PHP 8.2.0 Released!

finfo_file

finfo::file

(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

说明

过程化风格

finfo_file(
    finfo $finfo,
    string $filename,
    int $flags = FILEINFO_NONE,
    ?resource $context = null
): string|false

面向对象风格

public finfo::file(string $filename, int $flags = FILEINFO_NONE, ?resource $context = null): string|false

本函数用来获取一个文件的信息。

参数

finfo

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

返回值

返回 filename 参数指定的文件信息。发生错误时返回 false

更新日志

版本 说明
8.1.0 finfo 参数现在接受 finfo 实例,之前接受 资源(resource)
8.0.0 context 现在可以为 null。

范例

示例 #1 finfo_file() 示例

<?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

add a note

User Contributed Notes 13 notes

up
16
Schraalhans Keukenmeester
15 years ago
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
}
up
10
66Ton99 at gmail dot com
6 years ago
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";
?>
up
5
tim at savaslabs dot com
7 years ago
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.
up
8
contato at vfreitas dot com
10 years ago
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;
}

?>
up
3
Zane MegaLab.it
11 years ago
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.
up
2
darko at uvcms dot com
14 years ago
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);
}
up
1
powtac at gmx dot de
6 years ago
Be careful, files with BOM will not detected correctly!
up
1
niko dot jokipalo at gmail dot com
8 years ago
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
up
1
darko at uvcms dot com
14 years ago
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;
}
?>
up
-3
da_kooz at hotmail dot com
9 years ago
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);
}

?>
up
-3
scott at thebrain dot ca
13 years ago
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.
up
-9
info at tech dash bits dot net
11 years ago
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);
?>
up
-17
WebShowPro
15 years ago
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;
}

?>
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