File::MimeInfo(3pm) User Contributed Perl Documentation File::MimeInfo(3pm)
NAME
File::MimeInfo - Determine file type from the file name
SYNOPSIS
use File::MimeInfo;
my $mime_type = mimetype($file);
my $mime_type2 = mimetype('test.png');
DESCRIPTION
This module can be used to determine the mime type of a file. It tries
to implement the freedesktop specification for a shared MIME database.
For this module shared-mime-info-spec 0.13 was used.
This package only uses the globs file. No real magic checking is used.
The File::MimeInfo::Magic package is provided for magic typing.
If you want to determine the mimetype of data in a memory buffer you
should use File::MimeInfo::Magic in combination with IO::Scalar.
This module loads the various data files when needed. If you want to
hash data earlier see the "rehash" methods below.
EXPORT
The method "mimetype" is exported by default. The methods "inodetype",
"globs", "extensions", "describe", "mimetype_canon" and "mimetype_isa"
can be exported on demand.
METHODS
new()
Simple constructor to allow Object Oriented use of this module. If
you want to use this, include the package as "use File::MimeInfo
();" to avoid importing sub mimetype().
mimetype($file)
Returns a mimetype string for $file, returns undef on failure.
This method bundles "inodetype" and "globs".
If these methods are unsuccessful the file is read and the mimetype
defaults to 'text/plain' or to 'application/octet-stream' when the
first ten chars of the file match ascii control chars (white spaces
excluded). If the file doesn't exist or isn't readable "undef" is
returned.
inodetype($file)
Returns a mimetype in the 'inode' namespace or undef when the file
is actually a normal file.
globs($file)
Returns a mimetype string for $file based on the filename and
filename extensions. Returns undef on failure. The file doesn't
need to exist.
Behaviour in list context (wantarray) is unspecified and will change
in future releases.
default($file)
This method decides whether a file is binary or plain text by
looking at the first few bytes in the file. Used to decide between
"text/plain" and "application/octet-stream" if all other methods
have failed.
The spec states that we should check for the ascii control chars and
let higher bit chars pass to allow utf8. We try to be more
intelligent using perl utf8 support.
extensions($mimetype)
In list context, returns the list of filename extensions that map to
the given mimetype. In scalar context, returns the first extension
that is found in the database for this mimetype.
"describe($mimetype, $lang)"
Returns a description of this mimetype as supplied by the mime info
database. You can specify a language with the optional parameter
$lang, this should be the two letter language code used in the xml
files. Also you can set the global variable $File::MimeInfo::LANG to
specify a language.
This method returns undef when no xml file was found (i.e. the
mimetype doesn't exist in the database). It returns an empty string
when the xml file doesn't contain a description in the language you
specified.
Currently no real xml parsing is done, it trusts the xml files are
nicely formatted.
mimetype_canon($mimetype)
Returns the canonical mimetype for a given mimetype. Deprecated
mimetypes are typically aliased to their canonical variants. This
method only checks aliases, doesn't check whether the mimetype
exists.
Use this method as a filter when you take a mimetype as input.
mimetype_isa($mimetype)
"mimetype_isa($mimetype, $mimetype)"
When give only one argument this method returns a list with
mimetypes that are parent classes for this mimetype.
When given two arguments returns true if the second mimetype is a
parent class of the first one.
This method checks the subclasses table and applies a few rules for
implicit subclasses.
has_mimeinfo_database()
Check if there are mimeinfo database files available; returns 1 on
success. If you don't have the shared-mime-info package installed
or not in the PATH or @File::MimeInfo::DIRS does not contain
database directories, you will not get the successful reply.
New in version 0.30.
rehash()
Rehash the data files. Glob information is preparsed when this
method is called.
If you want to by-pass the XDG basedir system you can specify your
database directories by setting @File::MimeInfo::DIRS. But normally
it is better to change the XDG basedir environment variables.
rehash_aliases()
Rehashes the mime/aliases files.
rehash_subclasses()
Rehashes the mime/subclasses files.
DIAGNOSTICS
This module throws an exception when it can't find any data files, when
it can't open a data file it found for reading or when a subroutine
doesn't get enough arguments. In the first case you either don't have
the freedesktop mime info database installed, or your environment
variables point to the wrong places, in the second case you have the
database installed, but it is broken (the mime info database should
logically be world readable).
TODO
Make an option for using some caching mechanism to reduce init time.
Make describe() use real xml parsing ?
LIMITATIONS
Perl versions prior to 5.8.0 do not have the ':utf8' IO Layer, thus for
the default method and for reading the xml files utf8 is not supported
for these versions.
Since it is not possible to distinguish between encoding types (utf8,
latin1, latin2 etc.) in a straightforward manner only utf8 is supported
(because the spec recommends this).
This module does not yet check extended attributes for a mimetype.
Patches for this are very welcome.
This module uses the FreeDesktop.org shared mime info database. On your
desktop linux this is typically pre-installed so it's not a problem. On
your server you can install the shared-mime-info package via apt or dnf
or apk or whatnot.
To install on macOS, you can install it like this:
brew install shared-mime-info
AUTHOR
Jaap Karssenberg <pardus@cpan.org> Maintained by Michiel Beijen
<mb@x14.nl>
COPYRIGHT
Copyright (c) 2003, 2012 Jaap G Karssenberg. All rights reserved. This
program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
SEE ALSO
File::BaseDir, File::MimeInfo::Magic, File::MimeInfo::Applications,
File::MimeInfo::Rox
related CPAN modules
File::MMagic
freedesktop specifications used
<http://www.freedesktop.org/wiki/Specifications/shared-mime-info-spec>,
<http://www.freedesktop.org/wiki/Specifications/basedir-spec>,
<http://www.freedesktop.org/wiki/Specifications/desktop-entry-spec>
freedesktop mime database
<http://www.freedesktop.org/wiki/Software/shared-mime-info>
perl v5.38.2 2024-04-27 File::MimeInfo(3pm)
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