File::MimeInfo::Cookbook(3pm) User Contributed Perl Documentation File::MimeInfo::Cookbook(3pm)NAME
File::MimeInfo::Cookbook - various code snippets
DESCRIPTION
Some code snippets for non-basic uses of the File::MimeInfo module:
Matching an extension
A file does not have to actually exist in order to get a mimetype for it. This means that the following will work:
my $extension = '*.txt';
my $mimetype = mimetype( $extension );
Mimetyping an scalar
If you want to find the mimetype of a scalar value you need magic mimetyping; after all a scalar doesn't have a filename or inode.
What you need to do is to use IO::Scalar :
use File::MimeInfo::Magic;
use IO::Scalar;
my $io_scalar = new IO::Scalar $data;
my $mimetype = mimetype( $io_scalar );
In fact most other "IO::" will work as long as they support the "seek()" and "read()" methods. Of course if you want really obscure
things to happen you can always write your own IO object and feed it in there.
Be aware that when using a filehandle like this you need to set the ":utf8" binmode yourself if apropriate.
Mimetyping a filehandle
Regrettably for non-seekable filehandles like STDIN simply using an "IO::" object will not work. You will need to buffer enough of the
data for a proper mimetyping. For example you could mimetype data from STDIN like this:
use File::MimeInfo::Magic;
use IO::Scalar;
my $data;
read(STDIN, $data, $File::MimeInfo::Magic::max_buffer);
my $io_scalar = new IO::Scalar $data;
my $mimetype = mimetype( $io_scalar );
Be aware that when using a filehandle like this you need to set the ":utf8" binmode yourself if apropriate.
Creating a new filename
Say you have a temporary file that you want to save with a more proper filename.
use File::MimeInfo::Magic qw#mimetype extensions#;
use File::Copy;
my $tmpfile = '/tmp/foo';
my $mimetype = mimetype($tmpfile);
my $extension = extensions($mimetype);
my $newfile = 'untitled1';
$newfile .= '.'.$extension if length $extension;
move($tmpfile, $newfile);
Force the use of a certain database directory
Normally you just need to add the dir where your mime database lives to either the XDG_DATA_HOME or XDG_DATA_DIRS environment variables
for it to be found. But in some rare cases you may want to by-pass this system all together. Try one of the following:
@File::MimeInfo::DIRS = ('/home/me/share/mime');
eval 'use File::MimeInfo';
die if $@;
or:
use File::MimeInfo;
@File::MimeInfo::DIRS = ('/home/me/share/mime');
File::MimeInfo->rehash();
This can also be used for switching between databases at run time while leaving other XDG configuration stuff alone.
AUTHOR
Jaap Karssenberg <pardus@cpan.org>
Copyright (c) 2005, 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::MimeInfo
perl v5.14.2 2012-01-05 File::MimeInfo::Cookbook(3pm)
Check Out this Related Man Page
MIMETYPE(1p) User Contributed Perl Documentation MIMETYPE(1p)NAME
mimetype - Determine file type
SYNOPSIS
mimetype [options] [-] files
DESCRIPTION
This script tries to determine the mime type of a file using the Shared MIME-info database. It is intended as a kind of file(1) work-alike,
but uses mimetypes instead of descriptions.
If one symlinks the file command to mimetype it will behave a little more compatible, see "--file-compat". Commandline options to specify
alternative magic files are not implemented the same because of the conflicting data formats. Also the wording of the descriptions will
differ.
For naming switches I followed the manpage of file(1) version 4.02 when possible. They seem to differ completely from the spec in the
'utilities' chapter of IEEE Std 1003.1-2001 (POSIX).
OPTIONS -a, --all
Show output of all rules that match the file.
TODO: this method now just returns one match for each method (globs, magic, etc.).
-b, --brief
Do not prepend filenames to output lines (brief mode).
--database=mimedir:mimedir:...
Force the program to look in these directories for the shared mime-info database. The directories specified by the basedir
specification are ignored.
-d, --describe
Print file descriptions instead of mime types, this is the default when using "--file-compat".
-D, --debug
Print debug information about how the mimetype was determined.
-f namefile, --namefile=namefile
Read the names of the files to be examined from the file 'namefile' (one per line) before the argument list.
--file-compat
Make mimetype behave a little more file(1) compatible. This is turned on automatically when you call mimetype by a link called 'file'.
A single '-' won't be considered a separator between options and filenames anymore, but becomes identical to "--stdin". ( You can
still use '--' as separator, but that is not backward compatible with the original file command. ) Also the default becomes to print
descriptions instead of mimetypes.
-F string, --separator=string
Use string as custom separator between the file name and its mimetype or description, defaults to ':' .
-h, --help
-u, --usage
Print a help message and exits.
-i, --mimetype
Use mime types, opposite to "--describe", this is the default when _not_ using "--file-compat".
-L, --dereference
Follow symbolic links.
-l code, --language=code
The language attribute specifies a two letter language code, this makes descriptions being outputted in the specified language.
-M, --magic-only
Do not check for extensions, globs or inode type, only look at the content of the file. This is particularly useful if for some reason
you don't trust the name or the extension a file has.
-N, --noalign
Do not align output fields.
--output-format
If you want an alternative output format, you can specify a format string containing the following escapes:
%f for the filename
%d description
%m mime type
Alignment is not available when using this, you need to post-process the output to do that.
--stdin
Determine type of content from STDIN, less powerful then normal file checking because it only uses magic typing. This will happen also
if the STDIN filehandle is a pipe.
To use this option IO::Scalar needs to be installed.
-v, --version
Print the version of the program and exit.
ENVIRONMENT
XDG_DATA_HOME
XDG_DATA_DIRS
These variables can list base directories to search for data files. The shared mime-info will be expected in the "mime" sub directory
of one of these directories. If these are not set, there will be searched for the following directories:
$HOME/.local/share/mime
/usr/local/share/mime
/usr/share/mime
See also the "XDG Base Directory Specification" http://freedesktop.org/Standards/basedir-spec
<http://freedesktop.org/Standards/basedir-spec>
FILES
The base dir for all data files is determined by two environment variables, see "ENVIRONMENT".
BASE/mime/packages/SOURCE.xml
All other files are compiled from these source files. To re-compile them use update-mime-database(1).
BASE/mime/globs
Compiled information about globs.
BASE/mime/magic
Compiled information about magic numbers.
BASE/mime/MEDIA/SUBTYPE.xml
Descriptions of a mimetype in multiple languages, used for the "--describe" switch.
DIAGNOSTICS
If a file has an empty mimetype or an empty description, most probably the file doesn't exist and the given name doesn't match any globs.
An empty description can also mean that there is no description available in the language you specified.
The program exits with a non-zero exit value if either the commandline arguments failed, a module it depends on wasn't found or the shared
mime-info database wasn't accesable. See File::MimeInfo for more details.
TODO
The '--all' switch doesn't really show all matches, but only one per mime-typing method. This needs to be implemnted in the modules first.
BUGS
No known bugs, please mail the author if you find one.
mimetype doesn't provide a switch for looking inside compressed files because it seems to me that this can only be done by un-compressing
the file, something that defeats the purpose. On the other hand the option should exist for strict compatibility with file(1). Possibly a
subclass should be made for this one day.
AUTHOR
Jaap Karrssenberg <pardus@cpan.org>
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.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO file(1), update-mime-database(1), File::MimeInfo(3), http://freedesktop.org/Software/shared-mime-info
<http://freedesktop.org/Software/shared-mime-info>
perl v5.14.2 2012-01-05 MIMETYPE(1p)