters, there are references to the fact that it is a PDF (for example on screen I see

%PDF-1.3 %âãÏÓ 2 0 obj > /Type /XObject /Subtype /Image /Width 2480 /Height 3508 /BitsPerComponent 1 /ColorSpace /DeviceGray >> stream

So there must be a way to get the mime type from it with a function. Any help is appreciated! Edit. If anyone is interested here is a class that you can use to get the extension from the mime type. http://www.ustrem.org/en/articles/mime-type-by-extension-en/

7 Answers 7

NOTE: You could optionally use the finfo_buffer procedural function if that suites you better than using the object-oriented methodology.

You do not have to guess (aka autodetect) the MIME type.

Use $http_response_header to retrieve headers of the last file_get_contents call (or any call with http[s]:// wrapper).

$contents = file_get_contents("https://www.example.com/"); $headers = implode("\n", $http_response_header); if (preg_match_all("/^content-type\s*:\s*(.*)$/mi", $headers, $matches))

Parsing $http_response_header after file_get_contents is very unstable for me. In some cases, with very large number of requests one of another, I can’t find ‘Content-Type’ in headers. But they were there.

$content = file_get_contents($url); $fh = fopen('php://memory', 'w+b'); fwrite($fh, $content); $contentType = mime_content_type($fh); fclose($fh); 

/** * Given a string ($data) with a file's contents, guess and return the mime type * * Uses the standard unix program /usr/bin/file to handle the magic (pun intended) * * @param string $data */ public static function get_string_mime_type($data) < $file_cmd = '/usr/bin/file --brief --mime-type --no-buffer -'; return rtrim(self::exec_write_read($file_cmd, $data)); >/** * Executes $cmd, writes to $cmd's stdin, then returns what $cmd wrote to stdout */ private static function exec_write_read($cmd, $write, $log_errors = false) < $descriptorspec = array( 0 =>array("pipe", "r"), // stdin is a pipe that $cmd will read from 1 => array("pipe", "w"), // stdout is a pipe that $cmd will write to 2 => array("pipe", "w"), // stderr is a pipe that $cmd will write to ); $process = proc_open($cmd, $descriptorspec, $pipes); if (is_resource($process)) < // $pipes now looks like this: // 0 =>writeable handle connected to child stdin // 1 => readable handle connected to child stdout // 2 => readable handle connected to child stderr fwrite($pipes[0], $write); fclose($pipes[0]); $output = stream_get_contents($pipes[1]); fclose($pipes[1]); if( $log_errors ) < error_log(stream_get_contents($pipes[2])); >fclose($pipes[2]); // It is important that you close any pipes before calling // proc_close in order to avoid a deadlock $exit_code = proc_close($process); return $output; > else < throw new Exception("Couldn't open $cmd"); >> 

Источник

mime_content_type

Возвращает MIME-тип содержимого файла, используя для определения информацию из файла magic.mime .

Список параметров

Путь к проверяемому файлу.

Возвращаемые значения

Возвращает тип содержимого в формате MIME, например text/plain или application/octet-stream или false в случае возникновения ошибки.

Ошибки

В случае неудачного завершения работы генерируется ошибка уровня E_WARNING .

Примеры

Пример #1 Пример mime_content_type()

Результат выполнения данного примера:

Смотрите также

User Contributed Notes 21 notes

Fast generation of uptodate mime types:

echo
generateUpToDateMimeArray ( APACHE_MIME_TYPES_URL );
?>

Output:
$mime_types = array(
‘123’ => ‘application/vnd.lotus-1-2-3’,
‘3dml’ => ‘text/vnd.in3d.3dml’,
‘3g2’ => ‘video/3gpp2’,
‘3gp’ => ‘video/3gpp’,
‘7z’ => ‘application/x-7z-compressed’,
‘aab’ => ‘application/x-authorware-bin’,
‘aac’ => ‘audio/x-aac’,
‘aam’ => ‘application/x-authorware-map’,
‘aas’ => ‘application/x-authorware-seg’,
.

There is a composer package that will do this:
https://github.com/ralouphie/mimey

$mimes = new \ Mimey \ MimeTypes ;

// Convert extension to MIME type:
$mimes -> getMimeType ( ‘json’ ); // application/json

// Convert MIME type to extension:
$mimes -> getExtension ( ‘application/json’ ); // json

and string detection on text files may fail if you check a file encoded with signed UTF-8. The UTF-8 signature is a two bytes code (0xFF 0xFE) that prepends the file in order to force UTF-8 recognition (you may check it on an hexadecimal editor).

For me mime_content_type didn’t work in Linux before I added

to php.ini (remember to find the correct path to mime.magic)

using
function detectFileMimeType ( $filename = » )
$filename = escapeshellcmd ( $filename );
$command = «file -b —mime-type -m /usr/share/misc/magic < $filename >» ;

$mimeType = shell_exec ( $command );

return trim ( $mimeType );
>
?>
should work on most shared linux hosts without errors. It should also work on Windows hosts with msysgit installed.

Lukas V is IMO missing some point. The MIME type of a file may not be corresponding to the file suffix.

Imagine someone would obfuscate some PHP code in a .gif file, the file suffix would be ‘GIF’ but the MIME would be text/plain or even text/html.

Another example is files fetched via a distant server (wget / fopen / file / fsockopen. ). The server can issue an error, i.e. 404 Not Found, wich again is text/html, whatever you save the file to (download_archive.rar).

His provided function should begin by the test of the function existancy like :

function MIMEalternative($file)
if(function_exists(‘mime_content_type’))
return mime_content_type($file);
else
return ($file);
>

I see a lot of comments suggesting doing file extension sniffing (i.e. assuming .jpg files are JPEG images) when proper file-type sniffing functions are unavailable.
I want to point out that there is a much more accurate way.
If neither mime_content_type() nor Fileinfo is available to you and you are running *any* UNIX variant since the 70s, including Mac OS, OS X, Linux, etc. (and most web hosting is), just make a system call to ‘file(1)’.
Doing something like this:
echo system ( «file -bi »» );
?>
will output something like «text/html; charset=us-ascii». Some systems won’t add the charset bit, but strip it off just in case.
The ‘-bi’ bit is important. However, you can use a command like this:
echo system ( «file -b »» ); // without the ‘i’ after ‘-b’
?>
to output a human-readable string, like «HTML document text», which can sometimes be useful.
The only drawback is that your scripts will not work on Windows, but is this such a problem? Just about all web hosts use a UNIX.
It is a far better way than just examining the file extension.

Here’s a simple function to return MIME types, based on the Apache mime.types file. [The one in my previous submission, which has since been replaced by this one] only works properly if mime.types is formatted as Windows text. The updated version below corrects this problem. Thanks to Mike for pointing this out.

function get_mime_type ( $filename , $mimePath = ‘../etc’ ) <
$fileext = substr ( strrchr ( $filename , ‘.’ ), 1 );
if (empty( $fileext )) return ( false );
$regex = «/^([\w\+\-\.\/]+)\s+(\w+\s)*( $fileext \s)/i» ;
$lines = file ( » $mimePath /mime.types» );
foreach( $lines as $line ) <
if ( substr ( $line , 0 , 1 ) == ‘#’ ) continue; // skip comments
$line = rtrim ( $line ) . » » ;
if (! preg_match ( $regex , $line , $matches )) continue; // no match to the extension
return ( $matches [ 1 ]);
>
return ( false ); // no match at all
>
?>

Notes:
[1] Requires mime.types file distributed with Apache (normally found at ServerRoot/conf/mime.types). If you are using shared hosting, download the file with the Apache distro and then upload it to a directory on your web server that php has access to.

[2] First param is the filename (required). Second parameter is path to mime.types file (optional; defaults to home/etc/). [3] Based on MIME types registered with IANA (http://www.iana.org/assignments/media-types/index.html). Recognizes 630 extensions associated with 498 MIME types. [4] Asserts MIME type based on filename extension. Does not examine the actual file; the file does not even have to exist. [5] Examples of use:
>> echo get_mime_type(‘myFile.xml’);
>> application/xml
>> echo get_mime_type(‘myPath/myFile.js’);
>> application/javascript
>> echo get_mime_type(‘myPresentation.ppt’);
>> application/vnd.ms-powerpoint
>> echo get_mime_type(‘http://mySite.com/myPage.php);
>> application/x-httpd-php
>> echo get_mime_type(‘myPicture.jpg’);
>> image/jpeg
>> echo get_mime_type(‘myMusic.mp3’);
>> audio/mpeg
and so on.

To create an associative array containing MIME types, use:
function get_mime_array ( $mimePath = ‘../etc’ )
<
$regex = «/([\w\+\-\.\/]+)\t+([\w\s]+)/i» ;
$lines = file ( » $mimePath /mime.types» , FILE_IGNORE_NEW_LINES );
foreach( $lines as $line ) <
if ( substr ( $line , 0 , 1 ) == ‘#’ ) continue; // skip comments
if (! preg_match ( $regex , $line , $matches )) continue; // skip mime types w/o any extensions
$mime = $matches [ 1 ];
$extensions = explode ( » » , $matches [ 2 ]);
foreach( $extensions as $ext ) $mimeArray [ trim ( $ext )] = $mime ;
>
return ( $mimeArray );
>
?>

Источник

Работа с MIME-типами в PHP

«Internet Media Types» или «Медиа типы» — является стандартом RFC 6838, который описывает формат файла. Причем браузеры используют MIME-типы в качестве основного критерия, не воспринимая расширения файлов.

MIME-тип состоит из типа и подтипа — двух значений разделённых « / », без использования пробелов и в нижнем регистре, например HTML страница:

Полный список MIME типов можно посмотреть тут.

К медиа типу может быть добавлен параметр для указания дополнительных деталей (например кодировка):

Как узнать MIME-тип загруженного файла

При загрузке файла через форму, MIME-тип файла доступен в массиве $_FILES , например:

Для определения MIME уже загруженного файла существует PHP-функция mime_content_type().

echo mime_content_type(__DIR__ . '/image.png'); // image/png echo mime_content_type(__DIR__ . '/text.txt'); // text/plain

При работе с изображениями, MIME-тип можно получить с помощью функции getimagesize():

$filename = __DIR__ . '/image.png'; $info = getimagesize($filename); print_r($info);

Результат:

Array ( [0] => 221 [1] => 96 [2] => 3 [3] => width="221" height="96" [bits] => 8 [mime] => image/png )

Важно помнить что при проверке файлов нельзя полагаться только на проверку MIME, т.к. его значение может быть скомпрометировано. Поэтому нужно проводить более детальную проверку (например по размеру изображения или его пересохранить в предполагаемом формате).

Отправка файлов из PHP

В PHP-скриптах, перед отправкой файлов клиенту, необходимо отправлять заголовок Content-Type , например файл XML:

$content = '. '; header("Content-Type: text/xml; charset=utf-8"); echo $content; exit();

$file = ROOT_DIR . '/market.zip'; header('Content-type: application/zip'); header('Content-Transfer-Encoding: Binary'); header('Content-length: ' . filesize($file)); header('Content-disposition: attachment; filename="' . basename($file) . '"'); readfile($file); exit();

Вывод изображения в зависимости от расширения файла:

$filename = __DIR__ . '/image.png'; $ext = mb_strtolower(mb_substr(mb_strrchr($filename, '.'), 1)); switch ($ext) < case 'png': header('Content-type: image/png'); break; case 'jpg': case 'jpeg': header('Content-type: image/jpeg'); break; case 'gif': header('Content-type: image/gif'); break; case 'wepb': header('Content-type: image/webp'); break; >readfile($filename); exit();

Источник