LibMagic(3)

NAME
File::LibMagic - Perlwrapper for libmagic (file-4.x or file-5.x)

SYNOPSIS
The easy way:

          use File::LibMagic ':easy';

          print MagicBuffer("Hello World\n"),"\n";
          # returns "ASCII text"

          print MagicFile("/bin/ls"),"\n";
          # returns "ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV)"
          # on my system

To use all capabilities of libmagic use

          use File::LibMagic ':complete';

          my $handle=magic_open(0);
          my $ret   =magic_load($handle,"");  # use default magic file
          # OR $ret =magic_load($handle, '/home/someone/.magic');

          print magic_buffer($handle,"Hello World\n"),"\n";
          print magic_file($handle,"/bin/ls"),"\n";

          magic_close($handle);

Using the object-oriented interface:

    use File::LibMagic;

    my $flm = File::LibMagic->new();

    # determine a content description
    print $flm->describe_filename('path/to/file');
    print $flm->describe_contents('this is some data');

    # determine the MIME type
    print $flm->checktype_filename('path/to/file');
    print $flm->checktype_contents('this is some data');

Please have a look at the files in the example-directory.

ABSTRACT
The "File::LibMagic" is a simple perl interface to libmagic from the file-4.x or file-5.x package from Christos Zoulas (ftp://ftp.astron.com/pub/file/).

DESCRIPTION
The "File::LibMagic" is a simple perlinterface to libmagic from the file-4.x or file-5.x package from Christos Zoulas (ftp://ftp.astron.com/pub/file/).

You can use the simple Interface like MagicBuffer() or MagicFile(), use the functions of libmagic(3) or use the OO-Interface.

  Simple Interface
MagicBuffer()

fixme

MagicFile()

fixme

  libmagic(3)
magic_open, magic_close, magic_error, magic_file, magic_buffer, magic_setflags, magic_check, magic_compile, magic_load -- Magic number recognition library

  OO-Interface
new

Create a new File::LibMagic object to use for determining the type or MIME type of content.

Using the object oriented interface provides an efficient way to repeatedly determine the magic of a file. Using the object oriented interface provides significant performance improvements over using the ":easy" interface when testing many files. This performance improvement is because the loading of the magic database happens only once, during object creation.

Each File::LibMagic object loads the magic database independently of other File::LibMagic objects.

checktype_contents

Returns the MIME type of the data given as the first argument.

checktype_filename

Returns the MIME type of the given file. This will be the same as returned by the "file -i" command.

describe_contents

Returns a description of the data given as the first argument.

describe_filename

Returns the MIME type of the given file. This will be the same as returned by the "file" command.

  EXPORT
None by default.

DIAGNOSTICS

  MagicBuffer requires defined content
This exception is thrown if "MagicBuffer" is called with an undefined argument.

  libmagic cannot open %s
If libmagic is unable to open the file for which you want to determine the type, this exception is thrown. The exception can be thrown by "MagicFile" or "magic_file". '%s' contains details about why libmagic was unable to open the file.

This exception is only thrown when using libmagic version 4.17 or later.

  libmagic could not find any magic files
If libmagic is unable to find a suitable database of magic definitions, this exception is thrown. The exception can be thrown by "MagicBuffer", "MagicFile" or "magic_load".

With "magic_load", you can specify the location of the magic database with the second argument. Depending on your libmagic implementation, you can often set the MAGIC environment variable to tell libmagic where to find the correct magic database.

  libmagic out of memory
If libmagic is unable to allocate enough memory for its internal data structures, this exception is thrown. The exception can be thrown by "MagicBuffer", "MagicFile" or "magic_open".

  magic_file requires a filename
If "magic_file" is called with an undefined second argument, this exception is thrown.

BUGS

"normalisation"-problem:
    The results from libmagic are dependend on the (linux) distribution being used. A Gentoo-Linux might return "text/plain; charset=us-asci", an OpenSUSE "text/plain charset=us-asci" (no semicolon!). Please check this if you run your project on a different platform (and send me an mail if you see different outputs/return-values).

I'm still learning perlxs ...
still no real error handling (printf is not enough)

DEPENDENCIES/PREREQUISITES
This module requires these other modules and libraries:

  o) file-4.x or file-5x and the associated libmagic
        (ftp://ftp.astron.com/pub/file/)
  o) on some systems zlib is required.

RELATED MODULES
I created File::LibMagic because I wanted to use libmagic (from file-4.x) and the otherwise great Module File::MMagic only works with file-3.x. In file-3.x exists no libmagic but an ascii file (/etc/magic) in which all data (magic numbers, etc.) is included. File::MMagic parsed this ascii file at each request and is thus releativly slow. Also it can not use the new data from file-4.x or file-5.x.

File::MimeInfo::Magic uses the magic file from freedesktop which is encoded completely in XML, and thus not the fastest approach (
  http://mail.gnome.org/archives/nautilus-list/2003-December/msg00260.html ).

File::Type uses a relativly small magic file, which is directly hacked into the module code. Thus it is quite fast. It is also mod_perl save. It may be the right choice for you, but the databasis is quite small relative to the file-package.

HISTORY
April 2004 initial Release

April 2005 version 0.81

Thanks to James Olin Oden (joden@lee.k12.nc.us) for his help. Thanks to Nathan Hawkins <utsl@quic.net> for his port to 64-bit systems.

June 2006 version 0.8x (x>1) Michael Hendricks started to put a lot of work into File::LibMagic.

May 2009 latest relase.

AUTHOR
Andreas Fitzner <fitzner@informatik.hu-berlin.de>, Michael Hendricks <michael@ndrix.org>

COPYRIGHT AND LICENSE
Copyright 200[5-9] by Andreas Fitzner, Michael Hendricks

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.