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finfo_file

finfo::file

(PHP >= 5.3.0, PHP 7, PHP 8, PECL fileinfo >= 0.1.0)

finfo_file -- finfo::fileReturn information about a file

Description

Procedural style

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

Object-oriented style

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

This function is used to get information about a file.

Parameters

finfo

An finfo instance, returned by finfo_open().

filename

Name of a file to be checked.

flags

One or disjunction of more Fileinfo constants.

context

For a description of contexts, refer to Stream Functions.

Return Values

Returns a textual description of the contents of the filename argument, or false if an error occurred.

Changelog

Version Description
8.1.0 The finfo parameter expects an finfo instance now; previously, a resource was expected.
8.0.0 context is nullable now.

Examples

Example #1 A finfo_file() example

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

The above example will output something similar to:

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

See Also

add a note

User Contributed Notes 12 notes

up
22
Schraalhans Keukenmeester
17 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
8 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
6
tim at savaslabs dot com
9 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
12 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
13 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
16 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
niko dot jokipalo at gmail dot com
10 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
16 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
0
jesen at protonmail dot com
23 days ago
When using `finfo_file()`, you may encounter results similar to the following, which require attention: `image/png; charset=binary`
up
0
powtac at gmx dot de
8 years ago
Be careful, files with BOM will not detected correctly!
up
-2
scott at thebrain dot ca
15 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
-4
da_kooz at hotmail dot com
11 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);
}

?>
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