(PHP >= 5.3.0, PHP 7, PHP 8, PECL fileinfo >= 0.1.0)
finfo_file -- finfo::file — 返回一个文件的信息
过程化风格
$finfo,$filename,$flags = FILEINFO_NONE,$context = null面向对象风格
$filename, int $flags = FILEINFO_NONE, ?resource $context = null): string|false本函数用来获取一个文件的信息。
finfo经 finfo_open() 返回的 finfo 实例。
filename要检查的文件名。
flags一个 Fileinfo 常量或多个进行逻辑或。
context
关于 contexts 的更多描述，请参考 Stream 函数。
返回 filename 参数指定的文件信息。发生错误时返回 false。
示例 #1 finfo_file() 示例
<?php
$finfo = finfo_open(FILEINFO_MIME_TYPE); // 返回 mime 类型，也被称为 mime 类型扩展。
foreach (glob("*") as $filename) {
echo finfo_file($finfo, $filename) . "\n";
}
finfo_close($finfo);
?>以上示例的输出类似于：
text/html image/gif application/vnd.ms-excel
Tempting as it may seem to use finfo_file() to validate uploaded image files (Check whether a supposed imagefile really contains an image), the results cannot be trusted. It's not that hard to wrap harmful executable code in a file identified as a GIF for instance.
A better & safer option is to check the result of:
if (!$img = @imagecreatefromgif($uploadedfilename)) {
trigger_error('Not a GIF image!',E_USER_WARNING);
// do necessary stuff
}The way HOWTO get MIME-type of remote file.
<?php
class MimeStreamWrapper
{
const WRAPPER_NAME = 'mime';
public $context;
private static $isRegistered = false;
private $callBackFunction;
private $eof = false;
private $fp;
private $path;
private $fileStat;
private function getStat()
{
if ($fStat = fstat($this->fp)) {
return $fStat;
}
$size = 100;
if ($headers = get_headers($this->path, true)) {
$head = array_change_key_case($headers, CASE_LOWER);
$size = (int)$head['content-length'];
}
$blocks = ceil($size / 512);
return array(
'dev' => 16777220,
'ino' => 15764,
'mode' => 33188,
'nlink' => 1,
'uid' => 10000,
'gid' => 80,
'rdev' => 0,
'size' => $size,
'atime' => 0,
'mtime' => 0,
'ctime' => 0,
'blksize' => 4096,
'blocks' => $blocks,
);
}
public function setPath($path)
{
$this->path = $path;
$this->fp = fopen($this->path, 'rb') or die('Cannot open file: ' . $this->path);
$this->fileStat = $this->getStat();
}
public function read($count) {
return fread($this->fp, $count);
}
public function getStreamPath()
{
return str_replace(array('ftp://', 'http://', 'https://'), self::WRAPPER_NAME . '://', $this->path);
}
public function getContext()
{
if (!self::$isRegistered) {
stream_wrapper_register(self::WRAPPER_NAME, get_class());
self::$isRegistered = true;
}
return stream_context_create(
array(
self::WRAPPER_NAME => array(
'cb' => array($this, 'read'),
'fileStat' => $this->fileStat,
)
)
);
}
public function stream_open($path, $mode, $options, &$opened_path)
{
if (!preg_match('/^r[bt]?$/', $mode) || !$this->context) {
return false;
}
$opt = stream_context_get_options($this->context);
if (!is_array($opt[self::WRAPPER_NAME]) ||
!isset($opt[self::WRAPPER_NAME]['cb']) ||
!is_callable($opt[self::WRAPPER_NAME]['cb'])
) {
return false;
}
$this->callBackFunction = $opt[self::WRAPPER_NAME]['cb'];
$this->fileStat = $opt[self::WRAPPER_NAME]['fileStat'];
return true;
}
public function stream_read($count)
{
if ($this->eof || !$count) {
return '';
}
if (($s = call_user_func($this->callBackFunction, $count)) == '') {
$this->eof = true;
}
return $s;
}
public function stream_eof()
{
return $this->eof;
}
public function stream_stat()
{
return $this->fileStat;
}
public function stream_cast($castAs)
{
$read = null;
$write = null;
$except = null;
return @stream_select($read, $write, $except, $castAs);
}
}
$path = 'http://fc04.deviantart.net/fs71/f/2010/227/4/6/PNG_Test_by_Destron23.png';
echo "File: ", $path, "\n";
$wrapper = new MimeStreamWrapper();
$wrapper->setPath($path);
$fInfo = new finfo(FILEINFO_MIME);
echo "MIME-type: ", $fInfo->file($wrapper->getStreamPath(), FILEINFO_MIME_TYPE, $wrapper->getContext()), "\n";
?>Just noting (because I ran into it!) that the current implementation of finfo_file has a known bug which causes PHP to allocate huge amounts of memory when certain strings are present in text files that it is examining.
See https://bugs.php.net/bug.php?id=69224 for more info.Well, i have a great probleam with that, MS Office 2007 extensions (pptx, xlsx, docx) do not have a default Mime type, they have "application/zip" mime type, so, to fix that, i do one little function to verify the extension.
That function allow's you to be safe of fake extensions hack.
<?php
$arrayZips = array("application/zip", "application/x-zip", "application/x-zip-compressed");
$arrayExtensions = array(".pptx", ".docx", ".dotx", ".xlsx");
$file = 'path/to/file.xlsx';
$original_extension = (false === $pos = strrpos($file, '.')) ? '' : substr($file, $pos);
$finfo = new finfo(FILEINFO_MIME);
$type = $finfo->file($file);
if (in_array($type, $arrayZips) && in_array($original_extension, $arrayExtensions))
{
return $original_extension;
}
?>I was getting application/octet-stream or "<= not supported" for all the files.
I found out that in PHP 5.3 the magic file is built-in into PHP and that is what should be used. The magic file found on the system may not always be what libmagic expects, hence the error.Another interresting feature of finfo_file on Windows.
This function can return empty string instead of FALSE for some file types (ppt for example). Therefore to be sure do a triple check of output result and provide default type just in case. Here is a sample code:
$ftype = 'application/octet-stream';
$finfo = @finfo_open(FILEINFO_MIME);
if ($finfo !== FALSE) {
$fres = @finfo_file($finfo, $file);
if ( ($fres !== FALSE)
&& is_string($fres)
&& (strlen($fres)>0)) {
$ftype = $fres;
}
@finfo_close($finfo);
}I spent days looking and searching for a database with actual plain language descriptions for the media types, for example
finfo(.png) --> "image/png" --> "PNG image".
In Ubuntu based OS's you can find already translated database at /usr/share/mime
http://manpages.ubuntu.com/manpages/hardy/en/man5/gnome-mime.5.htmlOO (bit improved) version of the same thing
<?php
$file = '<somefile>';
$ftype = 'application/octet-stream';
$finfo = @new finfo(FILEINFO_MIME);
$fres = @$finfo->file($file);
if (is_string($fres) && !empty($fres)) {
$ftype = $fres;
}
?>Here is an wrapper that will properly identify Microsoft Office 2007 documents. It's trivial and straightforward to use, edit, and to add more file extentions/mimetypes.
<?php
function get_mimetype($filepath) {
if(!preg_match('/\.[^\/\\\\]+$/',$filepath)) {
return finfo_file(finfo_open(FILEINFO_MIME_TYPE), $filepath);
}
switch(strtolower(preg_replace('/^.*\./','',$filepath))) {
// START MS Office 2007 Docs
case 'docx':
return 'application/vnd.openxmlformats-officedocument.wordprocessingml.document';
case 'docm':
return 'application/vnd.ms-word.document.macroEnabled.12';
case 'dotx':
return 'application/vnd.openxmlformats-officedocument.wordprocessingml.template';
case 'dotm':
return 'application/vnd.ms-word.template.macroEnabled.12';
case 'xlsx':
return 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet';
case 'xlsm':
return 'application/vnd.ms-excel.sheet.macroEnabled.12';
case 'xltx':
return 'application/vnd.openxmlformats-officedocument.spreadsheetml.template';
case 'xltm':
return 'application/vnd.ms-excel.template.macroEnabled.12';
case 'xlsb':
return 'application/vnd.ms-excel.sheet.binary.macroEnabled.12';
case 'xlam':
return 'application/vnd.ms-excel.addin.macroEnabled.12';
case 'pptx':
return 'application/vnd.openxmlformats-officedocument.presentationml.presentation';
case 'pptm':
return 'application/vnd.ms-powerpoint.presentation.macroEnabled.12';
case 'ppsx':
return 'application/vnd.openxmlformats-officedocument.presentationml.slideshow';
case 'ppsm':
return 'application/vnd.ms-powerpoint.slideshow.macroEnabled.12';
case 'potx':
return 'application/vnd.openxmlformats-officedocument.presentationml.template';
case 'potm':
return 'application/vnd.ms-powerpoint.template.macroEnabled.12';
case 'ppam':
return 'application/vnd.ms-powerpoint.addin.macroEnabled.12';
case 'sldx':
return 'application/vnd.openxmlformats-officedocument.presentationml.slide';
case 'sldm':
return 'application/vnd.ms-powerpoint.slide.macroEnabled.12';
case 'one':
return 'application/msonenote';
case 'onetoc2':
return 'application/msonenote';
case 'onetmp':
return 'application/msonenote';
case 'onepkg':
return 'application/msonenote';
case 'thmx':
return 'application/vnd.ms-officetheme';
//END MS Office 2007 Docs
}
return finfo_file(finfo_open(FILEINFO_MIME_TYPE), $filepath);
}
?>I thought to use fileinfo to check if a file was gzip or bzip2. However, the mime type of a compressed file is "data" because compression is an encoding rather than a type.
gzip files begin with binary 1f8b.
bzip2 files begin with magic bytes 'B' 'Z' 'h'.
e.g.
<?php
$s = file_get_contents("somefilepath");
if ( bin2hex(substr($s,0,2)) == '1f8b' ) {/* could be a gzip file */}
if( substr($s,0,3) == 'BZh' ){/* could be a bzip2 file */}
?>
I am not an encoding expert. My only testing was using a few of my own encoded files.