XXXVIII. Fileinfo Functions

简介

The functions in this module try to guess the content type and encoding of a file by looking for certain magic byte sequences at specific positions within the file. While this is not a bullet proof approach the heuristics used do a very good job.

需求

magic_open library is needed to build this extension.

安装

安装此 PECL 扩展库的信息可在手册中标题为 PECL 扩展库安装的一章中找到。更多信息如新版本，下载，源文件，维护者信息以及更新日志等可以在这里找到： http://pecl.php.netfileinfo

运行时配置

本扩展模块在 php.ini 中未定义任何配置选项。

资源类型

There is one resource used in Fileinfo extension: a magic database descriptor returned by finfo_open().

预定义常量

以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。

FILEINFO_NONE (integer): No special handling.
FILEINFO_SYMLINK (integer): Follow symlinks.
FILEINFO_MIME (integer): Return a mime string, instead of a textual description.
FILEINFO_COMPRESS (integer): Decompress compressed files.
FILEINFO_DEVICES (integer): Look at the contents of blocks or character special devices.
FILEINFO_CONTINUE (integer): Return all matches, not just the first.
FILEINFO_PRESERVE_ATIME (integer): If possible preserve the original access time.
FILEINFO_RAW (integer): Don't translate unprintable characters to a \ooo octal representation.

目录
finfo_buffer -- Return information about a string buffer
finfo_close -- Close fileinfo resource
finfo_file -- Return information about a file
finfo_open -- Create a new fileinfo resource
finfo_set_flags -- Set libmagic configuration options

add a note User Contributed Notes

bujuzu A~T gmail.com
15-Jun-2007 05:22


If, like I was, you are looking for a quick and easy way to grab a mime type on a file, and don't feel like fiddling around with extentions or pear or any of that, a unix native 'file -i' command will usually do the trick - that is, if you are able to use shell commands.

mwwaygoo AT hotmail DOT com
07-Jun-2007 01:25


Be careful of using   system("file -i -b file.pdf");



I got some strange results as follows:-



1.

<?php

$type=system("file -i -b mime.php");

echo $type;

?>



text/plain; charset=us-ascii

text/plain; charset=us-ascii



2.

<?php

$type=system("file -i -b mime.php");

echo $type."<br/>\n";

$split=split(";",$type);

print_r($split);

$type=trim($split[0]);

echo $type;

?>



text/plain; charset=us-ascii

text/plain; charset=us-ascii<br/>

Array

(

    [0] => text/plain

    [1] =>  charset=us-ascii

)

text/plain



3.

<?php

$type=@system("file -i -b mime.php");

//echo $type."<br/>\n";   // just comment this line

$split=split(";",$type);

print_r($split);

$type=trim($split[0]);

echo $type;

?>



text/x-c++; charset=us-ascii

Array

(

    [0] => text/x-c++

    [1] =>  charset=us-ascii

)

text/x-c++

aidan at php dot net
15-Mar-2007 08:54


PHP Warning:  finfo::finfo(): Failed to load magic database at '/etc/magic'


PHP Warning:  finfo::file(): The invalid fileinfo object





These errors can be rectified by copying your magic database (depending on your distro, this file can be anywhere, on debian it's in /usr/share/file/magic) to /etc/magic.mime





libmagic automatically appends the .mime to the end of the filename, so PHP incorrectly reports the path it was looking for.





The same applies for:


PHP Warning:  finfo::finfo(): Failed to load magic database at '/etc/magic.mime'





Unfortunately users will have to call the magic file /etc/magic.mime.mime in this case.

Alexey
18-Feb-2007 02:39


Well, it is hard to install and use this extension. There is better alternative - use lunux comand "file". For  insturctions - "man file" from linux shell.



<?

echo system("file -i -b file.pdf");

?>



application/pdf

szotsaki at gmail dot com
01-Feb-2007 07:12


I am about to write how installed this package.



First of all, I tried with "pear install fileinfo" - as the manual says.

But the pear command said that 'Package "Fileinfo" is not valid,

install failed'.



Then the "pear install pecl/fileinfo" was a better way. But at that time the "phpize" command was missing.

I installed that (on openSUSE distributions it is in the php5-devel, but I think you can find it in your distro's corresponding php-devel package).



After that you may install "re2c" (I did). It's homepage is: http://sourceforge.net/projects/re2c



Copy the magic file of Apache (usually in /etc/apache2) into the following directory: /usr/locale/share/file/ or /usr/share/file/



Then you have to install "libmagic-dev". If you have Debian based system you can simply install it with apt.

But if you have an rpm based system (like me), you have to download the following package: http://packages.debian.org/unstable/libdevel/libmagic-dev

It contains the files we need. 

So, download the file, browse it with Midnight Commander (mc) (you have to apt and dpkg be installed) and simply extract (so copy) the /usr folder (it is inside the CONTENTS folder) of the .deb package to the root folder.



And now give the "pear install pecl/fileinfo" command another try :)



Ps: Don't forget to check whether the script has wrote the following line into the php.ini (on openSUSE: /etc/php5/apache2): extension=fileinfo.so



I hope, I could help.

motin at demomusic dot nu
10-Jan-2007 01:34


I had a real headache trying to install this package through pear/pecl. Ran into what looks like this bug: http://pecl.php.net/bugs/bug.php?id=7673 (phpize fails)



I found downloading the package manually and running ./configure helped show what the problem is:



...

checking for fileinfo support... yes, shared

checking for magic files in default path... not found

configure: error: Please reinstall the libmagic distribution

<quit>



I though this was because of a missing magic-database like magic.mime but examining the configure-script, magic.h is searched for. 



Problem for me was that include/magic.h was not found. After some googling about where to find magic.h led me to the dead

simple solution:



apt-get install libmagic-dev



This does NOT solve the original installation bug strangely enough, but allows for manual installation:



1. Find the url to the latest version of fileinfo from http://pecl.php.net/package/Fileinfo (atm: http://pecl.php.net/get/Fileinfo-1.0.4.tgz)



2. Download, compile and install

wget http://pecl.php.net/get/Fileinfo-1.0.4.tgz

gunzip Fileinfo-1.0.4.tgz

tar -xvf Fileinfo-1.0.4.tar

cd fileinfo-1.0.4

./configure

make

make install



3. Add extension=fileinfo.so in your php.ini file



4. Restart Apache

jausions at php dot net
08-Jul-2006 07:26


For Windows users:



1. Go to http://pecl4win.php.net/ to get the php_fileinfo.dll if your PHP installation didn't come with it, and you haven't installed the Extensions package.



2. Then make sure you have extension=php_fileinfo.dll somewhere in your php.ini



3. Restart your web server.

deanariel at gmail dot com
14-Apr-2006 06:16


Sometime "pear install fileinfo" won't work....

so you can try "pear install pecl/fileinfo"

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