finfo_file

finfo::file

(PHP >= 5.3.0, PECL fileinfo >= 0.1.0)

finfo_file -- finfo::file — 返回一个文件的信息

说明

过程化风格

string finfo_file ( resource $finfo , string $file_name = NULL [, int $options = FILEINFO_NONE [, resource $context = NULL ]] )

面向对象风格

public string finfo::file ( string $file_name = NULL [, int $options = FILEINFO_NONE [, resource $context = NULL ]] )

本函数用来获取一个文件的信息。

参数

finfo: finfo_open() 函数所返回的 fileinfo 资源。
file_name: 要检查的文件名。
options: 一个 Fileinfo 常量或多个 Fileinfo 常量进行逻辑或运算。
context: 关于 contexts 的更多描述，请参考 Stream 函数。

返回值

返回 file_name 参数指定的文件信息。发生错误时返回 FALSE 。

范例

Example #1 finfo_file() 例程

  <?php
$finfo  =  finfo_open ( FILEINFO_MIME_TYPE );  // 返回 mime 类型
 foreach ( glob ( "*" ) as  $filename ) {
    echo  finfo_file ( $finfo ,  $filename ) .  "\n" ;
}
 finfo_close ( $finfo );
 ?>

以上例程的输出类似于：

text/html
image/gif
application/vnd.ms-excel

参见

finfo_buffer() - 别名 finfo_buffer

用户评论:

[#1] tim at savaslabs dot com [2015-07-29 17:44:03]

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.

[#2] niko dot jokipalo at gmail dot com [2014-01-12 20:03:03]

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.html

[#3] da_kooz at hotmail dot com [2013-08-08 20:13:56]

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); } ?>

[#4] contato at vfreitas dot com [2012-03-01 18:31:50]

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; } ?>

[#5] Zane MegaLab.it [2011-06-13 08:38:57]

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.

[#6] info at tech dash bits dot net [2011-02-13 01:34:45]

While figuring out my problem using this new function, i had a brainwave in using the full path of the file instead of the relative path. For example:

<?php $folder = "somefolder/"; $fileName "aFile.pdf"; $finfo = finfo_open(FILEINFO_MIME_TYPE); finfo_file($finfo, $folder.$fileName); ?>

This will result in an error where it can't find the file specified.

This however fixxes that problem:

<?php $folder = "somefolder/"; $fileName "aFile.pdf"; $finfo = finfo_open(FILEINFO_MIME_TYPE); $mime = finfo_file($finfo, dirname(__FILE__)."/".$folder.$fileName); ?>

[#7] scott at thebrain dot ca [2009-01-06 21:29:01]

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' ) {} if( substr($s,0,3) == 'BZh' ){} ?>

I am not an encoding expert. My only testing was using a few of my own encoded files.

[#8] darko at uvcms dot com [2008-08-01 08:28:15]

OO (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; } ?>

[#9] darko at uvcms dot com [2008-04-24 09:53:46]

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);
}

[#10] WebShowPro [2007-09-25 14:01:49]

Just an improvement on the sample Ryan Day posted - slightly off topic since this method does not use finfo_file but in some cases this method might be preferable.

The main change is the -format %m parameters given to the identify call. I would suggest using the full system path to identify i.e. /usr/bin/identify to be a little safer (the location may change from server to server though).

<?php function is_jpg($fullpathtoimage){ if(file_exists($fullpathtoimage)){ exec("/usr/bin/identify -format %m $fullpathtoimage",$out); //using system() echos STDOUT automatically if(!empty($out)){ //identify returns an empty result to php //if the file is not an image if($out == 'JPEG'){ return true; } } } return false; } ?>

[#11] Schraalhans Keukenmeester [2007-05-21 15:20:48]

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
}