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Ce document utilise Manuel du site Web PHP chinois Libérer
(PHP >= 5.3.0, PECL fileinfo >= 0.1.0)
finfo_file -- finfo::file — 返回一个文件的信息
过程化风格
$finfo
, string $file_name
= NULL
[, int $options
= FILEINFO_NONE
[, resource $context
= NULL
]] )面向对象风格
$file_name
= NULL
[, int $options
= FILEINFO_NONE
[, resource $context
= NULL
]] )本函数用来获取一个文件的信息。
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 file_name
参数指定的文件信息。
发生错误时返回 FALSE
。
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 ( $finfo );
?>
以上例程的输出类似于:
text/html image/gif application/vnd.ms-excel
[#1] tim at savaslabs dot com [2015-07-29 17:44:03]
Just noting (because I ran into it!) that the current implementation of finfo_file has a known bug which causes PHP to allocate huge amounts of memory when certain strings are present in text files that it is examining.
See https://bugs.php.net/bug.php?id=69224 for more info.
[#2] niko dot jokipalo at gmail dot com [2014-01-12 20:03:03]
I spent days looking and searching for a database with actual plain language descriptions for the media types, for example
finfo(.png) --> "image/png" --> "PNG image".
In Ubuntu based OS's you can find already translated database at /usr/share/mime
http://manpages.ubuntu.com/manpages/hardy/en/man5/gnome-mime.5.html
[#3] da_kooz at hotmail dot com [2013-08-08 20:13:56]
Here is an wrapper that will properly identify Microsoft Office 2007 documents. It's trivial and straightforward to use, edit, and to add more file extentions/mimetypes.
<?php
function get_mimetype($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
}